A new acanthocephalan family, the Isthmosacanthidae (Acanthocephala: Echinorhynchida), with the description of Isthmosacanthus fitzroyensis n. g., n. sp. from threadfin fishes (Polynemidae) of northern Australia

Isthmosacanthus fitzroyensis n. g., n. sp. is described from two species of protandrous fish, Eleutheronema tetradactylum (Shaw) and Polydactylus macrochir (Günther), from the waters around the coast of northern Australian. The new species can be distinguished from all others by the following combination of characters: proboscis shape and armature (22 rows of 13-14 hooks), short neck, trunk spined anteriorly and having two swellings (one bulbous) with a narrow isthmus in between, long tubular lemnisci and six tubular cement glands. Although I. fitzroyensis has been confused with a species of Pomphorhynchus Monticelli, 1905 in the literature, it can be distinguished from all pomphorhynchids, including species of Longicollum Yamaguti, 1935 and Pyriproboscis Amin, Abdullah & Mhaisen, 2003, by the suite of characters listed above. The placement of the species of Pyriproboscis in the Pomphorhynchidae Yamaguti, 1939 is problematical, because it has a short neck, two distinct hook types comprising the proboscis armature and only two rather than six cement glands. A new family, the Isthmosacanthidae n. fam., is erected to contain Isthmosacanthus together with Gorgorhynchoides Cable & Linderoth, 1963 and Golvanorhynchus Noronha, Fabio & Pinto, 1978, genera having an elongate to clavate proboscis, anterior trunk spines, elongate lemnisci, and six tubular cement glands. The validity of this determination, based on the importance of cement gland number and phylogenetic analysis, is argued.     

A review of the Arhythmacanthidae (Acanthocephala) with a description of Heterosentis hirsutus n. sp. from Cnidoglanis macrocephala (Plotosidae) in Australia

Heterosentis hirsutus n. sp. is described from Cnidoglanis macrocephala (Siluriformes: Plotosidae) from the Swan Estuary, Western Australia. It is distinguished by having 14 longitudinal rows of 6-7 hooks per row on the proboscis, a trunk armed anteriorly and posteriorly (= genital spines) with minute spines and lemnisci that may extend to the posterior margin of the proboscis receptacle. The new species also has prominent fragmented nuclei in its trunk wall. New information is given for Heterosentis plotosi Yamaguti, 1935 from Plotosus lineatus (Siluriformes: Plotosidae) and H. paraplagusiarum (Nickol, 1972) Amin, 1985 from Paraplagusia guttata (Pleuronectiformes: Cynoglossidae), both from Queensland. A key to the species of Heterosentis Van Cleave, 1931 is provided. The Arhythmacanthidae subfamilies are reviewed: there is little utility in the recognition of these taxa because of the small number of genera involved and the validity of the characters on which they are based is in doubt, particularly whether trunk spines are present or absent. Only Acanthocephaloides Meyer, 1932, Breizacanthus Golvan, 1969, Euzetacanthus Golvan & Houin, 1964, Heterosentis, Hypoechinorhynchus Yamaguti, 1939 and Paracanthocephaloides Golvan, 1969 of the Arhythmacanthidae are considered valid. A key to these genera is provided. The monotypic genus Neoacanthocephaloides Cable & Quick, 1954 is considered a new synonym of Acanthocephaloides thus creating Acanthocephaloides spinicaudatus (Cable & Quick, 1954) n. comb. Arhythmacanthus Yamaguti, 1935 is maintained as a synonym of Heterosentis because the distinction between two and three hook types is made equivocal when the transition between the apical and subapical hooks is gradual.     

