phylum echinodermata Flashcards
the echinodermata fall into protosoma or deuterosoma? and what other phyla are with them?
deuterosome; echinodermata, hemichordata, chordata
Echinodermata display _____symmetry
pentaradial
are echinoderms cephalized?
no
list the main synapomorphies/unique features of echinodermata
water vascular system & associated tube feet, endoskeleton, mutable collagen, pedicillaria, nerve ring
madreporite
opening in skin, lets water in/out
extensions of the water-vascular system are:
tube feet
polian vesicles
reservours off water vascular system that control water prssure
tiedman’s bodies
small glands off the ring canal in water vascular system, produce coelomocytes
draw a water vascular system diagram
there is a center circle, the ring canal. off the center ring canal is 5 radial canals. between each radial canal is a polian vesicle and 2 tiedman’s bodies. in one section between radial canals is the madreporite. following one radial canal down there are small circles coming off called ampulla with a tube foot off each
coelomocytes
invertebrate immune cells, prod by tiedman’s bodies in echinoderm water vascular system
endoskeleton is made of:
dermal ossicles and is covered with epidermis
endoskeleton is derived from:
mesoderm
dermal ossicles are made of:
CaCO3 crystals
ambulacral grooves are formed by the ______ and are either open/closed depending on:
endoskeleton; whether the ossicles cover them or not
are ossicles living?
nope
mutable collagen is:
a unique feature of echinoderms, is a specialized connective tissue that can be locked/unlocked into place to stiffen/loosen without muscle use. it allows for rapid state changes using only nerve impulses
pedicillaria are:
specialized pincer-like ossicle structures. on body surface. they are used for prevention of epibionts, prey capture, defense against toxins, camoflauge (can hold small particles/objects)
pedicillaria are only found in:
asteroidea and echinoidea
nerve ring is:
a central ring around the mouth where nerves extend from into and along ambulacral grooves
there are 5 classes of echinoderm:
crinoidea, asteroidea, echinoidea, holothuroidea, ophiuroidea
crinoidea are commonly called:
sea lilies and sea daisies and feather stars
in crinoidea, the oral side faces ____
up
crinoidea have 5-200 _____ each with hundreds maybe of lateral _____
arms; pinnules
where is crinoidea madreporite?
they don’t have on
how do crinoidea control water?
cilia on oral surface
where are crinoidea tube feet?
they run along arms and pinnules, but lack suction cups
crinoidea are ____ feeders. how do they eat?
suspension; podia capture food and then podia + cilia move the food to their mouth along the arms
crinoidea reproduction
gonads are held in pinnules which rupture to release gametes into water (free-spawning)
asteroidea are commonly called
sea stars
asteroidea have ____ ambulacral grooves
open
asteroidea have madreporite on ____ surface
upside, aboral
asteroidea mouth faces:
down
what kind of feeding do asteroidea do?
predatorial or scavengers
asteroidea digestion
extracellular, and often extra-corporeal (outside body). they evert stomach and cover the desired prey to begin digesting outside body. then, they suck up the partially digested food
asteroidea eat ______. how?
bivalves. use tube feet to pull apart shells, extra-corporeal digestion of mollusc. can open multiple shells at once
asteroidea respiration
dermal gills that are extensions of the eucoelom that pass through gaps in the ossicles for gas exchange. they can also use podia for respiration
asteroidea have __ stomach
2: cardiac and pyloric
tube feet are also called
podia
ampulla
little connector between radial canal and tube feet. as muscles and valves to control movement, open and close tube feet
asteroidea have ____ for defense and structure
pedicillaria
echinoderms, although pentaradial display ____ symmmetry at ______ stage of lief
bilateral, larval
ophiuroidea are commonly called
brittle stars and basket stars
ophiuroidea mouth faces____ and madreporite faces ___
down; up
ophiuroidea ambulacral grooves are ____ similar to _____and unlike ______
closed; echinoidea; asteroidea
echinoidea are commonly called:
sea urchins, sand dollars, sea biscuits
echinoidea ossicles are fused into a solid structure called :
test
echinoidea are divided into 2 groups. what are they? how are they different?
regular and irregular
regular are radially symmetrical while irregular are bilaterally symmetrical. regular have aristotle’s lantern structure which is used for feeding/chewing.
irregular have been secondarily flattened and their ambulacral grooves have been modified into petaloids.
irregular are primarily burrowers and are deposit feeders/suspension feeders while regular ones are predators or detritivores
aristotle’s lantern
structure in regular echinoidea. chewing apparatus with 5 continually growing, self-sharpening teeth, plates & muscles for eating
echinoidea mouth faces ____and madreporite faces ____
down; up
echinoidea pedicillaria and ossicles are modified how?
pedicillaria are stalked, sometimes poisonous. ossicles are modified to spines
holothuroidea are commonly called:
sea cucumbers
holothuroidea mouth faces:
it’s lateral
holothuroidea trivium
3 abulacral grooves on the bottom of the body used for movement and have longer tube feet
holothuroidea bivium
two ambulacral grooves that are on top of the sea cucumber
most echinoderms are ____ symmetrical but holothuroidea are ___
radial or pentaradial; bilateral
holothuroidea have ____ arms
no
holothuroidea tentacles
tentacles are around the mouth and are made of enlarged tube feet
holothuroidea madreporite faces:
it is internal
holothuroidea move:
using tube feet on trivium
or worm-style with musculature or can swim
2 main feeding guilds of holothuroidea:
suspension feeders & non-selective deposit feeders
suspension feeders are elongate and have highly branching tentacles with mucus to trap particles. use tentacles around mouth to move food into mouth
non-selective deposit feeders injest sediments as they crawl and digest any organic materials, excreting clean sediment. these are important for ocean floor turnover, preventing coral disease
holothuroidea respiration:
respiratory “trees” that branch off the hind gut. water is pumped in and out of the anus, moves around the trees for gas exchange. can also use tentacles and podia for gas exchange
holothuroidea hold gametes:
at the base of tentacles are the gonopores.
cuverian tentacles:
located at the base of respiratory trees in holothuroidea, are sticky and ejected out of anus at a predator. like silly string, may be poisonous
eviseration
holothuroidea defense. can eject organs such as respiratory trees, gonads, digestive tract out of anus to distract predator while they escape. can regenerate whole systems
