<Emphasis Type="Italic">Pseudorhabdosynochus quadratus</Emphasis> n. sp. (Monogenea: Diplectanidae) from the white-streaked grouper <Emphasis Type="Italic">Epinephelus ongus</Emphasis> (Bloch) (Perciformes: Serranidae) off New Caledonia

Gill diplectanid monogeneans from the camouflage grouper Epinephelus polyphekadion (Bleeker) collected in the coral reef lagoon of New Caledonia, South Pacific, comprise four species. Very few monogeneans were found in most fish examined. Pseudorhabdosynochus dionysos n. sp. has a sclerotised vagina with a robust trumpet, a robust primary canal and two chambers of similar size; it is close to P. bacchus Sigura, Chauvet & Justine, 2007. P. viscosus n. sp. has a sclerotised vagina with a robust trumpet, long primary canal with an extremely thin wall and two small chambers, and a male quadriloculate organ with a characteristic thickening at the extremity of its cone. P. crassus n. sp., the most abundant species, has a sclerotised vagina with a thin-walled trumpet, thin-walled primary canal which is always coiled anteriorly and two small chambers. P. huitoe Justine, 2007, P. manifestus Justine & Sigura, 2007 and P. crassus have very similar sclerotised vaginae; however, species of this ‘huitoe complex’ can be distinguished by measurements of the haptoral hard parts. A few diplectanid specimens found in a single specimen of E. polyphekadion were attributed to P. huitoe, a species originally described from E. maculatus (Bloch) and also rarely found in E. cyanopodus Richardson in New Caledonia; specimens from these three fish species are morphologically indistinguishable.     

Four species of Pseudorhabdosynochus (Monogenea: Diplectanidae) from the camouflage grouper Epinephelus polyphekadion (Perciformes: Serranidae) off New Caledonia

Gill diplectanid monogeneans from the camouflage grouper Epinephelus polyphekadion (Bleeker) collected in the coral reef lagoon of New Caledonia, South Pacific, comprise four species. Very few monogeneans were found in most fish examined. Pseudorhabdosynochus dionysos n. sp. has a sclerotised vagina with a robust trumpet, a robust primary canal and two chambers of similar size; it is close to P. bacchus Sigura, Chauvet & Justine, 2007. P. viscosus n. sp. has a sclerotised vagina with a robust trumpet, long primary canal with an extremely thin wall and two small chambers, and a male quadriloculate organ with a characteristic thickening at the extremity of its cone. P. crassus n. sp., the most abundant species, has a sclerotised vagina with a thin-walled trumpet, thin-walled primary canal which is always coiled anteriorly and two small chambers. P. huitoe Justine, 2007, P. manifestus Justine & Sigura, 2007 and P. crassus have very similar sclerotised vaginae; however, species of this 'huitoe complex' can be distinguished by measurements of the haptoral hard parts. A few diplectanid specimens found in a single specimen of E. polyphekadion were attributed to P. huitoe, a species originally described from E. maculatus (Bloch) and also rarely found in E. cyanopodus Richardson in New Caledonia; specimens from these three fish species are morphologically indistinguishable.     

A redescription of Pseudorhabdosynochus epinepheli (Yamaguti, 1938), the type-species of Pseudorhabdosynochus Yamaguti, 1958 (Monogenea: Diplectanidae), and the description of P. satyui n. sp. from Epinephelus akaara off Japan

