Specimens of two undescribed and one known gonad-infecting species of Philometra Costa, 1845 (Nematoda: Philometridae) were collected in some marine fishes from off the southern coast of Iraq. Based on light and scanning electron microscopy, the following new species are described: Philometra tayeni n. sp. (males and nongravid females) from ovaries of the purple-spotted bigeye Priacanthus tayenus Richardson (Priacanthidae, Acanthuriformes), and Philometra nibeae n. sp. (males and gravid female) from the ovary of the blotched croaker Nibea maculata (Bloch et Schneider) (Sciaenidae, Acanthuriformes). Philometra tayeni is mainly characterised by a pair of postanal papillae and a V-shaped caudal mound in males and by their body lengths (2.42-2.99 mm), whereas P. nibeae differs from its gonad-infecting congeners parasitising scienids mainly based on the body length of males (2.29-2.49 mm) and their spicules (96-117 µm), absence of a pair of postanal papillae and shape of caudal mound consisting of two parts. Philometra piscaria Moravec & Justine, 2014 (males and nongravid females), a parasite of the orange-spotted grouper Epinephelus coioides (Hamilton) (Epinephelidae, Perciformes), is recorded from the Arabian (= Persian) Gulf for the first time; previously unknown females of this species are described.

• MeSH
• Dracunculoidea * MeSH
• Species Specificity MeSH
• Gonads parasitology   MeSH
• Nematoda * MeSH
• Microscopy, Electron, Scanning MeSH
• Fish Diseases * parasitology   MeSH
• Perciformes * parasitology   MeSH
• Bass * parasitology   MeSH
• Fishes MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Iraq MeSH

Nematodes of the family Philometridae Baylis & Daubney, 1926 (Dracunculoidea Stiles, 1907) are generally poorly known, and there are many taxonomic issues within the family. Philometrids are parasites of fish and are found in various locations throughout the host, including within the subcutaneous tissues and musculature, the abdominal cavity and gonads; vast sexual dimorphism often means the males are not collected, leading to many species being described solely on female characteristics. Although there have been a number of studies utilising molecular data, the vast majority of species are yet to be sequenced. This study undertook genetic sequencing of 15 recently described species of philometrids across 4 genera, many of which were from specimens collected from waters off Australia. All of the sequences obtained were closely related with representatives of the family Philometridae. Species were found to be distributed in the phylogenetic trees within 4 clades based on a combination of site of infection within the host and host habitat. Family of host and geographical location was not as important for position within the trees. Clade A contained philometrids collected from the abdominal cavities and head tissues of South American freshwater fish. Clade B contained philometrids primarily from the abdominal cavities of freshwater European cyprinids. Clade C contained philometrids primarily from the ovaries of marine fish. Clade D contained philometrids from the body tissues of marine and freshwater fish. The potential co-evolutionary patterns between philometrids and their fish hosts are highlighted as an area of future research. This research also highlighted the importance of correct identification of any sequenced specimen.

• Keywords
• Fish parasites, Molecular, Philometridae, Phylogeny,
• MeSH
• Dracunculoidea * MeSH
• Phylogeny MeSH
• Fish Diseases * MeSH
• RNA, Ribosomal, 18S MeSH
• Fishes MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• RNA, Ribosomal, 18S MeSH

Based on light and scanning electron microscopical studies, three new species of philometrids (Nematoda: Philometridae) are described from females collected in marine perciform fishes off the northern coast of Australia: Philometra gracilis n. sp. and Philometroides branchiarum n. sp. from tissues behind the gills and gill arches, respectively, of the John's snapper Lutjanus johnii (Bloch) (Lutjanidae), and Philometroides stomachicus n. sp. from the stomach wall of the blackspotted croaker Protonibea diacanthus (Lacépède) (Sciaenidae). Philometra gracilis differs from other congeners described from the Lutjanidae mainly in the presence of large caudal projections, short gravid females (28-42 mm long), the oesophageal gland extending anteriorly far anterior to the level of the nerve-ring, the site in the host and its geographical distribution. Philometroides branchiarum is mainly characterised by the possession of conspicuous, sclerotised oesophageal teeth and very short gravid females (6-8 mm long), whereas P. stomachicus can be differentiated by the body length of gravid females (85-90 mm), the length of the oesophagus (2.67 mm) representing 3% of the body length, the maximum width/body length ratio of gravid females (1:28-32), cuticular bosses densely distributed throughout the body but absent from the oesophageal region, the absence of oesophageal teeth and caudal projections, and the site in the host. The presence of P. gracilis and P. branchiarum in L. johnii and that of P. stomachicus in P. diacanthus confirm the possibility of the coexistence of more philometrid species in different sites within sympatric specimens of one and the same definitive host.

• MeSH
• Dracunculoidea anatomy & histology   classification   MeSH
• Species Specificity MeSH
• Microscopy, Electron, Scanning MeSH
• Perciformes parasitology   MeSH
• Gills parasitology   MeSH
• Animals MeSH
• Check Tag
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Australia MeSH
• Pacific Ocean MeSH

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 μm), the gubernaculum (63-93 μm 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 gubernaculum. A key to gonad-infecting species of Philometra parasitic in serranid fishes is provided.

