The polystomes (Monogenea, Polystomatidae) radiated across semi-aquatic tetrapods including all t... more The polystomes (Monogenea, Polystomatidae) radiated across semi-aquatic tetrapods including all three amphibian orders, freshwater turtles and the hippopotamus. Prior to this study, phylogenetic analyses revealed that the most diverse and widespread genus, Polystoma, was not monophyletic; a lineage comprising four undescribed species from the bladder of Zhangixalus spp. (Rhacophoridae) in Asia occupied a deep phylogenetic position. Regarding vicariance biogeography and molecular dating, the origin of this lineage is correlated with the breakup of Gondwanaland in the Mesozoic period. Based on a Bayesian analysis of four concatenated genes (18S, 28S, COI and 12S) and morphological evidence, one new genus, Indopolystoma n. gen., and three new species, sampled in Japan and China, are described here: Indopolystoma viridi n. sp. from Z. viridis of Japan, Indopolystoma elongatum n. sp. from Z. arboreus of Japan, and Indopolystoma parvum n. sp. from Z. omeimontis of China. Indopolystoma is unique amongst polystome genera infecting anurans by possessing a small haptor relative to the body size, posteriormost marginal hooklet C1 much bigger than hooklets C2-C8 with conspicuous broad blade and guard and a pair of hamuli lacking a deep notch. Eight species of Asian Polystoma, all from rhacophorids, are transferred as Indopolystoma
The insufficiently known nematode species Philometra filiformis (Stossich, 1896) (Philometridae) ... more The insufficiently known nematode species Philometra filiformis (Stossich, 1896) (Philometridae) is redescribed based on light and scanning electron microscopical (SEM) examinations of specimens collected from the ovaries of the type-host, the common pandora Pagellus erythrinus (Lin-naeus) (Perciformes, Sparidae), from off the Mediter-ranean coast of Tunisia. The male of this species was studied with SEM for the first time, which revealed some new, taxonomically important morphological features. The male posterior end has a caudal mound consisting of two lateral parts widely separated dorsally from each other, four pairs of small adanal papillae, a pair of large but moderately developed papillae located posterior to the cloacal aperture and a pair of small phasmids. The distal end of the guber-naculum is unique among all but one gonad-infecting species of Philometra Costa, 1845 by the chevron-shaped dorsal lamellar structures forming a median longitudinal range. Philometra filiformis is for the first time reported from Tunisian coastal waters, being the seventh philometrid species so far recorded from marine fishes off Tunisia.
Two gonad-infecting species of Philometra Costa, 1845 (Nematoda, Philometridae) were recorded for... more Two gonad-infecting species of Philometra Costa, 1845 (Nematoda, Philometridae) were recorded for the first time from marine perciform fishes off Tunisia and Libya: Philometra rara n. sp. from the rare, deep-water Haifa grouper Hyporthodus haifensis (Serranidae) off Libya and Philometra saltatrix Ramachandran, 1973 from the bluefish Pomatomus saltatrix (Pomatomidae) off Tunisia. Identification of both fish species was confirmed by molecular bar-coding. Light and scanning electron microscope studies of Ph. rara n. sp. showed that it is characterized by the length of spicules (216–219 lm) and the gubernaculum (90–93 lm), the gubernaculum/spicules length ratio (1:2.32–2.43), and mainly by the shape and structure of the distal end of the gubernaculum (shovel-shaped with a wide median smooth field in dorsal view), appearing as having a dorsal protuberance in lateral view, and by the structure of the male caudal mound (dorsally interrupted); large subgravid females (70–137 mm long) are characterized by the presence of four oval submedian cephalic elevations, each of them bearing a pair of cephalic papillae of the outer circle. The finding of Ph. saltatrix off Tunisia confirms that this species is widespread throughout the Mediterranean region. A molecular analysis of our Ph. saltatrix specimens and other available philometrid cytochrome c oxidase 1 (COI) sequences showed that most species have robust clades. Sequences of Ph. saltatrix from Tunisia diverge from Ph. saltatrix from Brazil and the USA, suggesting that speciation is currently occurring between populations from both sides of the Atlantic Ocean.
