Pseudorhabdosynochus quadratus n. sp. (Monogenea: Diplectanidae) from the white-streaked grouper Epinephelus ongus (Bloch) (Perciformes: Serranidae) off New Caledonia

Abstract

Pseudorhabdosynochus quadratus n. sp. is described from three specimens collected from the gills of a rarely examined fish, the white-streaked grouper Epinephelus ongus (Bloch), caught off Nouméa, New Caledonia. The description is based on Berlese slides and observations of live specimens; the soft parts are not described in detail. The species is characterised by a compact, sclerotised vagina with a robust trumpet, short primary canal, two closely associated chambers linked by a very short secondary canal and small accessory structure.

Parasite Fauna of the White-Streaked Grouper (Epinephelus ongus) from the Thousand Islands, Java, Indonesia

“…Parasites of this genus are usually host specific and very common in groupers [49] with P. quadratus having been described from E. ongus from New Caledonia in the past [33]. The high infestation of these diplectanid monogeneans coincides with findings of other studies [28,33,34]. Another generalist was the ectoparasite Alcirona sp.…”

“…Demand for E. ongus has increased steadily [28,29], also based on landings of E. ongus in Indonesia (Karimunjawa) [28,30]. With only seven previous studies on the parasite fauna of E. ongus in South-East Asia and Australia [28,[31][32][33][34][35][36], we herewith sample this fish species from the Thousand Islands archipelago in close proximity to the heavily polluted Jakarta Bay. Our objectives for this study are to assess the transmission risk of parasites from E. ongus to cogeners and vice versa and to determine parasite-borne health risks of E. ongus to consumers in terms of food safety and to mariculture fish.…”

Are all species of Pseudorhabdosynochus strictly host specific? — A molecular study

“…Euzet & Combes [24] discussed the problem of species in parasites and remarked that most monogeneans are strictly host-specific ("oioxenous specificity") but rejected the description of new species of parasites on the simple basis of their recovery from a new species of host. Several genera of monopisthocotylean monogeneans include many species: these include the gyrodactylid Gyrodactylus [25], the dactylogyrids Anacanthorus [26] and Dactylogyrus [27], the ancyrocephalids Haliotrema [28,29], Haliotrematoides [30] and Ligophorus [31], and the diplectanids Lamellodiscus [23,[32][33][34] and Pseudorhabdosynochus [1][2][3][4][5][6][7][8][9]20,[35][36][37][38]. Strict or non-strict host specificity does not follow a regular pattern within genera; if…”

Parasite fauna of white-streaked grouper, Epinephelus ongus (Bloch, 1790) (Epinephelidae) from Karimunjawa, Indonesia

“…The parasite identification was conducted by using taxonomic keys and original descriptions. For the ectoparasitic monogeneans the literature consulted was provided by Whittington et al (2001) and Schoelinck and Justine (2011), for the copepods by Ho and Dojiri (1977); Schmidt and Roberts (1989); Boxshall and Halsey (2004) and Ho and Lin (2004) and for the isopods by Kensley and Schotte (1989). Identification literature of endoparasites was provided by Bray and Cribb (1989) for the digeneans, by Palm (2004) for cestodes, and by Anderson et al (2009); Gibbons (2010) and Dewi and Palm (2013) for nematodes.…”

“…In contrast, not a single parasite was documented for E. ongus from Indonesian waters. So far, only three monogeneans, Pseudorhabdosynochus summanae (Young, 1969) (synonym: Diplectanum summanae Kritsky and Beverley-Burton, 1986), P. quadratus (Schoelinck and Justine, 2011) and Benedenia fieldsi (Deveney and Whittington, 2010) as well as two digeneans, Pearsonellum corventum (Lester and Sewell, 1989; Overstreet and Køie, 1989) and Lepidapedoides angustus (Bray et al 1996), have been recorded for this epinephelid. The present study is the first comprehensive analysis of the parasite fauna of E. ongus worldwide, discussing: (1) the infection pattern, (2) the use of the documented parasite community as environmental indicator and (3) the potential risk of parasite transmission into mariculture systems and vice versa.…”