Class Scaphopoda & Cephalopoda1

Phylum Mollusca

Class Scaphopoda

Class Cephalopoda

Class Scaphopoda & Cephalopoda2

Class Scaphopoda

Defining characteristics– Tusk shaped conical

shells, open at both ends– Development of anterior

thread-like adhesive feeding tentacles

Elongated tapering tubular shells that burrow in sandy bottoms

Class Scaphopoda & Cephalopoda3

Class Scaphopoda

Commonly called tooth shells or tusk shells

Have lost ctenida along with ability to filter feed

Never spirally wound but grows linearly

Class Scaphopoda & Cephalopoda5

Class Cephalopoda

Defining characteristics– Closed circulatory

system– Foot modified to form

flexible arms and siphons

– Ganglia fused to form a large brain encased in a cartilaginous cranium

Class Scaphopoda & Cephalopoda6

Cephalopod Characteristics

The most highly organized of all the molluscs, the foot is closely associated with the head

Can be as large as 1,000kg. and 18m.– Architeuthis spp.

Class Scaphopoda & Cephalopoda7

Defensive Mechanisms

Since they are susceptible to predation they have evolved chromatophores

An ink sac that is associated with the digestive system and discharged out the anus

Class Scaphopoda & Cephalopoda8

Sensory & Nervous System

Eyes– All but the nautilus have

image forming eyes that are like mammals

Convergent evolution

Class Scaphopoda & Cephalopoda9

Reproduction

Sexes are separate– Males have one modified

arm (hectocotylus) for sperm transfer

Sperm are enclosed in packets called spermatophores

Class Scaphopoda & Cephalopoda10

Squid

10 sucker bearing arms surround the mouth– 2 longer tentacular arms can shot forward and capture

prey

Form large schools and feed on crustaceans, and fishes

The shell is reduced and lies under the mantle Large folded gills and a circulatory system

distribute oxygen quickly

Class Scaphopoda & Cephalopoda11

Squid Internal Anatomy

Class Scaphopoda & Cephalopoda12

Squid Locomotion

The foot forms the funnel The upper end of the mantle

is extended into a pair of triangular fins

– Can move very quickly 5-10 m/s

Class Scaphopoda & Cephalopoda13

Octopus

Have 8 arms all equal in length– Rows of suckers from base to tip

Compact body with a greatly reduced shell The body is extremely flexible and assumes a streamlined shape

when swimming with squid-like jets through the funnel

Class Scaphopoda & Cephalopoda14

Learning and Memory

Benthic feeders on bivalves, crabs and fishes

Amazing ability to learn quickly and remember for several weeks

Class Scaphopoda & Cephalopoda15

Could an Octopus be your next Professor?