Diplectanid monogeneans are gill parasites that can infect fish in huge numbers and thus become h... more Diplectanid monogeneans are gill parasites that can infect fish in huge numbers and thus become harmful, especially in maricultured fish. It is therefore useful to have taxonomic tools, such as keys, to identify species. The following diplectanid species from groupers of the Mediterranean Sea were studied: five species of Pseudorhabdosynochus Yamaguti, 1958, including P. riouxi (Oliver, 1986) Kritsky & Beverley-Burton, 1986 from the dusky grou-per Mycteroperca marginata, P. enitsuji Neifar & Euzet, 2007, P. bouaini Neifar & Euzet, 2007, P. dolicocolpos Neifar & Euzet, 2007 and P. sinediscus Neifar & Euzet, 2007 from the goldblotch grouper M. costae, and Echinoplectanum echinophallus (Euzet & Oliver, 1965) Justine & Euzet, 2006 from the dusky grouper. New material was obtained from fish collected from off Tunisia and Libya and compared to the type-material and voucher specimens in museum collections. Identifications of fish were confirmed by barcoding of cytochrome c oxidase subunit I (COI) sequences. The sclerotized vagina was considered the most important structure for systematics. The three species P. riouxi, P. bouaini, and P. enitsuji share a common general structure of the sclerotized vagina with a conspicuous spherical secondary chamber. We thus propose the 'Pseudorhabdosynochus riouxi group' to accommodate them. Pseudorhabdosynochus dolicocolpos has an elongate vaginal structure that is completely different from all its congeneric species reported from the Mediterranean Sea, and Pseudorhabdosynochus sinediscus has a sclerotized vagina in which the secondary chamber is not visible, and a haptor without squamodiscs. A taxonomic key to diplectanid species on Mycteroperca spp. in the Mediterranean Sea is proposed; it includes ten species of Pseudorhabdosynochus and one species of Echinoplectanum.
Pseudorhabdosynochus Yamaguti, 1958 is a species-rich diplectanid genus, mainly restricted to the... more Pseudorhabdosynochus Yamaguti, 1958 is a species-rich diplectanid genus, mainly restricted to the gills of groupers (Epinephelidae) and especially abundant in warm seas. Species from the Mediterranean are not fully documented. Two new and two previously known species from the gills of Mycteroperca spp. (M. costae, M. rubra, and M. marginata) in the Mediterranean and Eastern Atlantic Ocean are described here from new material and slides kept in collections. Identifications of newly collected fish were ascertained by barcod-ing of cytochrome c oxidase subunit I (COI) sequences. Pseudorhabdosynochus beverley-burtonae (Oliver, 1984) Kritsky & Beverley-Burton, 1986 and P. sosia Neifar & Euzet 2007 are redescribed from type-specimens and new specimens collected off Tunisia and Libya from M. marginata and M. costae, respectively. Pseudorhabdosynochus oliveri n. sp., from M. marginata (type-host) off the Mediterranean coast of France (type-locality), is described from specimens found among voucher specimens of P. beverleyburtonae deposited by Guy Oliver in the collection of the Muséum National d'Histoire Naturelle, Paris. Pseudorhabdosy-nochus oliveri is distinguished by the shape of its sclerotised vagina; it was not found in the other localities investigated. Pseudorhabdosynochus hayet n. sp. is described from M. rubra (type host) off Senegal (type-locality) and Tunisia. Pseudorhabdosynochus hayet is morphologically similar to P. sosia (type-host: M. costae) but was distinguished by differences in measurements of the vagina and male copulatory organ, different host, and divergent COI sequences. The four species (P. beverleyburtonae, P. sosia, P. oliveri, and P. hayet) share common characteristics such as squamodiscs with 2 innermost circular rows of rodlets and a similar general structure of the sclerotised vagina; we propose to group them into a 'beverleyburtonae group' within Pseudorhabdosynochus.
Little is known of the diversity of the monogenean parasites infesting deep-sea groupers, and the... more Little is known of the diversity of the monogenean parasites infesting deep-sea groupers, and there is even less information available about their geographic distributions within the ranges of their hosts. To improve our understanding of these host-parasite relationships we conducted parasitological evaluations of the deep-water Haifa grouper Hyporthodus haifensis from the southern Mediterranean off Tunisia and Libya. We collected more than one species of diplectanid monogeneans from this host, but among these only one dominant species was abundant. This proved to be morphologically very similar to Pseudorhabdosynochus sulamericanus Santos, Buchmann & Gibson, 2000, a species originally described from the congeneric host H. niveatus off Brazil and also recorded from H. niveatus and H. nigritus off Florida. Here, we conducted a morphological comparison between newly collected specimens and those previously deposited in museum collections by other authors. Further, we used COI barcoding to ascertain the specific identity of the three host species to better elucidate the circumstances that might explain the unexpectedly broad distribution of P. sulamericanus. We assigned our specimens from H. haifensis to P. sulamericanus primarily on the basis of morphological characteristics of the sclerotized vagina. We also noted morphological characteristics of eastern and western Atlantic specimens that are not clearly described or not given in previous descriptions and so prepared a redescription of the species. We confirmed, by COI barcoding, that no sister-species relationships were evident among the three hosts of P. sulamericanus. Our observation that P. sulamericanus infects unrelated host species with putatively allopatric distributions was unexpected given the very limited dispersive capabilities and the high degree of host specificity common to members of Pseudorhabdosynochus.
