A new species of Philometra (Nematoda, Philometridae) from the gonads of the rock hind Epinephelus adscensionis (Osteichthyes) from the southern Gulf of Mexico

Abstract

A new species of parasitic nematode, Philometra mexicana sp. nov. (Philometridae), is described based on males and females parasitizing the gonads of the marine perciform fish (rock hind) Epinephelus adscensionis (Osbeck) (Serranidae) off the coast of the southern Gulf of Mexico (reefs of the Enmedio Island, Veracruz), Mexico, collected on 10 April 1990. The new species is characterized mainly by very small males (body length 1.63-1.86 mm) with equally long, needle-like spicules (length 90-120 µm) and the gubernaculum (57-66 µm) without the usual dorsal barb on the distal end, the body length of gravid females (178-230 mm), the presence of a well-developed anterior bulbous inflation on the female oesophagus, and by the length of the first-stage larvae (420-435 µm). A comparison with other congeners parasitizing the gonads of marine fishes is provided. The cephalic end of the gravid female of Philometra margolisi Moravec, Vidal-Martínez et Aguirre-Macedo, 1995, another related species from the gonads of Epinephelus [E. morio (Valenciennes)] in Mexico, has been studied by SEM for the first time; it confirms the arrangement of the cephalic papillae as reported in the original species description. Philometra mexicana is the fifth species of Philometra reported from the gonads of marine fishes in the West Atlantic region.

Some gonad-infecting species of Philometra (Nematoda, Philometridae) from offshore fishes of South Carolina and Georgia, USA, including Philometra charlestonensis sp. nov. from the scamp Mycteroperca phenax

“…Discussion Moravec (2006) listed a total of 16 gonad-infecting species of Philometra, of which P. nemipteri Luo, 2001 was designated a species inquirenda; however, he omitted Philometra neolateolabracis Rajyalakshmi, Hanumantha Rao et Shyamasundari, 1985, a species from the ovary of Johnius argentatus [= Pennahia argentata (Houttuyn)] in India (see Rajyalakshmi et al 1985), which also should be considered a species inquirenda because of its poor description. Three additional species, Philometra mexicana Moravec et Salgado-Maldonado, 2007, P. isaki Quiazon, Yoshinaga et Ogawa, 2008and P. madai Quiazon, Yoshinaga et Ogawa, 2008, were described since (Moravec and Salgado-Maldonado 2007, Quiazon et al 2008), and P. jordanoi (López-Neyra, 1951 was revalidated (Moravec 2008).…”

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

“…are frequently recorded as hosts of philometrid nematodes (Moravec 2006). To date, ten nominal gonad-infecting species of Philometra are known from these hosts, of which two (P. jordanoi and P. serranellicabrillae) occur in the Mediterranean region (Janiszewska 1949;López-Neyra 1951;Merella et al 2005;Moravec et al 2006); two (P. margolisi and P. mexicana) in the Gulf of Mexico (Moravec et al 1995(Moravec et al , 1997(Moravec et al , 2007; one (P. managatuwo) in Japan (Moravec et al 2002); three (P. cyanopodi, P. fasciati and P. piscaria) in New Caledonian waters Justine 2008, 2014); and three (P. indica sp. nov., P. piscaria and P. tropica sp.…”

New philometrids (Nematoda, Philometridae) from head tissues of two serranid fishes (Epinephelus morio and Mycteroperca microlepis) off Florida, northern Gulf of Mexico

“…in different geographical regions. According to Moravec (2006), Moravec and Salgado-Maldonado (2007) and Justine (2008, 2009), to date at least 18 species of Epinephelus were recorded as hosts of nine nominal and several unidentified species of Philometra. In the Gulf of Mexico, three species of Philometra have previously been recorded from Epinephelus spp.…”

“…Comments: At present, Philometra comprises 94 valid species in total (Moravec 2006;Moravec and Salgado-Maldonado 2007;Moravec et al , 2008aMoravec et al , b, c, 2009aJustine 2008, 2009;Quiazon et al 2008a, b;Caspeta-Mandujano et al 2009;Moravec and de Buron 2009b;Moravec and Bakenhaster 2010a, b). These parasites exhibit a relatively high degree of host specificity, and individual species are characterized, in addition to morphological features and molecular sequence data, by the location of gravid females in the host Rohde 1992, Moravec 1994).…”

“…Despite that these parasites are usually pathogenic and occur frequently in commercially important wild and cultured fish hosts (Moravec 2006), the fauna of these nematodes parasitizing marine and brackishwater fishes in the western North Atlantic, including the Gulf of Mexico, is little known. In total, 16 species of Philometra have so far been reported from this region (Moravec 2006;Moravec and Salgado-Maldonado 2007;Moravec et al 2008aMoravec et al , b, 2009aMoravec and Bakenhaster 2010a, b), but records of some of them are probably based on misidentifications (see Petter andRadujković 1989, Moravec 2006).…”