Characteristics:
• 1) skeleton made up of bone
• 2) lungs (early bony fish) or swim bladder
present
• 3) scales –cover body: protection and
reduce water resistance
eel
Yellow
Perch
Two-main groups:
• I -Lobe-finned –fleshy fins supported with a
series of bones (Most are extinct). Most are
lungfish. One species called the coelacanth is a
lobe-finned fish, thought to be extinct, but found
to exist in modern times. Extinct lobe-finned fish
are thought to be ancestors to amphibians.
• coelacanth – found off the coast of South
Africa in 1938,(5 feet long). Since then,
there have been many caught off the coast
of Madagascar & Mozambique.
II -Ray-finned – fins with long segmented
bony elements and no central bone support.
Yellow Perch
large mouth bass
Characteristics
• 2) operculum: hard plate over gills
king salmon scales
• 3) scales: overlapping, bone-like disks grow
from pockets in skin
5) Complete digestive system
• 6) Circulatory system:
• A fish heart has one atrium and one ventricle,
so you may think of it as a two-chambered
heart. Heart pumps blood to arteries, to
capillaries (in the gills where gas exchange
takes place), to veins, to the heart.
FISH HEART
Blood Flow
• 7) Fish kidneys filter chemical waste from the
blood. Urine is stored in the urinary bladder_,
& later expelled. By varying the amount of water
and salts in the urine, the kidneys help regulate
the water and ion balance. The gills also
regulate the concentration of ions in the body.
• 8) Swim bladder : Fish adjust their overall
density and thus their vertical position in the
water through the gas in the swim bladder.
This bladder is like a long balloon and is
connected to the fish's bloodstream through
tiny blood vessels called capillaries.
• The oxygen and other gases that the fish gets from
the water through its gills can go back and forth
from the blood to the bladder and from the bladder
to the blood. When the fish needs to dive, the bladder
gives up some gas to the blood and deflates a little. This
makes the fish a little more dense so its easier to go
down. When the fish needs to go toward the surface, the
blood gives gas to the bladder causing it to inflate. This
makes the fish less dense so it is easier
• 9) Brain, spinal cord, and various
sensory organs make up the nervous
system. Sensory organs are connected to
the brain by the cranial nerves.
• 10) Reproduction through spawning:
eggs and sperm released in the water.
Some fish bear live young (ovoviviparous)
--(Some nest-building)
• Albino ratfish
• Green-eyed and almost purely white, the albino ratfish's
front teeth look similar to those of a rodent. It appears
shiny thanks to a crystalline layer right under the surface
of its skin.
• But the eye-catching creature usually gets eaten by
predators -- before being able to pass on its mutant
genes, which stop the production of skin pigment.
Scientists discovered this albino anomaly in summer
2007 off Whidbey Island, Wash.
A deep-sea
Angler fish
Hawaii’s Round Belly Cowfish
JAPANESE SUNFISH
• Some Fish that washed up after the
South- East Asia Tsunami of 2005.
Goldfish Facts
Goldfish are tasty!
May Be the Largest Goldfish
Puffer Fish of “Blowfish”
The Story of Fugu – Edible,
Poisonous Puffer Fish
• Fugu (blow fish) is a fish which contains
deadly poison in the organs. Despite the
risk, fugu dishes remain as special feasts
in Japan. Even the milt is considered as a
great delicacy. Fugu is referred to as
blow/globe/puffer fish since it blows its
body up.
• It's reported that about 40 kinds of blow fish are
caught and cultured in Japan and that 10000
tons of blow fish are consumed each year.
Shimonoseki-city in Yamaguchi, is known as
fugu city and supplies a large amount of fugu.
• There is an old expression such that "I want to eat
fugu, but I don't want to die" in Japan. Since fugu's
poison can lead to instantaneous deaths of diners,
only licensed cooks are allowed to prepare fugu.
You must have special skills and knowledge about
fugu to be licensed. Poisonous parts of fugu differ,
depending on the kind of fugu. Because of the strict
regulations, the number of deaths is decreasing.
• Fugu dishes are usually expensive. One meal can cost
$100 to $200 per person at a famous restaurant. But
there are inexpensive fugu dishes (from $15 to $20)
available at some restaurants. It's said that the most
poisonous fugu, "Tora-fugu," is the most delicious. Torafugu is expensive and can cost over one hundred dollars
at a fish market. Nowadays, prepared-fugu are sold at
grocery stores and online stores, and fugu are eaten at
Japanese homes.
Expensive restaurant fugu
fugu at the fish market
Homer Simpson eating fugu