Structure of the female cephalic end and cuticular ornamentations of Paraphilometroides nemipteri (Nematoda:Philometridae), as revealed by SEM

Scanning electron microscopy (SEM) examination of a paratype specimen (gravid female) of the philometrid nematode Paraphilometroides nemipteri Moravec et Shaharom-Harrison, 1989, the type species of Paraphilometroides Moravec et Shaharom-Harrison, 1989, made it possible to recognise the true structure of the cephalic end and the shape of cuticular ornamentations on the body. In contrast to other philometrid genera, the cephalic end is angular in lateral view and rounded in dorsoventral view; large external cephalic papillae are fused together to form a marked dorsal and a ventral ala, each bent into a curve; six minute internal papillae, including a pair of previously not reported lateral papillae, were found; amphids were indistinct. Cuticular ornamentations (inflations) were found to be transversely elongated. These features, especially the unique cephalic structure, clearly distinguish Paraphilometroides from other philometrids and confirm the validity of this genus. Moravec and Shaharom-Harrison (1989) erected the hitherto monotypic philometrid genus Paraphilometroides Moravec et Shaharom-Harrison, 1989 with the type species P. Nemipteri Moravec et Shaharom-Harrison, 1989, described from females found in the fins and operculum of the marine fish (notchedfin threadfin bream) Nemipterusperonii (Valenciennes) from off the South China Sea coast, Malaysia. The male of P. nemipteri remains unknown. The authors distinguished Paraphilometroides from the related genus Philometroides Yamaguti, 1935 mainly by the unusual structure of the female cephalic end, which is unique within the family Philometridae (see Moravec 2006). However, P. nemipteri was studied only by light microscopy (LM), whereas some details of the cephalic structure, especially the cephalic papillae of gravid philometrid females are usually difficult to observe by LM due to a various degree of their reduction and atrophy (Moravec 2004); in the past, some philometrid species were even reported to have no cephalic papillae. Consequently, the only reliable method to study the cephalic structures in philometrids is the use of scanning electron microscopy (SEM). Therefore, one of the ethanol-preserved paratype specimens (gravid female) of P. nemipteri, deposited in the Helminthologi-cal Collection of the Institute of Parasitology, Biology Centre     

Two species of philometrid nematodes (philometridae) from marine fishes off Japan, including Philometroides branchiostegi sp. n. from Branchiostegus japonicus (malacanthidae)

Gravid females of two species of philometrid nematodes (Philometridae) were collected from marine perciform fishes in Japanese waters, mainly from the southern Sea of Japan. Based on light microscopy and scanning electron microscopy examinations, the previously described but poorly known species Philometra cryptocentri Yamaguti, 1961 is redescribed from specimens recovered from the abdominal cavity of Acanthogobius flavimanus (Temminck et Schlegel), Pterogobius elapoides (Günther) and P. zonoleucus Jordan et Snyder (all Gobiidae) (all new host records); the number (14) and arrangement of cephalic papillae in this species are described for the first time. The new species, Philometroides branchiostegi sp. n. from head tissues of Branchiostegus japonicus (Houttuyn) (Malacanthidae), based on a single specimen, is mainly characterized by the embossment of the entire body except for the cephalic end, presence of four submedian pairs of large cephalic papillae of external circle and two small lateral single papillae of internal circle, pair of large papilla-like caudal projections, the oesophagus with a distinct anterior inflation, by a markedly small body (length about 18 mm) and the larvae 306-465 microm long.     

Two new species of Philometra (Nematoda: Philometridae) parasitic in the perciform fish Cynoscion nebulosus (Sciaenidae) in the estuaries of South Carolina, USA

Two new nematode species of Philometra Costa, 1845, P. carolinensis sp. n. and P. cynoscionis sp. n., are described from the spotted seatrout, Cynoscion nebulosus (Cuvier) (Sciaenidae, Perciformes) in estuaries on the Atlantic coast of South Carolina, USA. Philometra carolinensis (males and gravid and subgravid females) parasitic in the host's ovary is most similar to P. lateolabracis (Yamaguti, 1935) in female morphology, but distinctly differs from it in possessing conspicuously short spicules (81-87 microm long) with heavily sclerotized distal parts, the gubernaculum bearing a reflected dorsal barb, and in the length ratio of the gubernaculum and spicules (1:1.23-1.42) in the male. Philometra cynoscionis (only gravid females) found subcutaneously in the host's tissue (lateral to the ascending process of the premaxilla and also posteromedial to the length of each maxilla) is characterized mainly by the presence of cephalic papillae arranged in two circles (8 large papillae in outer circle and 6 small papillae in inner circle), the absence of caudal projections, the body size (length of gravid female 20-33 mm) and the location in the host.     

