Acanthocolpidae (Digenea) of marine fishes off New Caledonia, with the descriptions of two new species

The following acanthocolpid species are reported from New Caledonia. Acaenodera nautili sp. n. from Conger cinereus Rüppel differs from other Acaenodera species in details of the body-spination, the sucker-ratio and the bipartite seminal vesicle; Stephanostomum murielae sp. n. from Carangoides hedlandensis (Whitley) differs from most species of Stephanostomum in the average of 36 circum-oral spines, the circum-oral spine rows with a ventral hiatus and the anterior extent of the vitellarium being > 10% of the hindbody length from ventral sucker. The species is distinguished from the three other species with these characters in a detailed review. The other species reported are: Stephanostomum aaravi Bray et Cribb, 2003 from Lethrinus miniatus and L. rubrioperculatus; Stephanostomum ditrematis (Yamaguti, 1939) from Gnathanodon speciosus; Stephanostomum japonocasum Durio et Manter, 1969 from Cephalopholis urodeta, Epinephelus areolatus, E. chlorostigma, E. maculatus, E. retouti, Lethrinus miniatus and Variola louti; Stephanostomum uku Yamaguti, 1970 and Pleorchis uku Yamaguti, 1970 from Aprion virescens.     

Five new species of philometrid nematodes (Philometridae) from marine fishes off Java, Indonesia

Based on light and scanning electron microscopical studies, the following five species of the Philometridae (Nematoda: Dracunculoidea) are described from female specimens collected from marine fishes off the southwestern coast of Java, Indonesia: Philometra lobotidis sp. n. from the abdominal cavity of the Atlantic tripletail Lobotes surinamensis (Bloch) (Lobotidae, Perciformes); Philometra javaensis sp. n. from the abdominal cavity of the immaculate puffer Arothron immaculatus (Bloch et Schneider) (Tetraodontidae, Tetraodontiformes); Philometra psettoditis sp. n. from the musculature of the Indian spiny turbot Psettodes erumei (Bloch et Schneider) (Psettodidae, Pleuronectiformes); Philometroides indonesiensis sp. n. from the musculature of the hound needlefish Tylosurus crocodilus crocodilus (Péron et Lesueur) (Belonidae, Beloniformes); and Philometroides trichiuri sp. n. from the dorsal fin of the largehead hairtail Trichiurus lepturus Linnaeus (type host) and the savalai hairtail Lepturacanthus savala (Cuvier) (both Trichiuridae, Perciformes). All these new species are distinguished from their congeners parasitizing marine fishes by morphological (mainly the shape and structure of the cephalic and caudal ends and of the oesophagus) and biometrical features. Besides previously known Philometra pellucida (J?gerski?ld, 1893) and Philometra ocularis Moravec, Ogawa, Suzuki, Miyazaki et Donai, 2002, they are the only nominal philometrid species recorded from Indonesian waters.     

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.     

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 gonad-infecting Philometra species (Nematoda: Philometridae) from the marine fish Lutjanus vitta (Perciformes: Lutjanidae) off New Caledonia

Two new gonad-infecting species of Philometra Costa, 1845 (Philometridae), P. brevicollis sp. n. and P. mira sp. n., are described from the ovary of the brownstripe red snapper, Lutjanus vitta (Quoy et Gaimard) (Lutjanidae, Perciformes), from the South Pacific Ocean off the coast of New Caledonia. Based on light and scanning electron microscopy examination, these new nematodes are compared with all other gonad-infecting species of Philometra. The former species (males and mature and gravid females available) mainly differs from its congeners in the length of males (5.39-5.92 mm), equally long spicules (279-312 microm), and the gubernaculum (151-168 microm), in that the distal end of the gubernaculum bears dorsolateral transverse lamella-like structures, and in the structure of the male caudal end. The latter species (only males available) is characterized by the length of males (3.47-3.66 mm), equally long spicules (96-105 microm), and the gubernaculum (78-84 microm), the absence of a dorsal reflected barb or lamella-like structures on the distal end of gubernaculum, and by the structure of the male caudal end. Judging from the occurrence in the host, P. brevicollis is the main philometrid parasitizing the gonads of L. vitta, in which it can reproduce, whereas this fish probably serves as only the paradefinitive host for P. mira. Both P. brevicollis and P. mira are the first nominal species of Philometra described from fishes of the family Lutjanidae.     

