Molecular detection of the swim bladder parasite Anguillicola crassus (Nematoda) in fecal samples of the endangered European eel Anguilla anguilla.

The European eel Anguilla anguilla is listed as critically endangered by the IUCN. Among many threats, the introduced parasitic nematode Anguillicola crassus is suspected to alter the eels' swim bladder and jeopardize their reproductive oceanic migration. To date, gaining knowledge about the distribution and prevalence of A. crassus requires individual sacrifice (over 50,000 eels were sacrificed for epidemiology studies since 2010). This paper describes a non-lethal molecular protocol for identifying prevalence of A. crassus in A. anguilla, based on searching for A. crassus DNA in the feces of eels. Tests using three DNA microsatellite markers specific to the nematode showed that molecular detection provided similar results to visual examination of the swim bladder in up to 80% of the cases, and allowed for comparison of prevalence among sites. Easy to implement, this non-lethal protocol for detecting A. crassus could be valuable for management plans of this endangered species.

Helminth diversity in Pimelodus blochii Valenciennes, 1840 (Osteichthyes: Pimelodidae) in two Amazon Rivers.

Structure of the helminth community and analyses of helminth population parameters of Pimelodus blochii collected in the Xapuri River in comparison with those in the Acre River were evaluated. Eight adult helminth species were found parasitizing P. blochii in the Acre River: the nematodes Orientatractis moraveci, Rondonia rondoni, Philometroides acreanensis, Cucullanus (Cucculanus) pinai pinai, Procamallanus (Spirocamallanus) pimelodus, Rhadochona acuminata, and Brasilnema sp., and the trematode Dadaytrema oxycephala. For Xapuri's fishes, nine helminth species were found: the nematodes O. moraveci, R. rondoni, C. (C.) pinai pinai, Procamallanus (Spirocamallanus) rarus, P. (S.) pimelodus, R. acuminata, Brasilnema sp., and Cystidicolidae gen. sp., and the trematode D. oxycephala. Nematode and Acanthocephala larvae were also reported. Helminth abundance, prevalence, and diversity were influenced by seasonality and locality (river). The helminth parasites from Acre's fishes formed a subset of the helminth community of the Xapuri's. The results indicate an influence of the environmental characteristics of the rivers on the helminth community structure and diversity. This is the first study of the parasite community of P. blochii in the Xapuri River. The paretheses of (Spirocamallanus) and (S.) should not be in italics all along the text and tables.

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.

The philometrid nematode Philometroides acreanensis n. sp. from the stomach wall of the catfish Pimelodus blochii in north-western Brazil.

A new nematode species, Philometroides acreanensis n. sp. (Philometridae), is described from female specimens recovered from the stomach wall of the freshwater catfish Pimelodus blochii Valenciennes (Pimelodidae) collected in the Acre River (Amazon River basin), Acre State, Brazil. Based on examination by light and scanning electron microscopy, the new species differs from the two other South American congeneric species mainly in the body length of the gravid female (240-280 mm), the length of the oesophagus (1.25 mm in holotype) representing 0.5% of the entire body length, the range of cuticular embossment, as well as the location in the host (stomach), order of the fish host (Siluriformes) and the geographical distribution (Amazon River drainage system). This is the third known species of Philometroides Yamaguti, 1935 reported from South America. A key to species of Philometroides occurring in the fish of America is provided.

Nematode parasites of four species of Carangoides (Osteichthyes: Carangidae) in New Caledonian waters, with a description of Philometra dispar n. sp. (Philometridae).

