Lecture 5 - Molluscs and Anthropods

Question 1

Body structures for Mollusca

Answer 1

Head (with mouth and feeding structures/radula)
Foot
Visceral mass
Mantle

Question 2

Marine Snails

Answer 2

C. Gastropoda

O Neogastropoda

Question 3

Nudibranchs

Answer 3

No deep sea

Question 4

Thecosomata and Gymnosomata

Answer 4

Foot in 2 wings

Thecosomata - smaller with shells
Gymnosomata - larger, predatory, no shells

Question 5

Bivalves are abundant where?

Answer 5

In deep sea sediments

Question 6

Characteristics of Solemyidae

Answer 6

Bivalves that live at great depths and have bacterial symbioses in their gills (`800m)

Question 7

Mussels

Answer 7

O. Filibranchia in C. Bivalvia

Use gills for feeding and specialize on enrichment/small habitats (sunken wood, whales, ect)

Question 8

C. Cephalopoda

Answer 8

up to 5000 m 
All marine squids/octopi 
Modified foot with tentacles
Shell reduced or absent
Well-developed nervous system and vision
Jet propulsion
Close circulatory system
chromatophores
ink sac
semelparous (single repro event for females)
Short lived

Question 9

Jet propulsion effectiveness

Answer 9

1/2 as effective as fins

Question 10

Nautilus

Answer 10

up to 700 m
shelled
multichambered for buoyancy

Question 11

Spirulida

Answer 11

C. Cephalopoda
up to 1000 m
internal spiraled shell

Question 12

True squids

Answer 12

down to 1000 m 
O. Teuthoidea 
8 arms, 2 tentacles that can retract 
all pelagic
suckers or hooks

Question 13

How do deeper squids carry eggs?

Answer 13

gelatinous material

Question 14

In some true squids, what changes with depth?

Answer 14

Go deeper as they mature

eye structure changes with depth

Question 15

Deep sea squids have been recorded as low as …

Answer 15

5000 m

Question 16

Which true squid has one large and one small eye?

Answer 16

f. Histioteuthidae (also has vertical migration)

Question 17

Largest squid

Answer 17

Colossal squid

Question 18

Two subOs of O. Octopoda

Answer 18

subO. Incirrata (no fins)

subO. Cirrata (fins)

Question 19

subO. Cirrata go as deep as …

Answer 19

> 5000 m, near bottom of pelagic

Question 20

Movement in deeper pelagic cephalopods (squid, octopi)

Answer 20

Reduce use of jet propulsion

Use fins for rowing/flying or arms/webbing for jellylike movement

Question 21

Vampire squid

Answer 21

O. Vampyromorpha
800-1000 m at low O2
Only cephalopod to eat non-living food
No suckers
Have luminescence on tentacles
Trailing filaments stick to food