A new gonad-infecting species of Philometra (Nematoda: Philometridae) from the red cusk-eel Genypterus chilensis (Osteichthyes: Ophidiidae) off Chile

Abstract

A new nematode species, Philometra genypteri sp. n. (Philometridae), is described from male and female specimens found in the ovary of red cusk-eel, Genypterus chilensis (Guichenot) (Ophidiidae, Ophidiiformes), from the eastern South Pacific Ocean off the coast of northern Chile. Based on light and scanning electron microscopy examination, the new species differs from most other gonad-infecting Philometra spp. in the length of spicules (126-135 μm), a gubernaculum with dorsal lamella-like structures on its distal end, and the number and arrangement of genital papillae in the male. From a few congeneric, gonad-infecting species with unknown males, it can be distinguished by some morphological and biometrical features found in gravid female (absence of caudal projections, length of first-stage larvae or oesophagus, moderately developed anterior oesophageal inflation) and by the host type (fish family) and geographical distribution. P. genypteri is the first philometrid species reported from a fish belonging to the order Ophidiiformes and the second nominal species of Philometra recorded from marine fishes of the eastern South Pacific.

Philometra chilensis (Nematoda, Philometridae) affects the fecundity of the red cusk-eel, Genypterus chilensis (Guichenot) (Pisces, Ophidiidae) in Chile

“…Specimens of Philometra chilensis were recorded only in ten mature fish females caught in April (see Moravec et al 2011) when the highest proportion of mature females was found (96.4%). Proportion of mature females for February and September was 67.7% and 80.7%, respectively.…”

Occurrence and consequence of the parasitic nematode Philometra piscaria (Moravec & Justine, 2014) on Epinephelus coioides (Hamilton, 1822) from the southeast coast of India

“…Moravec et al [6] reported a new gonad-infecting species of Philometra genypteri from the red cuskeel Genypterus chilensis off Chile and Philometra sp. in Johnius belengerii having 48% of infection.…”

“…High infections by these nematode parasites on both wild and cultured fishes have been recorded in many economically important species of Perciforms [2][3][4]. The large sized females of these nematodes are usually highly pathogenic, causing serious damages to the fish ovaries and affecting fish reproduction, which were recorded by Moravec and Bakenhaster [5], Moravec et al [6], and Moravec and Justine [7]. Parasitic species in the fish ovary is lethargically distributed to our knowledge mainly in the subtropical and tropical regions of the Indo-Pacific and so far it has been reported from the Indian Ocean.…”

Philometra johnii sp. nov. (Nematoda, Philometridae), a new gonad-infecting philometrid from the sin croaker Johnius dussumieri (Cuvier) (Perciformes, Sciaenidae) from marine waters of Iraq

“…At present, 36 gonad-infecting species of Philometra are known to infect marine and brackish-water fishes (Moravec and Manoharan 2013 Moravec et Manoharan, 2013, P. lateolabracis (Yamaguti, 1935, P. madai Quiazon, Yoshinaga et Ogawa, 2008, P. nemipteri Luo, 2001, P. priacanthi Moravec et Justine, 2009, P. saltatrix Ramachandran, 1973, P. sciaenae Yamaguti, 1941, P. scomberomori (Yamaguti, 1935 and P. terapontis Moravec, Gopalakrishnan, Rajkumar, Saravanakumar et Kaliyamoorthy, 2011 (see Quiazon et al 2008a, b;Moravec andJustine 2009, 2011;Moravec et al 2008Moravec et al , 2011aMoravec and Manoharan 2013). Of these, a distinct dorsal protuberance near the distal extremity of the gubernaculum, which occurs in the new species, is also present only in P. gerrei, P. lateolabracis, P. priacanthi and P. terapontis.…”