LEC 16 - INTERTIDAL ZONE I (ANIMALS)

Question 1

what are echinoderms? what type of symmetry do they have?

Answer 1

echinoderms are deuterostomia that have pental (5 way) symmetry, w gut at the centre

Question 2

how do echinoderms get around?

Answer 2

the water vascular system

1. water is absorbed into the madreporite
2. water is sent around to the arms. certain ampullae are squeezed, forcing water into the tube feet. the tube feet bind to the ground through the chem adhesive on the end
3. coordinate all the tube feet and boom u got movement babey

Question 3

how do echinoderms breathe?

Answer 3

through their skin

Question 4

what are echinoderm endoskeletons made of?

Answer 4

calcium carbonate + collagen to hold plates together

Question 5

how do echinoderms make their skeleton rigid? how do they relax it?

Answer 5

resting state has glycoamino glycans (GAGs) and calcium ions chilling in the ECM. calcium activates GAGs, causing them to crosslink

to make rigid: move calcium ions out of cell and into ECM

to make relaxed: move calcium ions into cell, out of ECM

Question 6

theoretically, a starfish comes across a delicious looking mussel. how would it go about eating said mussel?

Answer 6

1. tube feet have chem adhesives (NOT SUCTION) that attach to mussel shell
2. lock the endoskeleton to create tension
3. pull that bitch apart
4. external digestion using enzymes

Question 7

what do urchins do to eat, and how do they eat it?

Answer 7

grazers, eating things like kelp or algae

aristotle’s lantern: a mouth structure using for grazing

Question 8

what is the moulting process of arthropods called? why do arthropods need to do it?

Answer 8

arthropods need to undergo ecdysis because their growth is limited by their exoskeleton

ecdysis process:

1. arthropods have to shed their skin
2. they cash in their growth points and can grow significantly
3. shell rehardens and growth stops

Question 9

what are the arthropods parts we need to know about? (3)

Answer 9

thorax, from which 5 pairs of legs sprout

abdomen, tucked under thorax

claws for breaking shit

Question 10

how do some porcelain crabs feed?

Answer 10

filter feeding, using structures on claws

Question 11

how do some fish in the intertidal zone not get swept away?
- clingfish?
- pacific spiny lumpfish?

Answer 11

clingfish are slimy dudes that have hairlike suckers that use molecular adhesion (similar to geckos)

pacific spiny lumpfish got aaaaa sucker on their pelvic fin

Question 12

what distinguishes barnacles from others in their phylum?

Answer 12

barnacles are arthropods, but they’re unique in that flip themselves upside and stick they feet in the air to filter feed

Question 13

where do molluscs get their shell from?

Answer 13

secreted from the mantel

Question 14

how do predatory snails feed? herbivorous snails?

Answer 14

both feed using the radula. pred snails’ radula acts like shark teeth to drill a hole in the shells of prey, and then stick their probuscis in. herb snails graze.

Question 15

bivalves are also molluscs, but they differ from snails in how they feed. how?

Answer 15

sessile filter feeders; they use a crystalline rod (style) to grind up plankton

Question 16

what are chitons?

Answer 16

molluscs that got hella plated up

Question 17

what phylum do anemones fall under? what makes them unique from others in their phylum?

Answer 17

cnidaria, though they do not have the typical medusa larval stage

however some can move around, though this is only usually in response to serious predation threats

Question 18

if i were to say anemones are “colonial and clonal,” what would this mean?

Answer 18

clones can recognize themselves + feed cooperatively

colonies are known to fight with one another

Question 19

what animals are said to be colonial and clonal?

Answer 19

anemones

Question 20

how do anemones feed?

Answer 20

using cnidocysts (sticking cells)

Question 21

why are nemertea and flatworms not considered real worms?

Answer 21

they are posers that don’t have body segmentation like real annelids

Question 22

what are fan worms?

Answer 22

sessile dudes that make a huge cocksleeve out of calcium or proteins, who run up/down their tube using parapodia

Question 23

what is the point of the operculum? what animals use this?

Answer 23

the operculum is a similar to a lid that covers the tube of fan worms

it traps prey inside while also preventing desiccation when the tide goes out

Question 24

what are lophophorates? what is an example of one?

Answer 24

dudes w lophophores (ring of ciliated tentacles) for feeding. bryozoans are one example, which form colonies that share a stomach

Question 25

how do sponges feed?

Answer 25

filter feeding, pumping water into their bodies using choanocytes

Question 26

how do tunicates feed?

Answer 26

filter feeding, by forming a brachial basket and pumping water into it

Question 27

how do bryozoans feed?

Answer 27

they feed w a lophophore (ring of ciliated tentacles), which draws food in BUT NOT in a filter feeding way

they are colonial and share a stomach

Question 28

what are the roles of the WVS?

Answer 28

feeding, locomotion, respiration