Lab 6: Predator- Prey Interactions in Echinoderms and Molluscs

The predator species

Starfish

How Mollusks like Diodora (keyhole limpets) respond to a predator (starfish Pycnopodia)

• They may also clamp tightly to the substrate to avoid being dislodged.

• May move away slowly from the predator

Defense response of the sea urchin when touched by predator (starfish Pycnopodia)

• The spines of the sea urchin move or contract to make it harder for the predator to grab them.

Swimming escape in the scallop when touched with a glass rod , and a predator foot(starfish Pycnopodia).

Clap their shells to push water out and swim away.

Swimming escape in the sea cucumber when touched with a predator foot (starfish Pycnopodia).

contract their body, wiggle, or slowly crawl away to avoid the predator.

Response of sea cucumber when squirted with ‘Pycnopodia’ (starfish Pycnopodia) water

Close their mouths

Escape response of cockles when confronted by a sea star (Pycnopodia)

extend their muscular foot and push off the substrate to move or “hop” away.