Chapter 16 - Echinoderms - Test 3

characteristics

1. Pentaradiate symmetry

2. water vascular system

3. endoskeleton plates (ossicles)

4. Dermal brachiae

5. pedicellariae

function of aboral madreporite

water intake and exit to control volume in water vascular system

dermal branchaiae

cutaneous respiratory structures

pedicellariae

structure that clear debris from the skins surface

components of the endoskeleton and how does form follow function here

1. ossicles connected by “catch collagen” which is mutable (solid to liquid)

2. maintain posture with no additional effort

what are function of the water-vascular system

1. excretion

2. respiration

3. feeding

   1. locomotion’’

sea stars eat?

carnivores; clams

unusual about the stomach

evert part of stomach into prey

reproduction

1. dioceous

2. external fertilization

3. asexual

4. cleavage of central disc

5. regeneration

6. autonomy (defense mechanism)

able to regenerate lost parts

yes

autonomy

losing body part as defensive mechanism

how are arms of the brittle stars different than those of asteroids

all organs found in central disc

unusual about some soft tested urchins?

brightly colored; not boney; deliver poisons

Aristotles lantern?

part of sand dollar; has teeth and muscles

primary diet of sea urchins

scrape off food; graziers

characteristic distribution of tube feet in some species of sea cucumbers

sole (well-developed); locomotion

how do sea cucumbers feede

tentacles come out, nutrients trapped; filter-feeding

unusual defense mechanism of sea cucumber

self - evisceration = respiratory trees come out so predators ear that then reproduce them

sea cucumbers involved in commensalism?

animals live inside cloaca (fish)

how is their life history different than most echinoderms (feather stars)

sessile and stalked dyring metamorphisis; free-moving adults

feeding method of feather stars

passive filter feeders

how is the water vascular system different in feather stars

multiple madreporic pores instead of just one