Pseudorhabdosynochus epinepheli (Yamaguti, 1938) has been recorded from a variety of hosts, mainly groupers. All type-specimens of Diplectanum epinepheli Yamaguti, 1938, Pseudorhabdosynochus epinepheli Yamaguti, 1958 and Cycloplectanum hongkongensis Beverley-Burton & Suriano, 1981 are figured: it is concluded, as did Kritsky & Beverley-Burton (1986), that the three species are synonymous. In addition, numerous monogenean specimens from a deep-sea grouper, Epinephelus chlorostigma, collected off New Caledonia, South Pacific, were prepared using various methods and described. These specimens are also conspecific with P. epinepheli (Yamaguti, 1938) and represent a new geographical record. This species has a sclerotised vagina with a very characteristic primary chamber. The simultaneous presence of P. lantauensis (Beverley-Burton & Suriano, 1981) and P. epinepheli was noted in both type-slides of D. epinepheli from Japan (host: E. akaara) and C. hongkongensis from Hong Kong (host: E. bruneus). Several causes are suspected for the alleged ‘generalist’ character of P. epinepheli, including the misidentification of either fish or monogeneans and the accidental exchanges of monogeneans between fishes of different species kept alive in the same tank. Finally, the confirmed list of hosts of P. epinepheli includes E. akaara, E. awoara and E. chlorostigma; it is suggested that the latter, a widespread deep-sea fish, serves as a reservoir for the infection of the other species, which are associated with shallow waters. P. satyui n. sp. is described from two specimens found on slides from E. akaara (from the Inland Sea of Japan) deposited by Yamaguti; the new species has a sclerotised vagina with characteristic spherical chambers.

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Résumé   Pseudorhabdosynochus epinepheli (Yamaguti, 1938) a été mentionné chez différents h?tes, surtout des mérous. Tous les spécimens-types de Diplectanum epinepheli Yamaguti, 1938, Pseudorhabdosynochus epinepheli Yamaguti, 1958 et Cycloplectanum hongkongensis Beverley-Burton & Suriano, 1981 sont figurés, et on conclut, comme Kritsky & Beverley-Burton (1986), que les trois espèces sont synonymes. De plus, de nombreux spécimens de monogènes collectés chez un mérou de profondeur, Epinephelus chlorostigma, de Nouvelle-Calédonie, Pacifique Sud, ont été préparés avec des méthodes variées. Ces spécimens sont aussi conspécifiques de P. epinepheli (Yamaguti, 1938) et la Nouvelle-Calédonie représente une nouvelle mention géographique. L’espèce a une vagin sclérifié avec une chambre primaire très caractéristique. La présence simultanée de P. lantauensis (Beverley-Burton & Suriano, 1981) et P. epinepheli a été notée dans les lames-types de D. epinepheli du Japon (h?te, E. akaara) et de C. hongkongensis de Hong-Kong (h?te, E. bruneus). Plusieurs causes sont soup?onnées pour le caractère prétendument ‘généraliste’ de P. epinepheli, dont les mauvaises identifications de poissons, des monogènes, et l’échange accidentel de monogènes chez des poissons gardés vivants ensemble dans un même contenant. Finalement, la liste des h?tes confirmés de P. epinepheli comprend E. akaara, E. awoara et E. chlorostigma. On fait l’hypothèse que E. chlorostigma, espèce de profondeur, a servi de réservoir pour l’infestation des autres espèces, plus associées aux eaux peu profondes. P. satyui n. sp. est décrit de deux spécimens trouvés dans des lames de parasites de E. akaara (de la mer intérieure du Japon) déposées par Yamaguti. La nouvelle espèce a un vagin sclérifié avec des chambres sphériques caractéristiques.

     

<Emphasis Type="Italic">Pseudorhabdosynochus hirundineus</Emphasis> n. sp. (Monogenea: Diplectanidae) from <Emphasis Type="Italic">Variola louti</Emphasis> (Perciformes: Serranidae) off New Caledonia

Pseudorhabdosynochus hirundineus n. sp. is described from specimens collected from the gills of Variola louti off Nouméa, New Caledonia, South Pacific. No diplectanid was found on V. albimarginata from the same location. The male sclerotised quadriloculate organ of P. hirundineus is 42 μm in internal length, with a long posterior tube; and the sclerotised vagina, 36 μm in length, is composed of a long tube with anterior open trumpet and two posterior, heavily sclerotised chambers. The two squamodiscs, each with 11–15 rows of rodlets and no central closed row of rodlets, are dissimilar in shape, the ventral being round and the dorsal being oval. By the morphology of its sclerotised vagina, P. hirundineus appears close to P. epinepheli (Yamaguti, 1938) but it is differentiated from it by the shape of its squamodiscs. Pseudorhabdosynochus spp. previously recorded from epinephelines are parasites of species of Epinephelus and Mycteroperca; this is the first species from a species of Variola.

