''Ophryotrocha'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of marine

polychaete Polychaeta () is a paraphyletic class of generally marine Annelid, annelid worms, common name, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called c ...

worms in the family Dorvilleidae. ''Ophryotrocha'' comprises a multitude of extant species of polychaete worms with more thought to exist in both shallow and deep waters. Polychaetes of this genus thrive in nutrient-rich environments and can often be found in polluted marine areas that are often sites of human activity.''Ophryotrochas durability allows them to exist in a myriad of stressful environments. Found in the oceans surrounding Europe, Asia, the Mediterranean, and beyond, they can survive in low-oxygen environments and are known to be sulfide tolerant, allowing this genus to live in areas most species cannot. Most worms are between 1 and 5 mm in length, but some deep sea species have been documented to be much larger, ranging from 10 and 25mm. ''Ophryotrocha'' is often used as a scientific test species due to their high fecundity, stress tolerance, and myriad of sexual systems found within the genus. All polychaetes of this genus are laid in batches of roughly 100 eggs and the majority of species start out in a free-moving larval stage as protandrous hermaphrodites. During the protandrist stage of adolescence, small males will start producing sperm when the body length is still small but will continue to stay male if females are present in an effort to avoid the energetic costs of producing oocytes. As this genus continues to grow they develop into tube-building sessile adults. Although no study has documented their entire life process, all ''Ophryotrocha'' are documented to breed and die after the dispersal of offspring with parental care given to eggs by one or both sexes resting on the egg cocoon. Parental care is thought to act as a mode for cleaning the cocoon and is documented in all studied species within the genus.

Species

The

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catalogue and list of names of marine organisms. Content The content of the registry is edited and maintained by scien ...

