Description of a new trypanorhynch species (Cestoda) from Indonesian Borneo, with the suppression of Oncomegoides and the erection of a new genus Hispidorhynchus

A new species of Oncomegas Dollfus, 1929 is described from the cowtail stingray, Pastinachus atrus (Macleay), collected in the Makassar Strait, Indonesian Borneo. Oncomegas trimegacanthus n. sp. possesses 2 oval bothria, gland cells within the bulbs, prebulbar organs, a distinctive basal armature with a single macrohook on the bothrial surface of the asymmetrical basal swelling, and a heteroacanthous, heteromorphous metabasal armature with 10 hooks per principle row. It differs from congeners by its possession of additional enlarged hooks at the base of the tentacle. Because of apparent morphological similarities, we suppress the genus Oncomegoides Beveridge & Campbell, 2005 with Oncomegas, and place the type and only species, Oncomegoides celatus Beveridge & Campbell, 2005 , within Oncomegas as Oncomegas celatus n. comb. Three species of Oncomegas , namely, Oncomegas paulinae Toth, Campbell & Schmidt, 1992, Oncomegas australiensis Toth, Campbell & Schmidt, 1992, and Oncomegas aetobatidis Campbell & Beveridge, 2009, differ from other species, possessing testes posterior to the ovary and a metabasal armature consisting of tiny, relatively homeomorphous hooks, with more than 14 hooks per principle row. Based on these morphological differences, a new genus, Hispidorhynchus n. gen., is erected, with Hispidorhynchus australiensis n. comb. as the type species.     

Ancipirhynchus afossalis n. g., n. sp. (Trypanorhyncha: Otobothriidae), from two species of sharks off Indonesian and Malaysian Borneo

A new genus of trypanorhynch cestode is described from two species of sharks, the sliteye shark Loxodon macrorhinus Müller & Henle and the straight-tooth weasel shark Paragaleus tengi (Chen) collected in the Makassar Strait (off Indonesian Borneo) and Sulu Sea (off Malaysian Borneo). Ancipirhynchus afossalis n. g., n. sp. possesses two bothria and a heteroacanthous, heteromorphous tentacular armature with three distinctive files of hooks on the external tentacle surface but lacks prebulbar organs and gland cells within the tentacular bulbs. The hook arrangement of alternating files on the external surface of the tentacle resembles that seen in the superfamily Otobothrioidea Dollfus, 1942 in the genus Fossobothrium Beveridge & Campbell, 2005. However, the new species lacks the defining characteristic of this group, i.e. the paired bothrial pits. A Bayesian inference (BI) analysis of 37 LSU sequences of trypanorhynchs from three superfamilies provided evidence supporting the taxonomic placement of Ancipirhynchus afossalis n. g., n. sp. within the Otobothrioidea.     

Trypanorhynch cestodes from elasmobranchs from the Gulf of Oman, with the description of Prochristianella garshaspi n. sp. (Eutetrarhynchidae)

In a study on the order Trypanorhyncha Diesing, 1863, a total of 35 specimens belonging to nine species of elasmobranch in the Gulf of Oman, was examined. The following trypanorhynch species were identified: Pterobothrium lesteri Campbell & Beveridge, 1996, Otobothrium carcharidis (Shipley & Hornell, 1906), Eutetrarhynchus platycephali Palm, 2004, Parachristianella indonesiensis Palm, 2004, Pa. monomegacantha Kruse, 1959 and Prochristianella mooreae Beveridge, 1990. Prochristianella garshaspi n. sp. is described from Pastinachus sephen (Forsskål) and Rhinoptera sp. The new species is allocated to the genus Prochristianella Dollfus, 1946 on the basis of the presence of two bothria, prebulbar organs, and a heteroacanthous typical tentacular armature with relatively few hooks in each principal row, hollow hooks increasing in size from antibothrial and then decreasing towards the bothrial surface of the tentacle, hooks 1 and 1′ being separated, and a basal swelling with characteristic billhooks increasing in size towards the bothrial surface. The lack of microscopically visible microtriches on the scolex distinguishes the new species from P. hispida (Linton, 1890), P. clarkeae Beveridge, 1990, P. thalassia (Kovaks & Schmidt, 1980), P. multidum Friggens & Duszynski, 2005 and P. cairae Schaeffner & Beveridge, 2012. Prochristianella garshaspi n. sp. can be distinguished from the remaining species within the genus by a combination of the following morphological features: the presence of numerous gland-cells within the tentacular bulbs, the number of rows on the basal swelling, the number of hooks per half spiral row, the size of the principal hooks, the number of the testes and the presence of an external seminal vesicle.     

