Two New Species of Philometrid Nematodes (Philometridae), Barracudia Notabilis n. sp. and Philometra Consimilis n. sp., from the Ovary of the Hound Needlefish Tylosurus Crocodilus (Belonidae) Off Florida, USA.

Two new species of philometrid nematodes (Philometridae), Barracudia notabilis n. sp. and Philometra consimilis n. sp., are described from males found in the ovary of the hound needlefish Tylosurus crocodilus (Péron et Lesueur) (Belonidae) from off the Atlantic coast of Florida, USA. Both species are described and illustrated based on light and scanning electron microscopical examinations. Barracudia notabilis n. sp., the first representative of this genus from fishes in the Atlantic Ocean, can be differentiated from other congeners by the body length of the male (2.69 mm), the length of the gubernaculum (57 µm) and spicules (81 µm), and by the shape of the gubernaculum. Philometra consimilis n. sp. differs from all congeners mainly in the unique structure of the distal tip of the gubernaculum (bearing two smooth dorsal barbs) and the species is also characterized by the length of spicules (111 µm) and the length of the gubernaculum (84 µm). Further studies are needed to discover and describe so far unknown gravid females of Barracudia spp.

Heliconema Monopteri n. Sp. (Nematoda: Physalopteridae) from Monopterus Cuchia (Hamilton) (Osteichthyes: Synbranchidae) in India, with Notes on the Taxonomy of Heliconema Spp.

A new nematode species, Heliconema monopteri n. sp. (Physalopteridae), is described from the stomach and intestine of the freshwater fish Monopterus cuchia (Hamilton) (Synbranchidae) in Bijnor district, Uttar Pradesh, India. It is mainly characterized by the lengths of spicules (468 - 510 µm and 186 - 225 µm), the postequatorial vulva without elevated lips, the presence of pseudolabial lateroterminal depressions and by the number and arrangement of caudal papillae. This is the first representative of the genus reported from a synbranchiform fish. Another new congeneric species, Heliconema pisodonophidis n. sp. is established based on a re-examination of nematodes previously reported as H. longissimum (Ortlepp, 1922) from Pisodonophis boro (Hamilton) (Ophichthidae) in Thailand; ovoviviparity in this species is a unique feature among all physalopterids. Heliconema hamiltonii Bilqees et Khanum, 1970 is designated as a species dubia and the nematodes previously reported as H. longissimum from Mastacembelus armatus (Lacépède) in India are considered to belong to H. kherai Gupta et Duggal, 1989. A key to species of Heliconema Travassos, 1919 is provided.

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.

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.

Seasonal development and pathological changes associated with the parasitic nematode Philometroides sanguineus in wild crucian carp Carassius carassius (L.) in England.

Pathological changes associated with the parasitic nematode Philometroides sanguineus (Rudolphi, 1819) are described for the first time from observations of infections in wild crucian carp Carassius carassius (L.) in England. The damage caused by P. sanguineus was influenced strongly by host size, parasite development and the seasonal migrations of female nematodes within host tissues. Male and unfertilized female nematodes located on the swim-bladder wall caused only minor, localized changes. In contrast, the migration of gravid female nematodes into the fins during autumn provoked an acute inflammatory response comprising neutrophils, eosinophils and lymphocytes. This was accompanied by fin distortion, swelling of the dorsal and caudal tissues, degenerative changes and localized oedema. The encapsulation of female nematodes in connective tissue throughout winter limited additional tissue damage. The emergence of gravid nematodes from the fins in spring to facilitate larval dispersal caused necrosis, hyperplasia and loss of skin integrity. This activity was again accompanied by acute inflammatory reactions. Pathological changes were more severe in crucian carp measuring less than 60 mm in length, with no signs of debilitation in larger fish. These observations suggest that any impact of P. sanguineus is strictly seasonal and may be limited to fry. Lesions caused by this parasite, only recently recorded in Britain, may represent an additional pressure upon wild crucian carp populations already threatened by hybridization, competition and habitat loss.

[Description of a case of infection due to Dracunculoidea in French Polynesia]. / Un cas d'infection à Dracunculoidea en Polynésie française.

The purpose of this report is to describe a case of Dracunculoidea infection that led to acute arthritis of the knee in a young Polynesian. The implications of this first reported case of Dracunculoidea infection in French Polynesia are discussed.

Philometra floridensis sp. n. (Nematoda: Philometridae) from the ovary of red drum Sciaenops ocellatus (Osteichthyes: Sciaenidae) off the coast of Florida, USA.