– Based on light and scanning electron microscopical studies of nematode specimens (males and mat... more – Based on light and scanning electron microscopical studies of nematode specimens (males and mature females) collected from the ovary of groupers (Serranidae, Perciformes) in the Mediterranean Sea off Tunisia (near Tunis and Sfax), two gonad-infecting species of Philometra Costa, 1845 (Nematoda, Philometridae) are reported: Philometra inexpectata n. sp. from the mottled grouper Mycteroperca rubra and P. jordanoi (López-Neyra, 1951) from the dusky grouper Epinephelus marginatus. Identification of both fish species was confirmed by molecular barcoding. The new species is mainly characterized by the length of equally long spicules (147–165 lm), the guber-naculum (63–93 lm long) bearing at the tip two dorsolateral lamellar parts separated from each other by a smooth median field, a V-shaped mound on the male caudal extremity, the presence of a pair of large caudal papillae located posterior to the cloaca and by the body length of the males (1.97–2.43 mm). Philometra inexpectata n. sp. is the fifth known gonad-infecting philometrid species parasitizing serranid fishes in the Mediterranean region. The males of P. jordanoi were examined by scanning electron microscopy for the first time; this detailed study revealed some new taxonomically important morphological features, such as the number and arrangement of cephalic and caudal papillae, presence of amphids and phasmids and mainly the lamellate structures at the posterior end of the gubernac-ulum. A key to gonad-infecting species of Philometra parasitic in serranid fishes is provided.
Résumé – Deux espèces de Philometra (Nematoda : Philometridae) parasites des gonades de mérous (Serranidae) de Tunisie, avec une clé des espèces de Philometra infectant les gonades des Serranidae. Sur la base d'études, au microscope photonique et électronique, de spécimens de nématodes (mâles et femelles mûres) recueillis dans les ovaires de mérous (Serranidae, Perciformes) de la mer Méditerranée au large de la Tunisie (près de Tunis et Sfax), deux espèces de Philometra Costa, 1845 (Nematoda, Philometridae) parasites de gonades sont signalées : Philometra inexpectata n. sp. du mérou royal Mycteroperca rubra et P. jordanoi (López-Neyra, 1951) du mérou noir Epinephelus marginatus. L'identification des deux espèces de poissons a été confirmée par les codes-barres moléculaires. La nouvelle espèce est caractérisée principalement par la longueur des spicules (147-165 lm), de tailles égales, le gubernaculum (63-93 lm de long) portant à sa pointe deux parties lamellaires dorsolatérales séparées l'une de l'autre par un champ médian lisse, une bosse en forme de V sur l'extrémité caudale du mâle, la présence d'une paire de grandes papilles caudales situées en arrière du cloaque et par la longueur du corps des mâles (
Based on light and electron microscopical studies of males and mature females, two new gonad-infe... more Based on light and electron microscopical studies of males and mature females, two new gonad-infecting species of Philometra Costa, 1845 (Nematoda: Philometridae) are described from the ovary of groupers, Epinephelus spp. (Perciformes; Serranidae), in the Mediterranean Sea off Tunisia (near Sfax): Philometra aenei n. sp. from the white grouper E. aeneus (Geoffroy Saint-Hilaire) and P. tunisiensis n. sp. from the goldblotch grouper E. costae (Steindachner). Identification of both fish hosts was confirmed by barcoding of the infected fish specimens. Philometra aenei is mainly characterised by the length of conspicuously distended spicules (108-123 µm), the presence of a distinct dorsal barb at the middle region of the gubernaculum and a distinct protuberance consisting of two dorsolateral lamellar parts separated from each other by a smooth median field at its distal tip, a V-shaped mound on the male caudal extremity and by the body length of the males (2.34-3.05 mm). The male of this species was found to possess minute deirids in the cervical region, which is quite exceptional within the Philometridae. Philometra tunisiensis is distinguished from other gonad-infecting congeneric species parasitising serranids by the length of the needle-like spicules and gubernaculum (201-219 and 78-87 µm, respectively), spicule length representing 9-11% of body length, the gubernaculum/spicules length ratio of 1:2.52-2.77, the length of oesophagus in the male comprising 15-16% of the body length, the absence of a dorsal protuberance on the distal lamellar part of the gubernaculum and a pair of large papillae posterior to the cloaca, a dorsally interrupted mound on the male caudal extremity and the body length of the male (2.01-2.42 mm). The presence of three morphologically very different species of Philometra in congeneric hosts in the Mediterranean Sea confirms a high degree of host specificity of these gonad-infecting nematodes parasitising groupers.
