Monorchiid trematodes of the painted sweetlips,Diagramma labiosum (Perciformes: Haemulidae), from the southern Great Barrier Reef,including a new genus and three new species

Five monorchiid species are reported from Diagramma labiosum Macleay (Perciformes: Haemulidae) collected from Heron Island on the southern Great Barrier Reef (GBR): two described species, Helicometroides longicollis Yamaguti, 1934 and Diplomonorchis kureh Machida, 2005 and three new species, including one new genus, Asymmetrostoma heronensis n. g., n. sp., Lasiotocus arrhichostoma n. sp. and Proctotrema addisoni n. sp. Helicometroides longicollis and D. kureh were previously reported from the closely related species Diagramma pictum (Thunberg) from Japan. Two further monorchiid species known from D. pictum, Genolopa plectorhynchi (Yamaguti, 1934) and Paraproctotrema fusiforme Yamaguti, 1934, appear to be absent from the southern Great Barrier Reef. Previous reports of two other monorchiids from D. labiosum from the GBR, Paramonorcheides pseudocaranxi Dove & Cribb, 1998 and Helicometroides vitellosus (Durio & Manter, 1968), are shown to have been made in error. The high richness of monorchiids and other trematode families in D. labiosum is consistent with that seen in other haemulids elsewhere.     

Dramatic phenotypic plasticity within species of Siphomutabilus n. g. (Digenea: Cryptogonimidae) from Indo-Pacific caesionines (Perciformes: Lutjanidae)

A survey of Indo-Pacific lutjanids of the subfamily Caesioninae revealed the presence of Siphodera gurukun Machida, 1910 and two new cryptogonimid taxa from off Heron and Lizard Islands on the Great Barrier Reef, Australia, Ningaloo Reef, Western Australia and Rasdhoo Atoll, Maldives. A combined morphological and genetic characterisation of these species shows that they form a clade distinct from the type-species of Siphodera Linton, 1910, S. vinaledwardsii (Linton, 1901), and warrants the proposal of a new genus. Here we propose Siphomutabilus n. g. and transfer Siphodera gurukun Machida, 1986 as the type-species, Siphomutabilus gurukun (Machida, 1986) n. comb. Siphodera aegyptensis Hassanine & Gibson, 2005 is transferred to Siphomutabilus as S. aegyptensis (Hassanine & Gibson, 2005) n. comb. based on morphological and ecological similarities. Siphomutabilus raritas n. sp. is described from Caesio cuning (Bloch) off Lizard Island and S. bitesticulatus n. sp. is described from Pterocaesio marri Schultz off Heron Island. The two new species are unique in that they have two testes, making their morphology broadly consistent with that of Metadena Linton, 1910, yet the molecular analyses conducted here indicates that they are unequivocally united with Siphomutabilus gurukun (which has multiple testes) to the exclusion of Metadena lutiani (Yamaguti, 1942), which was sequenced here. The dramatic phenotypic plasticity observed among such closely related species of Siphomutabilus suggests a secondary modification of what is generally considered a robust generic diagnostic character within this and other digenean families, highlighting the need for a combined morphological and molecular diagnostic approach when characterising these taxa. Siphodera Linton, 1910 is amended to include just two species, the type-species S. vinaledwardsii (Linton, 1901) Linton, 1910 and S. cirrhiti Yamaguti, 1970, which are distinguished by their lack of oral spines and multiple testes that are primarily extracaecal. Siphodera ghanensis Fischthal & Thomas, 1968 is considered a species incertae sedis here based on significant morphological and ecological differences compared with species of Siphodera and Siphomutabilus n. g.     

