Gill ringworm
| Gill ringworm | ||||||||||||
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Gill ringworm ( Scoloplos armed ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Scoloplos poorer | ||||||||||||
| ( OV Müller , 1776) |
The gill ringworm ( Scoloplos armed ) is a cosmopolitan marine ringworm from the genus Scoloplos within the multi - bristle family of Orbiniidae .
features
The gill ringworm has a long body, broad and flat in front, which is slightly flattened on the back and rounded on the abdomen. The pointed, cone-shaped prostomium is longer than it is wide and has two small eyes . It becomes up to 12 cm long and then has over 200 segments , of which the thorax comprises 12 to 22 bristle-bearing segments. The notopodia on the thoracic segments are small and behind the bristles have a cone-shaped lobe with an acicula and a tuft of capillary-shaped bristles. The neuropodia on the thoracic segments, which have swollen to form tori, have small conical lamellae, many capillary-shaped bristles and conspicuous hooks behind the bristles. On the last 1 to 5 segments of the thorax and the first 1 to 7 segments of the abdomen there are 1 to 2 papillae under the parapodia, and a collar-like structure on the next segment of the abdomen. Behind the bristles, the notopodia of the abdomen have simple lobes with aciculae, capillary-shaped and forked bristles, but no interramal cirrus. The neuropodia of the abdomen are bilobed, have aciculae and have few capillary-like bristles as well as a small cirrus on the abdomen. From the 9th to 17th segment, tongue-shaped or lanceolate gills are attached to the bristle-bearing segments , which, like the notopodia and neuropodia, attach to the back of the segments of the abdomen. The pygidium is covered with two long cirrus peaks. The animal is light orange or pink.
Distribution, habitat and way of life
Scoloplos pooriger is cosmopolitan in all oceans, so also in the North Sea and in the Baltic Sea to the Gotland Basin .
The gill ringworm lives on soft subsoil from the intertidal zone down to a depth of around 2000 m. It usually digs 10 to 15 cm deep in the sediment and lines its passages with slime.
It feeds on bacteria that live in the substrate.
Life cycle
Scoloplos armed is sexually separated, with females and males of roughly equal size and with external fertilization. In the Wadden Sea of the North Sea near Sylt , two types of development have been demonstrated: While gill ringworms in the intertidal zone undergo their larval development in gelatinous cocoons and hatch as creeping worms, gill ringworms below the intertidal zone in the same sea region develop via a larva that floats freely as zooplankton , which later emerges sinks to the ground and metamorphosed into a creeping worm . Crossing experiments with bristle worms from the named populations showed that there were only offspring if both males and females came from either the intertidal zone or both came from the deeper sea region. According to the biological species definition , there are therefore two species.
literature
- PJ Hayward, JS Ryland: Handbook of the Marine Fauna of North-West Europe. Oxford University Press, Oxford 1995. pp. 213f.
Web links
- MJ de Kluijver et al .: Scoloplos armiger (OF Müller, 1776). Macrobenthos of the North Sea - Polychaeta, Marine Species Identification Portal
Individual evidence
- ^ Karsten Reise: Tidal Flat Ecology. An Experimental Approach to Species Interactions. Springer Science & Business Media, Berlin 2012. p. 41.
- ^ Inken Kruse, Matthias Strasser, Frank Thiermann (2004): The role of ecological divergence in speciation between intertidal and subtidal Scoloplos armiger (Polychaeta, Orbiniidae). Journal of Sea Research 51, pp. 53-62.
- ↑ Inken Kruse, Karsten Reise (2003): Reproductive isolation between intertidal and subtidal Scoloplos armiger (Polychaeta, Orbiniidae) indicates sibling species in the North Sea. Marine Biology 143 (3), pp. 511-517. DOI: 10.1007 / s00227-003-1112-x