Pomphorhynchus patagonicus n. sp. (Acanthocephala: Pomphorhynchidae) from freshwater fishes of Patagonia, Argentina

Pomphorhynchus patagonicus n. sp. is described from Lake Rosario, Chubut Province, Argentina. It is characterized by a long neck forming an asymmetrical bulb with 2 well differentiated dorsal protruberances and 14 alternating rows of 13 and 14 proboscis hooks, each row with a stout fourth hook. It most closely resembles Pomphorhynchus sebastichthydis Yamaguti, 1939, from Japan, but differs in the bulb protruberances and in having more rows of hooks and more hooks per row and in the shapes of the fourth and basal hooks. Among American species P. patagonicus shows some similarities to Pomphorhynchus yamagutii Schmidt and Hugghins, 1973, from Chile, but differs with respect to the longer neck, bulb protruberances, and proboscis armature. Pomphorhynchus patagonicus is endemic to Patagonia, where its definitive type host is the endemic fish Patagonina hatcheri (Atherinidae) and its intermediate host the endemic freshwater amphipod Hyalella patagonica. It has been found also in autochthonous fishes belonging to the families Galaxiidae and Percichthyidae and in introduced salmonid fishes.     

Four species of Stephanostomum Looss, 1899 (Digenea: Acanthocolpidae) from Seriola dumerili (Risso) (Teleostei: Carangidae) in the western Mediterranean,including S. euzeti n. sp.

Four species of Stephanostomum are described from various sites in Seriola dumerili from off Corsica, France. S. ditrematis (Yamaguti, 1939), from the stomach, pyloric caeca and duodenum, has 36 circum-oral spines. S. seriolae Yamaguti, 1970 is considered a synonym of S. ditrematis. S. filiforme Linton, 1940, from the mid-intestine, has 43-46 circum-oral spines. S. petimba Yamaguti, 1970, from the rectum, has a 42 circum-oral spines. S. euzeti n. sp. has 49-51 circum-oral spines, and differs from worms with a similar anterior extent of the vitellarium and circum-oral spine number in details of the vitelline distribution and the distances between the gonads. Attention is drawn to the presence in the rectum of S. dumerili of sympatric species differentiated mainly on circum-oral spine number.     

Neoechinorhynchus (Neoechinorhynchus) dorsovaginatus n. sp.(Acanthocephala: Neoechinorhynchidae) from the dusky kob Argyrosomus japonicus (Sciaenidae) on the southern coast of South Africa

Neoechinorhynchus (Neoechinorhynchus) dorsovaginatus n. sp. (Acanthocephala: Neoechinorhynchidae) is described from the dusky kob, Argyrosomus japonicus (Temminck & Schlegel) from the southern coast of South Africa in the Breede River Estuary. Like four other species of Neoechinorhynchus Stiles & Hassall, 1905, N. (N.) africanus Troncy, 1969, N. (N.) johnii Yamaguti, 1939, N. topseyi Podder, 1937 and N. (N.) tylosuri Yamaguti, 1939, the new species has a very long, slender body, cylindrical testes and cement-gland, anterior proboscis hooks much longer than the middle or posterior hooks, and a long neck. The new species is the only species of Neoechinorynchus having an antero-dorsal hump just posterior to the neck and a specialised vaginal sphincter and a gonopore on the dorsal side. It is closest to N. (N.) johnii, but is distinguished from it by: the size of the trunk, proboscis, anterior proboscis hooks, neck, and the posterior testis in relation to the cement-gland; the shape of cerebral ganglion and proboscis hook root; and the number of giant nuclei in the cement-gland.     

Chimaerarhynchus n. g. andPatellobothrium n. g., two new genera of trypanorhynch cestodes with unique poeciloacanthous armatures,and a reorganisation of the poeciloacanthous trypanorhynch families

