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Osteichthyes
"The Bony Fishes"
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TROPICAL FISH
COLD WATER
FISH
DEEP SEA FISH
MYSTERY
FISH
TROPICAL FISH
 Anemonefish/clownfish - Received from Walkner in Rio de Janeiro
Q: Clownfish produce a
mucus which covers their body and protects them from anemones.
I'd like to know how this mucus is created and which gland
produces this hormone.
A: Well,
all fish produce mucus to protect them and cut down on drag when
they swim. The secretion comes from pores in the skin, and is
not a hormone (which is a chemical that is produced within the
body to induce changes, like growth). With clownfish, this mucus
does protect them from the anemones that they live in and around,
but scientists aren't too sure exactly how it works. Here are
a few theories taken from Frien ds and Anemones:
One possible clue for the
source of the anemonefish's protective coating comes from a process
scientists call acclimation: The fish gently nestles among the
anemone's tentacles, apparently enduring nonlethal stings in
the process. Some scientists theorize that during the ritual,
the fish bathes and coats itself in the anemone's mucus. The
idea is that the fish then sneaks into the anemone undetected.
Research by zoologist Dietrich Schlichter of the University of
Cologne in Germany indicates that in the end, the fish and the
anemone are chemically identical on the exterior.
Another theory comes from
biologists William Brooks of Florida Atlantic University and
Richard Mariscal of Florida State University, who propose that
the anemonefish's own mucus protects it, altering as the need
arises.
To test the idea, in 1984
the two researchers glued cut-up rubber bands to a petri dish
to make a fake anemone. Then the team put one group of anemonefish
in a tank with the fake anemone and another group of the same
species of fish in a tank with the real anemone. Which fish changed
its mucus secretions more quickly? The fish that had lived with
the rubber impostor. For the researchers, that was proof the
anemonefish, not an anemone, was the source of the protective
mucus. Left unanswered for now is the question of whether the
mucus would shield the fish from a real anemone.
The third theory is that the
answer to the fish's protective mucus lies in the creature's
genes: Maybe the fish's coating naturally wards off anemone stings.
In 1995, Elliott and Mariscal exposed 30 hatchery-raised anemonefish,
one by one, to anemones in a tank. In certain combinations of
anemone and fish species, none of the anemones stung the fish.
But in other combinations, the fish were stung. "It's a
protection that's produced genetically," Elliott concludes. "We've
shown the anemone doesn't have to be involved at all." Well,
in some cases, anyway. In all, about half the fish were stung.
He adds, "In some species combinations the fish are innately
protected, and in other combinations they are not and may have
to go through acclimation behaviour to become protected."
Adds Mariscal, "What
is not known is why some species seem to be innately protected
and others do not. It seems like the more we learn, the more
confused we get."
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Clown
Fish - Received
from Rob in Chicago.
Q. I'm looking for info on clown fish for my daughters school assignment.
Where can I find it?
A. The clown anemonefish is dependent upon the protection offered
by the sea anemone, and is seldom found on the reef except in the
anemone's company. Sea anemones are carnivores that subdue their
prey by stinging them with the venomous nematocysts on their tentacles.
The anemonefish, through a process of acclimatization, is able
to live among, and be protected by, the anemone without being stung.
Acclimatization may take as little time as a few minutes, or many hours, depending
on the species of anemonefish and anemone. The fish approaches the anemone
and gingerly brushes against its tentacles with its tail or ventral surface.
It quickly pulls away upon being stung. But the anemonefish again returns and
gradually brings more of its body into contact with the tentacles, until it
is able to be engulfed in the tentacles with total impunity.
More information can be found in:
Sea Frontiers Jan-Feb 1988 pp. 17-21 "The Anemonefishes of the Indo-Pacific" by
S. Rosenberg and G. Cruz
Natural History No. 9 1989 pp. 43-47, "Sexual Stunts of Clownfish" by
D.G. Fautin.
Answered by Treva Ricou
Pufferfish -
Received from Kendrik Thomas
Q: What is a pufferfish?
A: Pufferfish are considered
one of the most advanced group of bony fish. They are classified
in the order Tetradontiformes. There are three families of pufferfish,
Tridontidae (a single three-toothed species), Tetradontidae (smooth
and sharpnose puffers with four teeth), and Diodontidae (the
spiny pufferfish, burrfishes, and porcupinefishes with two fused
teeth). Their fused teeth makes it great for crushing and grinding
hard food and therefore pufferfish can eat food such as, sponges,
sea urchins and hard corals. Pufferfish have few bones, because
most of their bones in their head and body, through time, have
fused together. Their skin is thick and feels leathery and is
covered by scales that have been modified into spines. Some types
of pufferfish have a poison (tetradotoxin) in their skin that
can cause death in humans. Pufferfish are mostly found in sub-tropical
and tropical marine waters In the Atlantic, Pacific and Indian
oceans. There are some tropical freshwater species (Tetraodon)
that are found in the Congo River and in southern Asia.
To get a look at some different
types of pufferfish click here.
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Puffer
fish information -
Received from Sammy in Iowa.
Q: What do puffer fish eat? Where do they live? What is their latin name? How
old are puffer fish? Are they as old as sharks?
A. Puffer Fish are in the family Terraodontidae. There are
more than 100 different species of fish in this family, so there
are quite a few latin names!! A common puffer fish species is called Arothron
hispidus, and is sometimes referred to as Maki-maki. It can
be found from the Panama Canal, throughout the tropical Pacific
to South America, Japan, the Indian Ocean and the Red Sea. A related
family of fish are the porcupine fish or family Diodontidae, with
about 15 different species. These fish can also inflate themselves
by "gulping" water, and are sometimes called puffers.
A common fish in this family is Diodon hystrix, which can
be found around the world in the tropics.
Puffer fish are not very fast swimmers, and eat a variety of small crustaceans,
small fish and whatever else they can catch. Owners of puffer fish and porcupine
fish in tropical aquariums report that their pets can be quite greedy, and
seem to eat anything!
It is generally thought that modern sharks arose from a shark-like ancestor
sometime in the Jurassic period, about 150 million years ago. Although there
were bony fish around at the same time, as these early sharks, the more specialized
body form of the puffer fish did not arise until relatively "recently" -
These fish are in the Superorder Acanthopterygii or spiny -finned fish, which
arose in the Upper Cretaceus, about 65 million years ago.
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Puffer
Fish Inflation -
Received from Ben in Washington.
Q: How do puffer fish blow up their spines?
A. Puffer
fish really do "puff up", but they do not blow up their
spines. They have spines all over their bodies, but normally
they lie flat, and are not extended. When a puffer fish is frightened,
it will gulp down a large quantity of water. This gulping of
water makes the fish expand like a balloon. When the fish expands,
the spines tend to stick straight out. When the fish stops being
afraid, it can release the water quickly, and get back to its
normal shape and size.
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Puffer
Fish Toxin - Received
from jonccc in university
Q: Hi, I have a few questions
about the puffer fish (fugu). I know it is poisonous. My question
is what is the mechanism of action of tetrodotoxin. and why
is it necessary to provide artificial respiration for someone
who is poisoned. Thank you
A: Tetrodotoxin
is one of the most potent molecules known. Once introduced, it
selectively blocks the voltage-sensitive sodium channels of excitable
tissues. As a result, tetrodotoxin inhibits or reduces the chances
of an action potential to be produced. Tetrodotoxin is complex
in structure and contains a imidazole ring. It is likely that
this ring is the part of the molecule that lodges in the channel
leaving the rest of the molecule blocking its outer mouth.
Recent research, done by David
Berkowitz from the US Food and Drug Administration, Rockville,
Maryland, USA., and Ilona Kryspin-Sorensen, from Institute of
Toxicology, National Food Agency of Denmark Soborg have further
strengthened the argument that in fact Tetrodotoxin comes not
from the puffer, but rather, bacteria. In their article, "Trangenic
Fish: Safe to Eat", they discuss several proofs. They include:
1. Puffer fish grown in culture
do not produce tetrodotoxin until they are fed tissues from a
toxin producing fish.
2. The blue-ringed octopus
found in Australian waters accumulates tetrodotoxin in a special
salivary gland and infuses its prey with toxin by bite. This
octopus contains tetrodotoxin-producing bacteria.
3. Xanthid crabs collected
from the same waters contain tetrodotoxin and paralytic shellfish
toxin.
4. Tetrodotoxin in algae species
Jania is produced by a bacteria species Alteromas .