Pseudangularia gonzalezi n. sp. and Gibsonilepis swifti (Singh, 1952) n. g., n. comb. (Cestoda, Dilepididae) from the House Swift, Apus affinis (J.E. Gray) (Aves, Apodiformes) from Franceville, Republic of Gabon

Nine specimens of Apus affinis (J.E. Gray) were studied at Franceville, Haut-Ogooué Province, Republic of Gabon, for the presence of helminth parasites. Two cestode species of the family Dilepididae were recorded. Pseudangularia gonzalezi n. sp. is distinguished from the most similar species P. europaea Georgiev & Murai, 1993 by having elliptical cirrus-sac, longer vagina, longer rostellar sheath and greater diameter of suckers. An identification key to the species of the genus Pseudangularia Burt, 1938 is proposed. The present study is the first record of the genus Pseudangularia in the Afrotropical Region. Our study confirms that, in dilepidids with vaginal sclerites from swifts, breaking off the cirrus after copulation is a frequent phenomenon. The genus Gibsonilepis n. g. is erected as monotypic for Vitta swifti Singh, 1952 (originally described from the same host species in India) and Gibsonilepis swifti n. comb. is proposed. Gibsonilepis n. g. is distinguished from Vitta Burt, 1938 by its highly elongate rostellum, rostellar sheath much bigger than rostellum, relatively small rostellar hooks possessing strongly developed guard, disc-shaped suckers with weak peripheral musculature and flat or convex central part, long and well-expressed neck, highly lobed two-winged ovary (lobes rounded) and presence of a band consisting of rows of spine-like microtriches along posterior margin of each proglottis. This is the first record of G. swifti in the Afrotropical Region. The separation of G. swifti from the genus Vitta (parasites of swallows) suggests that, contrary to previous opinions, no dilepidid genera are shared by Apodidae (swifts) and Hirundinidae (swallows).     

A review of the Tandanicolinae (=Monodhelminthinae) (Digenea: Fellodistomidae), with a description of Prosogonarium angelae n. sp.

The Tandanicolinae is reviewed, redefined and considered a subfamily of the Fellodistomidae. The Monodhelminthinae Dollfus, 1937, Mehratrematinae Srivastava, 1939, Prosogonariinae Mehra, 1963 and Buckleytrematinae Yamaguti, 1971 are synonyms of the Tandanicolinae. Genera included in the Tandanicolinae are Tandanicola, Monodhelmis, Buckleytrema and Prosogonarium. Burnellus and Mehratrema are made new synonyms of Monodhelmis. The composition of each genus is reviewed. Monodhelmis arii Yamaguti, 1952, Mehratrema arii Gu & Shen, 1979, Mehratrema dollfusi Srivastava, 1939, Monodhelmis philippinensis Velasquez, 1961, Mehratrema polynemusinis Chauhan, 1943 and Mehratrema skrjabini Karyakarte, 1969 are considered synonyms of Monodhelmis torpedinis. Monodhelmis elongatus Bilqees, 1970 is considered a species inquirenda. Prosogonarium angelae n. sp. is described from Euristhmus lepturus from Moreton Bay, Queensland. It is distinguished by the number and distribution of the vitelline follicles and the extent of the caeca. New records are given for Monodhelmis torpedinis from Arius graeffei and E. lepturus, M. trichofurcata from Tandanus tandanus, and Buckleytrema indica from A. graeffei, all from southern Queensland. Buckleytrema indica is redescribed and B. postacetabulorchis is synonymised with that species. Relationships within the Tandanicolinae were considered by cladistic analysis.     

Revision of Entomelas Travassos, 1930 (Nematoda: Rhabdiasidae) with a review of genera in the family

Summary Entomelas entomelas (Dujardin, 1845) Travassos, 1930, the type species of Entomelas, is redescribed based on specimens from Anguis fragilis and Ophisaurus apodus. The generic diagnosis is emended. E. dujardini (Maupas, 1916) Travassos, 1930, Paraentomelas kazachstanika (Sharpilo & Vakker, 1972) Sharpilo, 1976 and Hexadontophorus ophisauri Kreis, 1939 are synonymized with E. entomelas and the genera Paraentomelas and Hexadontophorus fall as synonyms of Entomelas. Kurilonema Szczerbak & Sharpilo, 1969 is synonymized with Entomelas and the type species, K. markovi, is reclassified as Entomelas markovi (Szczerbak & Sharpilo, 1969) n. comb. Entomelas cruszi n. sp. is described from agamid lizards of Sri Lanka. The genera in the Rhabdiasidae are reviewed and a key is provided. Ophiorhabdias Yamaguti, 1943 and Shorttia Singh & Ratnamala, 1977 are designated synonyms of Rhabdias Stiles & Hassall, 1905. ac]19790201     

