Icy Inverts
Animal Page
Below is a brief introduction to some of the animals that we will examine

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 because they have appendages


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

Amphipods: a group of laterally compressed crustaceans


Cirripedia: barnacles


Copepods: a very common planktonic crustacean


Euphausids: krill; planktonic shrimp-like animals


Isopods: a group of dorsal-ventrally flattened animals


Ostracods: planktonic crustaceans that look like clams

Ctenophores: transparent, planktonic jelly-like animals
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; body is star-shaped with five or more arms coming off a central disk


Crinoids: sea lilies and feather stars; body forms a cup with arms extending out from the cup


Echinoids: sea urchins and 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
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: octopus and squid; molluscs with a well- developed head


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


Pterobranchs: a small colonial group of hemichordates, related to echinoderms
Pycnogonids: sea spiders; marine members of the phylum Arthropoda, more closely related to spiders than crabs or insects
Radiolaria: planktonic protists with spines made of silica
Salps: marine planktonic members of the group Tunicata; closely related to sea squirts