Pseudorhabdosynochus regius n. sp. is described from the gills of the mottled grouper Mycteroperc... more Pseudorhabdosynochus regius n. sp. is described from the gills of the mottled grouper Mycteroperca rubra caught off Senegal, Tunisia and Libya (type-locality: off Dakar, Senegal). The species is distinguished from its congeners by the structure of its sclerotised vagina (length 26–35 lm), which exhibits a trumpet in continuity with the primary canal, a straight primary canal, and primary and secondary chambers included in a common sclerotised mass along the primary canal. The species is also characterised by small squamodiscs (length 20–40 lm) with 10–11 rows of rodlets. Its closest relatives (based on the structure of the sclerotised vagina) are species mostly found in the Mediterranean Sea and parasites on species of Mycteroperca. A second species of Pseudorhabdosynochus Yamaguti, 1958 is reported from the same host and localities but not described. A list of diplectanids from groupers in the Mediterranean Sea is provided. We point out that a recent article was not compliant with the new Article 8.5.3 of the International Code of Zoological Nomenclature; for this reason, three species, P. nhatrangensis Dang, Bristow, Schander & Berland, 2013, P. vietnamensis Dang et al., 2013 and P. brunei Dang et al., 2013, are invalid.
The polystomes (Monogenea, Polystomatidae) radiated across semi-aquatic tetrapods including all t... more The polystomes (Monogenea, Polystomatidae) radiated across semi-aquatic tetrapods including all three amphibian orders, freshwater turtles and the hippopotamus. Prior to this study, phylogenetic analyses revealed that the most diverse and widespread genus, Polystoma, was not monophyletic; a lineage comprising four undescribed species from the bladder of Zhangixalus spp. (Rhacophoridae) in Asia occupied a deep phylogenetic position. Regarding vicariance biogeography and molecular dating, the origin of this lineage is correlated with the breakup of Gondwanaland in the Mesozoic period. Based on a Bayesian analysis of four concatenated genes (18S, 28S, COI and 12S) and morphological evidence, one new genus, Indopolystoma n. gen., and three new species, sampled in Japan and China, are described here: Indopolystoma viridi n. sp. from Z. viridis of Japan, Indopolystoma elongatum n. sp. from Z. arboreus of Japan, and Indopolystoma parvum n. sp. from Z. omeimontis of China. Indopolystoma is unique amongst polystome genera infecting anurans by possessing a small haptor relative to the body size, posteriormost marginal hooklet C1 much bigger than hooklets C2-C8 with conspicuous broad blade and guard and a pair of hamuli lacking a deep notch. Eight species of Asian Polystoma, all from rhacophorids, are transferred as Indopolystoma
The insufficiently known nematode species Philometra filiformis (Stossich, 1896) (Philometridae) ... more The insufficiently known nematode species Philometra filiformis (Stossich, 1896) (Philometridae) is redescribed based on light and scanning electron microscopical (SEM) examinations of specimens collected from the ovaries of the type-host, the common pandora Pagellus erythrinus (Lin-naeus) (Perciformes, Sparidae), from off the Mediter-ranean coast of Tunisia. The male of this species was studied with SEM for the first time, which revealed some new, taxonomically important morphological features. The male posterior end has a caudal mound consisting of two lateral parts widely separated dorsally from each other, four pairs of small adanal papillae, a pair of large but moderately developed papillae located posterior to the cloacal aperture and a pair of small phasmids. The distal end of the guber-naculum is unique among all but one gonad-infecting species of Philometra Costa, 1845 by the chevron-shaped dorsal lamellar structures forming a median longitudinal range. Philometra filiformis is for the first time reported from Tunisian coastal waters, being the seventh philometrid species so far recorded from marine fishes off Tunisia.