New collections of blood flukes (Aporocotylidae) from fishes of the tropical Indo-west Pacific,including a new genus,two new species and molecular evidence that Elaphrobates chaetodontis (Yamaguti, 1970) is widespread in the region

We report new collections of the Aporocotylidae from Australia, French Polynesia, and Japan. A new species of Cardicola Short, 1953 is described from Scomberomorus commerson (Lacépède) (Scombridae), off Lizard Island. Cardicola nolani n. sp. can be distinguished from its congeners based on the position of the oötype, the position of the male genital pore, and the absence of an oral sucker. A new species is described from Abalistes stellatus (Anonymous) (Balistidae), also from off Lizard Island. Phylogenetically the new species forms a strongly-supported clade with Cardicola yuelao Yong, Cutmore & Cribb, 2018, which also infects balistids. These two species are distinct from all other aporocotylids in the combination of exceptionally short anterior and long posterior caeca, a lanceolate body, a single testis, an entirely post-ovarian uterus and the position of the oötype; a new genus, Balistidicola, is proposed for them. Balistidicola corneri n. sp. and B. yuelao (Yong, Cutmore & Cribb, 2018) n. comb. are essentially morphologically cryptic, only distinguishable by the form of the spination (B. corneri has five spines per row and B. yuelao has six). Elaphrobates chaetodontis (Yamaguti, 1970) is reported from 21 species of butterflyfishes (Chaetodontidae) from nine locations in tropical Indo-west Pacific; cox1 sequence data demonstrate extensive geographical structuring in this species. Braya jexi Nolan & Cribb, 2006, Elaphrobates milleri (Nolan & Cribb, 2006), and P. corventum Overstreet & Køie, 1989 are each re-reported from their type-hosts, and Pearsonellum pygmaeus Nolan & Cribb, 2004 and Balistidicola yuelao are each reported from a new host.     

Two new species of Pseudohapladena yamaguti, 1952 (Digenea: Waretrematidae) from mugilid fish from the Taiwan Straits,China

Two new species of Pseudohapladena Yamaguti, 1952 (Digenea: Waretrematidae) are described. Pseudohapladena megoorchis n. sp. was obtained from the intestine of Mugil engeli (Bleeker) (Mugilidae), and Pseudohapladena lizae n. sp. from the intestine of Liza carinatus (Cuvier and Valenciennes) (Mugilidae). Pseudohapladena megaorchis is the most closely related in general morphology to Pseudohapladena scatophagi Yamaguti, 1952, but differs from the latter in the position of the hermaphroditic sac, and in the nature and distribution of the vitellaria. Features of P. lizae distinguishing it from other species of the genus include the shorter uterus, which contains only 1 egg, and the lesser extent of the vitellaria.     

Glyphidohaptor safiensis n. sp. (Monogenea: Ancyrocephalidae) from the white-spotted rabbitfish Siganus canaliculatus (Park) (Perciformes: Siganidae) off Oman,with notes on its phylogenetic position within the Ancyrocephalidae Bychowsky & Nagibina, 1968 (sensu lato)

A new ancyrocephalid monogenean is described from the gills of wild White-spottedrabbitfish Siganus canaliculatus (Park) based on morphological and molecular analyses. Glyphidohaptor safiensis n. sp. can be distinguished from other members of the genus by the shape of the accessory piece of the male copulatory organ (MCO). Unlike its congeners, the rod-shaped accessory piece of G. safiensis n. sp. is distally broad and flattened. The MCO of G. safiensis n. sp. is curved, enclosed in a heavy sheath with a terminal flap. Partial large subunit (LSU), partial small subunit (SSU) and the partial SSU, entire internal transcribed spacer region 1 (ITS1) and partial 5.8S rDNA of the new species and two species of Tetrancistrum Goto & Kikuchi, 1917 from the same host and locality were sequenced and subjected to phylogenetic analysis. The LSU rDNA analysis grouped G. safiensis n. sp. with Tetrancistrum sp. from the gills of Siganus fuscescens Houttuyn from Australia, indicating a possible misidentification of the latter. Sequences of the SSU rDNA of the new species were most similar to those for Pseudohaliotrema sphincteroporus Yamaguti, 1953, demonstrating the close relatedness of the genera Pseudohaliotrema Yamaguti, 1953 and Glyphidohaptor Kritsky, Galli & Yang, 2007 within the Ancyrocephalidae. The comparison of the partial SSU (424 bp) and entire ITS1 and partial 5.8S rDNA (246 bp) sequences obtained for G. safiensis n. sp. with the only available sequence of another member of Glyphidohaptor Kritsky, Galli & Yang, 2007, G. pletocirra Paperna, 1972 (HE601931-HE601933) yielded on average 1.08% dissimilarity (a difference of 7 bases), with a p-distance of 0.010 ± 0.004%. This is the first record of a species of Glyphidohaptor from S. canaliculatus and from the Persian Gulf, the Gulf of Oman and the Arabian Sea.