Although if ingested, Tetrodotoxin
is potentially fatal, pufferfish is still considered a delicacy
in Japan. As a consequence, Japan also has the highest incidence
of textrodotoxin poisoning, even though one must be specially
licensed to prepare the fish. But those that are daring enough
seem to enjoy the fish. (Provided they survive the actual meal)
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Great
Barrier Reef Fish -
Received from Tina in Chicago.
Q.What is the most abundant big game fish that can be caught in the area of
the Great Barrier Reef?
A. There are many "big game" fish that people try to catch in
the area of the Great Barrier Reef. While we haven't been able to find a list
of catch statistics, or estimates of numbers of fish, here is a list of the
types of fish that sports fishermen are interested in catching, in approximate
order of size:
Black Marlin
Blue Marlin
Sailfish
Mackerel
Tuna
Wahoo
Dolphin Fish
Barracuda
The Black Marlin is probably the most sought after fish, because of its large
size (over 100 pounds).
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Coral
Reef Fish Diversity -
Received from Megan in Issaquah WA
Q: What fish live in coral
reefs?
A. Coral reefs are home to
more species and diverse fish communities than any environment
on earth. Atlantic reefs have up to 600 reef fish species and
there can be up to 2000 reef fish species on Indo-Pacific reefs.
Some of the groups of fish species found on coral reefs are as
follows; requiem sharks, moray eels, hawk fish, groupers, surgeonfish,
parrot fish, butterfly fish, sweepers, damselfish, wrasses, velvet
fish, puffers, gobies, filefish, triggerfish, squirrel fish,
angelfish, grunts, cardinal fish, halfbeaks, barracudas, blennies,
and anemone fish, just to name a few!
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Barracuda
information - Received
from Melissa in Chicago.
Q: Our school group will be going to Belize in may and we are each given a
subject to investigate. My subject is the barracuda. Would you be able to supply
me with information on the barracuda of Belize. Thank you.
Barracudas are in the family
of fish called Sphyraenidae. There are 20 species of barracuda
in the world's oceans. The species that is most commonly talked
about is the Great barracuda, Sphyraena barracuda. These fish
grow to 3 meters (10 feet) in length (possibly larger) but are
rarely seen over 1.5 meters (5 feet) long. They are torpedo shaped,
which makes them very fast swimmers. They are predators, and
eat many different species of fish. They have a formidable array
of teeth, which in some animals are visible as they swim around.
They have fairly large scales, and are greenish gray above, silvery
on the sides and white on the ventral surface.
They are often seen "cruising" in
deeper water just off of coral reefs, looking for prey.
Attacks on people by barracudas
are rare, but may be brought on by wearing shiny, dangling jewellery
(remove those earrings before snorkelling!)
People who catch and eat barracuda
rarely get a type of poisoning called "Ciguatara".
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Freshwater
Barracuda? - Received
from Osman in Iowa.
Q: I am trying to get information about freshwater Barracuda fish. What is
the scientific name for them and what do the feed on? Believe me I have searched
the net for two days and seems like no one in the world even knows what a Barracuda
is. Help!
A: As
far as we know, there is no such thing as a freshwater barracuda.
In the ocean, there are 20 different species of barracuda in
the world. They are in the family Sphyraenidae.
Probably the most well known
of these is the Great Barracuda, found in the Caribbean. It's
scientific name is: Sphyraena barracuda.
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Mystery
Fish - Received
from Daniel in Colorado.
Q: I am looking for the name of an animal. It looks like a baby alligator but
doesn't have legs instead it has fins .I saw one swimming off of Key West.
A. Hmmmmm. One suggestion around here is that you saw a Plesiosaurus, but
since they became extinct along with the other dinosaurs, this does not seem
too likely. One (serious) possibility is that you saw a Barracuda (Sphyraina
barracuda). This is a predatory fish, that can reach sizes of up to 3 meters
(10 feet), but is rarely seen over 1.5 meters (5 feet). They are greenish-gray
in colour, and often have scattered black blotches on its sides. The scales
on this fish are quite large, and may even resemble alligator scales. It has
an elongated snout, and very large teeth, which are easily visible to a nearby
swimmer. Their eyes are relatively large, and are situated on the upper portion
of its head. Many books about coral reef fish have photographs of the Barracuda
- perhaps you could get one out of your local library and see if our guess
is correct!
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Red
Fish?
Q: Is there a fish called
a Red Fish?
A: I was not able to find
anything by the name of Red Fish but I was able to find something
called a Red Grouper (Epinephelus morio) The Red grouper appears
to reach common weights of about 15 pounds and the record is
slightly over 39 pounds.
I also found something called a Reedfish (Erpetoichthyes Calabaricus) that
is a predatory fish that grows up to 90 centimeters or about three feet.
Thanks for the question.
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Tarpon
slime - Received
from Nelprod in Florida
Q: We caught a tarpon this sat. it seemed to have a lot of slime on it. what
is the slime for and how is it made.
My guess is that you are referring
to Tarpon atlanticus, a large, silvery fish that is common
to Atlantic waters. Most fish produce a mucus coating, which
serves a variety of purposes. The mucus is secreted from mucus
glands which are usually situated in the epidermal layer. The
mucus coating may act as a protective "shield" by containing
substances which act as antibiotics, or by preventing parasites
from attaching to the scales. The mucus may also allow the fish
to escape more easily from the mouths of predators (i.e. lubricant).
I have also heard that the mucus reduces frictional drag as the
fish moves through the water, thereby increasing swimming efficiency.
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Blue
Marlin - Received
from Jarrod in San Diego.
Q: where can I find info on the Blue Marlin?
A. The
Blue Marlin (Makaira nigricans) is in the family Istiophorida,
which includes the Sailfish, and Billfish, as well as other species
of marlin, such as the Black Marlin (Istiompax marlina).
The Blue Marlin is a famous sporting fish - they are very fast
swimming, and are found in warm, tropical waters.
You should be able to find
more information in a local library, as the blue marlin is such
a popular sport fish. If you search the internet, use the Latin
name for the fish, or the family name, rather than the common
name. This will make sure that you find exactly what you're looking
for, and won't get piles of hits on such things as sports teams
(eg. The Florida Marlins!)
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Flying
Fish - Received
from Robert in Cleveland.
Q. Tell me about the life cycle of flying fish.
Flying fish are in the family of fishes called Exocoetidae.
There are 50 different species of flying fish. The Atlantic Flyingfish, Cypselurus
heterurus is the one you might see off of the Atlantic coast
as far north as Canada, and in the Caribbean. Other species of
flying fish in the Atlantic live far out at sea, and are not normally
seen.
Contrary to their name, flying fish do not fly, but they can glide on rigid,
outstretched pectoral fins for long distances. The behaviour is presumably
to avoid predators.
The eggs of the Atlantic Flyingfish have long adhesive filaments so that they
can attach to clumps of floating seaweed or debris. Without this ability to
cling on to floating objects, the eggs would sink, as they are denser than
water. After hatching, they young look quite different from the adult fish
- they also have a short pair of barbels on the chin. The young sometimes come
inshore, where they can be dipnetted from piers, and in the past were thought
to be a different species from the adult. The young Atlantic Flyingfish matures
at about 25 cm (10 inches) in length, while an adult can grow to be about 43
cm (17 inches ). As adults, the fish inhabit the surface waters of the ocean,
where they feed on plankton and other small fishes.
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Pinecone
fish- Received
from David in Raleigh.
Q: Please tell me about
a "pine fish". I need to know what they are, habitat,
what they eat, and any interesting characteristics about them.
I found information on flounders and shrimp, but I could not
find them.
A: I
believe the "pine" fish you're referring to are actually
pinecone fishes of the Family Monocentridae. There are only two
known species of these fishes, both characterized by an external
covering of heavy plate-like scales giving them the appearance
of a pinecone. They have one large spine on the outer edge of
the pelvic fin, and dorsal fin spines which alternate direction,
one pointing towards the right followed by one pointing towards
the left. One of the most interesting features of pinecone fishes
is the presence of two light organs located under the lower jaw.
These organs house symbiotic phosphorescent bacteria which give
off flashes of light. Monocentris japonicus (the Japanese
pinecone fish) is 13 cm (5 in) in length and schools in deep
water throughout the Indo-Pacific region. Monocentris gloriae-maris (the
Australian pinecone fish) is the only other known species.
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Herring -
Received from Chattanooga, TN.
