Page 73 - Shark

gills Breathing organs of fish through oviduCt Egg tube of a female shark into
which oxygen is taken in and carbon dioxide which sperm is introduced by the male.
is expelled. In sharks and closely related
species, the gills appear as a series of ovipArous Producing eggs that hatch
between five and seven slits behind the head. outside the mother’s body.

ovovivipArous Producing eggs that
hatch inside the mother’s body.
pArAsite Animal or plant that lives on
another organism and draws nutrients
from it.

peCtorAl fin One of a pair of fins
located on the underside of the front
section of a fish’s body. Pectoral fins
provide lift, assist steering, and act as
brakes when necessary. Tagging
Nurse-shark gills
spirACle Additional, rounded gill
opening on top of the head in some
bottom-dwelling sharks.
inverteBrAte Animal without a
backbone or spinal column (opposite of Pectoral fin spirAl vAlve Shark’s efficient,
VERTEBRATE). corkscrew-shaped intestine.
Horn shark
lAmellAe Microscopic, capillary-filled tAgging Method of
branches that make up the feathery tracking and studying
filaments lying across a fish’s gill arches. sharks in the wild by
These structures absorb oxygen and attaching tags to their fins
expel carbon dioxide. so their movements can
be recorded.
tApetum Layer of cells lying behind the
retina in the eyes of some fish and nocturnal
animals. These cells reflect light, helping the
creature to see in the dark.

ventrAl Relating to the underside of the
pelviC fin One of a pair of fins body (opposite of DORSAL).
located on the underside of the rear
section of a fish’s body. Smaller than verteBrAte Animal that has a
lAterAl line Row of pressure-sensitive pectoral fins, pelvic fins also assist steering backbone or spinal column (opposite of
organs that run along each side of a shark’s and act as stabilizers. INVERTEBRATE).
body and around its head. These organs
can alert the shark to the movement and plAnkton Microscopic, sometimes vertiCAl migrAtion Movement of
the proximity of objects in the water by moving, organisms that provide food for marine creatures from deep to shallow
detecting tiny changes in pressure—a great some shark species. Whale sharks, for water or vice versa. Planktonic organisms
advantage when the sea is dark or murky. example, live mostly on plankton. migrate in this way daily, and they are
often followed by fish, whales, and other,
migrAtion Regular movement of an predAtor A creature whose natural similar, predators.
animal population from one area to another inclination is to prey on other animals.
and back again, often on a yearly basis. vivipArous Producing young that
shAgreen Dried shark skin used like remain in the mother’s body until they are
niCtitAting memBrAne Third, inner sandpaper to polish wood and stone. fully formed and ready to be born.
eyelid that moves across the surface of a
shark’s eye to clean and protect it. This
function is similar to that of human eyelids
when we blink.
olfACtory Relating to a creature’s
sense of smell.
oophAgy A form of prenatal cannibalism
in which some developing sharks feed on
eggs produced by the mother.
omnivorous Feeding on all types
of food, both plant and animal.

operCulum Gill cover present in bony
fish but not in sharks.
otoliths Calcium carbonate granules in
a shark’s ear that allow it to establish its
angle of tilt in the water. A predatory bull shark hunting in the shallows.

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