Eunicidae
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| Scientific name | ||||||||||||
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| Berthold , 1827 |
Eunicidae is the name of a family to very large mostly predatory, parasitic rare small polychaete (Polychaeta) in seas worldwide either free-living, tube-making can be found or digging.
features
The many bristles of the Eunicidae family have up to 1500 segments and are between 1 cm and 6 m long. The segmented body is not divided into larger sections, but the size and shape of the parapodia on the sides of the segments change along the body. Characteristic for the family are the 1 to 3 antennas on the bilobed or undivided prostomium (head lobe), which do not have any ringed antenna supports (ceratophores). In the genus Eunice there are 2 palps and 3 antennae, i.e. 5 appendages on the prostomium, while in other genera there may be fewer. The palps (buccal lips) can be reduced or well developed. Most species of the Eunicidae have eyes . The peristomium consists of two rings, on the rear of which, in some species, two peristomial cirruses sit. The parapodia are branched and the notopodium is only formed as a dorsal cirrus. The gills , if any, consist of simple or comb-like filaments. The upper neuropodia have clearly edged and comb-like bristles . The jaws consist of ventral unfused mandibles and dorsal maxilla mineralized with aragonite , which are composed of a pair of short beams and 4 to 5 plates on the right and 5 to 6 plates on the left.
The body structure is very uniform in the species of this family, so that in particular the shape and number of the processes on the prostomium as well as the number and distribution of the gills are important for the determination. Like most large polychaetes have the Eunicidae in its closed blood vessel system for binding of the oxygen than blood pigment hemoglobins that are free in the blood are released and not bound to blood cells. Because of their parapodial gills, which are colored red by the blood, many species are also referred to as "blood worms".
Females and males are the same size in the Eunicidae. Most species have mixonephridia in their segments with a simple excretory canal that also serves as an exit for the gametes . The egg cells are at least 0.1 mm in size and provide enough lecithin for a larva to live as plankton for several days without eating. As far as is known, the larval stage lasts about 3 to 8 days before metamorphosis into a creeping worm. Direct development without the larval stage is unknown in the family. In most species, the young worms initially crawl freely in crevices after metamorphosis, before they change to life as tube worms in many species .
Some sample styles
One of the largest and best-studied species of the Eunicidae is the up to 2 m long Eunice aphroditois , which is widespread in the Indian Ocean as well as in the Pacific Ocean, among others on the coast of South Australia , which lives in long tubes in the substrate and snaps at animals swimming by it also eats fish in addition to a large number of other prey . The equally large Palola viridis , which is also found in the Pacific, especially around Samoa , the Fiji Islands and the Lesser Sunda Islands , feeds on the symbiotic algae that live in corals . Similar to other representatives of the genus Palola, which is widespread in warm waters around the world , its reproductive behavior is linked to the phases of the moon . The posterior section of the body, known as epitoke , which contains the gonads , is pinched off at reproductive time and moves to the surface of the water, where it bursts open, releasing the gametes into the open sea. Due to the large number of male and female epitoks floating next to each other, external fertilization in sea water is ensured. Free-swimming trochophora larvae develop.
Predators
Despite their partially large Wehrhaftigkeit bristleworms form of Eunicidae family the main food of various predatory living gastropod species , including the sting screw Drupa morum , the ceramic vase ( Vasum ceramicum ) and the black and white cone shell ( Conus ebraeus ).
Genera
The Eunicidae family is divided into eleven genera :
- Aciculomarphysa Hartmann-Schröder in Hartmann-Schröder & Zibrowius, 1998
- Esconites Thompson & Johnson, 1977 †
- Eunice Cuvier, 1817
- Euniphysa Wesenberg-Lund, 1949
- Fauchaldius Carrera-Parra & Salazar Vallejo, 1998
- Leodice Lamarck, 1818
- Lysidice Lamarck, 1818
- Marphysa Quatrefages, 1866
- Nicidion Kinberg, 1865
- Palola Gray in Stair, 1847
- Treadwellphysa Molina-Acevedo & Carrera-Parra, 2017
literature
- Stanley J. Edmonds: Fauna of Australia, Volume 4A. Polychaetes & Allies. The Southern Synthesis 4. Commonwealth of Australia, 2000. Class Polychaeta. Pp. 127-130, Family Eunicidae.
- Kristian Fauchald (1992): A review of the genus Eunice (Polychaeta: Eunicidae) based upon type material. Smithsonian Contributions to Zoology 523, pp. 1-422.
Web links
Individual evidence
- ↑ John D. Taylor (1983): The food of coral-reef Drupa (Gastropoda). Zoological Journal 78 (4). Pp. 299-316.
- ↑ JD Taylor (1984): The diet of Indo-Pacific Vasum (Gastropoda: Vasidae). Journal of Conchology 31, pp. 375-382.
- ↑ TF Duda Jr., D. Chang, BD Lewis, T. Lee (2009): Geographic Variation in Venom Allelic Composition and Diets of the Widespread Predatory Marine Gastropod Conus ebraeus . PLoS ONE 4 (7), p. E6245.
- ↑ Eunicidae Berthold, 1827. WoRMS , 2018. Accessed May 10, 2018.