Redescription of <Emphasis Type="Italic">Cetorhinicola acanthocapax</Emphasis> Beveridge &; Campbell, 1988 (Cestoda: Trypanorhyncha) from the Basking Shark <Emphasis Type="Italic">Cetorhinus maximus</Emphasis> (Gunnerus)

Cetorhinicola acanthocapax Beveridge & Campbell, 1988 is redescribed based on adult specimens collected from a basking shark Cetorhinus maximus (Gunnerus) off the east coast of New Zealand. Both the mature and gravid segments are described for the first time, and the first scanning electron micrographs of the armature and scolex microtriches are provided. Novel features include the opening of the vagina anterior to the cirrus-sac and the extension of the vagina anterior to the cirrus-sac. Pectinate microtriches are present on the anterior quarter of the pars pedunculus scolecis scattered between filiform microtriches; the bothrial margins are covered with tridigitate microtriches, while the adherent surface of the bothria have pectinate microtriches. The additional morphological features described are consistent with a close association between Cetorhinicola Beveridge & Campbell, 1988 and the Eutetrarhynchoidea Guiart, 1927.     

Three new genera of trypanorhynch cestodes from Australian elasmobranch fishes

Three new genera of trypanorhynch cestodes from Australian elasmobranch fishes collected in the Arafura Sea, off the Northern Territory, are described. Fossobothrium perplexum n. g., n. sp. (Otobothriidae), from the spiral valves of Anoxypristis cuspidata (Latham) and Pristis zijsron Bleeker, is similar to the otobothriid genera Pseudotobothrium Dollfus, 1942 and Poecilancistrium Dollfus, 1929 in possessing bothrial pits and a band of hooks on the tentacle, but differs from all known otobothriid genera in having the pits joined by a prominent velum. Iobothrium elegans n. g., n. sp. (Otobothriidae), from the spiral valve of Himantura jenkinsi (Annandale), is placed in the Otobothriidae because it possesses bothrial pits, but differs from Otobothrium Linton, 1890 and other genera in lacking intercalary hooks between the principal rows and in possessing a chainette on the external surface of the tentacle in the metabasal region. Oncomegoides celatus n. g., n. sp. (Eutetrarhynchidae), from the spiral valve of Dasyatis microps (Annandale) and Himantura jenkinsi, resembles Oncomegas Dollfus, 1929 in possessing two bothria and a megahook on the bothrial surface of the basal armature, but differs in possessing an extra row consisting of four intercalary hooks formed by the overlapping of two intercalary hooks on the external tentacular surface between each of the opposing principal rows and is therefore an atypical heteroacanth.     

<Emphasis Type="Italic">Nataliella marcelli</Emphasis> n. g., n. sp. (Cestoda: Trypanorhyncha: Rhinoptericolidae) from Hawaiian fishes

A new trypanorhynch cestode from Hawaiian waters is described based on specimens in the collection of the Meguro Parasitological Museum, Tokyo, and newly collected specimens. Nataliella marcelli n. g., n. sp. is characterised by its elongate, craspedote scolex with four small, ear-shaped bothria, an elongate pars vaginalis and long bulbs. The homeoacanthous homeomorphous metabasal armature is comprised of five or six slender, solid hooks per half spiral row. A distinctive basal armature is present, including a combination of six characteristically shaped macrohooks not previously described for trypanorhynchs. The surface ultrastructure consists of gladiate spiniform microtriches that cover the distal and proximal bothrial surface and filiform microtriches on the scolex peduncle. The adults are not known. Nataliella is assigned to the family Rhinoptericolidae Carvajal & Campbell, 1975 based on its possession of four bothria, prebulbar organs and no chainette or intercalary hooks. The family diagnosis is amended to accommodate the new genus. Rhinoptericola megacantha Carvajal & Campbell, 1975 is considered the most closely related species, a position that has been confirmed by molecular analyses of the SSU and LSU rDNA. Nataliella n. g. is intermediate in morphology between the homeoacanth family Tentaculariidae Poche, 1926 (superfamily Tentacularioidea) and the Rhinoptericolidae and other eutetrarhynchid genera (superfamily Eutetrarhynchoidea), sharing characters of both superfamilies.     