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Résumé Résumé Pseudorhabdosynochus hirundineus n. sp. est décrit de spécimens récoltés sur les branchies de Variola louti au large de Nouméa, Nouvelle Calédonie, Pacifique sud. Aucun Diplectanidae n’a été trouvé chez V. albimarginata de la même origine. L’organe mâle sclérifié tétraloculé de P. hirundineus mesure 42μm de longueur interne et a un long tube postérieur, et le vagin sclérifié, long de 36μm, est composé d’un long tube avec une trompe antérieure et deux chambres postérieures très sclérifiées. Les deux squamodisques, chacun avec 11–15 rangées d’osselets et sans rangée close, sont de formes différentes, le ventral rond et le dorsal ovale. Par la morphologie de son vagin sclérifié, P. hirundineus semble proche de P. epinepheli (Yamaguti, 1938), mais s’en distingue par la forme de ses squamodisques. Les espèces de Pseudorhabdosynochus mentionnées auparavant chez les Epinephelinae étaient parasites d’espèces des genres Epinephelus et Mycteroperca; ceci est la première espèce chez Variola.

     

Parasite biodiversity in a coral reef fish: twelve species of monogeneans on the gills of the grouper Epinephelus maculatus (Perciformes: Serranidae) off New Caledonia, with a description of eight new species of Pseudorhabdosynochus (Monogenea: Diplectanidae)

Coral reefs are known for their high level of biodiversity, but parasite biodiversity has not been evaluated. Cases such as Epinephelus maculatus, described here, show that the numerical estimation of parasite biodiversity in coral reefs could reach more than ten times the number of fish species; consequently, the extinction of certain fish species from endangered coral reefs would result in the co-extinction of at least ten times the number of parasite species. E. maculatus is a grouper of intermediate size (1-2 kg) and common in the coral reefs of New Caledonia, South Pacific. Based on the examination of more than 800 monogenean specimens, 12 species of monogeneans (ten diplectanids and two ancyrocephalids) were differentiated on the gills. These species of diplectanids have not been found in other epinephelines in the same area and thus are considered as specific to this host. In addition, three species of copepods, and isopod larvae, are present on the gills; E. maculatus thus has a total of 16 species of gill ectoparasites, which can be found together on a single individual fish. Diplectanids include Laticola dae Journo & Justine, 2006, which is the most abundant species representing about 50% of the specimens, and nine species which are rare, each representing 2-7% of the specimens: Diplectanum uitoe n. sp. and eight species of Pseudorhabdosynochus Yamaguti, 1958. D. uitoe, provisionally attributed to Diplectanum Diesing, 1858, is characterised by a small conical penis with internal walls. Pseudorhabdosynochus auitoe n. sp., P. buitoe n. sp., P. cuitoe n. sp., P. duitoe n. sp., P. euitoe n. sp. and P. fuitoe n. sp. are differentiated on the basis of the morphology of the sclerotised vagina, but are very similar in other characteristics; P. guitoe n. sp. is characterised by a quadriloculate organ with very thick walls and a very small sclerotised vagina; and P. huitoe n. sp. is characterised by its sclerotised vagina and by very long ventral and dorsal haptoral bars. Two rare (2-3% of specimens) ancyrocephalids, Haliotrema epinepheli Young, 1969 and Haliotrema sp., are briefly described in relation to the male copulatory organs and haptoral bars; H. epinepheli is apparently a generalist species found in various epinephelines and other fish species. A table of the 50 species of diplectanids (Pseudorhabdosynochus, Laticola Yang et al., 2006, Echinoplectanum Justine & Euzet, 2006 and Diplectanum) from serranids is provided.     

Laticola dae n. sp. (Monogenea: Diplectanidae) from Epinephelus maculatus (Perciformes: Serranidae) off New Caledonia

Laticola dae n. sp. is described from specimens collected from the gill-filaments of the highfin grouper Epinephelus maculatus, a coral reef fish caught off Nouméa, New Caledonia, South Pacific. The species is characterised by a spoon-shaped sclerotised male copulatory organ, with four thin walls and 73–m in outer length, and a sclerotised vagina in form of a disc, 16–m in diameter, with a smaller hemisphere on one side. Laticola Yang et al., 2006 was described to accommodate diplectanids from Lates calcarifer (Centropomidae); this is the first Laticola described from a serranid. Other diplectanids, including several species of Pseudorhabdosynochus Yamaguti, 1958, were also found on the same species of fish; specimens of L. dae represented about half of the diplectanids collected; all other species were rare.

