Vine worms

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Vine worms
Cirratulus cirratus

Cirratulus cirratus

Systematics
Trunk : Annelids (Annelida)
Class : Polychaete (Polychaeta)
Subclass : Palpata
Order : Canalipalpata
Subordination : Terebellida
Family : Vine worms
Scientific name
Cirratulidae
Ryckholt , 1851

The tendrils worms or Fadenkiemer ( Cirratulidae ) are a family as filter feeders or substrate eaters living polychaete (Polychaeta) in seas worldwide with or without tube can be found in mud or rock crevices.

features

The Cirratulidae are 1 to 25 cm long and have a mostly cylindrical body with numerous segments, tapering at both ends. Some are dark green to black ( Dodecaceria ), others orange-red ( Cirriformia ). They have a cone-shaped or anteriorly rounded prostomium on which a pair of eye-spots sit in some species, while other species are blind. Antennae are absent in all Cirratulidae. The sometimes elongated peristomium is fused with at least the following two segments. In most species (in the genera Dodecaceria , Tharyx , Monticellina , Aphelochaeta , Chaetozone and Caulleriella ) there is a pair of palps with an eyelash groove at the rear end of the peristomium , while in other species (in the genera Cirriformia and Cirratulus ) it is on the dorsal side of the frontmost one or the front bristle-bearing segments have numerous filament-like palps in two rows. The anterior segments are usually very short compared to the middle and posterior segments, which can be pearl-shaped (Aphelochaeta, Chaetozone, Monticellina) or, like the others, more or less cylindrical ( Tharyx , Cirriformia ). The parapodia are branched and have papillary lobes and simple capillary-shaped, hook-shaped or spike-shaped bristles . On the back of each segment, there are paired, slender, thread-like gills , mostly across the entire body. The pygidium usually has a small abdominal flap and an anus at the end, but no cirrus.

The Cirratulidae have an unarmed, extensible pharynx located on the ventral side. The closed blood vessel system has a central heart . There are different blood pigments : In Cirriformia and Cirratulus there are the brown breath pigments coproporphyrin , coprohaematin and urohaematin , while in Dodecaceria there is a yellow-green, fluorescent , water-soluble breath pigment. The Cirratulidae have a single pair of excretory mixonephridia in front, and numerous pairs of gonoducts behind in most species . In some species such as Cirratulus anchylochaeta and Chaetozone setosa , however, these are absent, and it is assumed that the gametes are released by tearing the body wall or via the anterior mixonephridia.

Habitat and way of life

The Cirratulidae dig mostly by soft sediment, but some live in crevices or under large algae or seaweed . Some species build living tubes out of calcium carbonate , and still others can dig into hard substrate made of calcium carbonate such as coral skeletons or mollusc shells.

The Cirratulidae feed as filter feeders or substrate eaters of detritus and microorganisms.

Reproductive cycle

Most Cirratulidae are separate sexes, and both sexes release their gametes into the open sea where fertilization takes place. In a few species, including Cirratulus cirratus and in the genus Dodecaceria comes Epitokie ago. The zygotes develop into free-swimming larvae which, after a phase as zooplankton, sink down and metamorphose into crawling worms .

Asexual reproduction by architomy has been observed in some species of the genera Cirratulus , Timarete and Dodecaceria , and in the latter genus also parthenogenesis .

Genera

The genera of the Cirratulidae have not yet been systematically processed. Blake made a partial revision of the genera in 1996 and divided them into three groups: Cirratulidae with many tentacles (genera Cirratulus and Cirriformia ), Cirratulidae with two tentacles that live on soft substrate (genera Caulleriella , Chaetozone , Tharyx ) and Cirratulidae with two tentacles that live on hard substrate (genus Dodecaceria ).

The family Cirratulidae is divided into the following genera:

literature

  • Stanley J. Edmonds: Fauna of Australia, Volume 4A. Polychaetes & Allies. The Southern Synthesis 4. Commonwealth of Australia, 2000. Class Polychaeta. Pp. 281-284, Family Cirratulidae.
  • JA Blake: Family Cirratulidae Ryckholdt, 1851. pp. 263-384. In: JA Blake, B. Hilbig, PH Scott (Eds.): The Annelida. Part 3. Polychaeta: Orbiniidae to Cossuridae. Vol. 6. Taxonomic Atlas of the Benthic Fauna of the Santa Maria Basin and western Santa Barbara Channel. Santa Barbara Museum of Natural History, Santa Barbara (California) 1996.

Web links

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

Individual evidence

  1. Cirratulidae Ryckholt, 1851. WoRMS , 2018. Accessed October 7, 2018.