Ctenophores - Sea gooseberries
Ctenophores get their name from the 8 rows of combs or ctens used to move the animals through the waters in "stealth" mode. There are three major designs, those with 2 tenticles used in feeding, those with large lobes used to concentrate prey, and those with neither that suck in other ctenophores through large mouths. Those with tentacles have special sticky cells that differ significantly from the cnidarians.
Ctenophores are the most fragile of all the zooplankton. Most do not survive collection with nets, and cannot even be preserved because they are too watery. This means there are probably a large number of species that await discovery. Observations by divers and underwater robots show they can be common and important predators of other zooplankton.
Among the most primitive multi-cellular groups, basically two layers of skin with jelly in between them. They are also characterized by a bi-radial symmetry only found in a few other phyla.
Some deep-water species are the size of grapefruit or American footballs but most are slightly smaller, down to the size of grapes. Ctenophores an be found at all depths in all oceans. We have no idea how long they live in the Arctic.
Until recently only 5 species were known from the Arctic. ArcOD scientists have increased thie number to 10 species, several of which are undescribed (i.e. new species).
Page Author: Russ Hopcroft
Created: January 4, 2008