Fecal pill worm
| Fecal pill worm | ||||||||||||
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Fecal pillworm ( Heteromastus filiformis ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Heteromastus filiformis | ||||||||||||
| ( Claparède , 1864) |
The Kotpillenwurm ( Heteromastus filiformis ) is a cosmopolitan marine annelid from the genus Heteromastus within the polychaete - family of Capitellidae .
features
The fecal pillworm has a long, very thin, cylindrical body that resembles an earthworm in shape . The small, conical prostomium has no extensions and can be withdrawn into the two-ringed, bristle-free peristomium . The animal has two nuchal organs and small eyes in adolescence . It becomes up to 18 cm long, at most 1 mm wide and then has more than 150 segments , of which the thorax comprises eleven bristle-bearing segments. The parapodia on the segments are very poorly developed. The first four to five segments following the persitomium have only short, thick, capillary-like bristles . On the six posterior segments of the thorax there are tori with bristles with hooks and hoods on both sides, dorsally and ventrally. The anterior segments of the abdomen are long, cylindrical and double-ringed, but become shorter and more rounded towards the rear, and then bell-shaped with swollen parapodic ridges at the end. The hooks on the abdomen are shorter, thicker, and more serrated than those on the thorax. From around the 80th segment on, there are simple gills on both sides of each segment . From the 9th to the 12th segment there are a total of four pairs of genital openings, but they have no genital hooks. A single anal cirrus sits on the pygidium . The front section of the body is red, the back yellowish or reddish-green.
Distribution, habitat and way of life
Heteromastus filiformis is cosmopolitan in all oceans, including the Arctic , the Atlantic Ocean including the North Sea and the Kattegat , the Mediterranean and Black Seas , the Persian Gulf , the coasts of South Africa and the Pacific Ocean including the coasts of Australia and New Zealand .
The excrement pillworm prefers to live on muddy, sandy subsoil from the upper tidal zone to at least 4680 m depth. It digs in the sediment, lines its passages with slime and can be recognized by its dung pile. Heteromastus filiformis tolerates pollution and changing salinity of the water.
It feeds on detritus that adheres to the substrate.
Life cycle
Heteromastus filiformis is separate sexes with females and males of roughly equal size and external fertilization. The female attaches the gelatinous egg clutches at the exit of her living tube. Free-swimming trochophora larvae hatch from the eggs , which later metamorphose into crawling worms .
literature
- PJ Hayward, JS Ryland: Handbook of the Marine Fauna of North-West Europe. Oxford University Press, Oxford 1995. p. 187.
Web links
- MJ de Kluijver et al .: Heteromastus filiformis (Claparède, 1864). Macrobenthos of the North Sea - Polychaeta, Marine Species Identification Portal