A new nematode species, Philometra floridensis sp. n. (Philometridae), is described from male and female specimens found in the ovary of red drum, Sciaenops ocellatus (Linnaeus) (Sciaenidae, Perciformes), from the Gulf of Mexico off Treasure Island, Florida, USA. Based on light and scanning electron microscopy examination, the new species differs from most other gonad-infecting Philometra spp. in having a smooth gubernaculum with a distinct dorsal tooth on the distal tip. The new species is most similar to P. carolinensis Moravec, de Buron & Roumillat, 2006, but differs in length and shape of spicules. It can be distinguished from P. carolinensis and other species with unknown males, by the markedly greater body length of gravid females (up to about 100 cm). Philometra floridensis is the third valid gonad-infecting species of Philometra reported from sciaenids.

Surface morphology of Nicolla skrjabini (Trematoda: Opecoelidae), a common parasite of European freshwater fishes, as revealed by SEM.

Scanning electron examination of trematode specimens belonging to Nicolla skrjabini (Iwanitzky 1928), collected from brown trout Salmo trutta fario L. in the Czech Republic, made it possible to study their surface morphology including details not described previously. The tegument bears numerous characteristic papillae mainly around and inside the suckers and around the genital pore and minute sensory organs near the anterior body end. Surface morphology may prove to be useful in distinguishing Nicolla spp.

Tissue-dwelling philometrid nematodes of the fish Arapaima gigas in Brazil.

The nematode Rumai rumai Travassos, 1960 (Philometridae) is redescribed from the tissues of the mouth, tongue, operculum and head of the arapaima, Arapaima gigas (Schinz) (Osteichthyes), from Mexiana Island, Amazon River Delta, Brazil. Additional data on the related Nilonema senticosum (Baylis, 1922) from the same host and locality are also presented. Rumai rumai is characterized by the presence of a sclerotized formation on the female cephalic end, dorsal and ventral cephalic projections, the shape and structure of the oesophagus and a conical caudal extremity. Males of both R. rumai and N. senticosum, specific parasites of the ancient arapaima fish in the Neotropics, remain unknown. The relationship between these tissue-dwelling nematodes and the aquaculture system of Mexiana Island is commented upon.

Dracunculus brasiliensis sp. n. (Nematoda: Dracunculidae) from the anaconda, Eunectes murinus (Ophidia: Boidae).

Dracunculus brasiliensis sp. n. (Dracunculidae), is described based on a single female specimen found in the body cavity of the anaconda, Eunectes murinus (L.) (Ophidia: Boidae), from the Mexiana Island, Amazon River delta, Brazil and one female previously recorded from the subcutaneous tissue of this host species imported from South America into Europe (ZOO in the Czech Republic). The new species is characterised mainly by markedly large, anteriorly protruding dorsal and ventral double papillae of the internal circle and small lateral papillae of the same circle, a widely rounded caudal end, the excretory pore situated just posterior to the nerve ring, a distinctly transversely striated cuticle and by the length (396-429 mum) of larvae from uterus. This is the first species of Dracunculus described from reptiles in South America.

Two species of Philometra (Nematoda: Philometridae) from sparid fishes (porgies) off Sicily, Italy, including Philometra obladae sp. n. from the body cavity of Oblada melanura (Sparidae).

Two species of Philometra Costa, 1845 (Nematoda: Philometridae), were, for the first time, recorded from fishes of the family Sparidae (porgies) from the Tyrrhenian Sea off Sicily, Italy: Philometra obladae sp. n. from the body cavity of the saddled seabream Oblada melanura (Linnaeus) and Philometra filiformis (Stossich, Boll Soc Adriat Sci Nat 17:121-136, 1896) from the gonads of the common pandora Pagellus erythrinus (Linnaeus). The new species (a single gravid female available) is characterised mainly by a large body (335 mm long, 3.4 mm wide), minute cephalic papillae (14 in number) arranged in two circles, a relatively short (1.29 mm) oesophagus with a distinct anterior inflation, a rounded caudal end without any projections and the length of larvae (549-600 mum) from the uterus. A key to species of Philometra with females located in the body cavity of marine and brackish-water fishes is given. Some new data on the female morphology of a little-known gonad-infecting species P. filiformis are provided; new observations revealed, for the first time in this species, the presence of lateral cephalic papillae and the absence of previously reported black intestinal corpuscles in the larvae.

Stegodexamene anguillae (Digenea: Lepocreadiidae), an intestinal parasite of eels (Anguilla spp.) in New Caledonia.

