Morphological and genetic description of two new species of philometrid nematodes (Philometridae) parasitic in needlefishes (Belonidae) from estuaries of Florida, USA

Two new species of philometrid nematodes (Philometridae) from needlefishes (Belonidae) in Florida are described based on morphological and genetic characteristics: Philometra aequispiculata sp. n. (males and females) collected from the ovary of Strongylura marina (Walbaum) (type host) and Strongylura notata (Poey), and Philometra notatae sp. n. (females) from the swimbladder of S. notata. Both species are described and illustrated based on light and scanning electron microscopical examinations. Morphologically, P. aequispiculata sp. n. differs from all congeners mainly in the unique structure of the distal tip of the gubernaculum, whereas P. notatae sp. n. is mainly characterised by the presence of eight markedly large cephalic papillae of the outer circle in gravid and subgravid females, the body length of the gravid female (54 mm) and by the absence of caudal projections. Molecular characterisation of the new species was assessed from phylogenetic analysis of mitochondrial cytochrome c oxidase I (COI) and SSU rRNA small-subunit ribosomal RNA (SSU) sequences among closely related philometrids by way of Bayesian inference. Phylogenetic reconstructions based on COI and SSU sequences show each of the new species comprise discrete ancestor-descendent lineages.

Philometra longa n. sp. (Nematoda: Philometridae), a new parasite from the abdominal cavity of the eastern sea garfish Hyporhamphus australis (Hemiramphidae, Beloniformes) off Australia

A new nematode species, Philometra longa n. sp. (Philometridae), is described from male and female specimens collected from the body cavity of the marine fish, Hyporhamphus australis (Steindachner) (Hemirhamphidae, Beloniformes) from off the south-eastern coast of Australia. Based on examination by light and scanning electron microscopy, the new species differs from those parasitising other beloniform hosts mainly in the body length (4.69 mm), the length of spicules (141 µm) and the structure of the caudal end and the distal tip of gubernaculum in the male, and in the conspicuously long body (455-560 mm) of the gravid female. Philometra longa n. sp. is the first species of philometrids described from fishes of the family Hemiramphidae. It is the 26th nominal species of philometrids and the 19th species of Philometra so far recorded from Australian marine and brackish waters. Re-examined museum specimens of Philometra sp. from Hyporhamphus melanochir (Valenciennes) off Tasmania, as well as those previously reported from the same host species off the Australian coast, were found to be identical with P. longa sp. n.

Philometra barbata n. sp. (Nematoda: Philometridae) from the red mullet Mullus barbatus (Perciformes, Mullidae) off Tunisia

Helminthological examinations of the red mullet Mullus barbatus (Linnaeus) (Mullidae) from the Gulf of Hammamet, off Tunisia, revealed the presence of one undescribed gonad-infecting nematode species, Philometra barbata n. sp. (Philometridae). The new species as other congeneric species is mainly characterized by the shape of the caudal mound, the distribution of the caudal papillae and the shape of the gubernaculum with the presence of a dorsal protuberance consisting of two dorsolateral lamellar parts separated from each other by a smooth median field in the male. The new species differs from its gonadinfecting congeners in the body length of male, the length of spicules and gubernaculum. This is the second nominal species of Philometra reported from fishes of the family Mullidae and the 14th from the Mediterranean Sea.

Two new gonad-infecting species of Philometra Costa, 1845 (Nematoda: Philometridae) from Trachinus spp. (Osteichthyes: Trachinidae) in the Gulf of Hammamet, Tunisia

Based on light and scanning electron microscopical studies, two new gonad-infecting species of Philometra Costa, 1845, P. draco n. sp. and P. radiata n. sp. (Nematoda: Philometridae), are described from the marine perciform fishes Trachinus draco (Linnaeus) and T. radiatus (Linnaeus) (both Trachinidae), respectively, in the Gulf of Hammamet, off the northeastern coast of Tunisia. Philometra draco n. sp. and P. radiata n. sp. can be separated from other gonad-infecting species of this genus by the structures associated to the gubernaculum (e.g. dorsal protuberance, smooth field separating the dorsolateral longitudinal parts), as well as by the length of the body, spicules and gubernaculum. Philometra radiata n. sp. can be distinguished from P. draco n. sp. in having the dorsal side of the gubernaculum distal end provided with a median longitudinal smooth field demarcated by two dorsolateral lamellate parts. These two new species are the first philometrid species described from fishes of the family Trachinidae.

Two gonad-infecting species of Philometra (Nematoda: Philometridae) from groupers (Serranidae) off Tunisia, with a key to Philometra species infecting serranid gonads

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.