Q: I love to eat Admiral
fish steaks. I know it,s herring but would like to know a little
more about herring. The encyclopaedia doesn't tell me much
and fish is very general. I would like to know exactly what
I'm eating. Can you tell me?
A: Herring is a type of bony
fish classified in the family Clupeidae. The Pacific Herring
(Clupea  harengus
pallasi) is common in the Pacific Northwest and are an open-water,
pelagic, schooling fish. Herring lay their eggs near shore on
seaweed, such as seagrass, and the juvenile herring spend their
life in large schools in near shore habitats such as seagrass
beds and kelp forests. Adult herring are found in large schools
in the open ocean. Herring have large scales that can fall off
quite rapidly if they frightened and are therefore called deciduous
scales. By dropping some of their scales, the scales will reflect
light and temporarily blind a predator so that they may escape.
The maximum recorded length of a Pacific Herring is 46 cm (18
inches). Herring feed on zooplankton, but are themselves an important
food source for many marine animals, such as humpback whales,
salmon, seals, seabirds, and most large fish.
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Angelfish -
Received from Alex, Meg, and Robin from Louisiana
Q: We are doing a project
on angelfish and can;t find any info. on it. Do you think you
could help we could sure use it. We will take anything.Even
a type of angelfish.HELP PLEASE!
A: Angelfish are a type of
bony fish and are classified in the family Pomacanthidae. Angelfish
live in variety of habitats, coral reefs, tropical freshwater,
the open ocean. In fact, about three-quarters of all angelfish
species live in the Indo-Pacific. Some angelfish can undergo
extreme colour changes from when they are juveniles to adults.
The colour of angelfish is different between the different species.
The colouration of many angelfish has the effect of confusing
predators by having stripes (like a zebra) and sometimes a false
eye spot on or near the tail. The eye spot usually is a circle-shaped
colouration on the tail which a predator may mistaken for the
eye. A predator usually attacks the prey's head, where the eye
is, and a bite to the tail is definitely less fatal than one
to the head. Marine angelfish eat invertebrates that are attached
to the bottom, such as sponges, sea squirts and corals. Some
species of angelfish actually follow sea turtles and eat their
poo! There are also tropical freshwater angelfish, you can see
some of these species in your local pet store.
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Seahorse
information - Received
from Samantha in Houston.
Q: I have to do a report on seahorses and can't find any information. Where
can I find information or what can you tell me about them. Thank you for any
help you can give me.
A. We
can understand why you'd want to do a report on seahorses - they
certainly are interesting animals!
Seahorses are an interesting
type of fish. They are in the family of fish called "Syngnathidae",
which also includes the pipefishes. Seahorses are found in all
tropical seas, and may also be found along more temperate coasts.
There are around 150 different species of fish in this interesting
family. Two different species of seahorse from the Bahamas are
the lined seahorse, Hippocampus erectus, and the longsnout
seahorse, Hippocampus reidi.
Seahorses have the unusual
habit of carrying the eggs until hatched in a pouch of skin.
The males carry these eggs, and look after them until they are
hatched.
Seahorses is one of the slowest
fishes in the world.
To compensate for this slow
speed, seahorses and pipefishes have developed very effective
camouflage, so they can blend in with their surroundings.
General books on aquarium
fishes, or aquarium magazines often have articles about seahorses.
Try searching the net using
the family name "Syngnathidae" for scientific information,
or try searching using the terms "seahorse" and aquarium" and "fish" (this
will eliminate all of those sites that have the word "seahorse" in
the title, such as "Bob's Seahorse Motel".
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Seahorse
Weight and Migration - Received from Doug in California.
Q: My daughter has a question that I have been unable to locate the answer.
I have contacted Sea World, as well as other sources. Her questions are: 1.
How much does a seahorse weigh? 2. Do seahorses migrate? I would appreciate
any assistance you could render.
A. If
you've check out other seahorse answer on the OceanLink pages,
you'll already know that there are many different species of
seahorse - there isn't just one type.
Generally, the fish in the
family Syngnathidae, which includes seahorses and pipefish, are
pretty small. There are around 150 species in the world, ranging
from less than an inch to around 30 cm (12 inches) in length
(this last measurement is for a pipefish). In the Bahamas, the
Dwarf seahorse (Hippocampus zosterae) grows to 3.8 cm
(1.5) inches long, while the Lined seahorse, Hippocampus erectus grows
to 14 cm (5.5 inches) in length. The New Zealand Seahorse (Hippocampus
abdominalis) reaches 20 cm (7.9 inches) in length with the
tail uncurled. We haven't been able to track down any figures
for weights of seahorses (most fish are measured by length),
but they are not very heavy fish.
Seahorses swim very slowly,
and rely on camouflage to escape from predators. They generally
live in shallow areas, and do not travel very long distances.
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Characteristics
of seahorses -
Received from Becca.
Q: I would like to know
more about the size of a seahorse, what it eats, the average
life span and some fun facts about it.
A: There
are about 25 species of seahorses which are scientifically classified
in the Phylum Chordata, Class Osteichthyes, Subdivision Teleostei,
Order Gasterosteiformes, Family Syngnathidae and Genus Hippocampus.
Seahorses are some of the most unusually shaped fish, with long
tubelike snouts, a body encased in bony rings and a tail that's
used for holding onto plant stems. Seahorses swim upright, using
fins on their sides (pectoral fins) and back (dorsal fin) to
slowly propel themselves along.
The largest species of seahorse
is approximately 20 cm (8 in) long, while the smallest species
is only 4 cm (1.5 in) long. Since seahorses move very slowly,
they aren't able to chase their prey. Instead, they have developed
a suction mechanism using their long snout. If small planktonic
organisms like brine shrimp come within 4 cm (1.5 in) of the
seahorse's mouth, they are sucked in quicker than you can blink!
Seahorses generally live for
two or three years, and are very difficult to keep in captivity.
One of the most interesting facts about seahorses is that the
male, not the female, looks after the eggs until they hatch.
Males have a brood pouch located on the underside of their tail
with a very small opening at the top. The female lays her eggs
into this pouch, where they remain safe and warm until hatching
(at least 8 or 10 days). Once the baby seahorses can swim on
their own, the male expels them out of the pouch. Another fun
fact is that seahorses can move their eyes independently of each
other. They can basically have one eye looking down and the other
eye looking up at the same time!
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Seahorse
Sexes - Received
from Winnie
Q: Do seahorse have sexual
orientation? If so, is it the male seahorse that have the offsprings?
A. Yes, there are male and
female seahorses. The female produces the eggs and the male produces
sperm. During mating, the mating pair performs a rather peculiar
mating ritual in which the fertilized eggs are eventually transferred
to the brood pouch of the male. The developing embryos are brooded
by the male, and are eventually released through an opening.
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How
Seahorses Swim -
Received from Hannah in Wathena, Kansas
Q: how does a sea horse
swim?
A: Seahorses have a body that
is encased in bony rings, therefore their body is not very flexible.
The fin they use to swim is their dorsal fin, not the curly tail
part of the seahorse. The curly tail is not used for swimming
but to hold onto seaweed, objects and other seahorses. The dorsal
fin is the fin you would see on their back. They move this dorsal
fin back and forth to swim. Seahorses also have two pectoral
fins (the fins on the sides of their body), that they use for
manoeuvring and steering. In fact, seahorses are the slowest
swimming, that we know of, and can only swim at speeds of 0.01
mph.
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Info
about Eels - Received
from Daniel in Ohio.
Q: I am in the MH class. I am in 2nd grade. I need information about eels for
a report. Can you tell me any interesting facts about them?
A. One
of the most interesting things about the American Eel (Anguilla
rostrata) is the migration that they undergo. Young animals
migrate down rivers to the Atlantic Ocean, and then make their
way to the Sargasso Sea off Bermuda. They then mature into adults,
and breed there. The juveniles (called "elvers") then
return on the long journey back to the homes of their parents.
No one has yet discovered how they accomplish such a long trip,
and manage to find a stream that they have never seen.
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Eels -
Received from Tiffany.
Q: what is the scientific
name for a eel and also what dose it look like and how dose
the reproduction system work. Thanks alot.
A: There
are over 730 species of eels within the Order Anguilliformes,
all of which are characterized by the following traits: a reduced
skeleton, dorsal and anal fins that are continuous with the caudal
(tail) fin, the absence of pelvic (and often pectoral) fins,
and a lack of gill rakers. The majority of eels live in shallow
tropical and subtropical marine habitats, although they can also
be found in the deep sea, the open ocean, and freshwater lakes
and streams. In general, eels are mass spawners which release
huge numbers of sperm and eggs into the water for external fertilization.