Parasitological examination of marine perciform fishes belonging to four species of Carangoides, i.e. C. chrysophrys, C. dinema, C. fulvoguttatus and C. hedlandensis (Carangidae), from off New Caledonia revealed the presence of nematodes. The identification of carangids was confirmed by barcoding of the COI gene. The eight nematode species found were: Capillariidae gen. sp. (females), Cucullanus bulbosus (Lane, 1916) (male and females), Hysterothylacium sp. third-stage larvae, Raphidascaris (Ichthyascaris) sp. (female and larvae), Terranova sp. third-stage larvae, Philometra dispar n. sp. (male), Camallanus carangis Olsen, 1954 (females) and Johnstonmawsonia sp. (female). The new species P. dispar from the abdominal cavity of C. dinema is mainly characterised by the body length (5.14 mm), the lengths of markedly unequal spicules (163 and 96 µm) and gubernaculum (102 µm long) provided with a dorsal protuberance and a small, reflexed dorsal barb on its posterior portion. The finding of C. bulbosus represents the first record of this parasite a century after its discovery; the first study of this species by scanning electron microscopy (SEM) enabled detailed redescription. The finding of Johnstonmawsonia sp. in C. fulvoguttatus is the first record of a rhabdochonid nematode from a host belonging to the Carangidae family. Johnstonmawsonia africana Moravec & Puylaert, 1970 and J. campanae Puylaert, 1973 are transferred to Prosungulonema Roytman, 1963 as P. africanum (Moravec & Puylaert, 1970) comb. n. and P. campanae (Puylaert, 1973) n. comb.

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.

Three-spined stickleback Gasterosteus aculeatus, as a possible paratenic host for salmonid nematodes in a subarctic lake.

In Takvatn, a subarctic lake in northern Norway, 35 of 162 three-spined sticklebacks examined were infected with 106 specimens of third-stage larvae of Philonema oncorhynchi. The prevalence and mean intensity of P. oncorhynchi were 10 % and 2.0 in 2013 and 24 % and 3.0 in 2014, respectively. A single specimen of Cystidicola farionis was found in an additional sample. While the latter is considered an accidental infection, three-spined sticklebacks may function as paratenic hosts of P. oncorhynchi, potentially enhancing its transmission to salmonids due to their central role in the lacustrine food web of this subarctic lake.

Redescription of Philometra globiceps (Rudolphi, 1819) (Nematoda: Philometridae), the type species of Philometra Costa, 1845, including the first data obtained by SEM.

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.

A new gonad-infecting species of Philometra, P. barnesi sp. n. (Nematoda: Philometridae), from the marine fish Pomadasys argenteus (Haemulidae) off the northern coast of Australia.

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.

Redescription and genetic characterization of Philometra lagocephali Moravec et Justine 2008 (Nematoda: Philometridae) from Lagocephalus lunaris (Bloch and Schneider) (Tetraodontiformes: Tetradontidae) in the South China Sea.

Philometra lagocephali Moravec et Justine, 2008 was redescribed using light and scanning electron microscopy based on the new material collected from the lunartail puffer Lagocephalus lunaris (Bloch et Schneider) (Tetraodontiformes: Tetradontidae) in the South China Sea. Our specimens are identical with the original description in the body size of gravid female, the width of cephalic and caudal end, the number and arrangement of cephalic papillae, the relative length of the oesophagus to body length, the size of ventriculus, the morphology of oesophageal bulb and posterior end, and the body size of larvae. In addition, specimens of P. lagocephali were also characterized using molecular methods by sequencing and analysing the small ribosomal DNA (18S rDNA) and mitochondrial cytochrome c coxidase subunit 1 (cox1) target regions. Phylogenetic analyses of genus Philometra base on 18S rDNA sequences was made using Mega 5.2. The results confirmed P. lagocephali is a valid species. It's the first molecular study of this species. These new morphological and molecular data contributed to a more precise and rapid diagnosis of this hitherto poorly known philometrid nematode.

Two gonad-infecting species of Philometra (Nematoda: Philometridae) from marine fishes off the northern coast of Australia.

Two different gonad-infecting species of Philometra Costa, 1845 were collected from the ovary of marine perciform fishes, the blackspotted croaker Protonibea diacanthus (Sciaenidae) and the John's snapper Lutjanus johnii (Lutjanidae), from off the northern coast of Australia. Nematodes (males and females) from P. diacanthus represent a new taxon, Philometra protonibeae n. sp., which is mainly characterized by the body length of the males (3.37-3. 90 mm), broad, equally long spicules (length 126-141 µm) and the shape and structure of the gubernaculum with a dorsally lamellate distal tip. The nematodes (only females) from L. johnii may represent an undescribed species, but, because of the absence of conspecific males, they could not be specifically identified. Philometra protonibeae is the fifth nominal gonad-infecting species of this genus recorded from marine fishes in Australian waters and the seventh species of these parasites described from fishes of the family Sciaenidae.

