Molluscs are found inevery marine habitat, and have invaded fresh water and terrestrial habitats as well. Most species have shells, and all have a mantle and a muscular, powerful foot.
Phylum Mollusca
Pacific Northwest invertebrates come in all shapes, sizes, and colors. They populate the environment in vast numbers of both species and individuals, existing in all areas of the marine system. There are free swimmers such as the jellyfish, bottom-dwelling nudibranchs and crabs, plantlike hydroids and anemones, quick-swimming shrimp and slow-moving chitons.
We have divided these invertebrates into their respective phyla ( a classification used based mostly on internal characteristics); for further information on classifying marine species, see our Pacific Northwest Invertebrate ID class.
We have divided these invertebrates into their respective phyla ( a classification used based mostly on internal characteristics); for further information on classifying marine species, see our Pacific Northwest Invertebrate ID class.
Pelagia Photo Galleries - Pacific Northwest Invertebrates
Featured Classes
If the mention of worms conjures images of slimy wriggling creatures, the annelides are a welcome surprise. These worms are modified to live in the watery realm.
Phylum Annelida
Without a doubt, the arthropods are the most sucessful group of animals to inhabit the earth. They have penetrated every nook of every habitat, terrestrial and aquatic, on this planet.
Phylum Arthropoda
You might not have noticed these little guys, but they are everywhere. Bryozoans generally live in large colonies and encrust over rocks, kelp, or grow in branching forms that look like hard coral.
Phylum Bryozoa
Cnida...what? Pronounced "nI-dar-ee-uh", this group of invertebrates is characterized by tentacles laden with stinging cells. In fact, this is where they get their peculiar name.
Phylum Cnidaria
The most primitive of multicellular invertebrates, the sponges can take on various shapes and sizes, which are determined by the type of substrate and the velocity of the currents.
Phylum Porifera
Ctenophores, or comb jellies, look like jellyfish—but they aren't. They have eight rows of cillia along the body, which give them their name. They are generally small, the largest being only 7-10 cm.
Phylum Ctenophore
This subphylum is comprised of the tunicates, which are more closely related to humans than any other invertebrate phylum. They posess a rudimentary notochord in the larval stage.
Phylum Urochordata
The Echinoderms are the hedgehogs of the sea. Or at least that is what their name imples. "Echinos" is Greek for hedgehog. Look for spiny skin, tube feet, and pentaradial symmetry.