Scarlet Sea Cucumber
Scientific name: Psolus fabricii
Description: Scarlet sea cucumbers are bright red, and with a size up to 8in. The anus of scarlet sea cucumber is ringed with 5-6 granular scales. Its bottom is like sole of shoe, flat and rimmed with a marginal band of tube feet and a weaker row down the middle. Its top is domed, with the anus on a mound at one end, introvert (mouth and tentacles) at the other.
Distribution: Scarlet sea cucumbers are found from Arctic to Cape Cod, from lower inter-tidal zone depths greater than 90 meters, on hard bottoms.
Locomotion: Trivium surface is modified as a creeping foot-like sole, utilizing the tube feet.
Food gathering: Scarlet sea cucumbers are suspension feeders. They extend branched and mucus covered tentacles into water to trap suspended particles including live plankton. Tentacles then are pushed to mouth.
Gas exchange: Water is pumped in and out of the hind-gut and branches of respiratory trees; and gases are exchanged between the water and coelom and hemal system.
Reproduction: The sexes are separated, with eggs being fertilized externally. They also have a free-swimming larval stage. They are unique among echinoderms in possessing a single gonad that opens the outside between two pairs of tentacles.
Mercier Lab - Research on reproduction, larval development, ecology and growth is carried out on a wide variety of marine invertebrates in this lab.