Mollusca: Solenogastres

Question 1

Synapomorphies (4)

Answer 1

Vermiform body,

no radula or shell,

no ctenidia,

ventral
pedal groove instead of true food

Question 2

body wall (2) and support

Answer 2

Body wall: soft-bodied with no shell; covered in chitinous cuticle and
calcareous spicules;

mantle extends over the body

Support: depends on hydrostatic pressure

Question 3

locomotion (2) and body cavity

Answer 3

Locomotion: moves by gliding on mucus secreted by the ventral pedal
groove;

peristaltic body contractions

Body cavity: reduced coelom; hemocoel

Question 4

feeding/digestion and circulation

Answer 4

Feeding: carnivorous, using a specialized pharynx to suck in prey

Digestion: simple digestive system with glands that secrete digestive
enzymes

Circulation: open circulatory system with hemolymph

Question 5

excretion and gas exchange

Answer 5

Excretion: uses nephridia to filter waste

Gas exchange: diffuses through the mantle cavity

Question 6

nervous system (3)

Answer 6

Nervous system: ladder-like nervous system;

nerve ring;

chemosensory
cells

Question 7

reproduction and development

Answer 7

Reproduction: Hermaphrodites with both external and internal fertilization

Development: indirect development with a trochophore larvae

Question 8

habitat (3)

Answer 8

Deep-sea benthic,

burrowing in soft sediment;

can be found in
coral reefs or sponges

Question 9

fun fact (2)

Answer 9

No eyes, shell, or foot

Unlike crawling molluscs, they glide