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Moray
eels - Received
from Emily in Tennessee
Q: I am working on a thematic unit on oceans for kindergarten, and need some
information/pictures/activities about eels, specifically, the moray eel.
A. The moray eel includes
several species of fish in the Family Muraenidae. These animals
are heavier and more compressed than most other eels, and the
morays are readily distinguished by the small, round gill opening
and the absence of pectoral fins. The skin is thick and leathery,
the occipital region of he head is elevated, and the powerful
jaws are armed with knifelike or molarlike teeth. Morays typically
inhabit shallow coral reefs and rocky areas. They are most active
at night; by day they hidden holes and crevices. Most of the
morays are predators of crabs, shrimps, lobsters and various
fishes. Capable of inflicting deep wounds if disturbed, large
morays are dangerous to people in or out of the water. Some species
cause ciguatera poisoning when eaten. There are approximately
14 species in North America.
You should be able to find
more information on morays by searching the net using the scientific
names for the animals. Some of the scientific and common names
for some North American species are as follows:
California Moray - Gymnothorax
mordax
Spotted Moray - Gymnothorax moringa
Blackedge Moray - Gymnothorax nigormarginatus
So try searching the net using these names, or even the family name Muraenidae.
I would wager that there is a lot of scientific and popular literature about
these fascinating animals on the internet.
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Stonefish
Q: What
is a stonefish?
A: A stonefish is an amazing
fish! In fact it actually looks like a stone and rests on the
bottom half-buried in sand. A stonefish has a large head and
no swim bladder (which allows it to lay on the ocean floor).
A stonefish has no scales and has warty looking skin glands covering
it's body. At the base of their dorsal fin spines are venom glands.
When threatened or stepped on the stonefish sticks its dorsal
fin spines up and venom is released into whatever touches the
dorsal spines. The venom is a neurotoxin and is the most deadly
of all fish venom and can be fatal to humans! These fish are
found in the tropical marine waters in coastal Indo-Pacific,
South Africa east to Japan, Society Islands and Australia.
Also, if you live near Vancouver, British Columbia, take a visit to the Vancouver
Aquarium, they have a stonefish in their tropical exhibit.
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Humuhumunukunukuapua'a -
Received from Julie in Texas
Q: I have to do a two-page
report for school on the fish called humuhumunukunukuapuaa.
My mom says it's near Hawaii. i can't find any information
on it. We went to three libraries. Can you help me? I would
really be happy if you could. Thank you.
A: The
Humuhumunukunukuapua'a (also called the Picasso Triggerfish or Rhinecanthus  aculeatus)
is the official state fish of Hawai'i. They are pretty small
(up to 8"), carnivorous, and pretty aggressive when it come
to member of their own species of fish of similar size. Also,
they make a whirring sound when startled.
Members of this family have
acquired their common name 'triggerfish' from the characteristic
locking and unlocking of their first dorsal fin. Normally the
dorsal fin is positioned in a flat groove on the top of the body.
It can however, be locked in the upright position in order to
wedge the fish into some crevice in which it has taken refuge.
This keeps the fish from being removed from the crevice and eaten.
Triggers are relatively poor
swimmers, most of the time they move by undulating wave motions
of the dorsal and anal fins, only using the tail fin for emergencies!
In the sea they usually live alone and are intolerant of similar
species. This is why you usually see few triggerfish in the same
aquarium. Their teeth are very strong and often stick out which
is ideal for eating shelled invertebrates and sea urchins. Don't
put a triggerfish in an aquarium with invertebrates! When eating
a Crown of Thorns starfish, the trigger will first blow it over
onto it's back in order to get at the soft unprotected underbelly.
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Mud
Skippers - Received
from Eric in Ohio.
Q: What is the habitat, diet, general description, and the young of MUD SKIPPER
?
A. Mud-skippers are in the
family of fish known as Periophthalmidae. There are several different
species of mud-skippers in this family and they are found generally
in mangrove swamps of Africa and the Indo-Pacific. They are fairly
small fish - the different species range in length from 15 to
25 cm (6 to 10 inches). The mud-skippers are an interesting family
of fish, because they are truly amphibious, meaning that they
can live in or out of the water. They live on the muddy areas
of mangrove swamp areas. This location is periodically covered
by the tide, but the mud-skippers may spend quite a lot of time
out of the water. Their pectoral fins are modified so that they
can swim in the water, as well as jump and skip with remarkable
speed on land! They can store water in their gill chambers, so
that their gills are kept moist in air. They have large protruding
eyes with a movable lower lid, which is also an adaptation for
living in water and air.They eat a variety of food - they wriggle
and skip over rocks and mud in search of prey, and may even climb
up mangrove stems in search of crabs, snails and other invertebrates.
Eggs are laid in water in the shallow mangrove swamp areas, and
the young are very tiny when they hatch. The young do not immediately
move about on land - they must first grow larger by feeding on
small marine organisms in the water.
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Electric
Eel Voltage - Received from Jennifer
Q: What is the average
voltage given off by an electric eel?
A. The electric eel, Electrophorus (Electrophoridae),
can generate electrical pulses of over 500 volts. These pulses
are created by several electric organs that are embedded in the
lateral muscles of the eel's body. The largest of these electric
organs is made up of about 1000 electrocytes (current-generating
cells). Pretty impressive!
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Breeding
Jawfish - Received
from Dave in Kansas.
Q: I am interested in breeding yellow headed jawfish. I however only have a
ten gallon set aside for it as my 58 is a predator tank. I have put in about
5 inches of substrate, not too fine, and have put on the new marineland eclipse
so they can't jump ship. I work in a store that sells marine fish but we haven't
been able to get them in some time. I don't know anything about breeding marine
fish or the jawfish in general. will it work in a ten gallon set up for just
them? Where can I get the fish is a breeder pair, and how many should I get?
Any info you have would help as well as places to look for info. Thank you.
A. We can give you information about the Yellow Headed Jawfish, but for
detailed information about keeping them in captivity and captive breeding information,
you should probably consult a good aquarium magazine such as Freshwater and
Marine Aquariums. Often though, knowing something about the natural habitat
and behaviour of a fish can help you make sure that you are giving it optimum
conditions in your aquarium.
The Jawfishes are in the family Opistognathidae, and are generally smallish,
slender fish. We can see why you are interested in breeding them, as they have
a fascinating method for guarding the eggs. The male fish keeps the eggs in
his mouth while they are developing, and waits for them to hatch. He may periodically "spit
them out", only to suck them back into his mouth.
There are 12 different species of Jawfish around the world. Common names are
notoriously inaccurate, and we are assuming that your fish is Opistognathus
aurifrons, which is sometimes called the yellowhead jawfish in the Bahamas.
The fish makes a burrow, which in this species is usually found in areas of
crushed coral or sand, as opposed to firmer limestone as is found with other
species. (you should probably make sure that the depth of sand in your tank
is enough for a burrow). The burrow may be lined with small stones. This particular
species also has some different behaviours; it maintains itself six or eight
inches above its burrow, tail down, revolving slowly - the other species of
Caribbean jawfish stay in their burrows with only the head protruding. The
male keeps the eggs in his mouth while they develop - when he wants to feed,
he puts the egg mass in the burrow. The fish do not tend to travel long distances,
and prefer to stay near the burrow, so I imagine that a 10 gallon aquarium
would be sufficient. After laying the eggs, the female does not hang around,
but I'm not sure if the male would be territorial and try to chase her away.
A single pair would probably be enough, but I'm not sure how you'd know you
had a mating pair, as males and females look identical.
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The
prey of dolphin fish -
Received from Evelyn in Malta.
Q: I am doing my final year B.Sc. thesis on Dolphin fish. My query is: "What
is the relative abundance of the prey of Dolphin fish in its natural environment
(shrimps, clams and mussels)" If the question is too complex and time
consuming: "How is it possible to find such a relative abundance of the
prey of this species" Thank you.
A. First,
for those who may not know, we're referring here to the Dolphin
Fish, Coryphaena hippusus, which is not at all related
to the different mammal species known as dolphins.
Dolphin fish are in the family
Coryphaenidae, and are found in tropical oceans around the world.