Surface ultrastructure of the elasmobranchia parasitizing <Emphasis Type="Italic">Grillotiella exilis</Emphasis> and <Emphasis Type="Italic">Pseudonybelinia odontacantha</Emphasis> (Trypanorhyncha,Cestoda)

The surface ultrastructure of two monotypic trypanorhynch genera is described based on new material of Grillotiella exilis (Linton, 1909) and type material of Pseudonybelinia odontacantha Dollfus 1966. In G. exilis, spiniform microtriches cover the bothrial surfaces and the anterior part of the pars vaginalis posterior to the bothria. Bifurcate microtriches adorn the bothrial margins, filiform microtriches the scolex peduncle, and capilliform microtriches the posterior scolex end. This microthrix pattern resembles that found in, e.g., Grillotia erinaceus (van Beneden, 1858), with the difference that the anterior part of the pars vaginalis is covered with a collar of multidigitate palmate microtriches. The position of Grillotiella within the Grillotiinae, Lacistorhynchidae is supported based on these data. The bothria and scolex peduncle of P. odontacantha are covered with acerosate and unciniform microtriches on the distal bothrial surface and capilliform microtriches on the scolex peduncle. Short filiform microtriches cover the appendix. The microthrix pattern resembles that of the Tentaculariidae but with unciniform and acerosate microtriches densely covering the entire distal bothrial surface. Tegumental grooves are present on the posterior bothrial margin. They can be distinguished from bothrial pits in otobothrioid trypanorhynchs in having similar unciniform microtriches compared to the other parts of the bothrial surface and in lacking any spiniform microtriches. With the absence of bothrial pits as characteristic for the otobothrioids and its characteristic microthrix pattern, P. odontacantha together with Paranybelinia otobothrioides Dollfus 1966, both belonging to the Paranybeliniidae change their position in the most recent system from the Otobothrioidea into the Tentacularioidea.     

A new genus and species of the trypanorhynch family Otobothriidae Dollfus, 1942 from the slender weasel shark <Emphasis Type="Italic">Paragaleus randalli</Emphasis> Compagno,Krupp &amp; Carpenter (Hemigaleidae) in the Persian Gulf

A survey on the cestode fauna of Paragaleus randalli Compagno, Krupp & Carpenter in the Persian Gulf resulted in the discovery of a new trypanorhynch species of the family Otobothriidae Dollfus, 1942, the second otobothrioid species hosted by the family Hemigaleidae Hasse. The new species exhibits the closest morphological similarity to Pristiorhynchus palmi Schaeffner & Beveridge, 2013, the type- and only species of its genus. However, the new species differs from P. palmi in the position of the bothrial pits, the morphology and oncotaxy of the basal armature, the commencement of the hook files on the internal surface, a wider scolex peduncle in the pars bulbosa than in the pars vaginalis, a long neck and the presence of a lateral bothrial groove connecting the two bothrial pits to each other. The latter character is a unique trait within the Otobothrioidea Dollfus, 1942. Considering such differences, a new genus, Olgaella n. g., was erected to accommodate O. elenae n. g., n. sp. within the Otobothriidae. The evolutionary relatedness of the bothrial pits of the Otobothrioidea and the bothrial grooves of the Lacistorhynchoidea Guiart, 1927 is discussed.     

Gilquiniid cestodes (Trypanorhyncha) from elasmobranch fishes off New Caledonia with descriptions of two new genera and a new species

Cestodes were collected from deep-sea sharks caught off New Caledonia, South Pacific. Vittirhynchus squali n. g., n. sp. (Trypanorhyncha: Gilquiniidae) is described from the spiral valve of Squalus melanurus Fourmanoir & Rivaton. The new genus possesses four bothria and a typical heteroacanthous metabasal armature but has a file of three macrohooks forming a short chainette on the internal surface of the basal armature. Sagittirhynchus aculeatus n. g., n. sp., from the spiral valve of Centrophorus sp. (undescribed), also has four bothria and a typical heteroacanthous armature but lacks a distinctive basal swelling and has the final hooks of each principal row prominently enlarged. Gilquinia minor n. sp., from the spiral valve of Centrophorus sp. (undescribed), is distinguished by the presence of only five hooks per principal row compared with eight in congeners. Gilquinia sp. is reported from Squalus melanurus. G. robertsoni Beveridge, 1990 is reported from S. megalops (Macleay).     