     

New species and new records of Ergasilus Nordmann (Copepoda: Ergasilidae) from the gills of grey mullet (Mugilidae)

Four new Ergasilus species are described from five host species of grey mullet, family Mugilidae, held in the fish collections of The Natural History Museum, London. Ergasilus extensus n. sp. was found on Myxus petardi (Castelnau) from Australia, E. sittangenesis n. sp. on Sicamugil hamiltoni (Day) from Burma, E. piriformis n. sp. on Sicamugil cascasia (Hamilton Buchanan) from India, and E. ecuadorensis n. sp. on Mugil curema Valenciennes and M. hospes Jordan & Culver from Ecuador. New records of E. cyanopictus Caravalho, E. magnicornis Yin, E. orientalis Yamaguti and E. rostralis Ho, Jayarajian & Radhakrishnan on grey mullet are also given.     

The taxonomic status of <Emphasis Type="Italic">Opegaster</Emphasis> Ozaki, 1928 and the description of four new species of <Emphasis Type="Italic">Opecoelus</Emphasis> Ozaki, 1925 (Digenea: Opecoelidae) from marine teleosts in Australian waters

The similarities between Opecoelus Ozaki, 1925, Coitocaecum Nicoll, 1915, Opegaster Ozaki, 1928 and Paropecoelus Pritchard, 1966 and the difficulty of separating Opecoelus and Opegaster are discussed. It is proposed that Opegaster be reduced to synonymy with Opecoelus and the diagnosis of the latter amended to accommodate both forms. Four new species of Opecoelus are described from marine teleosts in Australian waters. These are Opecoelus woolcockae n. sp. from Acanthopagrus butcheri and A. australis from off South Australia, New South Wales and southern Queensland, O. pomatomi n. sp. from Pomatomus saltatrix off New South Wales, O. crowcrofti n. sp. from Atherinomorus ogilbyi off southern Queensland and O. queenslandicus n. sp. from Apogon fasciatus off southern Queensland. The following new combinations are formed: Opecoelus gonorhynchi (Gavrilyuk, 1979) n. comb., O. elongatus (Yamaguti, 1959) n. comb., O. pentadactylus (Manter, 1940) n. comb., O. apogonichthydis (Yamaguti, 1938) n. comb., O. cameroni (Caballero & Caballero, 1969) n. comb., O. dendrochiri (Yamaguti, 1970) n. comb., O. hawaiiensis (Yamaguti, 1970) n. comb., O. jamunicus (Srivastava, 1968) n. comb., O. longivesiculus (Yamaguti, 1952) n. comb., O. mastacembalii (Harshey, 1937) n. comb., O. mehrii (Harshey, 1937) n. comb., O. synodi (Manter, 1947) n. comb., O. tamori (Yamaguti, 1938) n. comb., O. bothi (Yamaguti, 1970) n. comb., O. caulopsettae (Manter, 1954) n. comb., O. beliyai (Pande, 1937) n. comb., O. brevifistulus (Ozaki, 1928) n. comb., O. cryptocentri (Yamaguti, 1958) n. comb., O. dactylopteri (Yamaguti, 1970) n. comb., O. dermatogenyos (Yamaguti, 1970) n. comb., O. ditrematis (Yamaguti, 1942) n. comb., O. gobii (Yamaguti, 1952) n. comb., O. hippocampi (Shen, 1982) n. comb., O. iniistii (Yamaguti, 1970) n. comb., O. lobulus (Wang, 1977) n. comb., O. macrorchis (Yamaguti, 1938) n. comb., O. parapristipomatis (Yamaguti, 1934) n. comb., O. pritchardae (Overstreet, 1969) n. comb., O. syngnathi (Yamaguti, 1934) n. comb., O. lutiani (Bravo-Hollis & Manter, 1957) n. comb., O. ovatus (Ozaki, 1928) n. comb., O. plotosi (Yamaguti, 1940) n. comb. and O. rectus (Ozaki, 1928) n. comb.; all the new combinations were previously species of Opegaster.     

