Pygospio elegans

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Pygospio elegans
Pygospio elegans. From: A monograph of the British marine annelids, 1915.

Pygospio elegans . From: A monograph of the British marine annelids , 1915.

Systematics
Trunk : Annelids (Annelida)
Class : Polychaete (Polychaeta)
Order : Spionida
Family : Spionidae
Genre : Pygospio
Type : Pygospio elegans
Scientific name
Pygospio elegans
Claparède , 1863

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

features

Pygospio elegans has a cylindrical, yellowish and greenish front body with around 60 segments up to about 1.5 cm long . The narrow prostomium is slightly incised in front and has 2 to 8 irregularly arranged eyes, but no antennae. At its rear end there is a caruncle that extends to the front edge of the 2nd segment. 2 long palps are available.

The lobes behind the bristles of the notopodia are oval to finger-shaped on the front segments, completely fused with the gills on the following, gill-bearing segments , and behind the gill-bearing segments are short and oval. The lobes behind the bristles of the neuropodia are oval on the anterior segments and broadly rounded on the segments behind. All notopodia have capillary-shaped bristles , the notopodia of the anterior segments also have lanceolate bristles. The neuropodia on the front segments have capillary-shaped bristles, while on the neuropodia from the 8th or 9th segment there are 4 to 5 bent hooks with hoods. The gills are located on the segments from the 11th to the 20th bristle-bearing segment, with the females having 7 to 9 pairs of gills and the males 20 to 28 pairs of gills. The males also have a pair of cirrus or gills on the 2nd bristle-bearing segment. On the pygidium there are 4 pointed lobes covered with papillae.

Distribution, habitat and way of life

Pygospio elegans is distributed throughout the North Sea , the Skagerrak , Kattegat , Öresund , the Baltic Sea , the northern Pacific Ocean , the northern Atlantic Ocean to the Mediterranean , the Black Sea , the Arctic Ocean and the coasts of South Africa and Australia .

The polychaet lives in the intertidal zone and below in rock crevices and abandoned mollusc shells, whereby it can also be found in the brackish water of estuaries .

Streblospio benedicti uses its two palps to collect food particles from detritus from the substrate surface and transport them to the mouth. Alternatively, as a filter feeder, the polychaete can also collect detritus from the water flow and for this purpose changes its feeding mode.

Development cycle

Pygospio elegans is separate from the sexes, and the development proceeds via a phytoplankton-eating larva that lives as zooplankton, which eventually sinks down in a number of 18 to 22 bristle-bearing segments and metamorphoses into a creeping worm .

Unlike many other polychaetes, Pygospio elegans also reproduces asexually through architomy.

literature

  • Antoine René Édouard Claparède : Observations made on anatomy and evolutionary history of invertebrates on the coast of Normandy. W. Engelmann, Leipzig 1863. pp. 37f.
  • Erik Rasmussen (1953): Asexual Reproduction in Pygospio elegans Claparède (Polychæta sedentaria). Nature 171, pp. 1161-1162.
  • Stefan G. Bolam (2004): Population Structure and Reproductive Biology of Pygospio elegans (Polychaeta: Spionidae) on an Intertidal Sandflat, Firth of Forth, Scotland. Invertebrate Biology 123 (3), pp. 260-268.
  • TC Hiebert: Pygospio elegans. A spy polychaete worm. In: TC Hiebert, BA Butler, AL Shanks (eds.): Oregon Estuarine Invertebrates: Rudys' Illustrated Guide to Common Species , 3rd ed. University of Oregon Libraries and Oregon Institute of Marine Biology, Charleston (Oregon) 2014.

Web links

Commons : Pygospio elegans  - collection of images, videos and audio files