A synthesis of our current knowledge of philometrid nematodes, a group of increasingly important fish parasites

First description of male Philometra thaiensis Moravec, Fiala et Dyková, 2004 (Nematoda: Philometridae) from the body cavity of the eyespot pufferfish Tetraodon biocellatus Tirant, and evolutionary relationships of this species with other dracunculoids as inferred from SSU rRNA gene sequences

“…Molecular taxonomy has raised some major points regarding the taxonomical positions of some genera within the dracunculoids. Despite the diverging ideas among different reports on the taxonomical relationship between Philometra and Philometroides species, a common conclusion remains that the genera Philometra and Philometroides should be re-evaluated and that the importance of using molecular tools in parallel with morphological identification cannot be overemphasized for philometrids (Moravec & de Buron, 2013). The suggestion of re-evaluation is strongly supported by the generated phylogenetic tree in the present study, wherein no clear separation between other Philometra spp.…”

“…With the remarkable size difference between the tiny males (up to 12 mm for Philometra katsuwoni Petter et Baudin-Laurencin, 1986) (Moravec, 2006) and large gravid females (up to 530 mm for Philometroides seriolae [Ishii, 1931] (Quiazon et al, 2010)), most of the identified species are known only from female specimens. Currently, there are 29 philometrid species in Asia (including Piscinema barakense Gambhir et Ng, 2014 [species inquirendum]) that infect freshwater fishes (from 6 genera: Clavinema Yamaguti, 1935; Dentiphilometra González-Solís, Moravec et Tuz Paredes, 2007;Dentirumai Quiazon et Moravec, 2012;Philometra Costa, 1845;Philometroides Yamaguti, 1935;Piscinema Gambhir et Ng, 2014 [genus inquirendum]) and 45 species that infect marine and brackish-water fishes (from 7 genera: Buckleyella Rasheed, 1963; Clavinema; Clavinemoides Moravec, Khosheghbal et Pazooki, 2013;Paraphilometroides Moravec et Shaharom-Harrison, 1989;Philometra;Philometroides;and Spirophilometra Parukhin, 1971) (Gambhir & Ng, 2014;Moravec, 2014;Moravec & de Buron, 2013;Moravec & Ali, 2014;Quiazon & Yoshinaga, 2013). Philometrid nematodes affecting fish reproduction belong to the genus Philometra.…”

“…Philometrid nematodes affecting fish reproduction belong to the genus Philometra. In Japan, the discovery of males of the gonad-infecting P. lateolabracis (Yamaguti, 1935) from the type host and locality resulted in further re-identifications of many previously misidentified P. lateolabracis from the other host fishes (Quiazon et al, 2008a;Moravec & de Buron, 2013). The morphological differences among males compared to females are very useful for species identification, especially among congeneric species.…”

Philometra dissimilis n. sp. from the ovary of Johnius belangerii (Sciaenidae) and other new records of philometrids (Nematoda: Philometridae) from fishes of the Bay of Bengal, India

“…At present, 67 gonad-infecting species of Philometra are known to parasitize marine fi shes (Moravec & de Buron, 2013;Quiazon & Yoshinaga, 2013;Moravec & Diggles, 2014aMoravec & Justine, 2014Moravec & Manoharan, 2014a, b;Moravec & Barton, 2015). However, as indicated by some recent studies of these nematodes from marine fi shes, they exhibit a high degree of host specifi city, when different morphologically well-distinguishable species of Philometra are recorded from different species of congeneric hosts in the same locality (Moravec & Manoharan, 2014a, b;Moravec et al, , 2016b.…”

Gonad-infecting species of Philometra (Nematoda: Philometridae) from groupers Epinephelus spp. (Osteichthyes: Serranidae) in the Bay of Bengal, India

“…Gonad-infecting species of Philometra Costa, 1845 (Philometridae, Dracunculoidea) are common parasites of a variety of marine fishes belonging to different families (Moravec 2006;Moravec and de Buron 2013). Although twelve nominal species of these nematodes have been reported from the region of the Indian Ocean, only seven of them can be considered to be correctly identified and valid (Moravec and Manoharan 2013;Moravec and Ali 2014).…”