Scolelepis squamata

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Scolelepis squamata
Scolelepis squamata

Scolelepis squamata

Systematics
Trunk : Annelids (Annelida)
Class : Polychaete (Polychaeta)
Order : Spionida
Family : Spionidae
Genre : Scolelepis
Type : Scolelepis squamata
Scientific name
Scolelepis squamata
( Abildgaard in OV Müller , 1806)
S. squamata (top center). A monograph of the British marine annelids 1915 .

Scolelepis squamata is a marine annelid from the family of Spionidae within the class of polychaete (Polychaeta) in seas is distributed worldwide.

features

When fully grown, Scolelepis squamata has a comparatively slender, bluish-green body with over 200 segments that is up to 14 cm long . The narrow, conical prostomium tapering to a point at both ends has 4 trapezoidal eyes, but no antennae. At its rear end there is a triangular caruncle that extends to the 2nd or 2nd bristle-bearing segment. 2 long palps are available.

The lobes behind the bristles of the notopodia are small and oval on the first segment, long, lanceolate and fused to the gills for more than half their length on the following, gill-bearing segments, shorter and almost completely separated on the posterior segments. The lobes behind the bristles of the neuropodia are short and rounded on the anterior segments and slightly bilobed from the 18th to the 20th segment. Gills sit on all segments except the first and the last seven segments. They have the shape of cirrus and are longer than the lobes behind the bristles of the notopodia. All parapodia have capillary- shaped bristles , the notopodia from the 26th to the 40th segment and the notopodia on the 60th to 65th segment also have hooks with hoods, usually two-toothed, sometimes single-toothed or with two small accessory teeth. The pygidium has a single lobe.

distribution and habitat

Scolelepis squamata is likely to be found in seas worldwide with the exception of the Arctic and Antarctic , including the North Sea to Öresund , on both sides of the Atlantic Ocean , in the Mediterranean , Caribbean and Gulf of Mexico . The polychaet lives on sandy beaches in the intertidal zone and below in pure or slightly muddy sand or shill, whereby it can also be found in the brackish water of estuaries . In the sediment he digs vertical living corridors, which he lines with slime. But it can also swim with snake-like movements.

nutrition

With its two palps, Streblospio benedicti collects food particles from detritus and microorganisms from the substrate surface and conveys them to the mouth by contracting the palps, which are missing eyelashes. If there is a sufficient flow of water, the polychaet can alternatively also act as a filter to collect detritus from the water column, for which the palps are twisted in a helical manner. Investigations of the intestinal contents show that the food particles consist of granules of sediment, balls of feces from other animals and a number of protozoa and small larvae.

Development cycle

Scolelepis squamata is separate sexes. On the south coast of the UK , males and females mate by releasing their gametes into open seawater from May to July, while on the coast of Brazil they do so year-round. Fertilization takes place in free water, and the zygotes develop into free-swimming larvae that live as zooplankton and eat phytoplankton, which after about 5 weeks sink to the sea floor and metamorphose into crawling worms . The annelid worm is short-lived and has a high reproductive rate.

literature

Web links

Commons : Scolelepis squamata  - Collection of images, videos and audio files

Individual evidence

  1. ↑ Stephen A. Bortone: Estuarine Indicators. CRC Press, 2004, p. 290. ISBN 978-1-4200-3818-7
  2. ↑ DM Duration (1983): Functional morphology and feeding behavior of Scolelepis squamata (Polychaeta: Spionidae). Marine Biology 77 (3), pp. 279-285 doi : 10.1007 / BF00395817