echinoderms

Question 1

Echinoderm

Answer 1

a marine invertebrate of the phylum Echinodermata, such as a starfish, sea urchin, or sea cucumber.

Question 2

Endoskeleton

Answer 2

an internal skeleton, such as the bony or cartilaginous skeleton of vertebrates.

Question 3

Pedicellariae

Answer 3

a defensive organ like a minute pincer present in large numbers on an echinoderm.

Question 4

Madreporite

Answer 4

a perforated plate by which the entry of seawater into the vascular system of an echinoderm is controlled.

Question 5

Radial canal

Answer 5

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.

Question 6

Ring canal

Answer 6

the circular water tube that surrounds the esophagus of echinoderms

Question 7

Arm / Ray

Answer 7

The arms have rows of little suckers on the undersides, called tube feet, with which the animal moves around and grasps prey.

Question 8

Radial Symmetry

Answer 8

symmetry around a central axis, as in a starfish or a tulip flower.

Question 9

Bilateral Symmetry

Answer 9

the property of being divisible into symmetrical halves on either side of a unique plane.

Question 10

Water Vascular System

Answer 10

(in an echinoderm) a network of water vessels in the body, the tube feet being operated by hydraulic pressure within the vessels.

Question 11

Ambulacral Groove

Answer 11

an have ambulacral parts that include ossicles, plates, spines, and suckers. For example, sea stars or “star fish” have an ambulacral groove on their oral side (underside). This ambulacral groove extends from the mouth to the end of each ray or arm.

Question 12

Ossicles

Answer 12

a small piece of calcified material forming part of the skeleton of an invertebrate animal such as an echinoderm.

Question 13

Pyloric Caecum

Answer 13

This organ with finger like projections is located near the junction of the stomach and the intestines. Its function is not entirely understood, but it is known to secrete enzymes that aid in digestion, may function to absorb digested food, or do both.

Question 14

Pyloric Stomach

Answer 14

The pylorus is considered as having two parts, the pyloric antrum (opening to the body of the stomach)

Question 15

Cardiac Stomach

Answer 15

A constriction separates it from the smaller, more ventral, pyloric stomach that lies in the posterior part of the thorax.

Question 16

Ampullae

Answer 16

The only function of the ampullae is to store the water that enters the vascular system and send it to the minuscule tube feet, located in the ventral side of the starfish’s arms.

Question 17

Gonads

Answer 17

gonads are called testes; the gonads in females are called ovaries

Question 18

Central Disc

Answer 18

is generally found with 5 arms that are attached to a central disc. This central disc is the activity centre of the starfish and also contains the mouth of the starfish.

Question 19

Tube feet

Answer 19

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.

Question 20

External Fertilization

Answer 20

a male organism’s sperm fertilizing a female organism’s egg outside of the female’s body.Internal fertilization

Question 21

Regeneration

Answer 21

the action or process of regenerating or being regenerated, in particular the formation of new animal or plant tissue

Question 22

Sea star

Answer 22

Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea. Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or “basket stars”.

Question 23

Brittle star

Answer 23

They crawl across the sea floor using their flexible arms for locomotion. The ophiuroids generally have five long, slender, whip-like arms which may reach up to 60 cm in length on the largest specimens.

Question 24

Sea urchin

Answer 24

spiny, globular animals, echinoderms in the class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal to 5,000 metres. Their tests are round and spiny, typically from 3 to 10 cm across.

Question 25

Sand dollar

Answer 25

extremely flattened, burrowing sea urchins belonging to the order Clypeasteroida. Some species within the order, not quite as flat, are known as sea biscuits

Question 26

Sea lilies

Answer 26

Crinoids are marine animals that make up the class Crinoidea of the echinoderms. The name comes from the Greek word krinon, “a lily”, and eidos, “form”. They live in both shallow water and in depths as great as 9,000 meters

Question 27

Feather stars

Answer 27

The name comes from the Greek word krinon, “a lily”, and eidos, “form”.

Question 28

Sea cucumbers

Answer 28

They are marine animals with a leathery skin and an elongated body containing a single, branched gonad.

Question 29

Sea daisies

Answer 29

Sea daisies make up an unusual group of deep-sea taxa belonging to the phylum Echinodermata, with three species described in the genus Xyloplax.