Chimaerarhynchus rougetae n. g., n. sp. is described fromSqualus acanthias andCentrophorus sp. from the coast of Senegal, and differs from all other trypanorhynch genera in having a chainette composed of dissimilar elements, that is, double-winged hooks alternating with pairs of hooks each with a single lateral wing. The new genus is allocated to the Gymnorhynchidae Dollfus, 1935.Patellobothrium quinquecatenatum n.g., n. sp. is described from the spiral intestine ofSphyrna mokarran from Darwin, Northern Territory, Australia and plerocerci fromRachycentron canadus from Queensland, Australia. The genus is distinguished from all others in possessing five chainettes. It is allocated to the family Mustelicolidae Dollfus, 1969. The relationships of all genera of trypanorhynchs possessing chainettes are discussed, and they are divided into three groups: (1) Dasyrhynchidae Dollfus, 1935, Lacistorhynchidae Guiart, 1927, Mustelicolidae and Hornelliellidae Yamaguti, 1954 are considered closely related since all genera possess two bothridia, a hermaphroditic duct and have hollow hooks; (2) Gymnorhynchidae, amended to contain onlyGymnorhynchus Rudolphi, 1819 andChimaerarhynchus n.g., is distinct in possessing four bothridia, an accessory seminal vesicle and hollow hooks; (3) Mixodigmatidae Dailey & Vogelbein, 1982, amended to includeMixodigma Dailey & Vogelbein, 1982 andHalysiorhynchus Pintner, 1913 has four bothridia, lacks seminal vesicles and a hermaphroditic duct and has solid hooks.A new family Molicolidae n. fam. is erected forMolicola Dollfus, 1935 andStragulorhynchus Beveridge & Campbell, 1988. The new family has a poeciloacanthous armature, and is distinguished by possessing a band of hooks on the external surface of the tentacle, four sessile bothridia and an acessory seminal vesicle.Myrmillorhynchus Bilqees, 1980 is suppressed as a synonym ofPterobothrium Diesing, 1850.Neogymnorhynchus Bilquees & Shah, 1982, is suppressed as a synonym ofPterobothrium, with the type species,N. platycephali becoming a synonym ofP. heteracanthum Diesing, 1850.Eulacistorhynchus Subhapradha, 1957 is considered agenus inquirendum;Gymnorhynchus cymbiumi Chincholikar & Shinde, 1977 is also a synonym ofPterobothrium heteracanthum Diesing, 1850.     

Dactylomyza gibsoni n. g., n. sp. (Digenea: Opecoelidae) from Schuettea woodwardi (Waite) (Monodactylidae) from off Western Australia

An opecoelid digenean, Dactylomyza gibsoni n. g., n. sp. is described and figured from Schuettea woodwardi (Waite), a monodactylid from off the coast of Western Australia. The new genus conforms to the concept of the opecoelid subfamily Opecoelinae. The resemblance of the new genus to three other opecoelid genera, Pseudopecoeloides Yamaguti, 1940, Opecoeloides Odhner, 1928 and Poracanthium Dollfus, 1948, is discussed. Dactylomyza n. g. is distinguished from these morphologically similar worms on the basis of its median genital pore, ventral sucker appendages, uroproct and the absence of an accessory sucker. Pseudopecoeloides equesi Manter, 1947 is transferred to the new genus as Dactylomyza equesi (Manter, 1947) n. comb.     

Morphological and molecular study of <Emphasis Type="Italic">Longicollum pagrosomi</Emphasis> Yamaguti, 1935 (Acanthocephala: Pomphorhynchidae) from the barred knifejaw <Emphasis Type="Italic">Oplegnathus fasciatus</Emphasis> (Temminck &amp; Schlegel) (Perciformes: Oplegnathidae) in the East China Sea

Longicollum pagrosomi Yamaguti, 1935 (Acanthocephala: Pomphorhynchidae) collected from the barred knifejaw Oplegnathus fasciatus (Temminck & Schlegel) (Perciformes: Oplegnathidae) in the East China Sea (off Zhoushan Islands) was studied using light and scanning electron microscopy. The SEM observations revealed for the first time the presence of about 28 well-developed sensory papillae arranged in a circle on the copulatory bursa. In addition, L. pagrosomi was characterised using molecular methods by sequencing of the internal transcribed spacer (ITS) of the ribosomal DNA based on the newly collected material. Longicollum pagrosomi is the first species of the genus with the ITS region sequenced for the purpose of species identification. These new morphological and molecular data contributed to a reliable and accurate specific identification and differentiation of species.     