Philometrid nematodes infecting fishes from the Everglades National Park, Florida, U.S.A

The following three species of the Philometridae (Nematoda: Dracunculoidea) are described from marine perciform fishes of the Everglades National Park (northern Gulf of Mexico), Florida, U.S.A.: Philometra brevispicula sp. n. (male and females) from the subcutaneous tissue of mouth of the gray snapper Lutjanus griseus (Linnaeus) (Lutjanidae), Philometroides grandipapillatus sp. n. (only females) from pectoral fin muscle of the crevalle jack Caranx hippos (Linnaeus) (Carangidae), and Caranginema americanum Moravec, Montoya-Mendoza et Salgado-Maldonado, 2008 (females) from the subcutaneous fascia of trunk muscle in crevalle jack C. hippos. Philometra brevispicula is mainly characterized by small cephalic papillae of the external circle, the absence of oesophageal teeth and the presence of small caudal projections in gravid female, markedly short spicules (45 microm) in male, and by its location in the host. Philometroides grandipapillatus differs from congeners mainly in the shape of the cephalic region (narrow, conspicuously protruding), large cephalic papillae of the external circle and the absence of caudal projections in female, and by the site of infection in the host. Caranginema americanum is for the first time recorded from the northern Gulf of Mexico.     

Two new species of Philometra (Nematoda: Philometridae) from needlefishes (Belonidae) in Iraq, with a key to Philometra spp. parasitic in the host's subcutaneous tissue, fins and musculature

Two new nematode species, Philometra strongylurae sp. n. and Philometra tylosuri sp. n., are described from female specimens collected from needlefishes (Belonidae, Beloniformes) off the Fao coast, Basrah, Persian Gulf, in Iraq. Philometra strongylurae (gravid females with larvae) was recorded from the subcutaneous tissue, muscles of beak and gills of Strongylura leiura (type host) and S. strongylura, whereas P. tylosuri (nongravid females) from the musculature and the subcutaneous tissue of Tylosurus crocodilus. The former is characterized mainly by the presence of eight markedly large cephalic papillae, conspicuously large anterior oesophageal bulb and by the length of body (15-20 mm); the latter by eight minute cephalic papillae, poorly developed oesophageal bulb and by the body length (46-72 mm). A key to Philometra spp. with gravid females parasitic in the subcutaneous tissue, fins or musculature of fishes is provided.     

Philometroides africanus sp. n. (Nematoda: Philometridae), a new tissue parasite of the African pike Hepsetus odoe (Pisces) in Botswana.

A new species of philometrid nematode, Philometroides africanus sp. n., is described from female specimens found encapsulated in gill arches and inner surface of gill covers of the African pike, Hepsetus odoe (Bloch), an endemic freshwater fish in Africa, from the Okavango River and Delta in Botswana. This new nematode is characterised mainly by a markedly small and plump body of gravid females (body length 6-9 mm), a separate anterior oesophageal bulb, a conspicuously small oesophageal gland, presence of four pairs of very small submedian cephalic papillae, and absence of any caudal processes. The prevalence of P. africanus in African pike of the Okavango Delta was 29%, with the intensity 1-8 (mean 3) encapsulated nematodes per fish. The genus Margolisianum Blaylock et Overstreet, 1999 is considered a junior synonym of Philometroides Yamaguti, 1935 and, consequently, its type species is transferred to the latter as Philometroides bulbosus (Blaylock et Overstreet, 1999) comb. n.     

