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Several other phyla figure prominently in our local tidepools.  These include the Cnidaria (sea anemones, jellyfish), Annelida (segmented worms), and Bryozoa (moss animals).

Phylum Cnidaria (Nettles)

One of the most prominently represented phyla in our area is the phylum Cnidaria (Stinging, or nettle-like), thanks to the abundance and sedentary nature of sea anemones.  Like the Echinoderms (sea stars), Cnidaria are radially symmetrical -- they have no front or back.  Under the hood, however, cnidarians are much less complex than sea stars.  They do not possess a central nervous system, have few or no specialized organs and remain radial throughout their entire life cycle.  What distinguishes Cnidaria, and what gives them their name, are specialized cells which shoot out harpoon-like stinging hairs to stun and capture prey. If you touch the tentacles of a sea anemone, the slight tug or stickiness you feel is the effect of these stingers being shot into your finger!

Cnidarians possess two distinct shapes: the polyp, as typified by the sea anemone, and the medusa, as typified by jellyfish.  Many Cnidarians, including jellyfish go through a polyp stage before maturing into a medusa.  The sea anemone and corals, however, never go through a medusa stage.

Class Anthozoa (Flower animals): Sea anemones, Corals

Giant green anemone  (Anthopleura xanthogrammica) The green is actually a symbiotic alga.	Moonglow sea anemone (Anthopleura artemisia)
Orange Cup Coral (Balanophyllia elegans)

Class Scypohozoa (Cup animal): Jellyfish

sorry, no images available yet.

Phylum Annelida (ringed)

Annelids, such as the familiar earthworms, are segmented worms.  Despite their simple appearance, segmented worms possess a full nervous system, circulatory system, and digestive system.  As with the molluscs, several marine worms are brightly colored; their beautiful forms are quite a contrast to the typical terrestrial worms.  Of course some are drab, too.

Class Polychaeta (many hairs): Polychaete worms

The tube worms spread out their feathery radioles to filter the surrounding water and trap tiny food particles and organisms.

Red Tube Worm (Serpula vermicularis)

18-Scaled Worm (Halosydna brevisetosa)

Phylum Ectoprocta = Bryozoa (moss animals)

Bryozoans are microscopic animals that form small plant-like colonies that are plainly visible to the eye.  The colony pictured below grows on seaweed and can be found at Houda Point at low tide.

Flustrellidra corniculata: A colony of Bryozoans.  These are animals, not a plant!