Polynoidae

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Polynoidae
Lepidonotus squamatus

Lepidonotus squamatus

Systematics
Empire : Animals (Animalia)
Trunk : Annelids (Annelida)
Class : Polychaete (Polychaeta)
Subclass : Aciculata
Order : Phyllodocida
Family : Polynoidae
Scientific name
Polynoidae
Kinberg , 1856

Polynoidae is the name of a family of medium to large, mostly predatory or as commensals living polychaete (Polychaeta) which about 748 species in about 165 genera are found in oceans worldwide.

features

The polynoidal family has a clearly visible segmentation , with many species having a constant number of segments. With a length of around 20 cm and a width of around 10 cm with a constant number of 40 segments, the flat and very wide Eulagisca gigantea is possibly the largest species.

The polynoid prostomium is bilobed or rounded, and the peristomium is formed only by the lips around the mouth. Most species have a pair of lateral and median antennas. The hingeless, tapered ventral palps are fused with the first segment. A pair of nuchal organs are present. There may be two pairs of eyes, but many species have no eyes. The longitudinal muscles are arranged in bundles. The first segment surrounds the prostomium and usually has very small forked parapodia , the neuropodia of which are fused with the underside of the head, as well as two pairs of tentacles - cirrus . The neuropodia are in all segments significantly longer than the notopodia , which are sometimes very short and have only a few bristles. Segments with dorsal cirrus and elytra alternate at least in the front part of the body, whereby elytra can be present or absent in the rear part, while ventral cirrus is always present. The animals have neither gills nor epidermal papillae. A pair of cirrus is sitting on the pygidium. Aciculae are present.

The animals have an axial buccal organ , a muscular everted pharynx with end papillae and two pairs of dorsoventral jaws. A throat membrane is absent and the intestine has a pair of blind sacs per segment. The closed blood vessel system has no central heart, and the blood has no blood pigment. Mixonephridia are found in many segments .

Way of life

The numerous species of Polynoidae are found in seas around the world, where they inhabit various benthic habitats.

The Polynoidae feed on partially predatory of small crustaceans and other small animals, but also partly from seaweed - often both. Many species are commensals that live on or in echinoderms , snails or mussels and, among other things, feed on leftover food or droppings from the hosts.

The Polynoidae are separate sexes, and in most species the eggs are fertilized in the open sea water and develop through a free-swimming larval stage. Only Harmothoe imbricata is known to fertilize the egg cells under the mother's elytra and then hatch the eggs here as well. About 16 days after fertilization, free-swimming larvae are released, which after a phase as zooplankton metamorphose into crawling worms .

Genera

The Polynoidae family has around 165 genera with around 748 species :

Admetellinae Uschakov, 1977
Arctonoinae Hanley, 1989
Bathyedithinae Pettibone, 1976
Bathymacellinae Pettibone, 1976
Branchinotogluminae Pettibone, 1985
Branchiplicatinae Pettibone, 1985
Branchipolynoinae Pettibone, 1984
Eulagiscinae Pettibone, 1997
Gesiellinae Muir, 1982
Lepidastheniinae Pettibone, 1989
Lepidonotinae Willey, 1902
Lepidonotopodinae Pettibone, 1983
Macellicephalinae Hartmann-Schröder, 1971
Macellicephaloidinae Pettibone, 1976
Macelloidinae Pettibone, 1976
Polaruschakovinae Pettibone, 1976
Polynoinae Kinberg, 1856
Uncopolynoinae woe, 2006
Vampiropolynoinae Marcus & Hourdez, 2002
Polynoidae incertae sedis

literature

  • Stanley J. Edmonds: Fauna of Australia, Volume 4A. Polychaetes & Allies. The Southern Synthesis 4. Commonwealth of Australia, 2000. Class Polychaeta. Pp. 151-155, Family Polynoidae.

Web links

Commons : Polynoidae  - collection of images, videos and audio files

Individual evidence

  1. ↑ Polynoidae Berthold, 1827 WoRMS , 2018. Retrieved on 10 May 2018th