New records of philometrids (Nematoda: Philometridae) from marine fishes off Iraq, with the erection of two new species and the first description of the male of Philometroides eleutheronemae Moravec & Manoharan, 2013

Based on light and scanning electron microscopical studies, the following five species of philometrid nematodes (Nematoda: Philometridae) are described from marine fishes from off Basrah, southern Iraq (Arabian Gulf): Philometra iraqiensis n. sp. (females) from the abdominal cavity and ovary of the Klunzinger's mullet Liza klunzingeri (Day) (Mugiliformes: Mugilidae), P. megalaspidis n. sp. (females) from the ovary of the torpedo scad Megalaspis cordyla (Linnaeus) (Perciformes: Carangidae), Philometra sp. 1 (females) from the ovary of the greater lizardfish Saurida tumbil (Bloch) (Aulopiformes: Synodontidae), Philometra sp. 2 (females) from the ovary of the bartail flathead Platycephalus indicus (Linnaeus) (Scorpaeniformes: Platycephalidae) and Philometroides eleutheronemae Moravec & Manoharan, 2013 (male and females) from the ovary of the fourfinger threadfin Eleutheronema tetradactylum (Shaw) (Perciformes: Polynemidae). The new species are characterised mainly by the body length, the length and structure of the oesophagus and caudal end and by the family of their fish hosts. The male and the gravid female of P. eleutheronemae are described for the first time; the finding of this species in Iraqi waters represents the first record of this nematode in the region of the Arabian (=Persian) Gulf.

New records of species of Philometra (Nematoda: Philometridae) from marine fishes off New Caledonia, including P. cephalopholidis sp. n. from Cephalopholis sonnerati (Serranidae)

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.

Gonad-infecting species of Philometra (Nematoda: Philometridae) from groupers Epinephelus spp. (Osteichthyes: Serranidae) in the Bay of Bengal, India

Based on light and scanning electron microscopical studies, two new and one specifically not identified gonad-infecting species of Philometra Costa, 1845 (Nematoda: Philometridae) are described from the ovary of marine fishes of the genus Epinephelus Bloch (Serranidae, Perciformes) in the Bay of Bengal, off the eastern coast of India: P. indica sp. nov. (male and females) from the honeycomb grouper E. merra Bloch, P. tropica sp. nov. (males and females) from the duskytail grouper E. bleekeri (Vaillant) and Philometra sp. (only females) from the cloudy grouper E. erythrurus (Valenciennes). Philometra indica is mainly characterized by the length of spicules 192-195 μm and the gubernaculum 84 μm, the distal tip of the gubernaculum without a dorsal protuberance, and by the presence of five pairs of caudal papillae. Philometra tropica is mainly characterized by the spicules conspicuously ventrally distended at their posterior halves, the distal tip of the gubernaculum with a dorsal protuberance, and the presence of three pairs of caudal papillae.

Additional observations on Philometra spp. (Nematoda: Philometridae) in marine fishes off Iraq, with the description of two new species

Based on light and electron microscopical studies, the following four species of Philometra Costa, 1845 (Nematoda: Philometridae) are described from marine fishes from off Basrah, southern Iraq (Arabian Gulf): P. brachiri n. sp. (males and females) from the ovary of the Oriental sole Brachirus orientalis (Bloch & Schneider) (Pleuronectiformes; Soleidae), P. piscaria Moravec & Justine, 2014 (female) from the ovary of the orange-spotted grouper Epinephelus coioides (Hamilton) (Perciformes: Serranidae), P. otolithi Moravec & Manoharan, 2013 (male and females) from the ovary of the tigerteeth croaker Otolithes ruber (Bloch & Schneider) (Perciformes: Sciaenidae) and P. tricornuta n. sp. (female) from the musculature of the caudal peduncle of the greater lizardfish Saurida tumbil (Bloch) (Aulopiformes: Synodontidae). Philometra brachiri is mainly characterised by the structure of the distal tip of the gubernaculum and the length of the spicules (132-135 μm) in male. Philometra tricornuta is distinguished by the presence of three large sclerotised oesophageal teeth and two tandem bulbous inflations at the anterior end of oesophagus in female. The female of P. piscaria is described for the first time. Philometra brachiri is the first species of this genus described from a fish belonging to the family Soleidae. The findings of P. piscaria and P. otolithi in Iraqi marine waters represent new geographical records.