New morphological data on the first-stage larvae of two Procamallanus species (Nematoda: Camallanidae) based on SEM studies

First-stage larvae of camallanid nematodes Procamallanus (Procamallanus) laeviconchus (Wedl, 1862) and Procamallanus (Procamallanus) sp. from naturally infected Distichodus niloticus (Hasselquist) and Clarias gariepinus (Burchell), respectively, from Lake Turkana, Kenya (new geographical records) are described, being for the first time studied by scanning electron microscopy. Larvae of both species are characterised by the presence of a dorsal cephalic tooth, four submedian cephalic papillae and a pair of amphids, and by the elongate tail with several terminal digit-like processes. The latter formations probably serve for the attachment of larvae to the substrate in water when the larvae attract copepod intermediate hosts by their movements; these structures, especially their numbers, may be of taxonomic importance in camallanid nematodes.     

Capillostrongyloides Ancistri sp. n. (Nematoda: Capillariidae) a new pathogenic parasite of aquarium fishes in Europe

A new nematode species, Capillostrongyloides ancistri sp. n., is described from the intestine of aquarium-reared catfish Ancistrus dolichopterus Kner in Czechoslovakia. This fish is of South American origin and, therefore, C. ancistri sp. n. has probably been brought into aquaria in Europe from there. The parasite is characterized mainly by the structure of the male caudal end (presence of two large postanal papillae and the cuticular bursa supported by two caudal lobes), the length of a spicule (0.258-0.297 mm), the presence of a non-spiny spicular sheath, shape of the female end, structure of the stichosome (23-30 stichocytes present), and the size of the eggs. The species appears to be highly pathogenic to aquarium-reared Ancistrus dolichopterus, causing death of these fish.     

Granulinema gen. n. a new dracunculoid genus with two new species (G. carcharhini sp. n. and G. simile sp. n.) from the bull shark, Carcharhinus leucas (Valenciennes), from Louisiana, USA

Two new species of dracunculoid nematodes, G. carcharhini sp. n. and G. simile sp. n., representing a new genus Granulinema gen. n. (Dracunculoidea: Micropleuridae) are described from the bull shark, Carcharhinus leucas, from Louisiana (Lake Borgne), USA; the site of their localization in the host is unknown (probably abdominal cavity). The nematodes of both species were found in tissue juice and only males, juvenile females and body fragments of more advanced but nongravid females were obtained. Granulinema gen. n. differs from Micropleura, the only other genus in the family Micropleuridae, mainly by the presence of marked, dark excretory corpuscles in lateral excretory canals, pointed tail in females, greater number (6) of postanal pairs of caudal papillae in males, and by the presence of conspicuous transverse cuticular ornamentations on the body surface of mature females. The two new species can be easily distinguished from each other by the length of their spicules (0.78-0.90 mm in G. carcharhini sp. n. and 0.20-0.36 mm in G. simile sp. n.); moreover, there are two pairs of preanal papillae in the male of G. carcharhini sp. n., while there are three pairs in G. simile sp. n.     

A new species of Acanthochondria (Copepoda: Chondracanthidae) parasitizing the flounder Xystreurys rasile (Pleuronectiformes: Paralichthyidae) from Argentina

A new copepod species, Acanthochondria sagitta sp. n., is described based on specimens collected from the flounder Xystreurys rasile (Jordan) (Pleuronectiformes, Paralichthyidae), caught in the coastal waters off Necochea, Buenos Aires Province, Argentina. The new species differs from its congeners by the following combination of characters: presence of three pairs of cephalic outgrowths; the triangular shape of the trunk with diverging postero-lateral processes; leg 2 of an intermediate shape between Types C and D, which projects laterally from the trunk, and Type B-V antennule bearing two proximal processes (one ventral and one dorsal) on the swollen basal portion.     

Pseudodelphis limnicola sp. n. (Dracunculoidea: Guyanemidae) from the heart of Percichthys trucha (Perciformes: Percichthyidae) in Patagonian Andean Lakes (Argentina)

During a survey of parasites of Percichthys trucha (Cuvier et Valenciennes) (Perciformes: Percichthyidae) in northwestern Patagonian lakes, a new dracunculoid of the family Guyanemidae was found parasitizing as adults the heart of the fish. This species belongs to the genus Pseudodelphis Adamson et Roth, 1990 by having deirids, glandular multinucleate oesophagus and anterior branch of the uterus, and by lacking caudal alae and a gubernaculum. Pseudodelphis limnicola sp. n. differs from Pseudodelphis oligocotti Adamson et Roth, 1990 by the number and distribution of the cephalic papillae, a muscular oesophagus submerged into the glandular portion and by lacking a peribuccal ring. This is the first record of a guyanemid inhabiting the heart of a Neotropical perciform fish.     