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Résumé Laticola dae n. sp. est décrit à partir de spécimens collectés sur les filaments branchiaux de la loche grisette, Epinephelus maculatus, un poisson de récif corallien pêché au large de Nouméa, Nouvelle-Calédonie, Pacifique Sud. L’espèce est caractérisée par un organe copulateur mâle sclérifié en forme de cuiller, avec quatre parois fines, long de 73–m, et un vagin sclérifié en forme de disque, de diamètre 16–m, avec un hémisphère plus petit d’un côté. Laticola Yang et al., 2006 a été décrit pour rassembler des Diplectanidae de Lates calcarifer (Centropomidae) ; ceci est le premier Laticola décrit d’un Serranidae. D’autres Diplectanidae, y compris plusieurs espèces de Pseudorhabdosynochus, ont aussi été trouvés chez ce poisson ; les spécimens de L. dae représentaient environ la moitié des Diplectanidae récoltés, toutes les autres espèces étaient rares.

     

Monogeneans of the grouper Epinephelus tauvina (Perciformes, Serranidae) off Moorea, French Polynesia, with a description of Pseudorhabdosynochus pai n. sp. (Monogenea: Diplectanidae)

Specimens of the greasy grouper Epinephelus tauvina (Forssk?l), caught off Moorea, French Polynesia, harboured four species of gill monogeneans. The diplectanid Pseudorhabdosynochus pai n. sp. is characterised by an extremely big male quadriloculate organ (inner length 77 μm, cone length 15, tube length 47), the largest of all members of the genus, and a sclerotised vagina with a very complex structure, including three secondary chambers instead of one as in most species. Pseudorhabdosynochus sp. is a species of the ‘cupatus group’; this species is not formally described but various measurements are provided. The ancyrocephalid Haliotrema sp. and the capsalid Benedenia sp. were rare; they are both mentioned but not described. The diplectanid fauna of E. tauvina corresponds to the pattern already found in a clade of grouper species, the members of which often harbour both a species of the ‘cupatus group’ and another species of Pseudorhabdosynochus Yamaguti, 1958.

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Résumé  Des spécimens du mérou Epinephelus tauvina (Forssk?l) pêchés à Moorea, Polynésie Fran?aise, hébergeaient quatre espèces de monogènes sur les branchies. Le Diplectanidae Pseudorhabdosynochus pai n. sp. est caractérisé par un organe tétraloculé male de très grande taille (longueur interne 77 μm, longueur du c?ne 15, longueur du tube 47), le plus grand de toutes les espèces du genre, et un vagin sclérifié à structure très complexe, comprenant trois chambres secondaires, au lieu d’une comme c’est le cas chez la plupart des autres espèces. Pseudorhabdosynochus sp. est une espèce du ‘groupe cupatus’ qui n’est pas formellement décrite, mais des mesures sont indiquées. Un Ancyrocephalidae, Haliotrema sp., et un Capsalidae, Benedenia sp., étaient rares, et sont mentionnés mais non décrits. La faune des Diplectanidae de E. tauvina correspond au patron déjà trouvé dans un clade d’espèces de mérous, dont les membres hébergent souvent à la fois une espèce du ‘groupe cupatus’ et une autre espèce de Pseudorhabdosynochus Yamaguti, 1958.

     

Pseudorhabdosynochus summanoides n. sp. (Monogenea: Diplectanidae) from Epinephelus coioides in Dapeng Bay, South China Sea, with observations on several similar species of Pseudorhabdosynochus Yamaguti, 1958

