ECHINODERM
VOCAB ONLY
A radially symmetrical marine invertebrate
with an endoskeleton, water-vascular system,
and tube feet such as a sea star, sea urchin or sea
echinoderm
cucumber _________________________
Special type of radial symmetry in which body
parts extend outward along 5 spokes
_______________
pentaradial
One of the small calcium carbonate plates that
forms the endoskeleton of echinoderms
________________
ossicle
Surface of a starfish on which the mouth is
located______________
Oral surface (ventral)
One of the many small, flexible, fluid filled tubes
that project from the body of an echinoderm and
are used in locomotion, feeding, gas exchange,
Tube feet
and nitrogen excretion _________________
Small pincher-like structure on the surface of
certain echinoderms that keep the surface clean
________________
pedicellaria
Surface opposite the mouth and a
Aboral surface (dorsal)
starfish_______________
Sieve-like opening on the aboral surface
of a starfish through which water
enters the water vascular system
madreporite
_________________
ganglion
A mass of nerve cells ________________
A network of water-filled canals in an
Water vascular system
echinoderm _____________
Part of the water vascular system that
connects the madreporite and ring
Stone canal
canal _____________
Bulb-like sac at the top of the tube foot
which controls water entering and
leaving the foot ________________
ampulla
Portion of an echinoderm’s stomach that
is extruded through the mouth during
feeding __________________
Cardiac stomach
The fluid that is circulated through the
body of an animal with an open
hemolymph
circulatory system _________________
Winged larva seen in echinoderms
bipinnaria
________________
Special type of symmetry seen in starfish with
Pentaradial symmetry
5 arms _____________
Development in which the offspring start as
small versions of adults
Direct development
Type of circulatory system in which blood is
closed
contained in vessels ___________________
In a sea star the stomach that is connected to
Pyloric stomach
the digestive glands__________________
The hemolymph-filled space or body cavity of
hemocoel
some invertebrates _________________
One of the many hollow tubes that project
from the surface of a sea star through
which gas exchange and nitrogen excretion
Skin gills
takes place ________________
Nerve that encircles the mouth in a sea
star __________________
Nerve ring
Organism whose embryonic blastopore
becomes the anus _______________
deuterostome
Organism without a backbone
invertebrate
________________
Type of development in which offspring
hatch as an immature larva and must
indirect
change into their adult form _____________
Joining of an egg and sperm outside the
female’s body _________________
external fertilization
Organism that lives in the ocean (salt water)
________________
marine
Nerve that runs along inside the ambulacral
ridge in each arm of a starfish
_____________
Radial nerve
Portion of the sea star’s water vascular
system that runs along inside the
ambulacral ridge in each arm
_________________
Radial canal
Groove on the oral surface of a sea star that
Ambulacral groove
holds the tube feet ________________
Greenish digestive enzyme that breaks down
bile
fat _____________
Space that surrounds the internal organs
_________________
coelom
Type of skeleton found inside the body
endoskeleton
________________
Type of symmetry seen in echinoderms in which
body parts are arranged around a central axis
_____________
Radial symmetry
Development in which the offspring start as an
immature larva and undergo metamorphosis to
become adults_________________
Indirect development
Type of circulatory system in which blood is NOT
contained in vessels and flows loose inside the
body cavity and tissue spaces
___________________
open