Mollusca: Candofoveata

Question 1

synapomorphies (4)

Answer 1

Vermiform/work-like body

no true foot - oral shield
used to burrow,

radula,

reduced ctenidia.

Question 2

body wall and support

Answer 2

Body wall: covered in chitinous cuticle with calcareous spicules; no shell

Support: hydrostatic pressure

Question 3

locomotion (2) and body cavity

Answer 3

Locomotion: contracts muscular body wall;

uses oral shield to burrow

Body cavity: Reduced coelom with a hemocoel

Question 4

feeding (2)/ digestion (2) and circulation

Answer 4

Feeding: detritivores or carnivores: feeds on organic matter and protozoan;

uses radula and oral shield to collect food

Digestion: simple digestive tract with specialized pharynx;

digestion occurs in the intestine

Circulation: open circulatory system, with a fluid distributing nutrients and
oxygen

Question 5

Excretion and gas exchange

Answer 5

Excretion: nephridia, with waste removed through pores

Gas exchange: through the body wall, since gills are reduced

Question 6

nervous system

Answer 6

Nervous system: simple, ladder-like system with chemosensory cells

Question 7

reproduction and development

Answer 7

Reproduction: dioecious sexes with external fertilization

Development: indirect development with a free-swimming trochophore
larva

Question 8

habitat

Answer 8

Habitat: Deep-sea marine sediment

Question 9

fun facts (3)

Answer 9

Most primitive living mollusc,

no muscular foot,

resembles
worms more than molluscs.