Echinoderm Flashcards
Echinoderm
a marine invertebrate of the phylum Echinodermata, such as a starfish, sea urchin, or sea cucumber.
Endoskeleton
an internal skeleton, such as the bony or cartilaginous skeleton of vertebrates.
Pedicellariea
a defensive organ like a minute pincer present in large numbers on an echinoderm.
Madreporite
a perforated plate by which the entry of seawater into the vascular system of an echinoderm is controlled.
Radial Canal
one of the numerous minute canals lined with choanocytes which radiate from the paragastric cavity in some sponges and end just below the surface of the sponge.
Ring Canal
the circular water tube that surrounds the esophagus of echinoderms. 2 : the circular canal in the edge of the umbrella of a jellyfish that links the radial canals.
Arm/ Ray
In some ophiuroids, one or several small, symmetrically arranged plates that are inserted between the dorsal arm plate and the lateral arm plate.
Radial Symmetry
symmetry around a central axis, as in a starfish or a tulip flower.
Bilateral Symmetry
the property of being divisible into symmetrical halves on either side of a unique plane.
Water Vascular System
a network of water vessels in the body, the tube feet being operated by hydraulic pressure within the vessels.
Ambulacral Groove
typically used in the context of anatomical parts of the phylum Echinodermata or class Asteroidea and Edrioasteroidea.
Ossicles
a very small bone, especially one of those in the middle ear.
Pyloric Caecum
one of the tubular pouches opening into the alimentary canal in the pyloric region of most fishes.
Pyloric Stomach
the distal aperture of the stomach, opening into the duodenum.
Cardiac Stomach
.consists of a mouth; an esophagus; a two-chambered foregut; a midgut with outpocketings called digestive glands, or hepatopancreas; and a hindgut, or rectum.
Ampullae
a roughly spherical flask with two handles, used in ancient Rome.
Gonads
an organ that produces gametes; a testis or ovary.
Central Disc
protrusion is a type of herniated or bulging disc that affects the spinal cord and could possibly result in nervous system disorders, such as radiating pain and muscle weakness as well as other symptoms stemming from nerve irritation.
Tube Feet
each of a large number of small, flexible, hollow appendages protruding through the ambulacra, used either for locomotion or for collecting food and operated by hydraulic pressure within the water-vascular system.
External Fertilization
a male organism’s sperm fertilizing a female organism’s egg outside of the female’s body.
Regeneration
the action or process of regenerating or being regenerated, in particular the formation of new animal or plant tissue.
Seastar
a starfish.
Brittle Star
any of a class or subclass (Ophiuroidea) of echinoderms that have slender flexible arms distinct from the central disk.
Sea Urchin
a marine echinoderm that has a spherical or flattened shell covered in mobile spines, with a mouth on the underside and calcareous jaws. Many species are harvested for food.
Sea Dollar
a flattened sea urchin that lives partly buried in sand, feeding on detritus.
Sea Lillies
a sedentary marine echinoderm that has a small body on a long jointed stalk, with featherlike arms to trap food.
Feather Star
an echinoderm with a small disklike body, long feathery arms for feeding and movement, and short appendages for grasping the surface.
Sea Cucumber
an echinoderm that has a thick, wormlike body with tentacles around the mouth. They typically have rows of tube feet along the body and breathe by means of a respiratory tree.
Sea Daisies
small, circular animals related to sea stars. There are only two species. Sea daisies have no arms, but the circle is rimmed with flat spines that look like daisy petals. The upper surface of the animal is delicately plated.