The first thing to do when looking for the relative abundance
of the prey of any animal, is to correctly find out what prey
they eat! Dolphin fish are typically open ocean fish, and eat
mainly other fish, although their diet also includes crustaceans
such as shrimp and crabs, as well as cephalopods such as squid.
The certainly don't eat clams or mussels! Many of the fish and
invertebrates included in their diet come from the community
that lives in and on sargassum seaweed.Basic research about the
dolphin fish will enable you to determine specifically the names
of the prey they eat. After this, you'll be able to look up the
prey species, and determine its abundance.
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Southern
Stargazer - Received from Gary in Southern Louisiana
Q: I have lived in south
La. all my life and thought I had seen all fish our waters
had to offer. On a recent fishing trip I caught what I think
was a "Southern Stargazer" or " Astroscophus
y-graecum" Although I was able to identify this fish I
can't seem to locate any other info on it. Any info you can
offer would be appreciated. Thank you!
A. The fish that you caught,
if it is Astroscopus y-graecum, is a member of the Family
Uranoscopidae. The fishes in this group are carnivorous and of
singular appearance, living on the sea bottoms in most warm regions.
There are a total of 7 Genera containing 20 species in the Uranoscopidae.
These fishes are common to the West Indies, and are occasionally
found inhabiting waters of the South Atlantic Coast.
Since this species is not
frequently found in the waters of Southern Louisiana, it is likely
considered an accidental species in that region. This means that
the species normally does not inhabit the waters of the S.Atlantic
Coast, but it is not unheard of to find it there. The area that
you live in is probably just outside the normal range for this
species. I would imagine that these fish are quite rare in La.,
which would explain why you have never seen it before. So in
a sense, I guess it is kind of a "prize catch" for
Louisiana waters!!
The species Astroscopus
y-graecum is dark brown above, paler below; upper parts
densely covered with small rounded white spots, each surrounded
by a black ring. The lower jaw and labial fringes are similarly
spotted. There is a conspicuous y-shaped bone on top of the
head (from which the species gets part of its name), and on
each sided of it there is a broad naked area. This area contains
electric sensory organs which these fish use for communication,
localization of prey and navigation. The signals produced by
the electric organs of these fishes can be modified in complex
ways, by varying factors such as discharge frequency, wave
form, and the times between discharges. As a consequence, electrical
discharges have all the functions visual and auditory signals
have in other fishes, including courtship, agonistic behaviour
and individual recognition.
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Transparent
Fish - Received
from Tyler in Missouri.
Q: I have heard about transparent fish. What are they called? Do they live
only in very dark areas? Is it true that they don't have eyes? If they don't,
then they must have a very good sense of what's going on around them. Maybe
they have a kind of sonar like bats.
A. Hello
Tyler. I apologize for taking so long to get back to you the
holidays slowed us down a bit. Yes, you are right, they're are
some fish that are virtually transparent. Many fish actually
start their lives as tiny, transparent larvae but they get colour,
or pigment, as they get older and grow bigger. Some fish however,
seem to remain transparent for much longer. One such fish is
the glass catfish. This tropical fish is popular with aquarists
so if you have an aquarium store nearby you might ask the owners
about this fish. There are also some types of eels that are transparent.
Apparently you can see right through them. These fish don't necessarily
live where it is dark. In fact, being transparent is a great
camouflage to enable these fish to hide from their predators.
These fish do have eyes (although others may not; if you have
some specific names, let us know) and this is the one place where
they do have some colour as eyes need pigment to be functional.
Answered by Adrienne Mason
Thanks to Alec Peden from the Royal B.C. Museum for his assistance
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Seadragons -
Received from Aaron Shencopp in Michigan
Q: I need the following
information on the Dragon Fish: physical characteristics, habitat,
movement, prey/nurtrition, predators, protection, babies, special
features. I am 8 years old and am having trouble finding any
detailed info on this fish.
A: The seadragon or dragonfish
is a rare and very beautiful fish found only in southern Australian
waters. Seadragons belong to the Syngnathid family along with
seahorses and pipefish, which are all distinguished by long,
slender bodies covered with bony plates. Syngnathid means tube-snouted
and thus refers to the distinct tube like mouth shared by these
three types of fish.
Seadragons live in rocky reef
areas, seaweed beds, seagrass meadows or any other area where
seaweed grows. Most often seadragons are found in shallow coastal
waters however they have been known to travel as deep as 50 meters.
There are two species of seadragon, the Weedy seadragon (Phyllopteryx
taeniolatus) and the Leafy Seadragon (Phycodurus eques). Both
seadragon species look like floating pieces of seaweed that can
make them hard to spot in their natural environment.
Although delicate in features
and small in size, seadragons have all the appearance of a mighty
hunter to the small larvae and shrimp-like sea lice that they
prey on. As far as we know seadragons have no predators in the
undersea world, however their populations are declining because
of pollution and fertilizers that run off shore and collect in
the seaweed beds they inhabit. Furthermore, because of their
mystical appearance, seadragons have been targeted by curious
collectors who have cleaned out the more accessible seagrass
areas along Australia's shores. Fortunately in 1991, seadragons
were protected from all collection.
One of the most amazing things
about seadragons is that, like seahorses, it is actually the
male that holds the eggs and gives birth to the young. However,
unlike seahorses, seadragon males do not have a brood pouch.
Instead the female lays her eggs (anywhere from 100-250 eggs)
on a special brood patch underneath the tail of the mail. There
the eggs are attached and fertilized and the developing babies
held for 4-6 weeks. Two to three days after birth, the young
seadragons are completely independent from their parents and
can hunt for small zooplankton.
Also check out this sites
for more info on seadragons:
Australian Museum of Fish
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Seahorse
distributions - received
from Chris in Indianapolis
Q: Where can I get a habitat
map for seahorses?
A: Aren't seahorses cool?!
Seahorses (generic name: Hippocampus) live in seagrass meadows,
coral reefs and mangroves in temperate and tropical coastal
waters around the world. Currently there is concern that extensive
habitat destruction and pollution may be endangering seahorse
populations. I could not find an actual map with geographic
distributions but I did find this:
12 Species of the genus Hippocampus & Geographical distribution:
H. ingens: West coast of (sub)tropical North-, Central- and South America
H. hippocampus:Mediterranean Sea, Atlantic Sea from Morrocco through South-east
France
H. reidi: South America's West coast through Carribean, Mexico, Florida
H. erectus: East coast of North, Central and South America from Argentina
through Canada
H. zosterae :Gulf of Mexico and Carribean
H. comes: Far East coast from Taiwan through Indonesia
H. histrix :Indian Ocean, Persian Gulf, Red Sea, Far East through Japan,
Australia
H. abdominalis:New Zealand, South and East Australia
H. bargibanti: New Caledonia
H. breviceps: South- and East Australia
H. whitei: East Australia
H. fuscus:Tropical coasts of Indian Ocean
This came from the Seahorse Park page
Other great sites for info about seahorse biology and conservation are:
Nova Kingdom of the Seahorse
Project Seahorse
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Seahorse
Classification - from Jessie in Texas
Q: Is a sea horse an invertebrate are vertebrate?
A: That's a good question! Seahorses are interesting
critters! They are fish, which are vertebrates. You
should check out the site at the Texas State Aquarium,
as they have a special display on right now about Seahorses.
The address is: http://www.texasstateaquarium.com
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Seahorse
Lifecycles - from Jodi in Alabama
Q: Please tell the life cycle
of a seahorse.
A: Seahorses are unique animals
in that it is the male that becomes pregnant! Seahorses have
a very social community structure and choose mates for life.
If one of the mates die, the surviving partner will not reproduce
for quite sometime and when he/she "re-pairs", the
reproductive output of the new pair is generally lower. Seahorse
reproductive output is already generally quite low, with each
pair hatching about 1000 young each year (compare with some fish
who produce 200 000 eggs at a time!). The young hatch live from
the father's brood pouch and must immediately start fending for
themselves. Seahorse populations are at risk due to over-fishing,
pollution and habitat destruction.
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Bony
Fish - received
from Dieuna in Florida
Q: May
you tell me about the habitat, deadly defenses, and distribution
of some bony fish?
A: A bony fish (class Osteichthyes)
is a "poikilothermic, aquatic chordate with appendage developed
as fins and whose chief respiratory organ are gills and whose
body is usually covered with scales" (from the Diversity
of Fishes by Helfman, Collette and Facey). It would be difficult
for me to tell you about the habitat, distribution and defenses
of bony fish in general because there are 23,000 living species
of bony fish. 41% live in freshwater, 58% in seawater and 1%
move between both. The highest diversity of fishes are found
in the tropics (especially the Indo-west Pacific and Indian Oceans).
