Capitella capitata is a

polychaete Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are ...

worm Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always). Worms vary in size from microscopic to over in length for marine polychaete worm ...

that grows up to 10 cm in length. It is often blood-red in colour. The species is sedentary and fragile, with a flexible body. ''Capitella capitata'' occurs on muddy sand, gritty sand, fine sand or rich mud on the lower shore to sub-littoral. It may be found under pebbles or small stones, with the burrows at or near the surface of the

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sa ...

. It is an opportunistic species tolerant of stressful conditions, and often found in polluted waters (sewer discharges, hydrocarbons, metals ...) where it out-competes less tolerant species. A large abundance of ''C. capitata'' can be seen as an indication of polluted waters. ''Capitella capitata'' is able to vary its reproductive strategy in accordance with its current environmental conditions. If local conditions are favorable, it can produce benthic larvae facilitating quick exploitation of local concentrations of organic matter. In contrast, ''C. capitata'' can produce planktonic larvae if there is a need to discover new habitats.J.F. Grassle and J.P. Grassle, "Opportunistic life histories and genetic systems in marine benthic polychaetes", J. Mar. Res. 3:253-284, 1974

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External links

* Polychaetes {{annelid-stub