Description of Pomphorhynchus spindletruncatus n. sp. (Acanthocephala: Pomphorhynchidae) from freshwater fishes in northern Iraq,with the erection of a new pomphorhynchid genus,Pyriproboscis n. g., and keys to genera of the Pomphorhynchidae and the species of Pomphorhynchus Monticelli, 1905

The status of species of Pomphorhynchus Monticelli, 1905 is examined and 23 species are recognised as valid. These include P. spindletruncatus n. sp., which is described herein from two species of freshwater fishes in northern Iraq, Aspius vorax Heckel and Barbus xanthopterus (Heckel) (Cyprinidae). Only one other species, P. yunnanensis Wang, 1981, has a spindle-shaped trunk similar to that of P. spindletruncatus, but is distinguished from it by a distinctly different proboscis armature. A key separating the new taxon from other species of Pomphorhynchus is included. P. heronensis Pichelin, 1997 is reassigned to a new pomphorhynchid genus, Pyriproboscis n. g., based on its unique proboscis shape and armature, short proboscis receptacle and tubular cement glands. A key to the genera of the Pomphorhynchidae is also included.     

Occurrence of the subgenus Acanthosentis Verma & Datta, 1929 (Acanthocephala: Quadrigyridae) in Japan, with the description of Acanthogyrus (Acanthosentis) alternatspinus n. sp. and A. (A.) parareceptaclis n. sp. from Lake Biwa drainage fishes and a key to the species of the subgenus

All 44 described species of the subgenus Acanthosentis Varma & Datta, 1929 are recognised as valid. These include two new species, Acanthogyrus (Acanthosentis)alternatspinus n. sp. from Rhodeus ocellatus ocellatus (Kner) (Cyprinidae) and A. (A.) parareceptaclis n. sp. from Cobitis biwae Jordan & Snyder (Cobitidae) in the Lake Biwa drainage, Japan. These are the first representatives of the subgenus Acanthosentis recorded from Japan. Most other species are found in the Indian subcontinent, but a few have been reported from China, elsewhere in Asia, Africa, Europe and Central America. Only A. (A.) alternatspinus has the lateral proboscis hooks in the apical and middle circles markedly displaced posteriorly but of equal size to the other hooks in the same circles and multi-branched lemnisci. Acanthogyrus (A.) parareceptaclis uniquely possesses parareceptacle structures in both sexes as well as a pair of cone-shaped genital jackets flanking the vagina (vaginal sleeve). Two new names are provided: Acanthogyrus (Acanthosentis) adriaticus nom. nov. for A. (A.) lizae Orecchia, Paggi & Radujkovic, 1988 nec Wang, 1896, and A. (A.) cheni nom. nov. for A. (A.) coiliae (Yamaguti) sensu Chen et al. (1973). A review of the species composition of Acanthosentis is provided and a key to its species and zoogeographical notes are included.     

Spiracanthus bovichthys n. gen. n. sp. (Acanthocephala: Arhythmacanthidae), a parasite of littoral fishes of the central south coast of Chile

A new acanthocephalan species, Spiracanthus bovichthys n. gen. n. sp., is described. Samples were taken from 26 marine fish species between 23 and 53 degrees S of Chile. The parasite was found in the intestine of 6 species and only between 36 and 40 degrees S, especially in those fish that prey on small crustaceans in the upper and sublittoral zone. The parasite was found in Bovichthys chilensis (Reagan). Auchenionchus variolosus (Valenciennes), Calliclinus genigutattus (Valenciennes), Sindoscopus australis (Fowler and Bean), Myxodes cristatus Valenciennes, and Gobiesox marmoratus (Jenyns). However, only the first species is a suitable host for the parasite as evidenced by the presence of mature females. This acanthocephalan belongs to Arhythmacanthidae, but it does not correspond to any genus described. Spiracanthus bovichthys is different in the number and spiralled distribution of its hooks in the proboscis. In the short proboscis, 3 groups of hooks are distinguished according to size, summing up to 150-190 hooks. The group of largest hooks are found in the apical part of the proboscis, and there are 10 diagonal rows of small hooks from the prebasal to basal proboscis. Its trunk is covered partially by small spines. Amphipod and isopods were the prey items shared among the host fish species and are the best candidates to be the intermediate hosts of S. bovichthys.     