Singhamoeba horticola (Singh & Hanumaiah, 1979) N. Comb., Type Species of Singhamoeba N. G.

ABSTRACT. Small cyst-forming amoebae described as Schizopyrenus horticolus Singh & Hanumaiah, 1979, were cultured from sediment samples taken from three sites along the Chester River, Kent County, MD. Morphological studies on cysts and trophozoites showed sufficient differences between Sch. horticolus and the type species, Sch. russelli Singh, 1952, to justify its removal from that genus. A new genus, Singhamoeba is proposed to accommodate the species horticolus .     

Zoogonidae (Digenea) from southern Great Barrier Reef fishes with a description of Steganoderma (Lecithostaphylus) gibsoni n. sp.

Two species of the Zoogonidae are recorded from Heron Island on the southern Great Barrier Reef. Steganoderma (Lecithostaphylus) gibsoni n. sp. is described from the intestine of Abudefduf whitleyi (Pomacentridae). The new species is distinguished by the combination of the following: pedunculate ventral sucker, caeca extending well past testes, presence of two-chambered internal seminal vesicle, vitelline follicles extending only to anterior margin of testes, and testes close to ventral sucker. Zoogonus pagrosomi Yamaguti, 1939 is recorded from Lethrinus atkinsoni (Lethrinidae). This species has been recorded previously only from a sparid from Japan. A new combination, Steganoderma (Lecithostaphylus) fugus (Zhang, Qiu & Li, 1986), is made.     

Eight new species ofHamatopeduncularia Yamaguti, 1953 (Monogenea: Ancyrocephalidae) from Ariidae of Peninsular Malaysia

Eleven species of Hamatopeduncularia Yamaguti, 1953 were found on six species of ariids caught off the west coast of Peninsular Malaysia. They are: H. arii Yamaguti, 1953 from Arius maculatus; H. thalassini Bychowsky & Nagibina, 1969 from A. thalassinus; H. simplex Bychowsky & Nagibina, 1969 from Osteogeneiosus militaris; H. isosimplex n. sp. from A. venosus, A. maculatus and A. sagor; H. malayanus n. sp. from A. caelatus; H. manjungi n. sp. from A. thalassinus; H. papernai n. sp. from A. maculatus; H. elongatum n. sp. from A. thalassinus; H. longicopulatrix n. sp. from A. venosus; H. venosus n. sp. from A. venosus; and H. malaccensis n. sp. from O. militaris and A. maculatus.     

A new species of <Emphasis Type="Italic">Pseudopandarus</Emphasis> Kirtisinghe, 1950 (Copepoda: Siphonostomatoida: Pandaridae) from sharks of the genus <Emphasis Type="Italic">Squalus</Emphasis> L. in New Caledonian waters

Both sexes of a new species of pandarid copepod are described from sharks of the genus Squalus L. (Squaliformes: Squalidae). Specimens of Pseudopandarus cairae n. sp. were collected from Squalus bucephalus Last, Séret & Pogonoski and S. melanurus Fourmanoir & Rivaton in New Caledonian waters, the first parasitic copepod to be described from either host species. This is the eighth nominal species of Pseudopandarus Kirtisinghe, 1950 and the first to be described from a shark of the order Squaliformes. Pseudopandarus cairae n. sp. is easily distinguished from P. australis Cressey & Simpfendorfer, 1988, P. longus (Gnanamuthu, 1951) Cressey, 1967, and P. pelagicus Rangnekar, 1977 in having the female genital complex concealed beneath an elongate dorsal genital shield with a trilobed posterior margin. It can be distinguished from P. gracilis Kirtisinghe, 1950 and P. scyllii Yamaguti & Yamasu, 1959 by the armature of the leg 4 endopod and by the proportions of the dorsal genital shield. The new species is unique among known species of Pseudopandarus in its possession of only 1 setal element on the distal endopod segment of leg 4. In addition to describing the new species, the host associations of all species of Pseudopandarus are reviewed and observations are made regarding sexual dimorphism and mode of attachment. A key to the species considered valid is provided.     

