Figure 1. Extensive beds of siboglinid polychaetes (beard worms) provide a habitat for many animals. Through evolution, these siboglinids have lost both their mouth and anus; they live on the energy which symbiotic bacteria provide.
Beard Worms
Image courtesy of CRROCKS/NSF. Download image (jpg, 254 KB).

Figure 1. Extensive beds of siboglinid polychaetes (beard worms) provide a habitat for many animals. Through evolution, these siboglinids have lost both their mouth and anus; they live on the energy which symbiotic bacteria provide.

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