One new species of diplectanid monogenean, Pseudorhabdosynochus summanoides n. sp., is reported and described from the marine fish Epinephelus coioides off Nan’ao Shenzhen, China. P. summanoides differs from its closest relative, P. summanae (Young, 1968), by the shape of its vaginal hard-parts, which have a tightly twisted distal region and an accessory patch on the proximal curve. During the course of this work, type-material of several species of Pseudorhabdosynochus was examined and aspects of the vagina and haptor are redescribed and/or figured. These species include P. americanus (Price, 1937), P. hargisi (Oliver & Paperna, 1984), P. amplidiscatus (Bravo-Hollis, 1954), P. epinepheli (Yamaguti, 1938), P. riouxi (Oliver 1986), P. melanesiensis (Laird, 1958), P. cupatus (Young, 1969), P. bocquetae (Oliver & Paperna, 1984), P. kritskyi Dyer et al., 1995, P. capurroi Vidal-Martinez, 1998, P. querni (Yamaguti, 1968) and P. summanae (Young, 1969). Several closely related species are considered in terms of their conspecificity: P. hargisi is proposed as a junior synonym of P. americanus; P. capurroi is suggested as a likely synonym of P. kritskyi; and it is suggested that P. cupatus and P. bocquetae may eventually be demonstrated to be consepcific with P. melanesiensis.     

Pseudorhabdosynochus venus n. sp. (Monogenea: Diplectanidae) from Epinephelus howlandi (Perciformes: Serranidae) off New Caledonia

Pseudorhabdosynochus venus n. sp. is described from specimens collected from the gills of Epinephelus howlandi off Nouméa, New Caledonia, South Pacific. The male sclerotised quadriloculate organ of P. venus, 61–101 μm in internal length, has an anterior chamber with a thin anterior wall, a very short cone and a short posterior tube. The sclerotised vagina, 50–67 μm in total length, is composed of an anterior open trumpet, an S-shaped canal, a tear-shaped principal chamber and a spherical accessory chamber; all parts are heavily sclerotised. The two squamodiscs have 10–11 rows of separate rodlets and no central closed row of rodlets. P. venus is differentiated from all other species of Pseudorhabdosynochus by the spectacular morphology of its sclerotised vagina. It is the first diplectanid described from E. howlandi.

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Résumé Pseudorhabdosynochus venus n. sp. est décrit à partir de spécimens collectés sur les branchies de Epinephelus howlandi, pêché au large de Nouméa, Nouvelle-Calédonie, Pacifique Sud. L’organe tétraloculé sclérifié mâle de P. venus (longueur interne 61–101 μm), possède une chambre antérieure avec une fine paroi antérieure, un cône très court, et un tube postérieur court. Le vagin sclérifié, long de 50–67 μm, est composé d’une trompette antérieure ouverte, d’un canal en S, d’une chambre principale en larme, et d’une chambre accessoire sphérique; toutes les parties sont fortement sclérifiées. Les deux squamodisques ont 10–11 rangées d’osselets séparés, sans rangée centrale fermée. P. venus se différencie de toutes les autres espèces de Pseudorhabdosynochus par la morphologie spectaculaire de son vagin sclérifié. Il s’agit du premier Diplectanidae décrit chez E. howlandi.

     

Pseudorhabdosynochus spp. (Monogenea: Diplectanidae) from the gills of Epinephelus spp. in Brazilian waters

Pseudorhabdosynochus sulamericanus n. sp. from the gills of Epinephelus niveatus has a reniform proximal region of the cirrus-bulb which is divided in four chambers and contains a large, round reservoir of the male accessory glands, a partly sclerotised vagina which is enclosed in a muscular funnel cap and squamodiscs with 15–16 open concentric rows of elements. P. beverleyburtonae (Oliver, 1984) is redescribed from E. marginatus with additional morphological data. These are the first reports of Pseudorhabdosynochus spp. in South American Atlantic waters, where the potentiality for the mariculture of Epinephelus spp. is currently being evaluated. Pseudorhabdosynochus hargisi (Oliver & Paperna, 1984) n. comb. is proposed for Diplectanum hargisi.     

