Cephalodiscus

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Cephalodiscus
Cephalodiscus dodecalophus

Cephalodiscus dodecalophus

Systematics
Over trunk : Neumünder (Deuterostomia)
Trunk : Gillfish (Hemichordata)
Class : Wing gill (Pterobranchia)
Order : Cephalodiscoidea
Family : Cephalodiscidae
Genre : Cephalodiscus
Scientific name of the  order
Cephalodiscoidea
Beklemishev , 1951
Scientific name of the  family
Cephalodiscidae
Harmer , 1905
Scientific name of the  genus
Cephalodiscus
M'Intosh , 1882

Cephalodiscus ( Gr . "Kephale" = head, + "diskos" = disk) is a genus of marine invertebrates from the class of wing gills (Pterobranchia). They live at depths of 100 to 600 meters, especially in the cool seas of the southern hemisphere, in South Africa, New Zealand and in the Southern Ocean , where they can be stock-forming. However, C. gracilis (Indo-Pacific) and C. indicus (Caribbean) also occur in shallow water (less than 20 m).

features

Like all wing gills, the Cephalodiscus species are worm-like animals only a few millimeters in size that inhabit self-produced tubes made of scleroprotein in colonies . They can be divided into head shield ( proboscis or protosoma ), collar ( mesosoma ) and trunk ( metasoma ). The head shield has a ventrally (downwards) directed, glandular adhesive disc with which the animals can crawl. Dorsally (above) on the collar there are usually nine pairs of lophophores (only one pair in Rhabdopleura ), which are covered with up to 50 ciliate tentacles arranged in two rows and which capture food particles ( filtration ). The sack-shaped trunk contains the U-shaped digestive tract and the simply built, paired gonads and ends in a long, retractable stem, which often ends in a disc-shaped widening with a suction cup. The mouth and gill slits are located on the collar, directly behind the adhesive disc, the anus on the opposite side behind the lophophores. The individual individuals of a Cephalodiscus colony are free; H. in contrast to Rhabdopleura, not connected by a stolon . They can also leave their living tube and crawl around freely, but usually remain anchored with the adhesive disk inside the tube. Cephalodiscus species grow up to 5 mm long (without a stem).

species

literature

Web links

  • Konikoff, C .; van der Land, J. (2013). Cephalodiscus M'Intosh, 1882 . In: Shenkar, N; Swalla, BJ; van der Land, J. (2013) Hemichordata World Database, World Register of Marine Species.