Two gonad-infecting species of Philometra Costa, 1845 (Nematoda, Philometridae) were recorded for... more Two gonad-infecting species of Philometra Costa, 1845 (Nematoda, Philometridae) were recorded for the first time from marine perciform fishes off Tunisia and Libya: Philometra rara n. sp. from the rare, deep-water Haifa grouper Hyporthodus haifensis (Serranidae) off Libya and Philometra saltatrix Ramachandran, 1973 from the bluefish Pomatomus saltatrix (Pomatomidae) off Tunisia. Identification of both fish species was confirmed by molecular bar-coding. Light and scanning electron microscope studies of Ph. rara n. sp. showed that it is characterized by the length of spicules (216–219 lm) and the gubernaculum (90–93 lm), the gubernaculum/spicules length ratio (1:2.32–2.43), and mainly by the shape and structure of the distal end of the gubernaculum (shovel-shaped with a wide median smooth field in dorsal view), appearing as having a dorsal protuberance in lateral view, and by the structure of the male caudal mound (dorsally interrupted); large subgravid females (70–137 mm long) are characterized by the presence of four oval submedian cephalic elevations, each of them bearing a pair of cephalic papillae of the outer circle. The finding of Ph. saltatrix off Tunisia confirms that this species is widespread throughout the Mediterranean region. A molecular analysis of our Ph. saltatrix specimens and other available philometrid cytochrome c oxidase 1 (COI) sequences showed that most species have robust clades. Sequences of Ph. saltatrix from Tunisia diverge from Ph. saltatrix from Brazil and the USA, suggesting that speciation is currently occurring between populations from both sides of the Atlantic Ocean.
Diplectanid monogeneans are gill parasites that can infect fish in huge numbers and thus become h... more Diplectanid monogeneans are gill parasites that can infect fish in huge numbers and thus become harmful, especially in maricultured fish. It is therefore useful to have taxonomic tools, such as keys, to identify species. The following diplectanid species from groupers of the Mediterranean Sea were studied: five species of Pseudorhabdosynochus Yamaguti, 1958, including P. riouxi (Oliver, 1986) Kritsky & Beverley-Burton, 1986 from the dusky grou-per Mycteroperca marginata, P. enitsuji Neifar & Euzet, 2007, P. bouaini Neifar & Euzet, 2007, P. dolicocolpos Neifar & Euzet, 2007 and P. sinediscus Neifar & Euzet, 2007 from the goldblotch grouper M. costae, and Echinoplectanum echinophallus (Euzet & Oliver, 1965) Justine & Euzet, 2006 from the dusky grouper. New material was obtained from fish collected from off Tunisia and Libya and compared to the type-material and voucher specimens in museum collections. Identifications of fish were confirmed by barcoding of cytochrome c oxidase subunit I (COI) sequences. The sclerotized vagina was considered the most important structure for systematics. The three species P. riouxi, P. bouaini, and P. enitsuji share a common general structure of the sclerotized vagina with a conspicuous spherical secondary chamber. We thus propose the 'Pseudorhabdosynochus riouxi group' to accommodate them. Pseudorhabdosynochus dolicocolpos has an elongate vaginal structure that is completely different from all its congeneric species reported from the Mediterranean Sea, and Pseudorhabdosynochus sinediscus has a sclerotized vagina in which the secondary chamber is not visible, and a haptor without squamodiscs. A taxonomic key to diplectanid species on Mycteroperca spp. in the Mediterranean Sea is proposed; it includes ten species of Pseudorhabdosynochus and one species of Echinoplectanum.
