Nereids (zoology)

from Wikipedia, the free encyclopedia
Nereididae
Amber Annelid (Alitta succinea)

Amber Annelid ( Alitta succinea )

Systematics
Trunk : Annelids (Annelida)
Class : Polychaete (Polychaeta)
Subclass : Palpata
Order : Aciculata
Subordination : Phyllodocida
Family : Nereididae
Scientific name
Nereididae
Blainville , 1818
The species Alitta virens becomes over a meter long

Nereids (Nereididae) are in the Zoology one family in the class of polychaete (Polychaeta).

features

The length of Nereids varies from a few millimeters (genus Micronereis ) to Alitta virens, which is over a meter long . The segmented body consists of 15 to several hundred segments in adult specimens. In living animals, the color ranges from transparent to brown or red with a variety of other color and pigment patterns. The eyes, if any, are designed as two pairs.

On the prostomium (rounded with Micronereis , triangular or rectangular with Namanereidinae or vice versa T-shaped), which is widest at the rear, there are two anterior antennae (rarely single or absent) and anteriorly two palpi . At merged with the first segment Peristomium two to four couples find of Tentakular - Cirrus clouds . The animals have nuchal organs in the form of short eyelashes as well as notopodia and neuropodia , each with at least one flattened lobe.

Characteristic of the Nereids is an evertable, two-part throat ( pharynx ), which is equipped with a pair of jaws and usually with, often conical, teeth.

Like most large polychaetes, the nereids have in their closed blood vessel system, which consists of a back vessel, an abdominal vessel and these connecting ring vessels, some of which are branched into capillaries, to bind the oxygen as blood pigment hemoglobins , which are freely dissolved in the blood and not bound to blood cells . Due to their very strong affinity for oxygen, the hemoglobins enable the nereids to survive in an oxygen-poor environment.

Occurrence

Nereids colonize all substrates in the ocean. They occur littoral to abyssal , but mainly in shallow water. Some species, for example in the genus Hediste , are also found in brackish water , the species Tylorrhynchus heterochaetus is an example of nereids that live in fresh water .

Systematics

Nereididae contains in the three subfamilies Gymnonereinae, Namanereidinae and Nereidinae more than 39 genera with about 535 species.

Types (selection)

Other types:

See also

Nereid (mythology)

literature

  • Stanley J. Edmonds: Fauna of Australia, Volume 4A. Polychaetes & Allies. The Southern Synthesis 4. Commonwealth of Australia, 2000. Class Polychaeta. Pp. 184-189, Family Nereididae.

Individual evidence

  1. ^ A b c d e Greg W. Rouse, Fredrik Pleijel: Polychaetes. , Oxford University Press, 2001, ISBN 978-0198506089 , pp. 96-98.
  2. ↑ a b c G. JB Ross, CJ Glasby, PL Beesley: Polychaetes & Allies: The Southern Synthesis. Fauna of Australia Volume 4A. CSIRO, 2000, ISBN 978-0643065710 , p. 139.

Web links

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