ECHINODERMATA

Question 1

Class?
sea lilies

Answer 1

Class Crinoidea

Question 2

Class?
Sea stars

Answer 2

Class Asteroidea

Question 3

Class?
brittle stars and basket stars

Answer 3

Class Ophiuroidea

Question 4

Class?
Sea urchins and sand dollars

Answer 4

Class Echinoidea

Question 5

Class?
sea cucumbers

Answer 5

Class Holothuroidea

Question 6

Type of symmetry?

Answer 6

Bilateral as larva
pentamerous radial as adults

Question 7

What are the podia?

Answer 7

tube feet

Question 8

Which arms (ambulacra) are the bivium?

Answer 8

Arms C and D
*arms lettered with reference to the madreporite. Ambulacrum opposite is A then proceed counterclockwise.

Question 9

Which arms (ambulacra) are the trivium?

Answer 9

A, B and E
*arms lettered with reference to the madreporite. Ambulacrum opposite is A then proceed counterclockwise.

Question 10

Function of mutable collagenous tissues?

Answer 10

Connective tissue that can change properties very quickly.
Under neuronal control
Normally rigid but can soften quickly.
Allows echinoderms to maintain fixed postures with minimal metabolic energy.

Question 11

Describe the Fluid of the water vascular system

Answer 11

Fluid similar to seawater but has coelomcytes and organic molecules.

Question 12

How is the fluid within the water vascular system moved?

Answer 12

Cilia

Question 13

What is the water vascular system

Answer 13

Fluid-filled canals for internal
transport and locomotion.

Question 14

Location and function of the madreporite?

Answer 14

On aboral surface. Grooved with ciliated epidermis. May allow seawater into vascular system.

Question 15

What is the ampulla?

Answer 15

looks like the turkey baster
under madreporite connected to water vascular system and hemal system.

Question 16

What does the stone canal do?

Answer 16

connects ampulla to the water vasc system and connects to the ring canal

Question 17

What does the ring canal do?

Answer 17

Leads to radial canals in each arm. Also has Polian vessicles
(maintain internal pressure) and Tiedemann’s bodies (produce coelomcytes).

Question 18

Where do radial canals lead?

Answer 18

to lateral canals

Question 19

Where do lateral canals lead?

Answer 19

pass thru pores in the skeletal plates and end in the tube feet

Question 20

What is the function of tube feet?

Answer 20

Tube feet used for locomotion, prey capture, adherence to substratum.
Terminal tube feet are chemosensory.
Also aid in gas exchange

Question 21

How do they support their bodies?

Answer 21

Calcareous endoskeleton with different degrees of calcification.
Holothuroids have very muscular body walls.

Question 22

How do Crinoids move?

Answer 22

They walk on the tips of their arms. Some swim.

Question 23

How do Asteroids move?

Answer 23

crawl with tube feet

Question 24

How do Ophiuroids move?

Answer 24

use flexible arms for crawling.

Question 25

How do urchins move?

Answer 25

Use tube feet and moveable spines

Question 26

How do sand dollars move?

Answer 26

use spines to burrow in sand

Question 27

How do cucumbers move?

Answer 27

crawl on podia of trivium or by muscular action of the body wall

Question 28

How do Crinoids feed?

Answer 28

Filter feed with oral side up and arms and pinnules outstretched. Food particles brought to mouth via cilia in ambulacral grooves.

Question 29

How do asteroids feed?

Answer 29

Most are predators and scavengers. Eversible portion of stomach (cardiac stomach) extruded onto or into prey.

Question 30

How do Ophiuroids feed?

Answer 30

Predators, scavengers, filter feeders, deposit feeders. Food collected and passed along podia and spines to mouth. *Digestive system reduced with no anus.

Question 31

How do Echinoids feed?

Answer 31

Herbivores, suspension feeders, detritovores. Urchins have Aristotle’s lantern. Hard plates and muscles that control protraction of five teeth. Teeth scrape algae off rocks and take bites of macroalgae. Can excavate holes in rocks.

Question 32

How do Holothuroids feed?

Answer 32

Suspension and deposit feeders. Extend mucus-covered buccal tentacles into water. Tentacles are pushed into mouth one at a time.

Question 33

What are Cuverian Tubules and which class are they present in?

Answer 33

Blind sticky tubes at base of respiratory tree. Entangle predators. Present in Holothuroids

Question 34

How do they achieve internal transport?

Answer 34

Internal transport by coeloms, water vascular system, and hemal systems.

Question 35

What is a hemal system?

Answer 35

An array of canals and spaces enclosed within coelomic channels called perihemal sinuses. Parallels water vascular system. Probably helps distribute respiratory gases and nutrients.

Question 36

Gas exchange in Holothuroids?

Answer 36

Holothuroids have respiratory trees. Water is actively pumped by muscular hind end. Gases picked up by coelom and hemal system.

Question 37

How do they osmoregulate?

Answer 37

Osmoconformers. Waste is usually ammonia lost across podia and dermal branchia.

Question 38

How do they reproduce asexually?

Answer 38

Most capable of regenerating lost parts. Holothuroids regenerate intestines and respiratory trees. Asteroids and ophiuroids regenerate lost arms and suckers.

Question 39

Gonochoristic or hermaphroditic?

Answer 39

Most gonochoristic

Question 40

Direct or indirect development?

Answer 40

Both - Free spawning with indirect development to brooding with direct development.