New oxyuroid nematodes of the genera Ichthyouris and Spinoxyuris from South American freshwater fishes

Three hitherto unknown oxyuroid nematode species of the family Pharyngodonidae are described from the intestine of South American freshwater fishes, two of them being established as species new to science: Spinoxyuris annulata sp. n. from Myleus ternetzi (Norman) (Serrasalmidae) from French Guiana (Sinnamary River) and Ichthyouris ovifilamentosa sp. n. from Cichlasoma sp. (Cichlidae) from Amazonas (Negro River, S?o Gabriel da Cachoeira), Brazil. A third species, recovered from the same host as the latter (Cichlasoma sp.), was identified only as Ichthyouris sp. because of the absence of the male, although it probably also represents a new species. S. annulata differs from the only other congeneric species, S. oxydoras Petter, 1994, mainly in the absence of egg filaments, the location of an unpaired postanal papilla in the male, a distinctly longer spicule, and in an approximately double length of the body. Ichthyouris ovifilamentosa is closest to I. ro Inglis, 1962, differing from it principally in the structure of the cephalic end, the position of the excretory pore, and in the presence of filamented eggs. Ichthyouris sp. females differ from their congeners mainly in a characteristic structure of the cephalic end, the extent of lateral alae and the shape of their posterior ends, and in the character of egg filaments.     

Camallanus cotti (Nematoda: Camallanidae), an introduced parasite of fishes in New Caledonia

A pathogenic Asian nematode species of Camallanus, C. cotti Fujita, 1927, was found in New Caledonia, South Pacific, for the first time; it was recorded from two native fishes, Awaous guamensis (Valenciennes) (Gobiidae) (prevalence 51%, intensity 1-25) and Kuhlia marginata (Cuvier) (Kuhliidae) (a single specimen found), of the La Foa River, about 100 km north of Nouméa; the latter represents a new host record. Morphological data on C. cotti based on New Caledonian specimens and those previously collected from aquarium-kept Misgurnus anguillicaudatus (Cantor) in Canada have been provided. The SEM examination of C. cotti, applied for the first time in this species, made it possible to study some of its morphological details; first-stage larvae from the female's uterus were found to possess several digit-like processes on the tail tip, not previously reported for any species of the Camallanidae. Camallanus moraveci Petter, Cassone et France, 1974 is considered a junior synonym of C. cotti. A list of hitherto recorded hosts of C. cotti is provided. Camallanus cotti is assumed to be introduced into New Caledonia along with the introduction of the exotic poeciliid fishes, which are known to be among the most common hosts of C. cotti in aquarium cultures worldwide.     

Some aspects of the taxonomy and biology of dracunculoid nematodes parasitic in fishes: a review

The nematode superfamily Dracunculoidea includes 166 recognized species, of which 150 (90%) are parasitic in about 300 species of freshwater, brackish-water and marine fishes. Fish dracunculoids are placed in 31 genera (86% of all dracunculoid genera) belonging to eight of the nine dracunculoid families: Anguillicolidae, Daniconematidae, Guyanemidae, Lucionematidae, Micropleuridae, Philometridae, Skrjabillanidae, and Tetanonematidae; the genus Lockenloia is considered incertae sedis. Because of difficulties in studying fish dracunculoids, associated with their morphological and biological peculiarities, most species of these largely histozoic parasites are poorly known and males of the majority of species and of eight genera have not yet been discovered. It is apparent that the present classification system of dracunculoids as a whole does not reflect phylogenetic relationships and a taxonomic revision of this nematode group, based on detailed morphological (including SEM and TEM), life history and molecular studies of individual species, is quite necessary. Data on the biology of fish dracunculoids is scarce. In known cases, their life cycles involve copepods, ostracods or branchiurids as intermediate hosts and, sometimes, fish paratenic hosts are known to occur in dracunculoid species parasitizing as adults piscivorous definitive hosts. However, nothing is known about the life cycles of representatives of 20 genera. Some species of dracunculoids, particularly of philometrids, are highly pathogenic and are known as agents of serious fish diseases. During recent years, especially the importance of Philometra spp. parasitizing the gonads of many species of marine fishes has increased due in particular to the rapid development of marine aquaculture, because they may significantly decrease fish reproduction or even cause full parasitic castration. Therefore, further detailed studies on fish dracunculoids are significant not only from the theoretical viewpoint, but they may also have practical implications.     