lists the following species in the genus: *'' Ophryotrocha adherens'' Paavo, Bailey-Brock & Akesson, 2000 *'' Ophryotrocha akessoni'' Blake, 1985 *'' Ophryotrocha alborana'' Paxton & Åkesson, 2011 *'' Ophryotrocha antarctica'' Szaniawski & Wrona, 1987 *'' Ophryotrocha atlantica'' Hilbig & Blake, 1991 *'' Ophryotrocha baccii'' Parenti, 1961 *'' Ophryotrocha batillus'' Wiklund et al., 2012 *'' Ophryotrocha bifida'' Hilbig & Blake, 1991 *'' Ophryotrocha birgittae'' Paxton & Åkesson, 2011 *'' Ophryotrocha cantabrica'' Núñez, Riera & Maggio, 2014 *'' Ophryotrocha claparedei'' Studer, 1878 *'' Ophryotrocha clava'' Taboada, Wiklund, Glover, Dahlgren, Cristobo & Avila, 2013 *'' Ophryotrocha cosmetandra'' Oug, 1990 *'' Ophryotrocha costlowi'' Paxton & Åkesson, 2010 *'' Ophryotrocha craigsmithi'' Wiklund, Glover & Dahlgren, 2009 *'' Ophryotrocha cyclops'' Salvo, Wiklund, Dufour, Hamoutene, Pohle & Worsaae, 2014 *'' Ophryotrocha diadema'' Åkesson, 1976 *'' Ophryotrocha dimorphica'' Zavarzina & Tsetlin, 1986 *'' Ophryotrocha dubia'' Hartmann-Schröder, 1974 *'' Ophryotrocha eutrophila'' Wiklund, Glover & Dahlgren, 2009 *'' Ophryotrocha fabriae'' Paxton & Morineaux, 2009 *'' Ophryotrocha flabella'' Wiklund et al., 2012 *'' Ophryotrocha gerlachi'' Hartmann-Schröder, 1974 *'' Ophryotrocha geryonicola'' (Esmark, 1878) *'' Ophryotrocha globopalpata'' Blake & Hilbig, 1990 *'' Ophryotrocha gracilis'' Huth, 1933 *'' Ophryotrocha hadalis'' Jumars, 1974 *'' Ophryotrocha hartmanni'' Huth, 1933 *'' Ophryotrocha irinae'' Tsetlin, 1980 *'' Ophryotrocha japonica'' Paxton & Åkesson, 2010 *'' Ophryotrocha jiaolongi'' Zhang, Zhou, Wang & Rouse, 2017 *'' Ophryotrocha kagoshimaensis'' Miura, 1997 *'' Ophryotrocha labidion'' Hilbig & Blake, 1991 *'' Ophryotrocha labronica'' Bacci & La Greca, 1961 *'' Ophryotrocha langstrumpae'' Wiklund et al., 2012 *'' Ophryotrocha lipovskyae'' (Paxton, 2009) *'' Ophryotrocha lipscombae'' Lu & Fauchald, 2000 *'' Ophryotrocha littoralis'' (Levinsen, 1879) *'' Ophryotrocha lobifera'' Oug, 1978 *'' Ophryotrocha longicollaris'' Wiklund et al., 2012 *'' Ophryotrocha longidentata'' Josefson, 1975 *'' Ophryotrocha lukowensis'' Szaniawski, 1974 *'' Ophryotrocha lusa'' Ravara, Marçal, Wiklund & Hilário, 2015 *'' Ophryotrocha maciolekae'' Hilbig & Blake, 1991 *'' Ophryotrocha macrovifera'' Paxton & Åkesson, 2010 *'' Ophryotrocha maculata'' Åkesson, 1973 *'' Ophryotrocha magnadentata'' Wiklund et al., 2012 *'' Ophryotrocha mammillata'' Ravara, Marçal, Wiklund & Hilário, 2015 *'' Ophryotrocha mandibulata'' Hilbig & Blake, 1991 *'' Ophryotrocha mediterranea'' Martin, Abello & Cartes, 1991 *'' Ophryotrocha minuta'' Levi, 1954 *'' Ophryotrocha natans'' Pfannenstiel, 1975 *'' Ophryotrocha nauarchus'' Wiklund et al., 2012 *'' Ophryotrocha notialis'' (Ehlers, 1908) *'' Ophryotrocha notoglandulata'' Pfannenstiel, 1972 *'' Ophryotrocha obtusa'' Hilbig & Blake, 1991 *'' Ophryotrocha orensanzi'' Taboada, Wiklund, Glover, Dahlgren, Cristobo & Avila, 2013 *'' Ophryotrocha pachysoma'' Hilbig & Blake, 1991 *'' Ophryotrocha paragerlachi'' Brito & Nunez, 2003 *'' Ophryotrocha paralabidion'' Hilbig & Blake, 1991 *'' Ophryotrocha permanae'' Paxton & Åkesson, 2010 *'' Ophryotrocha platykephale'' Blake, 1985 *'' Ophryotrocha puerilis'' Claparède & Mecznikow, 1869 *'' Ophryotrocha robusta'' Paxton & Åkesson, 2010 *'' Ophryotrocha rubra'' Paxton & Åkesson, 2010 *'' Ophryotrocha sadina'' Ravara, Marçal, Wiklund & Hilário, 2015 *'' Ophryotrocha scarlatoi'' Averincev, 1989 *'' Ophryotrocha schubravyi'' Tsetlin, 1980 *'' Ophryotrocha scutellus'' Wiklund, Glover & Dahlgren, 2009 *'' Ophryotrocha shieldsi'' Paxton & Davey, 2010 *'' Ophryotrocha socialis'' Ockelmann & Akesson, 1990 *'' Ophryotrocha spatula'' Fournier & Conlan, 1994 *'' Ophryotrocha splendida'' Brito & Nunez, 2003 *'' Ophryotrocha vellae'' Paxton & Åkesson, 2010 *'' Ophryotrocha vivipara'' Banse, 1963 *'' Ophryotrocha wubaolingi'' Miura, 1997

Sexual systems

The many species of polychaete worms within the genus ''Ophryotrocha'' exhibit a variety of sexual systems. Distinct species demonstrate different systems, with simultaneous hermaphroditism, gonochorism, and sequential hermaphroditism all documented. The ancestral state of this genus of worms is known to be simultaneous hermaphroditism. Generally, the simultaneous hermaphroditic species are protandrous as adolescents and mate in pairs. The formation of pairs is decided by a long courtship process where partners are linked together in a pseudocopulation. In simultaneous hermaphrodites, each adult has a pair of gonads that produce gametes which are emitted into the water column where external fertilization occurs. After courtship, both simultaneous hermaphroditic individuals repeat the process of egg-laying and fertilizing (known as egg trading to avoid sexual conflict between the two simultaneous hermaphrodites. As with many hermaphroditic species, ''Ophryotrocha'' polychaetes are thought to have evolved simultaneous hermaphroditism as an ancestral state because of lack of mate access to allow sexually viable individuals to produce offspring without sex barriers blocking reproduction opportunities as this genus cannot self-fertilize.

References

{{Authority control Polychaetes Polychaete genera