Ampharetidae

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Ampharetidae
Ampharete acutifrons. William C. McIntosh (1885): A monograph of the British marine annelids.

Ampharete acutifrons . William C. McIntosh (1885): A monograph of the British marine annelids .

Systematics
Trunk : Annelids (Annelida)
Class : Polychaete (Polychaeta)
Subclass : Palpata
Order : Canalipalpata
Subordination : Terebellida
Family : Ampharetidae
Scientific name
Ampharetidae
Malmgren , 1867

Ampharetidae is the name of a family of mostly small polychaeta (polychaeta) living in soft sediments in living tubes , which can be found in oceans worldwide as detritus eater .

features

The Ampharetidae have a short and compact body with a clear segmentation , with the segments of the thorax bearing both notopodia and neuropodia , while the segments of the abdomen only have neuropodia. The comparatively small prostomium is elongated, rounded or pointed and is located above a larger unit consisting of the fused first and second segments. The peristomium is reduced to lips and a "roof of the mouth". While antennae are completely absent, the palps on the peristomium are formed as short and slender mouth tentacles and attached to an overhead curtain in the oral cavity, but one or two much larger palps with eyelash grooves may occasionally be present. On the side of the prostomium there are comma-shaped nuchal organs , in some species there are also a pair of eye spots . The longitudinal muscles run in four strands. The parapodia appear from the 2nd, 4th or 5th segment. The notopodia on the thorax are short and cylindrical, while the neuropodia are tori throughout the body . On the front segments there are up to four pairs of gills , which, depending on the species, are the same or different in shape across the body. Epidermal papillae are absent, and the pygidium carries numerous or no cirrus depending on the species . Lateral organs are present, but back cirrus is missing. Aciculae are absent, and the bristles are capillary-shaped on the Notopodium and hook-shaped on the Neuropodium. In some species there can be paleae on the notopodia in front , in others large paired hooks.

There is a throat membrane in the first two segments. The buccal organ cannot be turned out, and the intestine is curved in most species and a straight tube in only a few species. The closed blood vessel system is well developed and equipped with a central heart . The nephridia are located in the first segments and are designed as mixonephridia, with the first pair serving as kidneys and the rest serving to discharge the gametes .

distribution and habitat

The Ampharetidae occur in seas around the world from the shores to the deep sea . They live in soft sediments, with species of the intertidal zone also staying under stones.

Development cycle

The Ampharetidae are separate sexes, in most species with external pollination, but there are numerous reproductive types in the family. Alkamaria romijina incubates its eggs, from which free-swimming larvae hatch, while in Ampharete grubei the eggs are fertilized in open seawater, but then develop directly into crawling worms. Hobsonia florida in turn incubates its eggs in its living tube, where they develop directly into crawling worms. Also Amphicteis floridus and Melinnexis arctica incubate their young in the maternal burrow. With Melinna elisabethae , on the other hand, the eggs are fertilized in open seawater and develop into larvae that are nourished by yolks.

nutrition

As far as is known, the Ampharetidae are detritus eaters who use their mouth tentacles to pick up food particles from the substrate, transport them to the mouth by striking the cilia and swallow them. In addition, unicellular algae and microscopic animals are also included.

Subfamilies and genera

The approximately 240 species of the Ampharetidae family are divided into 63 genera in 2 subfamilies:

literature

  • Stanley J. Edmonds: Fauna of Australia, Volume 4A. Polychaetes & Allies. The Southern Synthesis 4. Commonwealth of Australia, 2000. Class Polychaeta. Pp. 274-280, Family Ampharetidae.

Web links

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

Individual evidence

  1. ↑ Ampharetidae Malmgren, 1866. WoRMS , 2018. Retrieved December 7, 2018.