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 μm), de tailles égales, le gubernaculum (63-93 μm 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 (1.97-2.43 mm). Philometra inexpectata n. sp. est la cinquième espèce de Philometridae des gonades de poissons Serranidae dans la région méditerranéenne. Les mâles de P. jordanoi ont été examinés par microscopie électronique à balayage pour la première fois ; cette étude détaillée a révélé quelques nouvelles caractéristiques morphologiques taxinomiquement importantes, telles que le nombre et la disposition des papilles céphaliques et caudales, la présence d’amphides et de phasmides et principalement les structures lamellaires à l’extrémité postérieure du gubernaculum. Une clé des espèces de Philometra parasites des poissons Serranidae est fournie.

• MeSH
• Dracunculoidea anatomy & histology   classification   isolation & purification   MeSH
• Species Specificity MeSH
• Spirurida Infections parasitology   veterinary   MeSH
• Fish Diseases parasitology   MeSH
• Ovary parasitology   MeSH
• Bass parasitology   MeSH
• Food Parasitology MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Mediterranean Sea MeSH

A redescription of Philometra globiceps (Rudolphi 1819), the type species of Philometra Costa 1845 (Philometridae), is provided on the basis of specimens collected from the gonads, stomach, pyloric caeca, intestine and gallbladder of the marine fish Uranoscopus scaber Linnaeus (Uranoscopidae, Perciformes) caught in the Ionian Sea off Ugento, southern Italy. Light microscopical and scanning electron microscopical examinations (latter used for the first time in this species) of the specimens revealed some previously unreported morphological features, such as the location of submedian pairs of cephalic papillae of external circle on four elevated cuticular lobes in gravid females, the presence of amphids, genital papillae and phasmids in males, the lamellate structure of the distal end of gubernaculum appearing as a dorsal protuberance in lateral view and the structure of the male caudal end. A taxonomically important feature of P. globiceps is the details in the dorsal transverse lamella-like structures on the distal end of the gubernaculum, by which this species can be separated from other gonad-infecting species of this genus. Apparently, P. globiceps is a specific parasite of U. scaber and all previous records of this species from hosts belonging to other fish families are evidently based on misidentifications.

• Keywords
• Dracunculoidea, Italy, Marine fish, Parasitic nematode, Uranoscopus,
• MeSH
• Cecum parasitology   MeSH
• Dracunculoidea isolation & purification   ultrastructure   MeSH
• Gonads parasitology   MeSH
• Spirurida Infections parasitology   veterinary   MeSH
• Microscopy, Electron, Scanning MeSH
• Fish Diseases parasitology   MeSH
• Perciformes parasitology   MeSH
• Stomach parasitology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Italy MeSH

A new nematode species, Philometra barnesi sp. n. (Philometridae), is described from the ovary of the marine teleost Pomadasys argenteus (Fosskål) (Haemulidae) off the northern coast of Australia (near Darwin). The new species is characterized by short subequal spicules (84 and 87 μm long), a gubernaculum without a dorsal protuberance at its distal tip, the structure of male anterior and posterior body ends, the body lengths of males (1.67 mm) and gravid females (320-597 mm) and the structure of the oesophagus and caudal end of gravid females. Philometra barnesi is the sixth nominal gonad-infecting species of this genus recorded from marine fishes in Australian waters and the third species of philometrids described from fishes of the family Haemulidae.

• Keywords
• Australia, Dracunculoidea, Marine fish, Nematode parasite,
• MeSH
• Dracunculoidea classification   genetics   isolation & purification   MeSH
• Gonads parasitology   MeSH
• Spirurida Infections parasitology   veterinary   MeSH
• Fish Diseases parasitology   MeSH
• Perciformes parasitology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• Australia MeSH

Two different species of Philometra Costa, 1845 were collected from marine perciform fishes, the tomato hind Cephalopholis sonnerati (Valenciennes) (Serranidae) and the painted sweetlips Diagramma pictum (Thunberg) (Haemulidae), from off New Caledonia, South Pacific. Nematodes (only males) from the gonad of C. sonnerati represent a new taxon, P. cephalopholidis sp. n., which is mainly characterized by almost equally long spicules (length 186-228 μm), the shape and structure of the gubernaculum with a dorsally lamellate distal tip, and the structure of the caudal end. The nematodes (only gravid females) from abdominal tissues of D. pictum may represent an undescribed species, but, because of the absence of conspecific males, they could not be specifically identified. Philometra cephalopholidis is the sixth nominal species of this genus recorded from fishes off New Caledonia and the thirteenth species of these parasites described from fishes of the family Serranidae.

• MeSH
• Nematoda classification   isolation & purification   MeSH
• Nematode Infections epidemiology   parasitology   veterinary   MeSH
• Fish Diseases epidemiology   parasitology   MeSH
• Perciformes parasitology   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Geographicals
• New Caledonia epidemiology   MeSH