Dichelyne (Dichelyne) spinigerus sp. nov. (Nematoda: Cucullanidae) from the marine fish Otolithes ruber (Sciaenidae) off Iran and first description of the male of Philometra otolithi Moravec et Manoharan, 2013 (Nematoda: Philometridae).

Recent parasitological examinations of the marine perciform fish (tigerteeth croaker) Otolithes ruber (Bloch et Schneider) (Sciaenidae) from off Iran yielded one new and one previously known nematode species: Dichelyne (Dichelyne) spinigerus sp. nov. (Cucullanidae) from the host's intestine in the Persian Gulf and Philometra otolithi Moravec et Manoharan, 2013 (Philometridae) from the ovary in the Persian Gulf and the Sea of Oman. The new species D. spinigerus is mainly characterized by the tail tip of both sexes terminating in two shaply pointed spikes (one dorsal and one ventral) and bearing a pair of minute lateral cuticular spines at its base, situation of both deirids and the excretory pore well posterior to the level of the posterior end of oesophagus, absence of a precloacal sucker and the presence of one or two intestinal caeca. The male and small mature females of the gonad-infecting species P. otolithi are described for the first time, based on light and scanning electron microscopical studies. The male of P. otolithi is most similar to that of P. johnii Moravec et Ali, 2013, but differs from it by the structure of the cephalic end and the number of caudal papillae; both species also differ from each other by the presence of transverse lamellae in the buccal cavity of gravid and subgravid females of P. otolithi, which are missing in those of P. johnii.

Philometrids (Nematoda: Philometridae) in carangid and serranid fishes off New Caledonia, including three new species.

A recent examination of newly obtained specimens of philometrid nematodes (Philometridae) parasitising carangid and serranid fishes off New Caledonia, South Pacific, revealed the presence of several nematodes of the genus Philometra Costa, 1845, including three new species: P. austropacifica n. sp. (males and females) from the ovary of Alepes vari (Carangidae), P. piscaria n. sp. (males) from the ovary of Epinephelus coioides (Serranidae), and P. selaris n. sp. (males) probably from the abdominal cavity (found in washings) of Selar crumenophthalmus (Carangidae). The new species are characterised mainly by the length and structure of the spicules and gubernaculum, body size, their location in the host and the type of host. Philometra austropacifica n. sp. is the first known nominal gonad-infecting species of Philometra parasitising a carangid fish. In addition, the gravid female of P. fasciati Moravec & Justine, 2008 from the ovary of Epinephelus fasciatus (Serranidae) is described for the first time. Carangid host fish were identified by both morphology and DNA barcoding.

Gonad-infecting philometrid Philometra philippinensis sp. nov. (Nematoda, Philometridae) from the bigeye barracuda Sphyraena forsteri Cuvier (Sphyraenidae) off Mariveles, Bataan Province, Philippine archipelago.

We conducted a parasitological study to identify nematodes infecting the gonads of bigeye barracuda Sphyraena forsteri Cuvier (Sphyraenidae) caught in the West Philippine Sea, off the Mariveles coast, Bataan Province, the Philippine archipelago. Males and very tiny nongravid female philometrid nematodes were collected from the ovaries of the fish. Based on light and scanning electron microscope observations, and supported by molecular analyses of the partial nucleotide sequences of the 18S small subunit ribosomal DNA, the philometrid nematode was determined to be a new species belonging to the genus Philometra Costa, 1845 in the family Philometridae (Nematoda: Dracunculoidea), and was named P. philippinensis sp. nov. This new species was clearly distinguishable morphologically from other congeners that parasitize the gonads of marine fishes. Males have unique sickle-shaped spicules and gubernaculum, and a vulva-like cloacal opening. Following Dentirumai philippinensis Quiazon et Moravec, 2013 and Philometra robusta Moravec, Möller et Heeger, 1992, this is the third philometrid species and the first gonad-infecting philometrid from the Philippine archipelago.

Two philometrids (Nematoda: Philometridae) infecting the tigertooth croaker Otolithes ruber (Bloch & Schneider) (Teleostei: Sciaenidae) off Iran, including erection of a new genus.