Pseudorhabdosynochus argus n. sp. (Monogenea: Diplectanidae) from Cephalopholis argus, P. minutus n. sp. and Diplectanum nanus n. sp. from C. sonnerati and other monogeneans from Cephalopholis spp. (Perciformes: Serranidae) off Australia and New Caledonia

Monogeneans from three species of Cephalopholis, namely C. argus, C. sonnerati and C. boenak, are described from fish caught off New Caledonia, South Pacific, with comparisons with material from off Queensland, Australia. Pseudorhabdosynochus argus n. sp. from C. argus is present off New Caledonia and Australia; it is characterised by its male quadriloculate organ with very elongate cone, and its sclerotised vagina with anterior trumpet, coiled primary canal and distal part with two chambers and an accessory part. C. boenak has no monogeneans off New Caledonia, but off Australia it harbours Pseudorhabdosynochus sp., a new species which is morphologically related to P. argus. P. minutus n. sp. from C. sonnerati is characterised by its minute body and a sclerotised vagina with two spherical chambers. Diplectanum nanus n. sp. from C. sonnerati is characterised by its very small funnel-shaped male copulatory organ and minute body. A new species, Haliotrema sp. from C. sonnerati is characterised by a very elongate tubular penis; it is distinct from H. cromileptis Young, 1968 (redescribed herein from specimens collected from Cromileptes altivelis off New Caledonia). The species described here include the first members of Pseudorhabdosynochus and the first diplectanids described from species of Cephalopholis. There is no evidence for a clade of Pseudorhabdosynochus species specific to members of Cephalopholis, since the species described here share similarities with other species from Epinephelus. However, it is suggested that the gill structure of Cephalopholis spp. imposes selection toward small body sizes for monogeneans.     

Bucephaline digeneans (Bucephalidae) in <Emphasis Type="Italic">Sphyraena putnamae</Emphasis> Jordan &; Seale (Sphyraenidae) from the lagoon off New Caledonia

Lethrinitrema gibbus n. g., n. sp. and L. dossenus n. sp. are described from the fish Lethrinus rubrioperculatus Sato collected off New Caledonia, South Pacific. Members of Lethrinitrema n. g. (Ancyrocephalidae) are characterised by having two pyriform haptoral reservoirs and ventral anchors with lateral grooves. The elongate tubular distal end of each reservoir bifurcates, draining into a superficial lateral groove on each side of the ventral anchors. The haptoral reservoirs are postulated to store secretory products which assist in attachment to the host. Lethrinitrema spp. also possess tandem gonads, a male copulatory organ without an accessory piece or with thinly sclerotised accessory piece, and a dextrolateral, non-sclerotised vaginal bulb. The two new species have small, poorly demarcated haptors with small haptoral armament and a crown-like piece on the tip of the inner root of the ventral anchors. They differ from each other in the shape and size of the ventral bar and male copulatory organ (40–45 μm in length in L. gibbus vs 24–30 μm in L. dossenus). Three other species, previously included in Haliotrema Johnston & Tiegs, 1922, are transferred to Lethrinitrema, i.e. L. chrysostomi (Young, 1968) n. comb., L. fleti (Young, 1968) n. comb. (both briefly redescribed from paratypes) and L. lethrini (Yamaguti, 1937) n. comb. All species of Lethrinitrema parasitise Lethrinus spp. (Lethrinidae), and there is evidence for the existence of further Lethrinitrema spp. on Lethrinus spp. in the Indo-Pacific region.     

Some monogenean parasites of the generaCalceostoma van Beneden, 1852 andDiplectanum Diesing, 1858 fromArgyrosomus hololepidotus (Lacepède, 1802) (Sciaenidae: Teleostei) in Western Australia

The taxonomy of three species of monogeneans from the gills ofArgyrosomus hololepidotus is detailed.Calceostoma glandulosum is redescribed and compared to previously unpublished morphometric data onC. calceostoma collected from Tunis and the Gulf of Gascogne. Two species of the genusDiplectanum,D. oliveri n. sp. andD. glandulosum n. sp. differ from other closely related diplectanids in a range of morphological characters but most importantly in the different size and morphology of the penis.     

A new species of <Emphasis Type="Italic">Triloculotrema</Emphasis> Kearn, 1993 (Monogenea: Monocotylidae) from a deep-sea shark,the blacktailed spurdog <Emphasis Type="Italic">Squalus melanurus</Emphasis> (Squaliformes: Squalidae), off New Caledonia

Triloculotrema chisholmae n. sp. is described from three specimens collected from the nasal tissues of a deep-sea shark, the blacktailed spurdog Squalus melanurus Fourmanoir & Rivaton, caught off New Caledonia, South Pacific. The new species is distinguished from the only other and type-species of the genus, T. japanicae Kearn, 1993, by the morphology of the sclerotised male copulatory organ (shorter and straight versus curved) and shorter hamuli.