They occupy essentially all aquatic habitats from springs to
estuaries to deep ocean to wave pounded coasts. Some defense
strategies include: cryptic coloration, counter-shading (light
on the bottom and dark on top so they are hard to see against
the light of the sky and the dark of the bottom), schooling,
fast swimming or physical defenses like the spines of the balloonfish.
The book The Diversity of Fishes has lots of great info, so go to your local
library and check it out!!
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Mahi-Mahi
A Dolphin?
Q: Someone told me that the
Mahi-Mahi is a dolphin. Is this true?
A: I did some research and
can put your mind at ease that the Mahi-Mahi fish is not dolphin
meat. People probably just confuse this fish with dolphins sometimes
because its common name is the Dolphin fish. The family name
of Dolphin Fish (Mahi-Mahi) is Coryphaenidae and the species
name is Coryphaena Hippurus. Marine dolphins are from the family
name Delphinidae. So if you ever eat a Mahi-Mahi you have no
worries about accidentally eating dolphin meat.
Thanks for the great question.
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COLD WATER
FISH
Flounder
Appearance - Received
from Conrad
Q: What exactly do flounder
look like?
A: Thanks for your question!
When a flounder is young (a larval fish), it looks just like
any other fish, with one eye on each side of its body and swims
around in the water column. As it grows, the body of a flatfish
flattens out and either the right eye moves to the left side
of the body or the left eye moves to the right side of the body,
so that both eyes are same side of the body. The side the eye
moves to depends on the type of flounder, but this can also vary
within a species, just like how people can be right or left handed.
The bottom side (ventral side) of a flounder is white and the
top side (dorsal side) is usually sandy brown in colouration.
When flounders are adults they can lie on a sandy or muddy bottom
completely camouflaged with their sandy coloured body and both
of their eyes peeking out from beneath the sand. I have attached
a picture of a CO Sole (a type of flounder) for you to check
out!
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Arctic
Ocean Fish - Received
from Andrew and Travis in Colorado.
Q. What kind of fish live in the Arctic Ocean?
A. There are a variety of
fish that live in the Arctic Ocean but two of the more common
species are Arctic cod and Arctic char. Arctic cod are the centre
of life in many Arctic waters - many seabirds and mammals rely
on them to survive. Arctic cod eat smaller animals such as crustaceans
(shrimp, etc.) and are eaten by many animals including: ringed
seals, harp seals, narwhals, beluga whales, thick-billed murres,
black guillemots and more!
You probably asked this question
because you wonder how fish in cold Arctic waters survive? Some
fish, such as the Arctic cod, have a type of antifreeze in their
body. This prevents the fluid inside their body from freezing.
Answered by Adrienne Mason
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Scientific
name of mullet -
Received from Richter in Germany.
Q: the scientific name of yellow eyed mullet (NZ) perhaps German?
A: The
scientific name of the Yellow-eyed mullet is Aldrichetta forsteri.
It is also sometimes called "herring" or "sprat" in
New Zealand. (So-called "common names" are very confusing!)
It is often found in tidal flats and shoals in large numbers,
and feeds on small animals and plants.
We're not sure what the name
would be in German!
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Longeared
sunfish - Received
from Keshala in Ontario.
Q: is Lepomis megalotis (longeared sunfish) marine or freshwater fish?
A. The longeared sunfish (Lepomis
megalotis) is a freshwater fish. It is also known as "Cheery
Bream", and lives in freshwater areas west of the Appalachian
Mountains, as far North as Quebec, and as far South as North
Central Mexico.
A search on "Altavista" on
the genus and species revealed over 400 hits. There is more information
in the Texas
Parks and Wildlife site.
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Stranded
American Eel - Received from topnoodle in New York
Q: My husband saw what
I think was an eel in Lake Canderago, New York on a recent
visit. Could this be possible? The lake is a natural lake about
1 1/2 hours north east of Binghamton (A half an hour from Coopersown
New York). The eel was approx 12 inches in diameter with a
length of over 5 feet. I showed him a picture of an eel after
we had gotten home that I found on the internet and he is sure
that is what he saw. How could an eel survive in a lake with
no access to salt water. Everything that I have read indicates
that eels spawn in salt water. (at least I am not aware of
access to salt water from that lake) Please let me know how
I can research this further and whether an eel could exist
in a fresh water lake such as Lake Canderago.
A. I checked out a map to
find out exactly where this lake was, and I was surprised to
see how far inland it was. At first I thought it was kind of
weird to find an eel (probably Anguilla rostrata) so far
away from the ocean. However, after a little bit of digging,
I found out that these animals are often found even further inland,
as far west as Nebraska. On the map that I found, it appeared
that Lake Canderago drained into the Atlantic through a maze
of small streams and rivers. In fact, all of the lakes around
Binghamton flow to the Atlantic by way of the Delaware River
or the Susquehanna. The Delaware Branch follows the PA-NY stateline
and the Susquehanna flows generally south from Binghamton. So
it is quite reasonable for the eel to have made its way to the
lake from the Atlantic.
Apparently, it is only the
females that ascend rivers, where they remain for a number of
years. The eel you saw in the lake was, therefore, probably a
female. The family Anguillidae differs from most other eels by
having small scales embedded in the skin. In addition, they have
pectoral fins and a caudal fin that is continuous with the dorsal
and anal fins. After reaching sexual maturity, the freshwater
eels migrate out the the Sargasso Sea area of the Atlantic to
spawn. The eggs hatch into a leptocephalus (lepto= slender, cephalus=
head) larvae that pass through numerous stages as they transform
to adults.
I have also heard some other
remarkable facts about eels. Apparently, the European eel has
been found to move around very quickly around the English Channel
by swimming with the currents. Some eels have reportedly been
found to move faster than 50 kph, a speed which approximates
the strength of currents in the area.
Special thanks to NYS FOLA for assistance with this question.
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Trout
Lifespans - Received
from Sueli
Q: Please, just tell me
how long does a trout live if it doesn't get caught?.
A. There are approximately
40 different species of trout (Family Salmonidae) in North America.
The life span varies depending on the species that you are dealing
with. Coho Salmon (Oncorhynchus kisutch) have a lifespan
of about four years. Sockeye salmon (Oncorhynchus nerka)
have a lifespan between 3-7 years.
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King
(Chinook) Salmon -
Received from Jim in New York.
Q: I like some information about the behavior of King Salmon, I have searched
far and wide today and could not get even a byte... Sorry, bad pun....I am
specifically interested in the King Salmon of Lake Ontario...would that be
Atlantic King Salmon?
A. The
name "King Salmon" is another common name for the Pacific
coast chinook salmon (Oncorhynchus tshawytscha) It is
often called "king" salmon because it can grow to such
a large size (up to 126 pounds!) The Atlantic salmon (Salmo
salar) does not reach such sizes, and is not referred to
as "king salmon". The Atlantic salmon can inhabit freshwater
lakes, but it was fished out of lake Ontario prior to the year
1900. Chinook salmon have never been found anywhere near Lake
Ontario!
It seems that this may be
an explanation for why you have been unable to come up with any
information - you're looking for a fish that does not exist!
Perhaps "king salmon" is a local name for some type
of fish that is not actually a salmon species.
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Information
on Turbot - Received from Doane in Portland, Maine.
Q. Please give me information about the "turbot". I am most interested
in typical sizes, locations, and ranges of particular stocks. Specifically,
do individual fish tend to travel great distances in the ocean, or do they
remain pretty local throughout their lives?
A. The Greenland Turbot, Reinhardtius hippoglossoides is found off both
coasts of North America. Stocks off the west coast are found in the Aleutian
Islands and the Eastern Bering Sea. Catch of Greenland Turbot in this area
was 9,934 tons and 7,385 tons in 1994 and 1995 respectively.
On the East coast, they are found in the Davis Straight off the east coast
of Baffin Island (Sub Area 0), and off the east coast of Labrador and Newfoundland
(Sub areas 2 and 3). In 1995, the Northwest Atlantic Fisheries Organization
quota on turbot was 11,000 tonnes in Subarea 0, shared by Canada and Greenland.
The 1995 Canadian quota was 7,000 tonnes for Sub-area 2 plus Division 3K, and
3,000 tonnes for Divisions 3LMNO. The European Union is also allocated an allowable
catch in these areas. Note that allowable catch does not necessarily mean that
this amount of fish was actually caught!