Gonad-infecting philometrids (Nematoda: Philometridae) including four new species from marine fishes off the eastern coast of India

Based on light and scanning electron microscopical studies, the following five gonad-infecting species of the Philometridae (Nematoda: Dracunculoidea) are described from marine perciform fishes off the eastern coast of India (Bay of Bengal): Philometra sphyraenae sp. n. (males and females) from the pickhandle barracuda Sphyraena jello Cuvier (Sphyraenidae), Philometra gerrei sp. n. (males and females) from the whipfin silver-biddy Gerres filamentosus Cuvier (Gerreidae), Philometra otolithi sp. n. (single female) from the tigertooth croaker Otolithes ruber (Bloch et Schneider) (Sciaenidae), Philometra sp. (females) from the Belanger's croaker Johnius belangerii (Cuvier) (Sciaenidae), and Philometroides eleutheronemae sp. n. (females) from the fourfinger threadfin Eleutheronema tetradactylum (Shaw) (Polynemidae). All new species are distinguished from their congeners parasitizing gonads of marine fishes by morphological (mainly the gubernaculum structure in males and the shape and structure of the cephalic and caudal ends and of the oesophagus in females) and biometrical features. Philometra rajani Mukherjee, 1963 is considered a species inquirenda.

Philometroides acanthopagri sp. nov., a new philometrid (Nematoda, Philometridae) from the musculature of Acanthopagrus latus (Sparidae) from marine waters of Iraq

A new nematode species, Philometroides acanthopagri sp. nov. (Philometridae), is described from gravid and subgravid specimens found in the musculature near pectoral fins and in nasal cavity of the yellowfin seabream Acanthopagrus latus (Houttuyn) (Sparidae, Perciformes) from marine waters off the coast of southern Iraq. Based on light and scanning electron microscopical examination, the new species differs from its congeners in a combination of morphological and biometrical features. It is the first species of Philometroides reported from a sparid fish and the first representative of this genus recorded from fishes in the Arabian Gulf. A key to Philometroides species parasitizing marine and brackish-water fishes is provided.

A new gonad-infecting species of Philometra Costa, 1845 (Nematoda: Philometridae) from the marine fish Terapon jarbua (Forsskål) (Terapontidae) off the eastern coast of India

A new nematode species, Philometra terapontis n. sp. (Philometridae), is described from male and female specimens found in the ovary of the jarbua terapon Terapon jarbua (Forsskål) (Terapontidae, Perciformes) from the Bay of Bengal off the eastern coast of India. Based on light and scanning electron microscopical examination, the new species differs from most other gonad-infecting Philometra spp. in the length of the spicules (105-114 μm), a gubernaculum with dorsal, lamella-like structures and a distinct protuberance on its distal end, and a U-shaped, dorsally uninterrupted caudal mound in the male. From a few congeneric, gonad-infecting species with unknown males, it can be distinguished by morphological and biometrical features found in gravid females (i.e. length of body, length of first-stage larvae or oesophagus, and caudal structure), by the host type (fish family) and by the geographical distribution. Philometra terapontis is the first philometrid species reported from a fish belonging to the family Terapontidae. Philometra sawara Quiazon, Yoshinaga & Ogawa, 2008 is considered a junior synonym of P. scomberomori (Yamaguti, 1935). A key to gonad-infecting species of Philometra parasitising marine and brackish-water fishes is provided.

Some philometrid nematodes (Philometridae), including four new species of Philometra, from marine fishes off New Caledonia

Examinations of marine fishes off New Caledonia, South Pacific, carried out in 2003–2006, yielded some nematodes of the genus Philometra Costa, 1845, including the following three new species: P. cyanopodi sp. nov. (males and subgravid females) and P. lethrini sp. nov. (males and subgravid females) from the gonads of Epinephelus cyanopodus (Richardson) (Serranidae) and Lethrinus genivittatus Valenciennes (Lethrinidae), respectively, and P. lagocephali sp. nov. (gravid female) from the abdominal cavity of Lagocephalus sceleratus (Gmelin) (Tetraodontidae). Another congeneric species P. fasciati sp. nov. from the gonads of Epinephelus fasciatus (Forsskål) (Serranidae), originally reported as P. lateolabracis (Yamaguti, 1935), has been established with reference to the description of males and a mature female published by Moravec and Justine (2005). The new species are characterized mainly by the length of spicules and the length and structure of the gubernaculum, structure of the male caudal end (except for P. lagocephali), body size, location in the host and by the types of hosts. In addition, Philometra sp. (subgravid females) from the gonads of Lutjanus vitta (Quoy et Gaimard) (Lutjanidae) and Philometra cf. ocularis Moravec et al., 2002 (gravid female) from the oculo-orbit of Epinephelus areolatus (Forsskål) were found, the latter representing a new host record.