Pseudorhabdosynochus Yamaguti, 1958 is a species-rich diplectanid genus, mainly restricted to the... more Pseudorhabdosynochus Yamaguti, 1958 is a species-rich diplectanid genus, mainly restricted to the gills of groupers (Epinephelidae) and especially abundant in warm seas. Species from the Mediterranean are not fully documented. Two new and two previously known species from the gills of Mycteroperca spp. (M. costae, M. rubra, and M. marginata) in the Mediterranean and Eastern Atlantic Ocean are described here from new material and slides kept in collections. Identifications of newly collected fish were ascertained by barcod-ing of cytochrome c oxidase subunit I (COI) sequences. Pseudorhabdosynochus beverley-burtonae (Oliver, 1984) Kritsky & Beverley-Burton, 1986 and P. sosia Neifar & Euzet 2007 are redescribed from type-specimens and new specimens collected off Tunisia and Libya from M. marginata and M. costae, respectively. Pseudorhabdosynochus oliveri n. sp., from M. marginata (type-host) off the Mediterranean coast of France (type-locality), is described from specimens found among voucher specimens of P. beverleyburtonae deposited by Guy Oliver in the collection of the Muséum National d'Histoire Naturelle, Paris. Pseudorhabdosy-nochus oliveri is distinguished by the shape of its sclerotised vagina; it was not found in the other localities investigated. Pseudorhabdosynochus hayet n. sp. is described from M. rubra (type host) off Senegal (type-locality) and Tunisia. Pseudorhabdosynochus hayet is morphologically similar to P. sosia (type-host: M. costae) but was distinguished by differences in measurements of the vagina and male copulatory organ, different host, and divergent COI sequences. The four species (P. beverleyburtonae, P. sosia, P. oliveri, and P. hayet) share common characteristics such as squamodiscs with 2 innermost circular rows of rodlets and a similar general structure of the sclerotised vagina; we propose to group them into a 'beverleyburtonae group' within Pseudorhabdosynochus.
Little is known of the diversity of the monogenean parasites infesting deep-sea groupers, and the... more Little is known of the diversity of the monogenean parasites infesting deep-sea groupers, and there is even less information available about their geographic distributions within the ranges of their hosts. To improve our understanding of these host-parasite relationships we conducted parasitological evaluations of the deep-water Haifa grouper Hyporthodus haifensis from the southern Mediterranean off Tunisia and Libya. We collected more than one species of diplectanid monogeneans from this host, but among these only one dominant species was abundant. This proved to be morphologically very similar to Pseudorhabdosynochus sulamericanus Santos, Buchmann & Gibson, 2000, a species originally described from the congeneric host H. niveatus off Brazil and also recorded from H. niveatus and H. nigritus off Florida. Here, we conducted a morphological comparison between newly collected specimens and those previously deposited in museum collections by other authors. Further, we used COI barcoding to ascertain the specific identity of the three host species to better elucidate the circumstances that might explain the unexpectedly broad distribution of P. sulamericanus. We assigned our specimens from H. haifensis to P. sulamericanus primarily on the basis of morphological characteristics of the sclerotized vagina. We also noted morphological characteristics of eastern and western Atlantic specimens that are not clearly described or not given in previous descriptions and so prepared a redescription of the species. We confirmed, by COI barcoding, that no sister-species relationships were evident among the three hosts of P. sulamericanus. Our observation that P. sulamericanus infects unrelated host species with putatively allopatric distributions was unexpected given the very limited dispersive capabilities and the high degree of host specificity common to members of Pseudorhabdosynochus.
– Based on light and scanning electron microscopical studies of nematode specimens (males and mat... more – Based on light and scanning electron microscopical studies of nematode specimens (males and mature females) collected from the ovary of groupers (Serranidae, Perciformes) in the Mediterranean Sea off Tunisia (near Tunis and Sfax), two gonad-infecting species of Philometra Costa, 1845 (Nematoda, Philometridae) are reported: Philometra inexpectata n. sp. from the mottled grouper Mycteroperca rubra and P. jordanoi (López-Neyra, 1951) from the dusky grouper Epinephelus marginatus. Identification of both fish species was confirmed by molecular barcoding. The new species is mainly characterized by the length of equally long spicules (147–165 lm), the guber-naculum (63–93 lm long) bearing at the tip two dorsolateral lamellar parts separated from each other by a smooth median field, a V-shaped mound on the male caudal extremity, the presence of a pair of large caudal papillae located posterior to the cloaca and by the body length of the males (1.97–2.43 mm). Philometra inexpectata n. sp. is the fifth known gonad-infecting philometrid species parasitizing serranid fishes in the Mediterranean region. The males of P. jordanoi were examined by scanning electron microscopy for the first time; this detailed study revealed some new taxonomically important morphological features, such as the number and arrangement of cephalic and caudal papillae, presence of amphids and phasmids and mainly the lamellate structures at the posterior end of the gubernac-ulum. A key to gonad-infecting species of Philometra parasitic in serranid fishes is provided.
