Acoetidae

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Acoetidae
Polyodontes maxillosus, Museum fur Naturkunde, Berlin

Polyodontes maxillosus , Museum fur Naturkunde, Berlin

Systematics
Empire : Animals (Animalia)
Trunk : Annelids (Annelida)
Class : Polychaete (Polychaeta)
Subclass : Aciculata
Order : Phyllodocida
Family : Acoetidae
Scientific name
Acoetidae
Savigny in Lamarck , 1818

Acoetidae is the name of a family of long, tube-forming , predatory polychaeta that can be found in seas around the world.

features

The many bristles of the Acoetidae family have numerous segments and are up to 30 cm long and 4 cm wide. They live in fibrous tubes made of long silk-like chitin threads, which are separated from the segments' spinneret and spirally woven. Unlike all other tube worms, these tubes lack a membranous demarcation.

The Acoetidae have a well-developed head in which the prostomium and the first tentacle-bearing segment are more or less fused and on which there are long, jointless palps , lateral and median antennae, 2 pairs of tentacles - cirrus and eyes. The eyes, which are very large in some species, can sit directly on the head or in front of protruding ommatophores. A pair of nuchal organs are present. The peristomium is formed only by the lips around the mouth and is surrounded by the first segment, the parapodia of which are similar to those of the other segments, but are fused to the base of the prostomium. The neuropodia are significantly longer than the notopodia . As with other Aphroditiformia (including Polynoidae and Aphroditidae ), paired scale-like structures known as elytrs instead of the dorsal cirrus also sit in numerous segments in the Acoetidae, but ventral cirrus is always present. A pair of cirrus is sitting on the pygidium.

The evertable, muscular, axial pharynx bears two pairs of dorsoventrally aligned jaws, and terminal papillae sit around the mouth. A throat membrane is missing and the intestines have blind sacs. Metanephridia are present.

Distribution, way of life and example species

The Acoetidae are distributed in all seas with the exception of Arctic and Antarctic waters from the lower tidal zone to depths of about 1500 m.

The animals are carnivores who grab their prey with their jaws by partially leaving their living tube and then retreating back into this with their prey.

The Acoetidae are separate sexes, so either produce sperm or large yolk-rich eggs, but their mating behavior is just as unknown as their larval development.

A comparatively well-studied species of Acoetidae is Polyodontes maxillosus , which is widespread in the Mediterranean and also snaps at fish bait with its jaws.

Genera

The Acoetidae family is divided into 11 genera :

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 Acoetidae.

Web links

Commons : Acoetidae  - Collection of images, videos, and audio files

Individual evidence

  1. ↑ Acoetidae Berthold, 1827. WoRMS , 2018. Retrieved May 10, 2018.