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Résumé   Triloculotrema chisholmae n. sp. est décrit à partir de trois spécimens récoltés dans les tissus nasaux d’un requin de profondeur, l’aiguillat à queue noire Squalus melanurus Fourmanoir & Rivaton, pêché au large de la Nouvelle-Calédonie, Pacifique Sud. La nouvelle espèce est distinguée de l’espèce-type et seule autre espèce du genre, T. japanicae Kearn, 1993, par la morphologie de l’appareil copulateur male sclérifié (plus court, et droit au lieu de courbe), et par des hamuli plus courts.

     

The ‘Pseudorhabdosynochus cupatus group’ (Monogenea: Diplectanidae) on Epinephelus fasciatus, E. howlandi, E. rivulatus and E. merra (Perciformes: Serranidae) off New Caledonia, with descriptions of Pseudorhabdosynochus cyathus n. sp. and P. calathus n. sp.

Pseudorhabdosynochus cupatus (Young, 1969) is characterised by small lamellosquamodiscs made up of central telescopic rings and peripheral rows of rodlets, and a sclerotised vagina in the shape of a thin-walled coiled tube with three accessory chambers. Two new species of Pseudorhabdosynochus are herein described from epinepheline fish off New Caledonia, South Pacific, and are considered part of the 'P. cupatus group'. P. cyathus n. sp. from Epinephelus howlandi has lamellosquamodiscs made up of four telescopic rings and four rows of separate rodlets; there are dorsal tegumental scales. This species was found only in young hosts; older hosts harbour P. venus Hinsinger & Justine, 2006. P. calathus n. sp. from Epinephelus rivulatus has lamellosquamodiscs made up of four telescopic rings and five rows of separate rodlets; the tegument is smooth. The three species, P. cupatus, P. calathus and P. cyathus, are strictly species specific; although morphologically very similar, they can be distinguished by features of the tegumental scales and measurements of the vagina and haptoral hard parts. P. melanesiensis (Laird, 1958) from E. merra is close to the 'P. cupatus group' according to the morphology of its sclerotised vagina but is distinguished by its squamodiscs which lack telescopic rings. Rare specimens found in E. merra are tentatively attributed to P. coioidesis Bu et al., 1999. A paratype of P. coioidesis is figured for comparison. E. merra, E. fasciatus, E. rivulatus and E. howlandi each have a Pseudorhabdosynochus species of the P. cupatus lineage: these are the dominant species in each host. In addition, E. merra, E. fasciatus and E. howlandi harbour a rare species of Pseudorhabdosynochus, respectively P. cf. coioidesis, P. caledonicus Justine, 2005 and P. venus; these rare species are morphologically unrelated to each other and to the 'P. cupatus group'.     

Diplectanum squamatum n.sp. (Monogenea:Diplectanidae) fro the gills of Cynoscion guatucupa (Sciecidae) in southwest Atlantic waters

Diplectanum squamatum n. sp. is described from the gills of the sciaenid Cynoscion guatucupa collected off Mar del Plata, Argentina. The new species is distinguished from other species of the genus by the morphology of the hamuli and the male copulatory organ, and presence of scales on the haptor and body. This is the first species of Diplectanum to be reported from southwest Atlantic waters and, with the possible exception of D. cayennense Euzet & Durette-Desset, 1974, the only species from the Atlantic coast of South America.     

<Emphasis Type="Italic">Diplectanocotyla</Emphasis> Yamaguti, 1953 (Monogenea: Diplectanoidea) from <Emphasis Type="Italic">Megalops cyprinoides</Emphasis> (Broussonet) (Teleostei: Megalopidae) off Peninsular Malaysia