Three new species of Echinobothrium (Cestoda: Diphyllidea) from Indo-Pacific stingrays of the genus Pastinachus (Rajiformes: Dasyatidae)

Three new species of diphyllidean cestodes are described from stingrays of the genus Pastinachus from the Indian and Pacific Oceans. All three new species differ from all but 10 of the 36 valid species of Echinobothrium van Beneden, 1849 in that they bear lateral hooklets arranged in a continuous band across each lateral surface of the rostellum joining the groups of dorsal and ventral apical hooks, rather than arranged in distinct dorsal and ventral groups, on each side of the apical hooks. Echinobothrium nataliae sp. n. ex Pastinachus solocirostris off Borneo differs from other relatives in the following combination of characters: number of spines in each column on the cephalic peduncle, number of lateral hooklets and number of apical hooks. Echinobothrium reginae sp. n. ex Pastinachus cf. sephen off Madagascar differs from all congeners in the following combination of characters: number of hooklets and number of spines on the cephalic peduncle. Echinobothrium vojtai sp. n. from an undescribed species of Pastinachus off Borneo differs from its congeners in the following combination of characters: number of hooklets, number of apical hooks and number of spines in each column on the cephalic peduncle. The hook formula was modified to accommodate species with lateral hooklets arranged in a continuous band as follows: {(LH) AH(A)/AH(B)}, where (LH) is the total number of lateral hooklets in a band. A table of all nominal species of Echinobothrium, showing their taxonomic status, type host and locality, number of peduncle spines in a column and hook formula, is presented. Macrobothridium djeddensis and Macrobothridium sinensis are transferred to Echinobothrium. In addition, Echinobothrium deeghai is considered as a species inquirenda.     

Two new nematodes,Paraseuratoides ophisterni gen. et sp. n. (Quimperiidae) and Philometra ophisterni sp. n. (Philometridae), from the swamp-eel Ophisternon aenigmaticum in Mexico

Two new nematodes, Paraseuratoides ophisterni gen. et sp. n. (Seuratoidea: Quimperiidae) and Philometra ophisterni sp. n. (Dracunculoidea: Philometridae) are described based on specimens recovered from the intestine and mesentery, respectively, of the swamp-eel Ophisternon aenigmaticum Rosen et Greenwood (Synbranchiformes: Synbranchidae) from a canal of the Papaloapan River in Tlacotalpan, State of Veracruz, Mexico. The genus Paraseuratoides is mot similar to Paraseuratum Johnston et Mawson, 1940, differing from it mainly in the absence of a bulbous inflation on the anterior end of the oesophagus and in the structure of the mouth (presence of 6 spines in addition to 6 oesophageal teeth). Neoquimperia Wang, Zhao, Wang et Zhang, 1979 and Wuinema Yu et Wang, 1992 are synonymised with Ezonema Boyce, 1971 and Paragendria Baylis, 1939, respectively, and Haplonema hamulatum Moulton, 1931 is considered a junior synonym of Ichthyobronema conoura Gnedina et Savina, 1930. Philometra ophisterni (only females) is mainly characterised by minute cephalic papillae, a greatly developed anterior oesophageal bulb separated from the cylindrical part of the oesophagus, anterior extension of the oesophageal gland anterior to the nerve ring, and by the character of large caudal projections. This is the first Philometra species recorded from inland fishes in Mexico.     

Rhabdias kongmongthaensis sp. n. (Nematoda: Rhabdiasidae) from Polypedates leucomystax (Amphibia: Anura: Rhacophoridae) in Thailand

Rhabdias kongmongthaensis sp. n. is described based on specimens found in the lungs of the tree frog Polypedates leucomystax (Gravenhorst) (Amphibia: Rhacophoridae) from Kanchanaburi Province, western Thailand. The new species is similar to two North-American species, Rhabdias ranae and R. americanus, by presence of two lateral pseudolabia, each with two inner submedian protuberances. R. kongmongthaensis differs from both species by relative length and shape of the tail, and by its distribution and host specificity. Presence of lateral pseudolabia distinguishes the new species from the geographically closest Rhabdias species as well as from those parasitizing other rhacophorid frogs.     