Some aspects of the taxonomy and biology of adult spirurine nematodes parasitic in fishes: a review

About 300 species belonging to four superfamilies (Gnathostomatoidea, Habronematoidea, Physalopteroidea and Thelazioidea) of the nematode suborder Spirurina are known as the adult parasites of freshwater, brackish-water and marine fishes. They are placed in four families, of which the Gnathostomatidae, including Echinocephalus with a few species and the monotypic Metaleptus, are parasites of elasmobranchs, whereas Ancyracanthus contains one species in teleosts; the Physalopteridae is represented in fish by four genera, Bulbocephalus, Heliconema, Paraleptus and Proleptus, each with several species in both elasmobranchs and teleosts. The majority of fish spirurines belongs to the Rhabdochonidae, which includes 10 genera (Beaninema, Fellicola, Hepatinema, Heptochona, Johnstonmawsonia, Megachona, Pancreatonema, Prosungulonema, Rhabdochona and Vasorhabdochona) of species parasitizing mainly teleosts, rarely elasmobranchs, and the Cystidicolidae with about 23 genera (Ascarophis, Caballeronema, Capillospirura, Comephoronema, Crenatobronema, Cristitectus, Ctenascarophis, Cyclozone, Cystidicola, Cystidicoloides, Johnstonmawsonoides, Metabronema, Moravecnema, Neoascarophis, Parascarophis, Prospinitectus, Pseudascarophis, Pseudoproleptus, Salvelinema, Similascarophis, Spinitectoides, Spinitectus, Sterliadochona), with many species parasitic in teleosts only. Because of difficulties in studying fish spirurines, associated with their morphological and biological peculiarities, most species of these parasites are poorly known. It is apparent that their present classification system does not reflect phylogenetic relationships and a taxonomic revision of this nematode group, based on detailed morphological (including SEM and TEM), life history and molecular studies of individual species, is quite necessary. In Cystidicolidae, several genera have been based on details in the cephalic structures visible only with the aid of SEM, but it will be evident whether or not these tiny features are of generic importance only when more cystidicolids are described using SEM and comparative molecular data become available. Data on the biology of fish spirurines are scarce. In known cases, their life cycles involve aquatic arthropods (crustaceans or insects) as intermediate hosts, in which, sometimes, the larvae undergo a precocious development and may even attain adulthood and become gravid in these invertebrates; sometimes, fish paratenic hosts are known to occur in cystidicolids parasitizing as adults piscivorous definitive hosts. Some spirurine species are pathogenic and are known as causative agents of serious fish diseases. Consequently, further detailed studies on fish spirurines are significant not only from the theoretical viewpoint, but they may also have practical implications.     

A new genus of parasitic copepod (Siphonostomatoida: Caligidae) from the razorback scabbardfish, Assurger anzac (Trichiuridae) off New Caledonia

A new genus and species, Avitocaligus assurgericola gen. et sp. n., of the family Caligidae is established based on an ovigerous female collected from a razorback scabbardfish, Assurger anzac (Alexander), caught off New Caledonia. This is the first record of any parasitic copepod from this fish. The new genus is placed in the Caligidae since it possesses the caligid cephalothorax incorporating the first to third pedigerous somites. It also exhibits biramous first and fourth swimming legs but lacks dorsal plates on the fourth pedigerous somite. This combination of characters serves to differentiate the new genus from existing genera. In addition, it possesses loosely coiled, uniseriate egg sacs, concealed between the middle lamellar plates on the genital complex and the ventral plates on the abdomen. Preliminary phylogenetic analysis with a restricted matrix suggests that the new genus represents the earliest offshoot from the main caligid lineage since it does not exhibit the dominant exopod on the fourth swimming leg found in all other members of the Caligidae, including the genus Euryphorus. It strongly supports the newly recognized monophyletic status of the Caligidae, incorporating the genera formerly placed in the Euryphoridae.     