Two known and two new species of Diplectanocotyla Yamaguti, 1953 (D. gracilis Yamaguti, 1953, D. megalopis Rakotofiringa & Oliver, 1987, D. langkawiensis n. sp. and D. parva n. sp.) were collected from Megalops cyprinoides (Megalopidae) off Langkawi, Kedah and Matang, Perak, Peninsular Malaysia. All four species possess similar types of sclerotised male and female reproductive structures and similar soft anatomical features. The squamodisc sclerites of all four species have spine-like projections with varying degrees of visibility and shapes (sharp-pointed to triangular). In D. megalopis and D. langkawiensis n. sp. the spines are sharp-pointed and distinct on sclerites from rows 5–6 onwards. In D. gracilis and D. parva n. sp. the sclerite spines are triangular, lightly sclerotised and occur on almost all of the sclerites. D. parva n. sp. has comparatively the smallest set of anchors, bars, squamodiscs and squamodisc suckers. The anchors and bars of the other three species are almost similar in overall size, and the main distinguishing feature is the relative lengths of the inner and outer roots of the ventral anchors. In D. gracilis the outer root is very much smaller than the inner root and they are disposed almost at a right angle to each other. In D. megalopis the outer root is usually about half the length of the inner root and the roots are inclined at c.60° to each other. In D. langkawiensis n. sp. the roots are inclined at c.40° degrees and the outer root is of a similar length or only slightly shorter than the inner root. The openings of the two squamodisc suckers of all four Diplectanocotyla species are surrounded by tiny scale-like spines. Bifid tegumental spines are found in the posterior region of all four species, differing only in their extent: in D. parva n. sp. the tegumental spines are only distributed in the peduncular region and not beyond, whilst in the other three species the tegumental spines extend from the posterior level of the testis to the end of the peduncle. An amended diagnosis of Diplectanocotyla and a key to its species are appended.     

Didymozoid trematodes (including new genera and species) from marine fishes of the Waltair coast,Bay of Bengal

Summary Fifteen species of didymozoid trematodes are recorded form marine fishes off the Waltair coast, Bay of Bengal, India. These include three new genera, namely, Platocystoides, Indodidymozoon and Renodidymocystis and six new species, namely, Didymozoon lobatum from Euthynnus affinis, Allodidymozoon cylindricum from Sphyraena obtusata and S. picuda, A. operculare from Sphyraena obtusata and S. picuda, Indodidymozzon platycephali from Platycephalus scaber, Renodidymocystis yamagutii from Rastrelliger kanagurta and Metanematobothrioides branchialis from Pristipomoides typus. Other species reported are: Didymocystis wedli Ariola, 1902, Coeliodidymocystis kamegaii Yamaguti, 1970, Platocystoides polyaster (Job, 1962), Neometadidymozoon polymorphis (Oshmarin & Mamaev, 1963), Lobatocystis yaito Yamaguti, 1965, Metadidymozoon branchiale Yamaguti, 1970; Allonematobothrium epinepheli Yamaguti, 1965; Gonapodasmius spilonotopteri Yamaguti, 1970 and Pseudocolocyntotrema yaito Yamaguti, 1970. Two new combinations made are: Allodidymozoon apharyngi (Job, 1961) for Didymozoon apharyngi Job, 1961 and Platocystoides polyaster (Job, 1962) for Platocystis polyaster Job, 1962.     

Two new species of Pseudorhabdosynochus Yamaguti, 1958 (Monogenea: Diplectanidae) from the deep-sea grouper Epinephelus morrhua (Val.) (Perciformes: Serranidae) off New Caledonia

Three species of monogeneans were collected from Epinephelus morrhua, a deep-sea grouper from the external slope of the coral reef, off New Caledonia, South Pacific, and are the first parasites recorded from this fish species. Pseudorhabdosynochus morrhua n. sp. is characterised by: a sclerotised vagina with small sclerotised chambers and a short secondary canal; squamodiscs with central rows of rodlets which form closed ovals; and a scaly tegument. P. variabilis n. sp. has: a male quadriloculate organ with a characteristic structure; a sclerotised vagina in which the primary canal, secondary canal and accessory structure are very long and the different parts have various arrangements in different specimens; its squamodiscs have central rows of rodlets which form closed circles; and a smooth tegument. A prominent vaginal structure, comparable to that of P. variabilis, has been found only in P. dolicocolpos Neifar & Euzet, 2007, but the species can be distinguished by details of the vagina and other structures. A species of Haliotrema Johnson & Tiegs, 1922 (Ancyrocephalidae) is reported but not described. Specimens of each of the three species were present in similar numbers.