Alvinellidae

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Alvinellidae
Paralvinella sulfincola

Paralvinella sulfincola

Systematics
Trunk : Annelids (Annelida)
Class : Polychaete (Polychaeta)
Subclass : Palpata
Order : Canalipalpata
Subordination : Terebellida
Family : Alvinellidae
Scientific name
Alvinellidae
Desbruyères & Laubier , 1986

Alvinellidae is the name of a family of small polychaeta (polychaeta) that live in tubes in the deep sea and are endemic to hydrothermal vents.

features

The Alvinellidae have a body with numerous short segments which vary in number and which are not divided into larger sections. The prostomium is reduced and the buccal apparatus has tentacles with an eyelash groove and a dorsal organ, both of which can be withdrawn into the buccal cavity; there is also a ventral buccal organ . In the genus Alvinella there are two rows of lamellae on four pairs of gill stems , and in the genus Paralvinella simple unbranched filaments. The first pair of gills is located in adults on the first, bristle-free segment. The parapodia are mostly branched. On the notopodia there are capillary-like bristles , on the neuropodia a single row of simple short-winged hooks. The parapodia on the first or the first two segments are modified in that instead of the capillary-shaped bristles on the notopodium there are a few large needle-shaped hooks.

The Alvinellidae form their upright living tubes from secreted mucus, from which they stretch their feathery gills, which are strongly supplied with blood and thus red in color. In contrast to the Siboglinidae , which also live in deep-sea hydrothermal springs , the Alvinellidae have an intestinal canal.

Habitat and way of life

The Alvinellidae are endemic to deep-sea hydrothermal springs and are therefore extremely heat-tolerant. Alvinella pompejana is considered to be the type of eukaryote that can withstand the highest temperatures. Your mitochondria only begin to fail at 50 to 55 ° C. In laboratory tests, Paralvinella sulfincola preferred temperatures of 50 ° C, but for a short time also moved into areas of 55 ° C. The animals feed through a symbiosis with thermophilic , chemoautotrophic bacteria . These grow in large numbers on the back of the annelid worm and presumably protect it from overheating. Investigations of the intestinal contents of various species of the Alvinellidae show that the animals swallow mineral particles to which detritus as well as bacteria adhere, including possibly numerous thermophilic bacteria. As the annelids digest the bacteria and other organic components, they excrete the mineral particles unchanged. Thus the Alvinellidae also live as substrate eaters .

Genera and species

In the family Alvinellidae 11 species in 2 genera are known:

literature

  • Daniel Desbruyères, Lucien Laubier (1991): Systematics, phylogeny, ecology and distribution of the Alvinellidae (Polychaeta) from deep-sea hydrothermal vents. Ophelia, Supplement 5, 31-45.

Web links

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

Individual evidence

  1. ↑ Study finds worms thriving in hot-water . CNN.com, April 14, 2006 ( April 17, 2006 memento on the Internet Archive ).
  2. ↑ Alvinellidae Desbruyères & Laubier, 1986. WoRMS , 2018. Accessed May 10, 2018.