Observations on some nematodes parasitic in freshwater fishes in Laos

In 1989, samples of some freshwater fishes collected in Vientiane Province (R. Mekong basin) in Laos were examined for helminths. This material comprised 11 species of parasitic nematodes (7 adults and 4 larvae), including 3 species new to science: Camallanus (Camallanus) hampalae sp. n. from Hampala macrolepidota, Procamallanus (Punctocamallanus) punctatus sp. n. from Mystus rhegma and Mystus sp., and Rhabdochona (Globochona) equispiculata sp. n. from Hampala macrolepidota and H. dispar. Zeylanema Yeh, 1960 is considered a subgenus of the genus Camallanus, Dentocamallanus subgen. n. (type species C. (D.) sweeti (Moorthy, 1937)) is proposed for the species of Paracamallanus with teeth in the buccal capsule, and Punctocamallanus subgen. n. (type species P. (P.) punctatus sp. n.) for the species of Procamallanus with the buccal capsule ornamented with punctations. The name Rhabdochona wangi nom. nov. is proposed for R. bagarii Wang et Guo, 1983 (a homonym to R. bagarii Gupta et Srivastava, 1982) and Camallanus gomtii Gupta et Verma, 1978 is newly synonymized with Neocamallanus ophiocephali (Pearse, 1933). All the nematodes are recorded from Laos for the first time. The parasites are briefly described and illustrated and some problems concerning their taxonomy and geographical distribution are discussed.     

Prosorhynchus maternus sp. n. (Digenea: Bucephalidae) from the Malabar grouper Epinephelus malabaricus (Perciformes: Serranidae) off New Caledonia

A new species, Prosorhynchus maternus sp. n., is described from the serranid fish Epinephelus malabaricus (Bloch et Schneider) in the waters off New Caledonia. It belongs to a group of Prosorhynchus species from serranids in which the uterus is restricted to the postovarian region. Its distinguishing features include the vitellarium relatively distant from the rhynchus, the cirrus-sac relatively distant from the posterior testis, the distinctly pre-equatorial mouth and several other somatic ratios. New records of Prosorhynchus longisaccatus Durio et Manter, 1968 from Epinephelus cyanopodus (Richardson) and Prosorhynchoides lamprelli Bott et Cribb, 2005 from Caranx papuensis Alleyne et Macleay off New Caledonia are also included.     

Observations on cucullanid nematodes from freshwater fishes in Mexico, including Dichelyne mexicanus sp. n

A new cucullanid nematode, Dichelyne mexicanus sp. n., is described from the intestine of three species of fishes, Agonostomus monticola (Bancroft) (Mugilidae, Perciformes) (type host), Ictalurus balsanus (Jordan et Snyder) (Ictaluridae, Siluriformes) and Cichlasoma beani (Jordan) (Cichlidae, Perciformes), from three rivers (La Maquina River, Veracruz; Chontalcoatlán River, Guerrero and Santiago River, Nayarit) in central Mexico. This species is characterised by the absence of a ventral sucker in the male (subgenus Dichelyne) and it differs from its congeners mainly in possessing very unequal and dissimilar spicules (left 0.465-0.768 mm and right 293-548 mm long), an asymmetrical gubernaculum, and two intestinal caeca. Another cucullanid nematode, Cucullanus caballeroi Petter, 1977, is reported from Dormitator maculatus (Bloch) (Eleotridae, Perciformes) from the La Palma and La Maquina Rivers and Balzapote stream, Veracruz, being briefly described and illustrated; this represents a new host record. Findings of D. mexicanus and C. caballeroi represent a new record of cucullanid nematodes from fishes in Mexican fresh waters.     