Adult trematodes of the genus Stegodexamene Macfarlane, 1951 were recorded from the intestines of two species of freshwater eels, the Pacific short-finned eel Anguilla obscura Günther and the speckled longfin eel Anguilla reinhardtii Steindachner from the Pouembout and La Foa Rivers, New Caledonia, South Pacific. They were identified as Stegodexamene anguillae Macfarlane, 1951, a species previously reported only from eels in New Zealand. The morphology of adult S. anguillae seems to be practically identical with that of the later described Stegodexamene callista Watson 1984 from eels in Australia. The finding of S. anguillae in A. obscura and A. reinhardtii in New Caledonia represents new geographical and host records. In addition to this trematode, two larval specimens of a cestode of the order Proteocephalidea were found in the intestine of one A. obscura from the Pouembout River. No monogenean was found in eels of New Caledonia.

Nematode parasites of fishes: recent advances and problems of their research.

Although nematodes (Nematoda) belong to the most frequent and the most important parasites of fishes in the freshwater, brackish-water and marine environments throughout the world, the present knowledge of these parasites remains still incomplete, especially as to their biology and ecology, but also taxonomy, phylogeny, zoogeography, and the like. However, a certain progress in the research of fish nematodes has been achieved during recent years. An overview of some of the most important discoveries and results obtained is presented. As an example, existing problems in the taxonomy of these nematodes are shown in the dracunculoid family Philometridae (presently including 109 species in 9 genera), where they are associated mainly with some biological peculiarities of these mostly important tissue parasites. Nematodes of the Dracunculoidea as a whole remain poorly known; for example, of 139 valid species parasitizing fishes, 81 (58%) are known by females only and the males have not yet been described for members of 8 (27%) of genera. A taxonomic revision of this nematode group, based on detailed morphological, life history and molecular studies of individual species, is quite necessary; for the time being, Moravec (2006) has proposed a new classification system of dracunculoids, where, based on previous molecular studies, the Anguillicolidae is no longer listed in Dracunculoidea, but in an independent superfamily Anguillicoloidea. Important results have recently been achieved also in the taxonomy of fish nematodes belonging to other superfamilies, as well as in studies of their geographical distribution and diversity in different parts of the world and those of their biology. Opportunities for more detailed studies of fish nematodes have recently greatly improved with the use of some new methods, in particular SEM and DNA studies. There is a need to create a new classification system of these parasites reflecting phylogenetic relationships; a prerequisite for this is taxonomic revisions of different groups based on detailed studies of individual species, including mainly their morphology, biology and genetics. Further progress should concern studies on various aspects of biology, ecology and host-parasite relationships, because these data may have practical implications.

Procamallanus (Spirocamallanus) anguillae sp. n. (Camallanidae) and some other nematodes from the Indonesian shortfin eel Anguilla bicolor in Thailand.

A new species of parasitic nematode, Procamallanus (Spirocamallanus) anguillae sp. n. (family Camallanidae), is described based on specimens recovered from the intestine of the Indonesian eel Anguilla bicolor McClelland (type host) from southern Thailand (type locality Phuket Island). It is characterized mainly by the presence of 10-13 spiral ridges in the buccal capsule, length of spicules (366-372 microm and 198-216 microm), presence of a gubernaculum, arrangement of caudal papillae, and by the broad female tail with a digit-like projection bearing two cuticular spikes. In addition, two species of larval nematodes, Physalopteridae gen. sp. and Anisakis cf. simplex (Rudolphi 1809), were recorded from A. bicolor. All species are briefly described and illustrated.

Anguillicola papernai (Nematoda: Anguillicolidae) and other helminths parasitizing the African longfin eel Anguilla mossambica.

