Quiver worm
| Quiver worm | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Quiver worm, Lagis koreni (left animal, right tube) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Lagis koreni | ||||||||||||
| Malmgren , 1866 |
The caddis worm or ordinary quiver worm ( Lagis koreni , synonym Pectinaria koreni ) is a sessile, in a burrow as filter feeders living polychaete (Polychaeta), which in the eastern Atlantic Ocean can be found.
features
The quiver worm has a short, conical body that becomes narrower towards the rear and can reach a length of about 5 cm. Like other combworms , it has a fixed number of 22 segments , the rear of which, however , are fused to form an end-scaphe, a bowl-shaped structure covered with spiky bristles on the sides . Of the 15 bristle-bearing segments, 3 form the thorax and 12 form the abdomen.
The two palps or tentacles are short and have an eyelash groove. The tentacle membrane is wide and folded in large individuals, usually with 15 to 20 notches. The edge of the back is smooth. On the first segment sit on each side of the Notopodien each 8 to 17 long and pointed Paleae . A pair of lateral cirrus sits on the 2nd and 3rd segment . The 4th and 5th segments each have a pair of lateral, leaf-shaped gills . There are dorsal bristles on 15 segments, beginning with the 6th segment . On 12 segments, beginning with the 9th segment, there are hook bristles ventrally. At the base of the end-scaphe 3 to 7 strong and distally curved spines are deeply embedded laterally. There are two types of bristles on the notopodia: on the one hand, straight, smooth and, on the other hand, subdistally bent, toothed. On the neuropodia there are comb-like hooks with 3 to 4 vertical rows of 6 to 8 teeth each. There are 3 pairs of club-shaped papillae on the end-scaphe. A thin, moderately long, broadly rounded anal tongue with a finely sawn edge and a tiny cirrus sit on the pygidium.
The animal is colorless to pink, the gills are red.
Residential tube
.jpg)
The quiver has a worm for the comb worms characteristic conical, slightly curved, up to 8 cm long, to an ice cream cones reminiscent, but open at both ends burrow he cemented together with autologous mucus from sand grains. The wider end with the head is directed downwards in the sediment.
Distribution, habitat and way of life
Pectinaria koreni is in the eastern Atlantic Ocean from the Barents Sea to Angola , in the Mediterranean , Black Sea , on the coasts of Iceland , the Faroe Islands , in the North Sea , the Skagerrak and Kattegat , the Oresund , the Great and Little Belt , the Bay of Kiel and Spread to Warnemünde .
The polychaet lives with its living tube buried in the intertidal zone and down to depths of 500 m in various sedimentary soils from mud and silt to coarse sand, preferably in mixed sediments of mud and fine sand at moderate depths.
With his gold-colored paleae he digs himself into the substrate, while he picks up the substrate particles with his palps and transports them to the mouth with his eyelashes . Protozoa and small animals such as chamberlings , ciliates , roundworms and copepods are also included. The organic components of the swallowed substrate - detritus , small animals and microorganisms - are digested, while the mineral components are excreted as pseudofaeces and deposited on the surface of the seabed via the small hole at the tip of the living tube.
Development cycle
The quiver worm is segregated and lives around a year old. The mating season is spring and summer, after which the sex partners die. Both sexes release their gametes into the open sea water, where fertilization takes place. Free-swimming larvae develop from the zygotes and live as zooplankton for several weeks and, as mature but still swimming larvae, begin to build a living tube out of slime before they sink down and metamorphose into crawling worms . In the sediment, they are now beginning to cement grains of sand together for their conical living tube, and they grow rapidly - interrupted by a rest period in winter.
literature
- Gesa Hartmann-Schröder (1996): Annelida, Borstenwürmer, Polychaeta. Tierwelt Deutschlands 58, pp. 1–648, here p. 446, Pectinaria (Lagis) koreni Malmgren, 1865.
- John D. Fish, Susan Fish: A Student's Guide to the Seashore . Cambridge University Press, Cambridge 2011. 540 pages. Pectinaria koreni Malmgren , p. 168.
- A. Nicolaidou (1983): Life history and productivity of Pectinaria koreni Malmgren (Polychaeta). Estuarine, Coastal and Shelf Science 17 (1), pp. 31-43.
- Fred C. Dobbs, Teresa A. Scholly (1986): Sediment processing and selective feeding by Pectinaria koreni (Polychaeta: Pectinariidae). Marine Ecology - Progress Series 29, pp. 165-176.
Web links
- MJ de Kluijver et al .: Pectinaria koreni (Malmgren, 1866). Macrobenthos of the North Sea - Polychaeta, Marine Species Identification Portal
- M. van Couwelaar: Pectinaria koreni (Malmgren, 1866). Zooplankton and Micronekton of the North Sea, Marine Species Identification Portal
- EM Mayhew: Lagis koreni Malmgren, 1866. In: H. Tyler-Walters, K. Hiscock (Eds.): Marine Life Information Network, Biology and Sensitivity Key Information Reviews. Marine Biological Association of the United Kingdom, Plymouth 2007.