Redescription of Metabronema magnum (Nematoda: Cystidicolidae), a swimbladder parasite of the carangid fish Gnathanodon speciosus off New Caledonia

The cystidicolid nematode Metabronema magnum (Taylor, 1925) is redescribed from specimens collected from the swimbladder of the fish (golden trevally) Gnathanodon speciosus (Forssk?l) (Carangidae, Perciformes) off New Caledonia, South Pacific (a new geographical record). The light and scanning electron microscopical examination made it possible to study in detail the morphology of this so far little-known species. Its pseudolabia were found to possess distinct anterior protrusions (protuberances), sublabia are absent, only four cephalic papillae are present, deirids are bifurcated, and the male possesses six pairs of postanal papillae. By its morphology, M. magnum seems to be most similar to species of Salvelinema Trofimenko, 1962, also from the swimbladder of fishes, differing from them mainly in the presence of median wedge-shaped outgrowths in the mouth, lateral alae, the longer spicule on the right side, and a fewer number of pairs of preanal papillae in the male. Since the morphology of M. magnum considerably differs from that of other representatives of the Cystidicolidae, Metabronema in Rasheed's (1966) conception is considered a valid genus.     

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.     

New asperxanthone and asperbiphenyl from the marine fungus Aspergillus sp

BACKGROUND: Marine fungi are of great importance as potential sources of agricultural pesticide leads. To continue work on new and biologically active metabolites from marine fungi, culture extracts of selected isolates were screened for inhibitory activity against tobacco mosaic virus (TMV), a typical member of the tobamovirus group of plant viruses. RESULTS: A new difuranxanthone, asperxanthone (1), and a new biphenyl, asperbiphenyl (2), as well as seven known unsaturated fatty acid glycerol esters, were isolated from a selected marine fungus, identified as Aspergillus sp. (MF-93), collected in the Quan-Zhou Gulf. Two-dimensional NMR methods and FAB-MS established the structures of the new compounds. Among the compounds, 1 and 2 showed moderate activity (inhibitory rates 62.9 and 35.5% respectively) in inhibiting multiplication of TMV, higher than that of the other seven known lipids but much lower than that of the extract at the identical concentration of 0.2 mg mL(-1). CONCLUSION: Two new compounds, asperxanthone and asperbiphenyl, were identified as active components from Aspergillus sp. (MF-93).     

Phylogenetic relationships of some spirurine nematodes (Nematoda: Chromadorea: Rhabditida: Spirurina) parasitic in fishes inferred from SSU rRNA gene sequences

Abstract: Small subunit rRNA sequences were obtained from 38 representatives mainly of the nematode orders Spirurida (Camallanidae, Cystidicolidae, Daniconematidae, Philometridae, Physalopteridae, Rhabdochonidae, Skrjabillanidae) and, in part, Ascaridida (Anisakidae, Cucullanidae, Quimperiidae). The examined nematodes are predominantly parasites of fishes. Their analyses provided well-supported trees allowing the study ofphylogenetic relationships among some spirurine nematodes. The present results support the placement of Cucullanidae at the base of the suborder Spirurina and, based on the position of the genus Philonema (subfamily Philoneminae) forming a sister group to Skrjabillanidae (thus Philoneminae should be elevated to Philonemidae), the paraphyly of the Philometridae. Comparison of a large number of sequences of representatives of the latter family supports the paraphyly of the genera Philometra, Philometroides and Dentiphilometra. The validity of the newly included genera Afrophilometra and Caranginema is not supported. These results indicate geographical isolation has not been the cause of speciation in this parasite group and no coevolution with fish hosts is apparent. On the contrary, the group of South-American species ofAlinema, Nilonema and Rumai is placed in an independent branch, thus markedly separated from other family members. Molecular data indicate that the skrjabillanid subfamily Esocineminae (represented by Esocinema bohemicum) should be either elevated to the rank of an independent family or Daniconematidae (Mexiconema africanum) should be decreased to Daniconematinae and transferred to the family Skrjabillanidae. Camallanid genera Camallanus and Procamallanus, as well as the subgenera Procamallanus and Spirocamallanus are confirmed to be paraphyletic. Paraphyly has also been found within Filarioidea, Habronematoidea and Thelazioidea and in Cystidicolidae, Physalopteridae and Thelaziidae. The results of the analyses also show that Neoascarophis, Spinitectus and Rhabdochona are monophyletic, in contrast to the paraphyletic genus Ascarophis. They further confirm the independence of two subgenera, Rhabdochona and Globochona, in the genus Rhabdochona. The necessity of further studies of fish-parasitizing representatives of additional nematode families not yet studied by molecular methods, such as Guyanemidae, Lucionematidae or Tetanonematidae, is underscored.