27 Flashcards by Miles Hurd

Deuterostomia extant phyla

Echinodermata, Hemichordata, Chordata

How well did you know this?

Not at all

Perfectly

symmetry Echinodermata

pentaradially symmetrical

How well did you know this?

Not at all

Perfectly

what is the armor of Echinodermata

endoskeleton made of calcium carbonate ossicles

How well did you know this?

Not at all

Perfectly

Echinodermata ossicles

connected by mutable collagenous tissues allowing them to quickly go from rock hard
to soft and floppy without rock hard state expending energy on muscular contraction

How well did you know this?

Not at all

Perfectly

what do Echinodermata have instead of a circulatory system

water-vascular system open to sea-water

How well did you know this?

Not at all

Perfectly

echinoderms surfaces

oral and aboral surfaces

How well did you know this?

Not at all

Perfectly

what are the exceptions of the echinoderm sufaces

exceptions are sea cucumbers

How well did you know this?

Not at all

Perfectly

why was radial symmetry selected

suspension-feeding lifestyle

How well did you know this?

Not at all

Perfectly

do other group of animals shows a 5-part radial symmetry

no other groups

How well did you know this?

Not at all

Perfectly

what lie along ambucular tracts

5 rows of tube feet

How well did you know this?

Not at all

Perfectly

what are tubular feet also called

podia

How well did you know this?

Not at all

Perfectly

what give the name echinodermata

porous, calcareous, intradermal ossicles

How well did you know this?

Not at all

Perfectly

how do ossicles originate

originates intracellularly

How well did you know this?

Not at all

Perfectly

how are ossicles connected

ossicles are connected to each other with
collagen, and spaces between them filled
with living tissue

How well did you know this?

Not at all

Perfectly

ways ossicles can be arranged

-3-D meshwork
-interlocking chain
-rigid test with movable spines
-small and isolated

How well did you know this?

Not at all

Perfectly

ossicles specialized as tiny jaws

pedicellariae
-they pinch

How well did you know this?

Not at all

Perfectly

pedicellariae

-defense
-anti-fouling
-capture prey
-can be venomous and shot at predators

How well did you know this?

Not at all

Perfectly

how many eucoelomic systems echinoderms

five different

How well did you know this?

Not at all

Perfectly

large eucoelomic systems echinoderms
what do they aid with

perivisceral
coelom and water-vascular system
that aid with circulation of oxygen and nutrients

How well did you know this?

Not at all

Perfectly

what are perivisceral coelom and water-vascular system lined with?

cilia

How well did you know this?

Not at all

Perfectly

are perivisceral coelom and water-vascular system isosmotic

no, they have added potassium

How well did you know this?

Not at all

Perfectly

water-vascular system what does it do and how does it work

operate the tube feet through
water enters through madreporite to ring canal to 5 radial canals going down ambulacral grooves

How well did you know this?

Not at all

Perfectly

how do tube feed extend and retract or bend

hydrostatic pressure via ampullae and retract of bend them muscles

How well did you know this?

Not at all

Perfectly

how do suckers on tube feet work

sticky mucus, and vaccume

How well did you know this?

Not at all

Perfectly

original function of the water vascular system and tube feet was who still has this

feeding -crinoids

when an external madreporite is present

it is off-centre

echinoderms lacking

-no brain, central nervous cord or ganglia -excretory organs -lack specialized gas-exchange system -lack intestines and/or anal opening -lack image-forming eyes

instead of brain, central nervous cord or ganglia echinoderms have

arrays of nerve fibres a nerve ring around mouth radial cords to arms

echinoderms sexes

separate

echinoderms breeding

always broadcast sperm eggs broadcast or brooded

larvae produced by broadcast vs brooded echinoderms

broadcast have little yolk and planktotrophic brooded yolky and lecithotrophic

development

classical deuterostomous style of development

larva in echinoderm

1st stage called primary larva larvae are bilaterally symmetrical

transformation to the juvenile and adult involves

-conversion of bilateral to radial symmetry -changes in the 3-part larval eucoelomic system

3-part larval eucoelomic system echinoderms

separate left and right pockets

changes in the 3-part larval eucoelomic system in juvenile to adult echinoderms

-parts expand or shrink asymmetrically -some fuse to yield the adult coelomic cavities, and others disappear

gut morphology in extant echinoderms

-almost torsion-like -gut is looped rather than linear

what di end-Permian extinction do

reduced diversity to current five classes

Crinoidea

-basal sea lilies, feather stars

Crinoidea diet

suspension feeders

two body forms of Crinoidea

-sea lilies are stalked -feather stars lack stalks, can swim

Crinoidea oral surface faces

upwards

Crinoidea main arms

multiples of five 10 to 200 pinnules ciliated ambulacral grooves

Asteroidea

sea stars

Asteroidea arms

not clearly set off from the central disc

Asteroidea oral vs aboral face

oral surface faces substrate aboral (with madreporite and anus

Asteroidea movement

crawl

Asteroidea feeding

opportunistic feeders -evert their stomach -food is liquefied with enzymes -sucked up

Ophiuroidea

brittle stars, basket stars

oral side facing Ophiuroidea

down

arms osteroidea

clearly demarcated from the disc; always have 5 arms

brittle stars vs basket stars arms

-basket stars curl their arms and many arm branches vertically -brittle stars can only move their arms laterally

Ophiuroidea excretion and digestion

no intestine or anus

brittle stars diet

detritivores and predators with some being suspension-feeders

basket stars diet

suspension-feeding’ predators bucket-brigade’ analogy

what is bucket-brigade’ analogy

tube feet hand shit to more precise tube feet

Echinoidea

sea urchins, sand dollars

Echinoidea body

globular or or flat, and armless

echinoidea ossicles

fused in rigid test with small holes for tube feet; have moveable spines

Echinoidea characteristics

-Aristotle’s lantern -have pedicellariae -spines - covered in epithelium with muscles attached to them

Echinoidea spines

each spine can move independently used for defense and walking

Aristotle’s lantern what is it ad what does it do

-consists of five blade-like calcareous teeth -teeth are protruded through the mouth -teeth sharpened by scraping against eachother

kelp and echinoidea

urchins are major enemies of kelp, destroy entire kelp forests

teeth of sea urchins

-cut holes in coral and soft rock -very sharp

sand dollar feeding

deposit feed

how do sanddollars avoid being lifted by waves

store sand in special gut pouches

Holothuroidea

sea cucumbers

Holothuroidea symmetry

-externally bilaterally symmetrical -internally pentaradial symmetry difficult to see except in oral tentacles

skeleton Holothuroidea

endoskeleton reduced

madreporite Holothuroidea

madreporite is internal

Holothuroidea larval transition

-do not go through the full larval metamorphosis -retain the bilateral symmetry of the early developmental stages

Holothuroidea gill

respiratory tree wth Cuvierian tubules branching off

Cuvierian tubules

sticky tubules can be ejected as defense

gut of Holothuroidea

gut retains its ancestral ‘torsion’ loop

how do sea cucumbers deposit-feed

branched, mucus-covered oral tentacles passing shit to the mouth in a swiping motion or by stuffing whole tentacle into the mouth

what is not involved in sea cucumber feeding

tube feet are not involved in feeding

what sea cucumbers have more emaborate oral tentacles

suspension feeders that are quite sedentary