Cephalopods

Question 1

What are Cephalopods general characteristics

Answer 1

Bilaterally symmetrical - Fused head/foot - Tentacles around head - Prominent eyes - Mouth with radula/beak. Mostly no mantle - Water -> Siphones aerates gills/removes waste

Question 2

What are the shell types within the Cephalopods family

Answer 2

Nautiloids = Full shell
Cuttlefish = Spongy plate
Squid = Quil shell
Octopus = Lost shell

Question 3

What are the Predatory adaptations of Cephalopods

Answer 3

Loss of shell for more mobility (Fish competitors)

Gas cavity = Buoyancy - Efficient gut - Salivary gland secretions (Poison?) - Closed high pressure circulatory system.

Question 4

What are some features of a Cephalopods circulatory system?

Answer 4

Closed high pressure system + Accessory hearts increase BP = Rapid O2 exchange.
Haemocyanin aids in O2 exchange (is 20% as haemoglobin)

Question 5

What are some key features regarding Cephalopods brain

Answer 5

Large short/long term memory
Tentacles each have a processing centre
Chromatophores - Colour changing cells

Question 6

How do Cephalopods reproduce

Answer 6

Dioecious -> elaborate courtship -> Copulation -> Direct development.
Heterocutylus arm (Reproduction arm) in some species -> inserts Spermatophores