The male and subgravid female of Philometra serranellicabrillae Janiszewska, 1949 (Philometridae) collected from the gonads of Serranus cabrilla (Linnaeus) (Serranidae) off Tunisia are described for the first time based on light and scanning electron microscopical studies. The male of this nematode can be separated from other congeneric gonad-infecting nominal species in the structure and shape of the gubernaculum (e.g. absence of a dorsal protuberance and a median smooth field). The shape of the male posterior region is unique in that it bears a pair of big circular papillae posterior to the cloacal opening, which is also present in other Philometra spp. from serranids, i.e. P. indica Moravec & Manoharan, 2014, P. inexpectata Moravec, Chaabane, Justine & Neifar, 2016 and P. jordanoi (López-Neyra, 1951) Yamaguti, 1961. Moreover, P. serranellicabrillae differs from its congeners in other fish families from the Mediterranean Sea, in the length of spicules and gubernaculum.

• MeSH
• Dracunculoidea anatomy & histology   ultrastructure   MeSH
• Species Specificity MeSH
• Gonads parasitology   MeSH
• Microscopy, Electron, Scanning MeSH
• Fish Diseases parasitology   MeSH
• Bass 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
• Tunisia MeSH

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 (Linnaeus) (Perciformes, Sparidae), from off the Mediterranean 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 gubernaculum 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.

• MeSH
• Dracunculoidea anatomy & histology   classification   ultrastructure   MeSH
• Species Specificity MeSH
• Microscopy, Electron, Scanning * MeSH
• Ovary 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
• Mediterranean Sea MeSH
• Tunisia MeSH

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 barcoding. Light and scanning electron microscope studies of Ph. rara n. sp. showed that it is characterized by the length of spicules (216-219 μm) and the gubernaculum (90-93 μm), 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.

Deux espèces de Philometra Costa, 1845 (Nematoda, Philometridae) parasites des gonades sont, pour la première fois, signalées de poissons perciformes marins au large de la Tunisie et de la Libye : Philometra rara n. sp. (Serranidae) du mérou de Haïfa Hyporthodus haifensis, une espèce rare, au large de la Libye et Philometra saltatrix Ramachandran, 1973, du tassergal Pomatomus saltatrix (Pomatomidae) au large de la Tunisie. L’identification des deux espèces de poissons a été confirmée par barcode moléculaire. Des études en microscopie photonique et microscopie électronique à balayage de Ph. rara n. sp. ont montré que l’espèce se caractérise par la longueur des spicules (216-219 μm) et du gubernaculum (90-93 μm), le rapport gubernaculum/spicules (1: 2.32-2.43) et principalement par la forme et la structure de l’extrémité distale du gubernaculum (en forme de pelle avec un large champ médian lisse en vue dorsale), apparaissant comme ayant une protubérance dorsale en vue latérale, et par la structure du monticule caudal mâle (interrompu dorsalement); les grandes femelles subgravides (70-137 mm de long) se caractérisent par la présence de quatre élévations céphaliques ovales sous-médianes, chacune portant une paire de papilles céphaliques sur le cercle extérieur. La découverte de Ph. saltatrix au large de la Tunisie confirme que cette espèce est répandue dans la région méditerranéenne. Une analyse moléculaire de nos spécimens de Ph. saltatrix et d’autres séquences disponibles de COI de Philometridae montre que la plupart des espèces présentent des clades robustes. Les séquences de Ph. saltatrix en provenance de Tunisie divergent de Ph. saltatrix du Brésil et des États-Unis, ce qui suggère qu’une spéciation se produit actuellement entre les populations des deux côtés de l’océan Atlantique.

• MeSH
• Dracunculoidea anatomy & histology   classification   genetics   ultrastructure   MeSH
• Spirurida Infections epidemiology   parasitology   veterinary   MeSH
• Microscopy, Electron, Scanning MeSH
• Fish Diseases epidemiology   parasitology   MeSH
• Bass genetics   parasitology   MeSH
• Prevalence MeSH
• Fishes MeSH
• DNA Barcoding, Taxonomic veterinary   MeSH
• Animals MeSH
• Check Tag
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Geographicals
• Libya MeSH
• Mediterranean Sea MeSH
• Tunisia MeSH

Based on light and scanning electron microscopical studies, two new species of Philometra Costa, 1845 (Nematoda: Philometridae) are described from two species of Mycteroperca Gill (Serranidae), marine perciform fishes, in coastal waters off Florida, USA: Philometra deburonae n. sp. from the inner side of operculum of the yellowfin grouper Mycteroperca venenosa (L.) and P. incognita n. sp. from the ovary of the gag M. microlepis (Goode & Bean). Philometra deburonae n. sp. is mainly characterised by the body length of males (1.90-2.38 mm), the length of the spicules (78-84 µm) and gubernaculum (54 µm) and the presence of small outer cephalic papillae, a pair of fairly large caudal projections and the oesophageal gland extending anteriorly beyond the nerve-ring in subgravid females. Philometra incognita n. sp. is distinguished by the caudal mound consisting of two lateral reniform parts widely separated dorsally from each other, the absence of a pair of large papillae situated posteriorly to the cloaca, the shape and structure of the distal end of the gubernaculum plus the lengths of the spicules (117-141 µm) and gubernaculum (60-81 µm) in the male, the absence of caudal projections and the comparatively large larvae in the uterus (660-675 µm long) of the gravid female, as well as, the body length of both males (2.45-3.11 mm) and gravid females (120-180 mm). The present descriptions of an additional two new philometrids increases the number of recorded nominal species of Philometra parasitising groupers (Serranidae) in the Gulf of Mexico to nine.

• MeSH
• Species Specificity MeSH
• Nematoda anatomy & histology   classification   MeSH
• Bass 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
• Research Support, U.S. Gov't, Non-P.H.S. MeSH
• Geographicals
• Atlantic Ocean MeSH
• Gulf of Mexico MeSH
• United States MeSH