Résumé – Deux espèces de Philometra (Nematoda : Philometridae) parasites des gonades de mérous (Serranidae) de Tunisie, avec une clé des espèces de Philometra infectant les gonades des Serranidae. Sur la base d'études, au microscope photonique et électronique, de spécimens de nématodes (mâles et femelles mûres) recueillis dans les ovaires de mérous (Serranidae, Perciformes) de la mer Méditerranée au large de la Tunisie (près de Tunis et Sfax), deux espèces de Philometra Costa, 1845 (Nematoda, Philometridae) parasites de gonades sont signalées : Philometra inexpectata n. sp. du mérou royal Mycteroperca rubra et P. jordanoi (López-Neyra, 1951) du mérou noir Epinephelus marginatus. L'identification des deux espèces de poissons a été confirmée par les codes-barres moléculaires. La nouvelle espèce est caractérisée principalement par la longueur des spicules (147-165 lm), de tailles égales, le gubernaculum (63-93 lm de long) portant à sa pointe deux parties lamellaires dorsolatérales séparées l'une de l'autre par un champ médian lisse, une bosse en forme de V sur l'extrémité caudale du mâle, la présence d'une paire de grandes papilles caudales situées en arrière du cloaque et par la longueur du corps des mâles (
Based on light and electron microscopical studies of males and mature females, two new gonad-infe... more Based on light and electron microscopical studies of males and mature females, two new gonad-infecting species of Philometra Costa, 1845 (Nematoda: Philometridae) are described from the ovary of groupers, Epinephelus spp. (Perciformes; Serranidae), in the Mediterranean Sea off Tunisia (near Sfax): Philometra aenei n. sp. from the white grouper E. aeneus (Geoffroy Saint-Hilaire) and P. tunisiensis n. sp. from the goldblotch grouper E. costae (Steindachner). Identification of both fish hosts was confirmed by barcoding of the infected fish specimens. Philometra aenei is mainly characterised by the length of conspicuously distended spicules (108-123 µm), the presence of a distinct dorsal barb at the middle region of the gubernaculum and a distinct protuberance consisting of two dorsolateral lamellar parts separated from each other by a smooth median field at its distal tip, a V-shaped mound on the male caudal extremity and by the body length of the males (2.34-3.05 mm). The male of this species was found to possess minute deirids in the cervical region, which is quite exceptional within the Philometridae. Philometra tunisiensis is distinguished from other gonad-infecting congeneric species parasitising serranids by the length of the needle-like spicules and gubernaculum (201-219 and 78-87 µm, respectively), spicule length representing 9-11% of body length, the gubernaculum/spicules length ratio of 1:2.52-2.77, the length of oesophagus in the male comprising 15-16% of the body length, the absence of a dorsal protuberance on the distal lamellar part of the gubernaculum and a pair of large papillae posterior to the cloaca, a dorsally interrupted mound on the male caudal extremity and the body length of the male (2.01-2.42 mm). The presence of three morphologically very different species of Philometra in congeneric hosts in the Mediterranean Sea confirms a high degree of host specificity of these gonad-infecting nematodes parasitising groupers.
Pseudorhabdosynochus regius n. sp. is described from the gills of the mottled grouper Mycteroperc... more Pseudorhabdosynochus regius n. sp. is described from the gills of the mottled grouper Mycteroperca rubra caught off Senegal, Tunisia and Libya (type-locality: off Dakar, Senegal). The species is distinguished from its congeners by the structure of its sclerotised vagina (length 26–35 lm), which exhibits a trumpet in continuity with the primary canal, a straight primary canal, and primary and secondary chambers included in a common sclerotised mass along the primary canal. The species is also characterised by small squamodiscs (length 20–40 lm) with 10–11 rows of rodlets. Its closest relatives (based on the structure of the sclerotised vagina) are species mostly found in the Mediterranean Sea and parasites on species of Mycteroperca. A second species of Pseudorhabdosynochus Yamaguti, 1958 is reported from the same host and localities but not described. A list of diplectanids from groupers in the Mediterranean Sea is provided. We point out that a recent article was not compliant with the new Article 8.5.3 of the International Code of Zoological Nomenclature; for this reason, three species, P. nhatrangensis Dang, Bristow, Schander & Berland, 2013, P. vietnamensis Dang et al., 2013 and P. brunei Dang et al., 2013, are invalid.
