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Gymnolaemata

(Class)

Overview

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Gymnolaemata is a class of the phylum . Gymnolaemata typically live under seawater and grow on surfaces of rocks, kelps, and even in some cases, on animal species like fish. They are mostly marine bryozoans with cylindrical or flattened zooids. The lophophore is protruded by action of muscles pulling on frontal wall. This order includes the majority of living bryozoan species.

Photos

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Taxonomy

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The Class Gymnolaemata is further organized into finer groupings including:

Orders

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Cheilostomata

Cheilostomata, an order under class , are exclusively marine, colonial invertebrate animals. Cheilostome colonies are composed of calcium carbonate and grow on a variety of surfaces, including rocks, shells, seagrass and kelps. The colony shapes range from simple encrusting sheets to erect branching and even unattached forms. As in other bryozoan groups, each colony is composed of a few to thousands of individual polypides, which has a U-shaped gut, and no respiratory, circulatory, or nerve system. Unique among bryozoans, cheilostome polypides are housed in a box-shaped zooids, which do not grow larger once the zooid is mature. The opening of through which the polypide protrudes is protected by a calcareous or chitinous lidlike structure, an operculum. Cheilostomes possess avicularia, which have modified the operculum into a range of mandibles (possibly for defense) or hair-like setae (possibly for cleaning). [more]

Ctenostomata

[more]

Cyclostomata

Cyclostomata is a group that describes the living jawless fish, which includes the lampreys and hagfishes. [more]

At least 299 species and subspecies belong to the Order Cyclostomata.

More info about the Order Cyclostomata may be found here.

Sources

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Last Revised: November 18, 2008