Turbot are cold water fish, and are not commonly found in waters to the south.
The therefore do not move over large distances in the ocean, but it is thought
that they do move from place to place, at least over distances of hundreds
of miles. Based on fisheries research by Ianelli et. al., fish from the Eastern
Bering Sea are thought to perhaps move to the Aleutian Islands, both as juveniles
and adults. The fish in both of these areas are managed by the U.S. government
as one stock.
Of course, turbot stocks from the East and West coast do not mix. It would
be pretty hard for them to move from one coast to another!
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Mackerel
Info - Received from Teena on Vancouver Island
Q: Can you give me some
info on the life cycle of a Pacific mackerel. Where do they
spawn, how long do they live, what do they feed on.
A. I've been waiting for this
question to pop up. I hope you enjoyed your visit to Bamfield
and the Marine Station.
 The
mackerel species that is found in the Pacific is commonly known
as Chub Mackerel, and bears the scientific name Scomber japonicus.
This species is in the Family Scombridae, which includes many
kinds of tropical and temperate marine fishes like the Skipjack,
Bluefin and Albacore tuna.
This species of fish can be
found in Pacific waters from Banderas Bay and Mazatlan, Mexico
and the Gulf of California, through Baja California, California,
Washington, British Columbia to southeast Alaska and the Gulf
of Alaska. In the west Pacific, this species ranges from Russia
all the way down to Japan, Korea and beyond. S. japonicus is
fairly abundant off the west coast of Vancouver Island, but occurs
sporadically, often in conjunction with the northward movement
of warmer waters during El Nino years.
Spawning is not known to take place on the British Columbia coast. In California
waters, spawning occurs near shore from late April to July at depths down to
about 92m. A single female may produce over a million pelagic eggs, which float
in the water column. These eggs are extremely small, averaging between 0.9
and 1.3 millimeters in diameter. The eggs hatch after approximately three days,
depending on the water temperature, yielding larvae that are about 3mm long.
These young larva feed on plankton in the water column, and continue to grow
and develop adult features. Some mature in their second year, but most reach
sexual maturity at a length of about 33cm. These fish may live for 9 or 10
years. Adult mackerel are opportunistic, gluttonous feeders with a diet that
consists of crustaceans, squids, small fishes and Velella (jellyfish).
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Pipefish - Received from David in Raleigh.
Q: Please tell me about
a "pipe fish." I need to know what they are, habitat,
what they eat, and any interesting characteristics about them.
I found information on flounders and shrimp, but I could not
find them.
A: Pipefishes
are in the Family Syngnathidae along with the seahorses. There
are over 150 species of pipefishes found in marine, brackish
and freshwater habitats. It has been said that these fishes look
like a pipestem cleaner come to life, since they are very long
and skinny with pointed snouts. Pipefishes are also characterized
by an external armour of bony plates arranged in rings around
the body, and the presence of a brood pouch on the underside
of the male. The male incubates fertilized eggs in this pouch
for at least 8 to 10 days (depending on water temperature), until
they hatch and the young swim out. The smallest species of pipefish
measures 2.5 cm (1 in) in length, while the largest species can
reach 46 cm (18 in) in length. Pipefishes feed on planktonic
organisms (such as small crustaceans and fish larvae) by using
a special suction method to rapidly draw prey into their tube-like
mouths from over 4 cm (1.5 in) away.
To learn more about fishes
in the Family Syngnathidae, check out the recent question on Characteristics
of Seahorses.
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Countershading
in fish - received from Resemead, California
Q: What is countershading?
A: Countershading refers to
the colouration of many fishes that are darker on the back than
on the sides and belly. With this arrangement, illumination from
above lightens the back and the light coloration on the sides
and belly lighten the shadows of the underside. This type of
colouration is thought to help conceal the fish from predators.
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Fish
Camouflage - received
from Aaron in North Carolina
Q: Say a fish is dark colored
on its dorsal side, and light colored on its ventral side, how
is that an example of camoflauge?
 A:
This type of colouration in fish is thought to be a form of camouflage
because it helps them blend into their background whether you
are looking at them from above of below. From above, the depths
of the sea look very dark, so a fish needs to be dark on top
in order to blend in. Light from the water surface will reflect
off of the top of the fish, so a dark colour helps to correst
for that.
If you look up from below the water looks very light, because the sunlight
is shining into it. In order to blend in from this point of view, a fish needs
to have a light-colored belly.
This form of camouflage is called countershading.
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Schooling
fish - received from Dana Lee in California
Q: Why do fish swim in schools?
 A:
Fish behaviour is a very interesting topic, I'm glad you asked
about fish schooling. Fish generally arrange themselves into
schools for two reasons:
For defense against predators - by being in a large group, fish have a better
chance of escaping predators. Predators become confused by many fish swimming
together, and the fish as a group are more likely to detect large hungry
predators that may be nearby.
- To capture prey - predatory
fish may cooperate by hunting together in schools by surrounding
prey and forcing them to surface, making them easier to catch.
Another interesting point
about fish is that they only form schools when it helps them
to hunt or defend themselves better than if they were alone.
Fish that form schools generally do not have specialized defense
structures such as poison glands or barbs.
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Flatfish
Camoflauge
Q: I would like information
regarding flatfish camoflauge and why they are flattened.
A: Most different species
of flatfish have different coloration and not all species have
good camoflauge. One interesting fact is that most species only
have coloration on the side that faces upwards. The side that
faces the bottom of the ocean is usually white or very pale in
coloration. For your second question I found that flatfishes
are laterally compressed fish. When flatfish are born they are
like any other bony fishes but as they reach their juvenile form
they undergo some major changes. First the flatfish eyes move
to one side of the flatfish body. This involves a major change
in the fishes nervous system. Secondly the fish then lives on
its side. The moving of the eyes allows the fish to maintain
vision out of both eyes when the flatfish is living on its side.
Thanks for the great question.
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Salmon
Slime
Q: I
would like to know what the chemical formula for the slime on
pacific sockeye salmon is and what type of compound is it (acid/base/salt)?
The reasons I ask the question is because recently I handled
a live Sockeye salmon with my hands and it left my hands stinging
afterwards.
A: I talked to a salmon specialist
and he informed me that no one really knows the chemical formula
for salmon slime. He did say however that its a form of mucus
polysaccharide. Its possible that you experienced an allergic
reaction to something on the salmon that you handled and it caused
the stinging sensation on your hands. Sometimes wild salmon will
have skin infections or sea lice and you may even be allergic
to that. I wish that I could have been more help on this one.
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DEEP SEA FISH
Viper
Fish and Gulper Eel - Received from Steven and Ricky in Texas.
Q: Please give us some general interesting information on the viper fish and
the gulper eel. We are writing reports on these fish as part of an ocean unit
for our class. Thanks.
A. These
fish are found in deep waters of the open ocean. You're not likely
to catch one with a hook and line!
The viper fish is not a single species, but rather there are many different
species that are commonly referred to as viper fish. Viper fish generally live
in the "twilight" area of the ocean, at depths of 500-2,000 feet.
They are slender, and taper from a large head to a small tail. They have huge
jaws, with very large fangs. Indeed, the teeth are so large that the fish cannot
close its mouth all the way. The mouth is very deep, and can open wide enough
to catch very large prey. You don't have to worry too much about being eaten
by a vicious viper fish - not only are they found only in deep water, but the
different species range in size from a few inches to just under a foot.
Gulpers are also deep water
fish - there are several different species that are commonly
called Gulper Eels. They live at depths of 9,000 feet or more,
where there is no light from the surface at all. At these depths,
there is very little life, and therefore not much to eat. The
gulpers have solved this problem by evolving a huge mouth, and
a stomach that can expand to many times its normal size. They
can eat other fish that are larger than themselves. They have
tiny eyes - a 4.5 foot long specimen has an eye of less than
a quarter of an inch in diameter. They have very long whip-like
tails, with a reddish glowing spot on the end which may serve
to attract prey in the perpetual darkness of the deep sea.
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Deep-sea
dragon fish - Received from Morgan in Oregon.
Q: I read in Science News
about a fish called a loose jaw or dragon fish. These fish
are the only known animals to use chlorophyll in their eyes.
They are a rare fish that is only found in the deeper parts
of the ocean. Well anyway I am doing a report on them and need
some more info. I have checked everywhere on the internet finding
nothing. If you have any info whatsoever please tell me.