Acanthoparyphium shinanense n. sp. (Digenea: Echinostomatidae) from Experimental Chicks Infected with Metacercariae Encysted in Brackish Water Clams in the Republic of Korea

Acanthoparyphium shinanense n. sp. (Digenea: Echinostomatidae) is described from chicks experimentally infected with the metacercariae encysted in 2 brackish water clam species, Ruditapes philippinarum and Coecella chinensis, in the Republic of Korea. The metacercariae were round to oval, armed with 23 collar spines, and 0.216 (0.203–0.226) mm in diameter. From 5 chicks experimentally infected each with 200 metacercariae, 34 juvenile (5-day-old worms) and 104 adult flukes (7-day-old worms) were harvested from their small intestines, with the average worm recovery rate of 13.8%. The adult flukes were 3.18 (2.89–3.55) mm long and 0.68 (0.61–0.85) mm wide, with an elongated, posteriorly tapering body, and a prominent head collar armed with 23 collar spines arranged in a single uninterrupted row. The posterior testis of A. shinanense was longitudinally elongated, which is similar to Acanthoparyphium spinulosum Johnston, 1917 but unique from the other closely related species, including Acanthoparyphium tyosenense Yamaguti, 1939, Acanthoparyphium kurogamo Yamaguti, 1939, and Acanthoparyphium marilae Yamaguti, 1934. The eggs of A. shinanense were larger than those of A. spinulosum, and the anterior extent of 2 lateral groups of vitellaria was slightly more limited in A. shinanense than in A. spinulosum. Molecular analysis of nuclear and mitochondrial genes revealed low homology with A. spinulosum from USA (96.1% in 5.8S rRNA) and Ukraine (97.9% in 28S rRNA), Acanthoparyphium n. sp. from USA (98.0% in 28S rRNA), and Acanthoparyphium sp. from Australia, Kuwait, and New Zealand. Biological characteristics, including its first intermediate host and natural definitive hosts, as well as its zoonotic capability, should be elucidated.     

The Morphology of Paranemertes sanjuanensis sp.n. (Nemertea, Monostilifera) from Washington, U.S.A.

The morphology of Paranemertes sanjuanensis sp.n., a new monostiliferous hoplonemertean from San Juan Island, Washington, is described. As in other members of the genus, P. sanjuanensis has numerous eyespots, a proboscis sheath that extends one-half to two-thirds the length of the body, well-developed cephalic and subepidermal glands, and two distinct layers of longitudinal muscles in the body wall of the cerebral region. A precerebral septum is absent, as only fibers from the inner longitudinal layer extend into the proboscis. The cerebral sense organs are well developed and lie just anterior to the brain. The esophagus opens into the rhynchodaeum and leads posteriad, into a highly folded stomach. The intestinal caecum is short and lacks anteriorly directed pouches. Gravid females have numerous ovaries in the posterior two-thirds of their bodies. The proboscis is relatively large and contains an average of 5 reserve stylet sacs, each of which contains 2 to 3 stylets. The stylets are stout and have prominent, helically-arranged grooves.     

Aploparaksis kornyushini n. sp. (Cestoda: Hymenolepididae), a parasite of the woodcock Scolopax rusticola (L.), and its life-cycle

Aploparaksis kornyushini n. sp. is described from a woodcock Scolopax rusticola L. from Lithuania, Russia (Tver' Region) and the Ukraine. Initially, one specimen of this tapeworm was described and figured by Kornyushin (1975) as A. scolopacis Yamaguti, 1935 together with another specimens belonging to the latter species. A. kornyushini n. sp. and A. scolopacis are morphologically very similar species. They can be distinguished by the slightly different length of the rostellar hooks and by the shape of the cirrus, which lacks basal bulbus in the new species. A. kornyushini can be readily distinguished from the remaining species of Aploparaksis Clerc, 1903 from woodcocks by the structure of its fully-developed embryophore, which has polar thickenings and two large or a few smaller lateral projection; this combination of characters is unknown for embryophores other Aploparaksis spp. (except for A. scolopacis). The life-cycle of A. kornyushini was studied under experimental conditions in Lithuania. The metacestodes were located under the chlorogogenous tissue of the intestine of Dendrobaena octaedra (Lumbricidae). The metacestode exhibits a pattern of postembryonal development typical for the cysticercoid modification termed an 'ovoid diplocyst'.     