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Papers by Amira Chaabane
Résumé – Deux espèces de Philometra (Nematoda : Philometridae) parasites des gonades de mérous (Serranidae) de Tunisie, avec une clé des espèces de Philometra infectant les gonades des Serranidae. Sur la base d'études, au microscope photonique et électronique, de spécimens de nématodes (mâles et femelles mûres) recueillis dans les ovaires de mérous (Serranidae, Perciformes) de la mer Méditerranée au large de la Tunisie (près de Tunis et Sfax), deux espèces de Philometra Costa, 1845 (Nematoda, Philometridae) parasites de gonades sont signalées : Philometra inexpectata n. sp. du mérou royal Mycteroperca rubra et P. jordanoi (López-Neyra, 1951) du mérou noir Epinephelus marginatus. L'identification des deux espèces de poissons a été confirmée par les codes-barres moléculaires. La nouvelle espèce est caractérisée principalement par la longueur des spicules (147-165 lm), de tailles égales, le gubernaculum (63-93 lm de long) portant à sa pointe deux parties lamellaires dorsolatérales séparées l'une de l'autre par un champ médian lisse, une bosse en forme de V sur l'extrémité caudale du mâle, la présence d'une paire de grandes papilles caudales situées en arrière du cloaque et par la longueur du corps des mâles (
rubra caught off Senegal, Tunisia and Libya (type-locality: off Dakar, Senegal). The species is distinguished from
its congeners by the structure of its sclerotised vagina (length 26–35 lm), which exhibits a trumpet in continuity with
the primary canal, a straight primary canal, and primary and secondary chambers included in a common sclerotised
mass along the primary canal. The species is also characterised by small squamodiscs (length 20–40 lm) with 10–11
rows of rodlets. Its closest relatives (based on the structure of the sclerotised vagina) are species mostly found in the
Mediterranean Sea and parasites on species of Mycteroperca. A second species of Pseudorhabdosynochus Yamaguti,
1958 is reported from the same host and localities but not described. A list of diplectanids from groupers in the Mediterranean
Sea is provided. We point out that a recent article was not compliant with the new Article 8.5.3 of the International
Code of Zoological Nomenclature; for this reason, three species, P. nhatrangensis Dang, Bristow, Schander &
Berland, 2013, P. vietnamensis Dang et al., 2013 and P. brunei Dang et al., 2013, are invalid.
Résumé – Deux espèces de Philometra (Nematoda : Philometridae) parasites des gonades de mérous (Serranidae) de Tunisie, avec une clé des espèces de Philometra infectant les gonades des Serranidae. Sur la base d'études, au microscope photonique et électronique, de spécimens de nématodes (mâles et femelles mûres) recueillis dans les ovaires de mérous (Serranidae, Perciformes) de la mer Méditerranée au large de la Tunisie (près de Tunis et Sfax), deux espèces de Philometra Costa, 1845 (Nematoda, Philometridae) parasites de gonades sont signalées : Philometra inexpectata n. sp. du mérou royal Mycteroperca rubra et P. jordanoi (López-Neyra, 1951) du mérou noir Epinephelus marginatus. L'identification des deux espèces de poissons a été confirmée par les codes-barres moléculaires. La nouvelle espèce est caractérisée principalement par la longueur des spicules (147-165 lm), de tailles égales, le gubernaculum (63-93 lm de long) portant à sa pointe deux parties lamellaires dorsolatérales séparées l'une de l'autre par un champ médian lisse, une bosse en forme de V sur l'extrémité caudale du mâle, la présence d'une paire de grandes papilles caudales situées en arrière du cloaque et par la longueur du corps des mâles (
rubra caught off Senegal, Tunisia and Libya (type-locality: off Dakar, Senegal). The species is distinguished from
its congeners by the structure of its sclerotised vagina (length 26–35 lm), which exhibits a trumpet in continuity with
the primary canal, a straight primary canal, and primary and secondary chambers included in a common sclerotised
mass along the primary canal. The species is also characterised by small squamodiscs (length 20–40 lm) with 10–11
rows of rodlets. Its closest relatives (based on the structure of the sclerotised vagina) are species mostly found in the
Mediterranean Sea and parasites on species of Mycteroperca. A second species of Pseudorhabdosynochus Yamaguti,
1958 is reported from the same host and localities but not described. A list of diplectanids from groupers in the Mediterranean
Sea is provided. We point out that a recent article was not compliant with the new Article 8.5.3 of the International
Code of Zoological Nomenclature; for this reason, three species, P. nhatrangensis Dang, Bristow, Schander &
Berland, 2013, P. vietnamensis Dang et al., 2013 and P. brunei Dang et al., 2013, are invalid.