Zooplankton
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Bryozoa
Taxonomy
| Superphylum |
Lophotrochozoa |
| Phylum |
Bryozoa |
Size
- Tiny colonial animals (zooids).
- Range from mm to m in size.
- Adult colonies are sessile and usually attached to hard substrates though some can be found encrusting on seaweed. Some colonies are erect and plant-like and can be up to 1 m across.
Description
- Bryozoans, or moss animals, are in fact colonies.
- Larvae of bryozoans are called cyphonaute larvae, and come from non-brooding bryozoans.
- Approximately 5,000 known living species.
Distinguishing characteristics
- Larvae are triangular in shape and greatly compressed.
- Each lateral surface covered by a chitinous valve.
- Apical tuft of cilia present.
Distribution
- Prefer warm tropical waters, but occur worldwide.
Ecology
- Cyphonautes develop in the plankton from small eggs and grow extensively during a planktonic stage.
- Only larvae of non-brooding bryozoans possess a functional digestive tract and feed during their larval existence.
- Larvae that feed might live in the plankton for several months, while those from non-brooding species are non-feeding and have a very brief larval existence prior to settling.
- Upon settling, the larvae attach via adhesive sacs and metamorphose to the adult form.