Amapacanthus amazonicus n. g., n. sp. (Acanthocephala: Diplosentidae: Allorhadinorhynchinae) from Arius passany and Anableps microleps (Pisces) at Maraca Island off northern Brazil

Amapacanthus amazonicus n. g., n. sp. is described from the intestine of Arius passany (Valenciennes) and Anableps microleps Müller. The most important diagnostic features are: a small globular proboscis armed with 6 diagonal rows of 3 stout hooks; middle hooks conspicuously stouter and larger than anterior ones; terminal hooks as long as middle hooks but straighter and more slender; a double-walled proboscis receptacle; a trunk bearing spines anteriorly; and two tubular cement glands in the males. Amapacanthus n. g. is differentiated from Allorhadinorhynchus, Golvanorhynchus and Slendrorhynchus, the other genera of the Allorhadinorhynchinae, by the presence of a globular proboscis armed with a small number (18) of hooks. A key to the species of the Allorhadinorhynchinae is presented.     

Renivermis crocodyli (Digenea: Exotidendriidae) n. g., n. sp. from the kidneys of the saltwater crocodileCrocodylus porosus in Australia

Renivermis crocodyli, n. g., n. sp., is described from the kidneys of the saltwater crocodileCrocodylus porosus Schneider from northern Australia. The genusRenivermis is grouped withExotidendrium Mehra, 1935 andSimhatrema Chattopadhyaya, 1970 in the family Exotidendriidae Mehra, 1935. An amended diagnosis of the family and a key to its genera are given.     

Some ascaridoid nematodes of fishes: Paranisakis and Mawsonascaris n. g.

As a result of examination of type-material and other specimens representing species previously assigned to Paranisakis Baylis, 1923, it is proposed that this genus be reduced to one species, namely P. squatinae Baylis, 1923. The other species are distributed as follows: pastinacae Rudolphi, 1819, australis Johnston & Mawson, 1943 and laymani Mozgovoy, 1950 are assigned to a new genus Mawsonascaris. The main features differentiating Mawsonascaris from Paranisakis are: dentigerous ridges on the lips (absent in Paranisakis), digitiform extensions of the labial pulp (absent in Paranisakis), excretory pore posterior to the nerve-ring (anterior to the nerve-ring in Paranisakis) and long filiform spicules (short and stout in Paranisakis). The following new host records are reported: Rhinobatos cemiculus for P. squatinae; and Aptychotrema banksii, Rhinobatos batillum, Rhynchobatus dijddensis and Taeniura lymma for M. australis. Specimens were not available from teleosts. It is considered that the proposal of Yamaguti (1961) to raise the subgenus Ortoanisakis Mozgovoy, 1951 to full generic status be upheld provisionally, Ortoanisakis containing species from teleosts, formerly in Paranisakis, but described as having no dentigerous ridges and no gubernaculum. These include O. lophii (Yamaguti, 1935), O. halieutaeae (Yamaguti 1941), O. muraenesocis (Yamaguti, 1935), O. lophii hoplobrotulae (Yamaguti, 1941) and O. sciaenae Khan & Begum, 1971. The remaining species formerly in Paranisakis are relegated to the status of species inquirendae.     

Palaearctic species of the genus Confluaria Ablasov (Cestoda,Hymenolepididae): redescriptions of C. multistriata (Rudolphi, 1810) and C. japonica (Yamaguti, 1935), and a description of Confluaria sp.

Confluaria multistriata (Rudolphi, 1810) is redescribed on the basis of specimens from Tachybaptus ruficollis from the material of Rudolphi and Dollfus and new specimens from the same host species from Bulgaria. The types of C. japonica (Yamaguti, 1935) from T. ruficollis are also redescribed and figured. A single specimen from the collection of Krabbe, described as Taenia multistriata, is re-examined and recognised as belonging to a different species of Confluaria, the status of which remains to be established. Criteria for distinguishing the three species are proposed. In view of the present results, some of the previous records of C. multistriata and C. japonica are re-evaluated. The synonymy of the genera Colymbilepis Spasskaya, 1966 and Confluaria Ablasov in Spasskaya, 1966 is confirmed.