Philometra is a genus of nematodes, a parasite of marine and freshwater fishes.
Species in this genus are worldwide. They parasitize the body cavities, tissues and ovaries of both marine and freshwater fishes. When still in the larval stages, these worms move to the body cavities or subcutaneous tissues in the host. This migration can cause damage to skeletal joints, result in internal bleeding, and inflame visceral organs. Emaciation and lowered growth rates may result from this.
Infestation produces nodules under the skin. When the worms are in the adult or juvenile stage, these nodules may be visible between the rays of the fins or may cause the scales to raise up. Larger nodules may be the result of gravid females which may rupture the skin surface. Once ruptured, the female disintegrates. This allows the release of the live larvae into the water. This wound on the fish then heals, leaving almost no scarring.
Species of Philometra require two hosts to complete their lifecycle. After the larval worms are released from the host fish, they are ingested by copepods which act as an intermediate host. Once inside the copepod, the larvae molt several times. Fish may then eat the infested copepod.
This genus is known to parasitize numerous species of fish, including:
Blacktip grouperHerring scadBigeye scadThe following species are recognized by the World Register of Marine Species:
Philometra gerrei Moravec & Manoharan, 2013Philometra globiceps (Rudolphi, 1819)Philometra lagocephali Moravec & Justine, 2008Philometra onchorhynchi Kuitinen-Ekbaum, 1933Philometra otolithi Moravec & Manoharan, 2013Philometra ovata (Zeder, 1803)Philometra priacanthi Moravec & Justine, 2009Philometra rischta Skrjabin, 1917Philometra rubra (Leidy, 1856)Philometra saltatrix Ramachandran, 1973Philometra sanguinea (Rudolphi, 1819)Philometra scombresoxis Nikolaeva & Naidenova, 1964Philometra sphyraenae Moravec & Manoharan, 2013Philometra tauridica Ivashkin, Naidenova, Kovaleva & Khromova, 1971Philometra translucida Walton, 1927Philometra brevicollis Moravec & Justine, 2011Philometra carolinensis Moravec, de Buron & Roumillat, 2006Philometra cephalus Ramachandran, 1975Philometra charlestonensis Moravec, de Buron, Baker & González-Solís, 2008Philometra cyanopodi Moravec & Justine, 2008Philometra cynoscionis Moravec, de Buron & Roumillat, 2006Philometra fasciati Moravec & Justine, 2008Philometra filiformis (Stossich, 1896)Philometra floridensis Moravec, Fajer-Avila & Bakenhaster, 2010Philometra genypteri Moravec, Chávez & Olivia, 2011Philometra gymnothoracis Moravec & Buron, 2009Philometra inimici Yamaguti, 1941Philometra isaki Quiazon, Yoshinaga & Ogawa, 2008Philometra jordanoi (López-Neyra, 1951)Philometra justinei Moravec, Ternengo & Levron, 2006Philometra katsuwoni Petter & Baudin-Laurencin, 1986Philometra lateolabracis (Yamaguti, 1935)Philometra lethrini Moravec & Justine, 2008Philometra macroandri (Shchepkina, 1978)Philometra madai Quiazon, Yoshinaga & Ogawa, 2008Philometra managatuwo Yamaguti, 1941Philometra margolisi Moravec, et al., 1995Philometra mexicana Moravec & Salgado-Maldonado, 2007Philometra mira Moravec & Justine, 2011Philometra nemipteri Luo, 2001Philometra neolateolabracis Rajyalakshmi, Hanumantha Rao & Shyamasundari, 1985Philometra neptomeni Mateo, 1972Philometra obladae Moravec, Gaglio, Panebianco & Giannetto, 2008Philometra obturans (Prennant, 1886)Philometra ocularis Moravec, Ogawa, Suzuki, Miyazaki & Donai, 2002Philometra overstreeti Moravec & de Buron, 2006Philometra pellucida (Jägerskiöld, 1893)Philometra rajani Mukherjee, 1963Philometra sciaenae Yamaguti, 1941Philometra scomberomori (Yamaguti, 1935)Philometra sebastisci Yamaguti, 1941Philometra serranellicabrillae Janiszewska, 1949Philometra strongylurae Moravec & Ali, 2005Philometra tenuicauda Moravec & Justine, 2009Philometra terapontis Moravec, Gopalakrishnan, Rajkumar, Saravanakumar & Kaliyamoorthy, 2011Philometra tylosuri Moravec & Ali, 2005