A: While
loosejaws and dragon fishes are classified in the same family
(Stomiidae), they represent a number of different species all
having barbels with light organs located on their chins. I believe
the fish you're interested in is the deep-sea dragon fish (Malacosteus
niger), which uses a derivative of chlorophyll to enhance
its long-wavelength sensitivity. This fish is a mesopelagic zooplanktivore,
which means that it lives in the midwaters of the open ocean
(between 200 and 1000 m) and preys on zooplankton. M. niger lacks
gill rakers, has enlarged teeth, a head that hinges upwards,
and lacks a floor in its mouth to allow for jaw expansion. These
characteristics initially led deep-sea ichthyologists (fish biologists)
to believe that the deep-sea dragon fish went after large prey
items. However, a recent study demonstrated that M. niger feeds
primarily on copepods.
For some pictures and information
on deep-sea animals, check out the Deep
Sea Pages.
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Gulper
eel - Received from Robert in Washington State.
Q: I am looking for information
on the "Gulper Eel". Could you please give me some
general info in this animal. Thank you. :)
There is currently only one
recognized species of gulper eel, Eurypharynx pelecanoides,
in the Family Eurypharyngidae. This fish is believed to inhabit
depths of 500 to 3000 m, although the maximum depth that one
has been collected at is only 1532 m. E. pelecanoides has
a very large gape, weak jaws and an extremely flaccid body. It
has been surmised that the gulper eel behaves like a living net,
engulfing prey by slowly swimming over them with its mouth open.
Its prey includes fishes, shrimp and zooplankton (copepods).
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Angler
and Viper Fish - Received from Davey in New York
Q: Are the angler fish
and the viper fish located in the twilight zone?
A. The twilight zone, or in
more technical terms, the Mesopelagic zone, is the area of the
ocean bordered by the sunlight, or photic zone above, and the
darkness below. It's in this zone where most animals show bioluminescence
and very curious features such as large eyes, sharp teeth and
expandable jaws and stomachs as a result of the conditions of
their deep environment. The viperfish does in fact live in the
twilight zone and with its large eyes, sharp teeth and wide jaw,
is an example of this kind of deep sea adaptation. Viperfish
have a specially adapted hinged skull which is why their jaws
can open so wide. They have a long dorsal fin with a lure-like
photophore on the end, and have been seen hanging motionless
in the water with the lure in front of their mouths waiting for
their prey. This way they don't have to actively hunt, and can
conserve precious energy. Although they are often thought of
as deep sea fish, they have been found at depths of only 80m,
presumable coming up to feed at night.
The angler fish on the other
hand is most typically found in deeper waters in the area we
call the Bathypelagic zone (from 1000m down to 4000m), but can
range from the surface down to the darkest depths. There are
many kinds of angler fish, each with different looks, but they
have all adapted a huge gaping mouth and a lure like the viperfish.
Anglers have teeth in their throats to prevent prey from escaping.
I hope this is answers your
question. If you want to checkout some cool pictures of angler
fish and viper fish, plus other neat deep sea animals, go to
the Deep Sea page under the OceanInfo section on the OceanLink
website.
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Angler
Fish Eating Habits - Received from Paige in Dallas,
Texas
Q: hello I am wondering
why does the "Deep Sea Angler Fish" eat other fishes
poop? Is it because it is good for it or just to gross people
like me and my friends out? Please answer this Question to
the e-mail address that I said before and i will print it out
and bring to show my teacher and my class mates. Thank you
soooooooo much for your cooperation in helping me and my class
learn about the JASON Project and go exploring the ocean floor
and up in space. Again I thank you so much.
A: I have never heard of the
deep sea angler fish eating other fishes' poop. If you could
email me back the website or book you read this in, I would like
to check it out. The information I did find out about the deep
sea angler fish about how and what it eats is as follows. The
lure that extends in front of the angler fish is thought to be
used like a lure, the same way as the lure that people use on
their fishing rod. The lure, which is lit (bioluminescences)
in deep sea species is used to attract smaller prey. There are
many kinds of angler fish with different looks, but all have
a huge gaping mouth and teeth in their throats to prevent prey
from escaping. Some of the food items of angler fish include
lantern fish, hatchet fish, other angler fish, shrimp-like crustaceans,
arrowworms and squids. If you would like to check out a picture
of a deep sea angler fish visit the OceanLink Deep
Sea Page.
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Coelacanths
- Received from John in Barrington, Illinois.
Q: I dont know how to spell
this fish's name: "seal-a-kamp". How do you spell
this? where can i get info? this is a critter that lives in
caves off Africa, but recently discovered off Fiji (i think)
it has legs (and maybe arms) i heard about it on NPR today...Thanks!
A: I
believe the fish you're referring to is the coelacanth (Latimeria
chalumnae). Living specimens of this species were "discovered" in
1938 off the coast of South Africa. Previously thought extinct,
coelacanths were known only from fossils which are over 70 million
years old. Before observations were made of living fishes, ichthyologists
believed that coelacanths "walked" on the bottom using
their lobed fins. However, using a small submarine these fishes
were observed to drift in currents close to the bottom, with
the head pointed downwards at an angle and the fins used as stabilizers.
They have neither arms nor legs.
Living at depths of 150-250
m, coelacanths gather in caves during the day to rest. They have
a special electric organ in their snout, which helps them to
detect prey when they feed at night. Coelacanths feed on a number
of bottom-dwelling fishes, including small sharks. L. chalumnae can
reach up to 2 m in length and have a skeleton made up of both
bone and cartilage. Their fin spines are also cartilaginous and
are hollow, giving them their common name ("coel" =
hollow and "acanth" = spine).
Another population of coelacanths
was indeed discovered recently in northern Indonesia.
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Rattail
or Grenadier Fish - Received from Davey in New York
Q: I have another question.
Can you give me some info on the Grenadier Fish or
the Rattail Fish?
A. Grenadiers or Rattail fish
are a relative of cod of the order GADIFORMES, family MACROURIDAE.
They are deep water fish that are most commonly found in the
Bathypelagic and Abyssopelagic zones of the ocean, however, they
can be found as shallow as 200m. Rattail fish are benthopelagic
fish which means that they hang out just above the ocean floor
cruising for animals or carcasses of animals to feast on. Rattails
have huge heads and eyes to match, along with long slender tails
(thus their name). To see some cool pics of rattails check out
http://www.bmi.net/yancey/fish.html or to find out more about
what lives in the Bathypelagic and Abyssopelagic zones of the
ocean check out the Deep Sea page on the OceanLink website (in
the OceanInfo section).
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Fangface - Received from KC in Indiana
Q: I am doing a fact sheet
on anoplogasters (almost as hard to find information on as
it is to spell) I'm almost done but I still need to find out
What it preys on,what preys on it,and its lifespan.I hope you
can help me or my lifespan may be drastically shortened.:-)
A: Fear
not, I have some information for you. Anoplogasters (aka fangface,
ogrefish; aptly named when you check out the pics below) are
fierce looking but pretty small, being a maximum of only 15cm.
Stomach contents of captured individuals turned up small crustacean,
fish, and cephalopods (squid, most likely). I'm not sure what
eats them, but considering the nature of the abyssal zone, anything
bigger than an anoplogaster would make a meal of it. I also couldn't
find any information about life spans, but that's not surprizing.
Considering how difficult it is to study deep sea animals in
their habitat, only rudimentary information on known.
 
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Oarfish - Received from Ontario
Q: Info on OAR FISH including
pics, sightings,general info.Thanks.
A:
A:
The Oar fish is a beautiful deep sea creature, and the longest
bony fish ever found. It has been documented reliably as
8 meters long, but specimens up to 17 meters in length have
been reported!
It's
latin name is Regalecus glesne - this is useful if
you want to find information off the internet - typing in
the latin name for a species in quotation marks is a good
way to find info about organisms.
 The name of the oarfish
comes either from the fact that its body resembles an
oar, or that its pelvic fins resemble oars - or most
likely from reports that it's pelvic fins actually act
like oars, sculling the water as it swims, helping it
turn and pivot.
The oarfish is found
world wide, thought to live in waters 20-200 m deep.
They are rarely seen because they only come up to the
surface when they are sick or dying. The Oarfish has
no teeth and but a small mouth, which makes it well adapted
to straining out small crustaceans from its gill rakers
to its mouth.
It is thought that
reports of sea serpents throughout history - especially
those described as having with "wild red manes"-
were actually sightings of the Oarfish.
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