Chrysopetalidae

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Chrysopetalidae
Systematics
Empire : Animals (Animalia)
Trunk : Annelids (Annelida)
Class : Polychaete (Polychaeta)
Subclass : Aciculata
Order : Phyllodocida
Family : Chrysopetalidae
Scientific name
Chrysopetalidae
Ehlers , 1864

The Chrysopetalidae are a family of medium to large, mostly predatory or as scavengers living polychaete (Polychaeta), which about 42 species are found in oceans worldwide.

features

The multi-bristle of the family Chrysopetalidae have a clearly visible segmentation , with many species having a constant number of segments. With a length of around 20 cm and a width of around 10 cm with a constant number of 40 segments, the flat and very wide Eulagisca gigantea is possibly the largest species.

The multi-bristle of the family Chrysopetalidae have a short or elongated, mostly flattened and fragile body with few or many segments . All segments carry a fan or a transverse row of paleae , bristles with golden, silver or copper color on their back . The clearly separated prostomium (head flap) has tentacles and eyes as well as a nuchal organ behind , and the buccal segment has 2 or 4 tentacle cirrus on each side . The parapodia are single or double with dorsal cirrus on all segments. The ventral bristles are assembled. Two cirrus or conical appendages sit on the pygidium. The pharynx is equipped with two jaws.

distribution

The Chrysopetalidae are distributed in seas of temperate to tropical latitudes worldwide from the intertidal zone to a depth of 4000 m.

nutrition

The Chrysopetalidae live as scavengers and carnivores , actively looking for their food, in rock crevices, boreholes of other species in coral skeletons , dead shells or shells, between seaweed plants and between the burrows of tube worms and worms from the shore to great depths in muddy and sandy sediments, which contain gravel or schill. Habitat and diet vary considerably within the family. Species of the genus Paleaequor live almost exclusively on sand. The genus Strepternos consists of deep-sea species with sinterized, blunt sawn, stiletto pine and were feeding on lithophagous molluscs : (Pholadidae genus xylophaga observed). Species of the genera Paleanotus and Treptopale , however, feed on large algae . In the genus Paleanotus there are also species that live as commensals or parasites in the gills or the carapace of mussels or crabs . Many genera of the subfamily Calamyzinae also live in close association with other invertebrates, most of them in the gills of mussels.

Development cycle

The Chrysopetalidae are sexually separated. Males and females release their gametes into the open sea water, where fertilization takes place. The eggs are often pink and, depending on the species described, measure between 27 and 100 μm in diameter. The fertilized eggs develop into free-swimming trochophora larvae, which are initially rich in yolk and only begin to eat phytoplankton in later stages. But there are also species that live on yolk reserves or fat droplets in the intestinal canal until the animal sinks with 6 to 7 segments and first paleae and its metamorphosis into a creeping worm. The floating phase to a stage with six segments can take up to three weeks and the metamorphosis can be delayed until a suitable substrate is found, which enables the larvae to spread widely.

Genera

The species of the family Chrysopetalidae are counted to 28 genera in 3 subfamilies:

literature

  • Stanley J. Edmonds: Fauna of Australia, Volume 4A. Polychaetes & Allies. The Southern Synthesis 4. Commonwealth of Australia, 2000. Class Polychaeta. Pp. 162-168, Family Chrysopetalidae.
  • Darbyshire, T. & Brewin, PE 2015. Three new species of Dysponetus Levinsen, 1879 (Polychaeta: Chrysopetalidae) from the South Atlantic and Southern Ocean, with a re-description of Dysponetus bulbosus Hartmann-Schröder, 1982. Zootaxa, 4040 (3 ), pages 359-370, doi : 10.11646 / zootaxa.4040.3.7
  • Watson, C. 2015. Seven new species of Paleanotus (Annelida: Chrysopetalidae) described from Lizard Island, Great Barrier Reef, and coral reefs of northern Australia and the Indo-Pacific: two cryptic species pairs revealed between western Pacific Ocean and the eastern Indian Ocean. IN Hutchings, PA & Kupriyanova, EK (eds.), 2015: Coral reef-associated fauna of Lizard Island, Great Barrier Reef: polychaetes and allies. Zootaxa, 4019 (1), pp. 707-732, doi : 10.11646 / zootaxa.4019.1.24

Individual evidence

  1. ↑ Ascensão Ravara, M. Teresa Aguado, Clara F. Rodrigues, Luciana Génio, Marina R. Cunha: Description of a new genus and species of Chrysopetalidae (Annelida: Polychaeta) from the NE Atlantic, with some further records of related species . In: European Journal of Taxonomy . tape 0 , no. 539 , July 26, 2019, ISSN  2118-9773 , doi : 10.5852 / ejt.2019.539 ( europeanjournaloftaxonomy.eu [accessed April 7, 2020]).
  2. ↑ Chrysopetalidae Ehlers, 1864. WoRMS , 2018. Accessed December 12, 2018.
  3. ↑ Naoto Jimi, Takeya Moritaki and Hiroshi Kajihara. 2019. Polychaete meets Octopus: Symbiotic Relationship Between Spathochaeta octopodis gen. Et sp. nov. (Annelida: Chrysopetalidae) and Octopus sp. (Mollusca: Octopodidae). Systematics and Biodiversity. DOI: 10.1080 / 14772000.2018.1520753