Two philometrid nematodes (Philometridae) are described from the marine perciform fish (tigertooth croaker) Otolithes ruber (Bloch & Schneider) (Sciaenidae) from off Iran: Clavinemoides annulatus n. g., n. sp. based on female specimens from the caudal fin of fish from the Persian Gulf and Philometra otolithi Moravec & Manoharan, 2013 from subgravid and nongravid females collected from the ovary of fishes in the Sea of Oman and the Persian Gulf. The monotypic genus Clavinemoides n. g. is mainly characterised by a triangular oral aperture, a markedly large anterior oesophageal bulb, a distinctly annulated body and numerous fine elevated transverse cuticular bands. The finding of P. otolithi in Iranian waters represents a new geographical record of this parasite species. An updated key to the genera of the Philometrinae Baylis & Daubney, 1926 is provided.

Philometra johnii sp. nov. (Nematoda, Philometridae), a new gonad-infecting philometrid from the sin croaker Johnius dussumieri (Cuvier) (Perciformes, Sciaenidae) from marine waters of Iraq.

A new nematode species, Philometra johnii sp. nov. (Philometridae), is described from male and female specimens found in the ovary of the sin croaker, Johnius dussumieri (Cuvier) (Perciformes, Sciaenidae), in the Arabian Gulf, off the southern coast of Iraq. Based on light and scanning electron microscopical examination, the new species differs from all other gonad-infecting Philometra spp. with dorsal lamella-like structures on the distal tip of the gubernaculum in having a dorsal bipartite protuberance formed by two subdorsal lamellated parts separated from each other by a smooth longitudinal field. This gubernaculum structure is unique among all philometrids. Other distinguishing features include the structure of the male tail, number (6 pairs) and arrangement of genital papillae and the length of spicules (102-153 µm). From eight congeneric, gonad-infecting species with unknown males, the new species can be distinguished by some morphological and biometrical features found in gravid females (absence of caudal projections, length of oesophagus, moderately developed anterior oesophageal inflation, length of first-stage larvae) by the host type (fish family) and geographical distribution. Philometra johnii sp. nov. is the fourth known philometrid species recorded from marine waters of Iraq.

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.

Natural Anguillicola novaezelandiae infection--is there seasonality in New Zealand?

Knowledge of natural Anguillicola infections of Short-finned eels (Anguilla australis) in New Zealand is very limited. So far, no study contains data on all life cycle stages of Anguillicola novaezelandiae in naturally infected eels. In order to study the frequency of A. novaezelandiae in New Zealand Short-finned eels, we examined eels of the North and the South Island for the presence of the swim bladder parasite. The results show that A. novaezelandiae is a common parasite of the Short-finned eel. The parasite was present in both regions. Eels from both localities show differences in their infection status with respect to prevalence, abundance and intensity. While eels of the South Island were only infected with larval stages, adult and preadult stages could be detected in eels of the North Island. Nevertheless, infrapopulations at both sites were dominated by larval parasite stages. This unique composition of infrapopulations has never been described for any Anguillicola species before and suggests a seasonal occurrence as a possible reason. Export of live eels should be handled cautiously to prevent the spread of A. novaezelandiae throughout other eel populations.

Dentirumai philippinensis n. gen., n. sp. (Nematoda: Philometridae), a new tissue-infecting philometrid nematode from the loach goby Rhyacichthys aspro (Valenciennes) (Rhyacichthyidae) in the Philippines.

A new genus and species of the philometrid nematode Dentirumai philippinensis n. gen., n. sp. Philometrinae, Philometridae, are described on the basis of the female specimens found in the loach goby, Rhyacichthys aspro (Valenciennes), from the upper Bianuan River, Municipality of Casiguran, Aurora Province, in the Philippine Archipelago. Dentirumai philippinensis was collected from the body cavity, subcutaneous tissues near the bases of the pectoral and pelvic fins, and surrounding body tissues in the hypaxial musculature of R. aspro. Based on light microscopic and scanning electron microscopic examination, the new nematode species is morphologically close to the genus Rumai Travassos, 1960 except for one major difference, i.e. the presence of a sclerotized ring in the oral aperture armed with distinct numerous minute teeth on its inner surface. This important taxonomic feature makes it possible to erect a new genus, Dentirumai n. gen. to accommodate the newly discovered philometrid species. A key to genera of the Philometrinae is provided.