The swim bladder nematode Anguillicola papernai Moravec & Taraschewski, 1988 has been investigated as regards its occurrence in longfin eels Anguilla mossambica (Peters) in rivers in South Africa. A. papernai revealed a prevalence of around 50% and a mean intensity of about 6 adult worms at 1 sampling site but were less abundant in 3 others. Field observations suggest a more narrow habitat preference than that of Anguillicola crassus and a seasonal pattern of abundance. African longfin eels harboured a poor helminth community. In addition to A. papernai, 2 gastro-intestinal nematodes occurred, the stomach worm Heliconema longissimum Ortlepp, 1923 as the dominant species, and the intestinal Paraquimperia africana Moravec, Boomker & Taraschewski, 2000. Experiments were undertaken using European eels Anguilla anguilla (Linnaeus) and copepods as laboratory hosts. The morphology of larvae and adult parasites obtained from these experimental hosts is described. The ultrastructure of adult worms recovered from wild longfin eels was studied. The 'papilla-like excrescences of fibrous structure' on the adult worms' cuticle, as mentioned in the original description, are in fact the attachment points of thick cords of fibers interconnecting the epicuticle with the hypodermis. Such a structure has not yet been described from any other species of Anguillicola Yamaguti, 1935. At present in South Africa, Mozambique and Madagascar attempts are on the way to establish an eel management like in Asia and Europe including eel farming. In this context, care should be taken to prevent the introduction of non-endemic eel parasites into Africa and Madagascar. On the other hand, the future commercial management of African eel species should not lead to the spread of A. papernai or other parasites of African eel species to Europe or elsewhere. In this study A. papernai has been experimentally demonstrated to be capable of reproducing in the European eel and of using European copepods as intermediate hosts.

Egg shell ultrastructure of the fish nematode Huffmanela huffmani (Trichosomoididae).

The egg shell of Huffmanela huffmani Moravec, 1987 forms three main layers: an outer vitelline layer, a middle chitinous layer, and an inner lipid layer. The vitelline layer, forming the superficial projections of the egg shell, comprises two parts: an outer electron-dense, and an inner electron-lucid part. The chitinous layer is differentiated into three parts: an outer homogenous electron-dense part, a lamellated part, and an inner electron-dense net-like part. The lipid layer comprises an outer net-like electron-lucid part, and an inner homogenous electron-lucid part. The polar plugs are formed by electron-lucid material with fine electron-dense fibrils.

First description of the male and redescription of the female of Philometra salgadoi Vidal-Martínez et al., 1995 (Nematoda: Philometridae) from the ocular cavity of the marine fish Epinephelus morio in Mexico.

A redescription of the female and the first description of the male of the philometrid nematode Philomnetra salgadoi Vidal-Martínez, Aguirre-Macedo et Moravec, 1995 are presented on the basis of specimens collected from the type host, the red grouper. Epinephelus morio (Valenciennes; Pisces: Serranidae), in the Gulf of Mexico off the northern coast of Yucatan, Mexico. The morphology of this species is compared with that of related congeneric species.

Observations on the biology of Rhabdochona kidderi texensis, a parasite of North American cichlids.

An examination of a sample of benthic invertebrates collected from the Upper San Marcos River in southwestern Texas, USA in September 1999 revealed that the nymph of the ephemeropteran Tricorythodes curvatus served as natural intermediate host of the nematode Rhabdochona kidderi texensis (Nematoda: Rhabdochonidae), an intestinal parasite mainly of the Rio Grande perch (Cichlasoma cyanoguttatum) in this locality; the prevalence of the parasite's third- and fourth-stage larvae in mayflies was 6.8% with the intensity of 1-2 larvae per nymph. Live R. kidderi texensis eggs collected from nematodes recovered from C. cyanoguttatum in Texas were transported to the Czech Republic, where they were used to experimentally infect nymphs of the palaearctic mayfly species Paraleptophlebia submarginata; the development of infective third- and fourth-stage larvae in this experimental intermediate host was completed after approximately 10 days at 19 degrees C. Infected nymphs were fed to aquarium-reared fishes, four Cichlasoma nigrofasciatum and one Oreochromis niloticus, of which only three of the former became infected. The last (fourth) moult of a male nematode was observed in C. nigrofasciatum 23 days p.i. and adult males and gravid females with not fully mature (non-embryonated) eggs in uteri on days 40 and 51 p.i. The prepatent period of R. kidderi texensis is approximately two months.

Common sculpin Cottus gobio as a natural paratenic host of Proteocephalus longicollis (Cestoda: Proteocephalidae), a parasite of salmonids, in Europe.

Common sculpins Cottus gobio L. (Pisces: Cottidae), from the Mlýnský Brook near Ceské Zleby in the Sumava National Park, southwestern Bohemia, Czech Republic, were found to harbour in their intestines juvenile cestodes Proteocephalus longicollis (Zeder, 1800), a common parasite of holarctic salmonids, with a prevalence of 60% and intensity of 1 to 11 (mean 5) parasites per fish; undoubtedly, these prey fish serve as paratenic hosts. In this locality, the definitive host of P. longicollis is the brown trout Salmo trutta m. fario L., large specimens of which apparently acquire infection of this parasite by feeding on infected sculpins. C. gobio is the first known natural paratenic host of P. longicollis in Europe.