Some nematodes and acanthocephalans from exotic ornamental freshwater fishes imported into Germany

Five species of adult nematodes, unidentifiable nematode larvae, and three species of acanthocephalans, were found in freshwater ornamental fishes newly imported into Germany from Brazil, Colombia, Indonesia, Malaysia, Nigeria, Peru, Sri Lanka and Thailand. The following species were identified: Adult Nematoda: Pseudocapillaria tomentosa, Capillariidae gen. sp., Dichelyne hartwichi sp. n., Procamallanus (Spirocamallanus) pintoi and Spinitectus allaeri; Acanthocephala: Pseudogorgorhynchus arii gen. et sp. n., Neoechinorhynchus sp. and Pallisentis sp. The nematode Dichelyne hartwichi sp. n. (male only) from the intestine of Chelonodon fluviatilis (Hamilton) from Thailand is characterised mainly by the presence of minute cuticular spines on the tail tip, length of spicules (510 microns) and arrangement of caudal papillae. The acanthocephalan Pseudogorgorhynchus arii sp. n. from the intestine of Ariopsis seemanni (Günther) from Colombia represents a new genus Pseudogorgorhynchus gen. n., differing from other genera of the Rhadinorhynchidae mainly in possessing a small proboscis armed with markedly few (18) hooks arranged in six spiral rows. Spinitectus macheirus Boomker et Puylaert, 1994 and Spinitectus moraveci Boomker et Puylaert, 1994 are considered junior synonyms of Spinitectus allaeri Campana-Rouget, 1961.     

Rhabdochona mexicana sp. n. (Nematoda: Rhabdochonidae) from the intestine of characid fishes in Mexico

A new nematode, Rhabdochona mexicana sp. n., is described based on specimens recovered from the intestine of two species of fishes, Astyanax mexicanus (De Filippi) (type host) and Astyanax fasciatus (Cuvier) (Characidae: Characiformes) in central Mexico. This species is characterised by the following characters: 10 anteriorly directed teeth in the prostom, a larger (left) spicule which is slender in form with a small bifurcation at its distal tip covered by a cuticular membrane, a smaller (right) spicule without a barb at its distal tip, eggs bearing an irregular flock-like coating, and a conical tail without a cuticular spike (in both sexes).     

A new species of Neoascarophis (Nematoda: Cystidicolidae) parasitic in Mullus argentinae (Perciformes: Mullidae) from the Atlantic coast of South America

A new nematode species (Neoascarophis mariae n. sp.) is described based on specimens collected from the Argentine goatfish Mullus argentinae (Hubbs et Marini) from coastal waters off the state of Rio de Janeiro, Brazil. In the genus, the new species belongs to the group of species with females that have the vulva near the posterior end of the body. Only males of Neoascarophis longispicula Moravec et Klimpel, 2009 are known and can be distinguished from those of the new species by their larger body, developed and somewhat dorsoventrally expanded flat inner part of the pseudolabia, bifurcate deirids and larger spicules (the left one with a rounded tip) with a different length ratio. Other species with females that have the vulva near the equatorial region are N. yarihige Machida, 1976 and N. bathygadi Machida, 1976. Both males and females of N. yarihige are longer than those of the new species and have a shorter vestibule; males have shorter spicules with a different length ratio. Neoascarophis bathygadi is the only member of the genus that shares the presence of a cephalic vesicle with the new species, which, however, is shorter and arises at 40 microm from the anterior end instead from the deirids, as in the new species. Both males and females of N. bathygadi are also longer than those of the new species and have a shorter vestibule; males have a larger left spicule, but shorter right spicule and a different length ratio. Ascarophis upeneichthys Johnston et Mawson, 1945, a parasite ofa mullid host, is transferred to Neoascarophis Machida, 1976 and is distinguished from the new species by having a shorter vestibule in females and shorter spicules (left spicule with a pointed tip) with a different length ratio in males.