Icy Inverts Antarctica Cruises Nov-Dec 2013 - Organisms

Below is a brief introduction to some of the organisms that will be collected on the cruise.

Annelids: invertebrate phylum of about 16,500 species of segmented worms that include familiar species such as earthworms, leeches and a wide variety of other forms including sand and tube worms.

Polychaetes: most marine worms belong to this group.

Crustaceans: animals such as krill, shrimp and lobsters that have a hard external shell that protects their body.

Amphipods: laterally compressed crustaceans.
Barnacles: crustaceans that are often attached to hard surfaces.
Copepods: a very common planktonic crustacean.
Euphausids: krill; planktonic shrimp-like crustaceans.
Isopods: a group of dorsal-ventrally flattened crustaceans.
Ostracods: planktonic crustaceans that look like clams.

Ctenophores: transparent, planktonic jelly-like animals that are sometimes mistaken for jellyfish.

Some ctenophores, like Beroe (right), lack tentacles.

Echinoderms: marine invertebrate phylum of about 7,000 species that includes sea stars, sand dollars, sea urchins and others that have 5-part symmetry; most adults in this phylum are benthic.

Asteroids: sea stars - star-shaped body with five or more arms off a central disk.
Crinoids: sea lilies & feather stars - body forms a cup with arms extending out from the cup.
Echinoids: sea urchins & sand dollars -body is globe-shaped with spines.
Holothuroids: sea cucumbers - body is sausage-shaped and long.
Ophiuroids: brittle stars - body has five arms distinctly separated from a central disk.

Foraminiferans: planktonic protists with a calcareous shell.

Most foraminiferans are small in size.

Molluscs: invertebrate phylum of about 93,000 species almost all of which have an inner or outer shell and a soft body; includes clams, snails, sea slugs, octopus, squid and other shelled invertebrates.

Bivalves: molluscs with two shells hinged together.
Cephalopods: octopi & squid; molluscs with well-developed heads.
Gastropods: molluscs with a single, often spiraled shell.
Nudibranchs: a group of shell-less gastropods.

Nemerteans: ribbon worms; unsegmented worms that can extend their bodies.

Nemerteans secrete toxins that deter many predators.

Pterobranchs: a small colonial group of hemichordates, related to echinoderms.

Pterobranchs are small filter-feeders, often in deep waters.

Pycnogonids: sea spiders; marine members of the phylum Arthropoda.

They are closer relatives to spiders than crabs or insects.

Radiolaria: planktonic protists with spines made of silica.

Radiolarian skeletal remains cover large portions of the ocean bottom.

Salps: marine planktonic members of the group Tunicata; closely related to sea squirts.

The most abundant concentrations of salps are near Antarctica.

Last updated: 11/12/2013