Trochozoa: Nemertea

Question 1

Parborlasia

Answer 1

Antarctic, natural body up to a meter long, abundant as predators/scavengers

Question 2

Nemertean Trochozoans

Answer 2

Pilidium
Bear extensions of ciliated bands; can be played or pointed for swimming/turning
Metamorphosis in which epidermis develops invaginations that grow and proliferate inwards to make the epidermis and body wall (worm develops inside and eats the outside skin)

Question 3

Anatomy of Nemertea (Space between Gut and Outer Body Wall, Coelom)

Answer 3

• The space between the gut and outer body wall is mostle mesenchyme (connective tissue layer)
• Gonads are not coelomic, they are epidermal invaginations
• “Blood vessels” that are coelomic, not true blood vessels because BVS flows blood over basal lamina, not apical sides of own cells, and these have no contractile parts

Question 4

Proboscis

Answer 4

Simple invaginations of epidermis on anterior end of worm associated with 2nd coelomic space

• Proboscis can be everted to capture prey
• Ejector muscles run circular to coelomic epithelium to compress fluid to force proboscis out

Question 5

Anopla vs Enopla

Answer 5

Anopla: branched proboscis; epithelium of proboscis secretes mucous to entangle prey

Enopla: distal end of proboscis is equipped with calcarious stylet to puncture prey