2.1.2 Mollusca (Gastropods, Tusk Shells, Cephalopods)

5) Gastropods

gastropods

are gastropods diverse?

yes, the most diverse molluscan group

3 main subgroups of gastropods:

typical snails, nudibranchs, slugs and pond snails

Where is the gastropod anus located?

by the mouth, this is casued by torsion

how common are typical snails

most common

where to typical snails live

mostly marine, some freshwater and terrestrial

how old are typical snails

most primitive group of gastropods

red abalone is an example of a

typical snail

red abolone are often ___ in california

harvested and farmed

cone snails are an example of

typical snails

cone snail environment

marine

what do cone snails eat

the are carnivourous

what type of waters to cone snails live in

mostly warm and tropical oceans

cone snails can consume fish with their

probascus, they have no antiveno,

slugs and pond snails are a group of

gatropods

slugs and pond snails have a highly vascularized mantle for

gas exchange

how many spp of slugs and pond snails are there

17,000

examples of slugs and pond snails

leopard slug, eastern white lip, dusky

another word for nudibranchs are

sea slugs

sea slugs do not have a

shell

how many spp of sea slugs are there

3,000 spp

sea slugs have no gills, where does the gass exhange take place

cerata

what causes bright colors in sea slugs

aposematism

aposematism

warning color usually to scare predators

nudibranchs have a cnidosac pore in order to

eat cnidarians, which their cnidosacs go into their own

dorid nudibranch has

plume

6) tusk shells

tusk shells

what do tusk shells have open at both ends

a tusk/shell

how long are tusk shells

0.5 - 15 cm long

how are tusk shells distributed

worldwide

hpw far down do tusk shells live

up to 7,000 m deep

what do tusk shells eat

soft, silty marine sediments

how many spp of tusk shells are there

900 spp

how do tusk shells eat

with tentacles that are sticky

7) cephalopods

cephalopods

what are the four types of cephalopods

squid, nautilus, cuttlefish, and octopus

how many spp of cephalopoda are there

700 spp

cephalopod arm vs tentacles

arms have suckers along most of the length, while tantacles have suckers only near the ends

how many arms/tentacles to ocopus have

8 arms

how many arms/tentacles do squid/cuttlefish

8 arms and 2 tentacles

chromatophores

pigment containing and light reflective cells used for camouflage and signaling

ink and venom usage

to escape predation, most are venemous

are blue ringed octopus dangerous

yes, bites can kill they have a nearotoxin that slows down breathing

what do nautiloids use for buoyancy

gas-filled chambers

how many fossil spp of nautiloids are there

2,500

how many living spp of nautiloids are there

9

what do nautiloids eat

they are mostly scavangers

how many arms to octopods have

8

are ocotpods predators or prey

predators

how do males release sperm

through enclosed packets call spermatophores

where is the common octopus live

worldwide

where does the two-spot octopus live

pacific and indian oceans

largest and longest lived octopus

giant pacific octopus

how long does the giant pacific octupus get

up to 30'

how heavy is the giant pacific octopus

over 600 lbs

what does the giant octopus eat

shrimp, clams, lobsters, fish, sharks, and birds

where does the mimic octopus live

indondesira and malaysia

where do vampire squid live

in temperate and tropical waters, oxygen minimum zone

cuttlefish have a cuttlebone, a

calcified internal shell, aids in buoyancy

cuttlefish live in

shallow seas

cuttlefish tentacles __

retract

how many spp of cuttlefish are there

100 spp

squids are ____ adapted for ___ than octopuses

better, swimming

how many arms and tentacles to squids have

8 arms and 2 tentacles

the squid pushes water in and out through the

siphon

how many spp how the giant squid are there

up to 8 spp

where do giant squid live

deep sea

where are giant squid distributed

worldwide

when were giant squid first photgraphed

2002

what is the largest invertevrate

colossal squid

where do colossal squid live

deep sea, antarcica

how heavy do colassal squid get

up to 1,090 lbs

humboldt squid are agressive, pack _

hunters

how big do humboldt squid get

1.5 m in size

how far down to humboldt squid live

200-700m down

humbold squid have bioluminescent

chromatophores