Pseudobacciger cheneyae n. sp. (Digenea: Gymnophalloidea) from Weber’s chromis (Chromis weberi Fowler & Bean) (Perciformes: Pomacentridae) at Lizard Island,Great Barrier Reef,Australia

A new species of digenean, Pseudobacciger cheneyae n. sp., is described from the intestines of Weber’s chromis (Chromis weberi Fowler & Bean) from off Lizard Island, Great Barrier Reef, Australia. This species differs from the three described species of Pseudobacciger Nahhas & Cable, 1964 [P. cablei Madhavi, 1975, P. harengulae Yamaguti, 1938 and P. manteri Nahhas & Cable, 1964] in combinations of the size of the suckers and the length of the caeca. The host of the present species is a perciform (Family Pomacentridae) which contrasts with previous records of the genus which are almost exclusively from clupeiform fishes. The genus Pseudobacciger is presently recognised within the family Faustulidae (Poche, 1926) but phylogenetic analyses of 28S and ITS2 rDNA show that the new species bears no relationship to species of four other faustulid genera (Antorchis Linton, 1911, Bacciger Nicoll, 1924, Paradiscogaster Yamaguti, 1934 and Trigonocryptus Martin, 1958) but that instead it is nested within the Gymnophalloidea (Odhner, 1905) as sister to the Tandanicolidae (Johnston, 1927). This result suggests that the Faustulidae is polyphyletic.     

Description of a New Genus and Three New Species of Figitinae (Hymenoptera: Cynipoidea: Figitidae) from Colombia

A new genus and three new species of Figitinae (Hymenoptera: Figitidae) are described from Colombia: Ferpereira Pujade-Villar n. gen., Ferpereira fiorellae Pujade-Villar n. sp., Neralsia levis Pujade-Villar & Petersen-Silva n. sp., and Figites colombiensis Pujade-Villar & Paretas-Martínez n. sp., which is the first species of Figites Latreille from Colombia and the second from South America. The diagnostic characters of these new taxa are illustrated.     

Monogeneans from <Emphasis Type="Italic">Epinephelus chlorostigma</Emphasis> (Val.) (Perciformes: Serranidae) off New Caledonia,with the description of three new species of diplectanids

Gill monogeneans from the brownspotted grouper Epinephelus chlorostigma (Val.) collected in deep water off the coral barrier reef of New Caledonia, South Pacific, comprise seven species. These include the ancyrocephalid Haliotrema sp., the capsalid Allobenedenia cf. epinepheli Yamaguti, 1968, and five diplectanids, namely Pseudorhabdosynochus epinepheli (Yamaguti, 1938), reported in a previous paper, P. cyanopodus Sigura & Justine, 2008 and P. podocyanus Sigura & Justine, 2008, two species originally described from E. cyanopodus Richardson, P. stigmosus n. sp., P. exoticoides n. sp. and Diplectanum femineum n. sp. P. stigmosus is characterised by a sclerotised vagina with a straight primary canal, large ovoid primary chamber and spherical secondary chamber. P. exoticoides is a highly aberrant species, with a thick-walled male quadriloculate organ and a discoid sclerotised vagina with an exceptional structure. Interestingly, P. exoticoides resembles P. exoticus Sigura & Justine, 2008, a species from E. cyanopodus, and P. stigmosus resembles P. cyanopodus and P. podocyanus, also both from E. cyanopodus, suggesting close relationships between the diplectanid faunae of these two fish species. D. femineum belongs to a group of diplectanids, provisionally classified as ‘Diplectanum’ Diesing, 1858, which all share a small funnel-shaped male copulatory organ. In contrast to other members of this group which have no sclerotised vagina, D. femineum has a sclerotised vagina with the same organisation as those of species of Pseudorhabdosynochus Yamaguti, 1958. This suggests that the species of ‘Diplectanum’ from groupers are closer to Pseudorhabdosynochus than suggested by the structure of the male organs.     

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.