| ampullae
of Lorenzini:
natural
electrical detectors located in the heads of sharks and rays that
are sensitive to the electronic signals emitted by potential prey.
Aristotle's
lantern:
a feeding structure of echinoids that is formed from several calcareous
elements and includes the jaws.
baleen:
the comb-like fibrous plates hanging from the upper jaw of some
whales, that are used to sieve food from seawater, often called
whalebone.
barbel:
a slender, fleshy protruberance on the lower jaw of some fish
and sharks, equipped with sensory and chemical receptors and used
to locate food.
benthic:
living on or near the seabed or under the sediment
bilaterally symmetrical:
animals which can be divided into two equal halves by a line drawn
down the centre.
bivalve:
an animal with a shell in two parts hinged together e.g. mussels
and clams.
bryozoans:
minute sedentary aquatic animals superficially resembling coelenterate
polyps, usually living in colonies and having a calcareous exoskeleton.
calcareous:
rich in calcium salts, usually calcium carbonate, generally hard
such as a sea shell.
caudal: pertaining
to the tail region
caudal
fin:
tail fin
chitin:
a horny fingernail-like substance usually tough and brown that
forms the sucker rings, hooks and beaks of cephalopods, l the
trapdoor of a snail shells and most of the hard parts of arthropods.
.
cirrus (pl.=cirri):
a limb of a barnacle that extends and contracts during feeding
also a slender jointed appendage that projects from the base of
a feather star and is used for attachment or locomotion; hair-like
or finger-like tactile or sensory processes on many animals and
plants.
claspers:
the modified inner edges of the pelvic fins in male sharks and
rays, used for the transfer of sperm to the female.
cloaca:
a common opening for the reproductive, excretory and digestive
tracts.
commensal:
living: together for mutual benefit in a less intimate association
than symbiosis; a close association between species where one
(the commensal) gains benefit while the other (the host) is not
adversely affected.
cuttlebone:
calcareous supporting plate in the upper side of the mantle of
cuttlefish.
cusp:
a projection (point) on a tooth; many teeth have just one large
cusp but some have additional side cusps.
demersal:
found at the bottom or near the bottom of the sea or other aquatic
habitat.
denticles:
the tooth like scales of sharks and rays.
dorsal:
the upper surface of the body or head
dorsal
fins:
the unpaired fin or fins along the upper surface of the back
endemic
species: restricted
to a particular geographic region and thought to have originated
there.
flagellum
(pl.=flagella):
a long whip-like process the extends from the surface of the call.
flukes:
in cetaceans the horizontally flattened tail.
gastropod:
a class of molluscs which includes snails slugs and sea-hares,
having a distinct head, with eyes and tentacles and often have
a single shell.
hermaphrodite:
a plant or animal with both male and female sexual organs.
krill:
tiny shrimp-like crustaceans that occur in the open seas and are
a major part of the diet of the baleen whales.
larvae:
early young that are completely unlike the adults.
mantle:
a type of tissue on the body surface, which only occurs in molluscs,
which secretes and protects the shell.
medusa
(pl= medusae):
a free swimming animal shaped like a saucer, with tentacles projecting
from the underside.
melon:
in many toothed whales the bulging forehead containing oil, muscles
and nasal air sacs and passages, believed to be used in focusing
sounds for echolocation.
nematocyst:
a stinging cell of a cnidarian.
oophagy,
oviphagous:
egg eating; in some shark species the older embryos feed on unfertilised
eggs and smaller embryos within the uterus.
oscule:
the exhalant opening of a sponge.
oviparous:
egg laying; little or no development occurs within the mother's
body, instead embryos develop outside and each egg eventually
hatches to a young animal.
ovoviviparous:
giving birth to well developed young from eggs that hatch within
the mother's body. The young are almost exact replicas of the
adult.
pectoral
fins:
paired fins located just behind or below the gill slits in sharks
and used for lift and control of movement. Also called flippers
in cetaceans In rays enlarged pectoral fins are attached to the
back of the skull and united to form a body disc.
pedicellaria: a
stalked pincer like structure projecting from the surface of asteroids
and echinoids.
pelagic:
of,
or inhabiting the water column rather than the sea floor; this
term is usually applied to free swimming species;
living in open water away from the bottom, organism that drift
are plankton, those that swim actively are nekton.
pelvic
fins
(=ventral fins): paired fins on the underside of the body in sharks
and near the tail in rays.
phytoplankton:
small plants which drift in open water and carry out photosynthesis,
plant plankton, the basis of the aquatic food chain.
plankton:
minute plants and animals that live in open water and are primarily
transported by currents.
planula (pl. = planulae):
a mobile invertebrate larva that is small, flattened and covered
by cilia.
polyp:
an individual member of a coelenterate colony
having a mouth surrounded by a ring of
tentacles
radial
symmetry:
radula:
a ribbon of replaceable, chitinous teeth that is found only in
molluscs.
rhinophore: a protruding
tentacle like structure on the head of opisthobranchs, thought
to have a sensory function.
rostrum:
a
projection that extends forward from the head between the eyes.
sessile: permanently
attached to the substrate.
siphon:
fleshy tube through which water is pumped for respiration and/or
feeding but sometimes also for locomotion (e.g. octopus)
species:
a group of animals or plants which are capable of mating and producing
viable offspring who are themselves capable of reproduction.
spermatophores:
packets of sperm found in cephalopods.
spicule:
a calcareous or siliceous structure that provides internal support
to an animal; small hard structures of diverse shapes providing
skeletal support for a variety of invertebrates e.g. sponges,
sea-cucumbers, ascidians.
spiracle:
an auxiliary respiratory opening behind the eye in sharks and
rays through which water can be taken in when the animal is at
rest on the bottom or when the mouth is being used for feeding
spongin: a fibrous
protein that is use as skeletal material in sponges.
symbiosis:
a relationship between two organisms that results in mutual benefit.
symphysial
groove:
taxonomy:
the science of classifying all living things by arranging them
in groups according to the relationship of each to the others.
tube
foot:
an external extension of the water vascular system of echinoderms,
generally located in a row and terminating in a suction disc.
tubercle:
a small wart-shaped projection on the surface of an animal.
tunic:
a tough outer covering over the body of ascidians.
ventral:
the lower surface or underside of the body or head.
viviparous:
giving birth to live young, the embryo develops entirely within
the uterus.
water
vascular system: a
water filled system of tubes that is used for respiration, location
and excretion in echinoderms.
zooid:
a member of a joined colony e.g. a coral polyp or individual in
a colonial ascidian.
zooplankton:
small animals that drift in open water including amphipods, copepods,
isopods, krill, polychaetes and pterapods.
zooxanthellae:
single celled symbiotic algae, often golden brown in colour, that
live in the tissues of many hard and soft corals, providing the
host with energy from photosynthesis.
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