Two new species of Echinobothrium (Cestoidea: Diphyllidea) from myliobatiform elasmobranchs in the Gulf of California, México

Two new species of diphyllidean cestodes, Echinobothrium mexicanum n. sp., and Echinobothrium fautleyae n. sp., are described, the former from the spiral intestines of the bat rays Myliobatis californicus and Myliobatis longirostris and the latter from the spiral intestine of the cownose ray Rhinoptera steindachneri, all caught in the Gulf of California, México. Echinobothrium mexicanum is most easily distinguished from the majority of the species of the genus by the number of large apical hooks in each dorsoventral group (23) and from the remainder in the number of lateral hooklets in each group on the scolex. Echinobothrium fautleyae differs conspicuously from all other members of the genus in that the first and last lateral hooklets in each group are distinctly larger than the other hooklets in each group. Serial sections of the scoleces of these 2 new species confirm that the attachment structures on the scolex are bothria, rather than bothridia, as has been described in other species in the genus, suggesting that the attachment structures of the scolex should be examined in more detail in the genus in general. Palmate microtriches of various forms cover the proximal bothrial surfaces of both new species and are also found on the dorsal bothrial surfaces of E. fautleyae. The distal bothrial surfaces of E. mexicanum are covered with slender spiniform and short filiform microtriches. The cephalic peduncles of both species possess short filiform microtriches only. Comparison of these 2 new species with the other 3 species in this genus that have been examined with SEM suggests that the various forms and distributions of these microtriches is unique in each of these 2 species. We believe these features will prove to be taxonomically useful.     

Poecilorhynchus perplexus n. g., n. sp. (Trypanorhyncha: Eutetrarhynchidae) from the brownbanded bambooshark, Chiloscyllium punctatum Müller & Henle, from Australia

A new genus of trypanorhynch cestodes is described from the brownbanded bambooshark, Chiloscyllium punctatum Müller & Henle (Hemiscylliidae) from off Nickol Bay, Western Australia. Poecilorhynchus perplexus n. g., n. sp. is placed in the Eutetrarhynchidae Guiart, 1927 because it is characterised by an elongate, acraspedote scolex with two oval bothria, the absence of bothrial pits, elongate bulbs, the presence of gland-cells within the bulbs and prebulbar organs, retractor muscles inserting at the base of each bulb and an acraspedote strobila. It can be distinguished from all other genera in this family by its possession of a poeciloacanthous typical armature, with a chainette composed of two longitudinal files of uncinate hooks on the external tentacular surface.     

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.     

Review of the genus Eutetrarhynchus Pintner, 1913 (Trypanorhyncha: Eutetrarhynchidae), with the description of Eutetrarhynchus beveridgei n. sp.

The genus Eutetrarhynchus Pintner, 1913 is revised. Eutetrarhynchus beveridgei n. sp. is described from the spiral intestine of the dwarf whipray, Himantura walga (Müller & Henle) (Myliobatiformes: Dasyatidae), from the South China Sea off the Malaysian part of Borneo. The new species is characterised by a slender, elongate scolex, two oval bothria, muscular bulbs, retractor muscles inserting at the base of the bulbs, and the presence of gland-cells and prebulbar organs. The tentacular armature is typical heteroacanthous with heteromorphous hooks. Eutetrarhynchus beveridgei n. sp. is allocated to the genus due to its distinct segment morphology featuring two internal seminal vesicles and scattered testes occupying the complete intervascular space. It differs from congeners in its relatively small size, much smaller scolex regions and in the presence of a basal armature with a distinct basal swelling. Eutetrarhynchus cortezensis Friggens & Duszynski, 2005 is transferred to Dollfusiella Campbell & Beveridge, 1994, as D. cortezensis n. comb., on the basis of its segment morphology, with testes in a linear arrangement and the absence of internal seminal vesicles. A new generic diagnosis and a key for the identification of species of Eutetrarhynchus is provided.     

Redescriptions of species of Tetrarhynchobothrium Diesing, 1850 and Didymorhynchus Beveridge & Campbell, 1988 (Cestoda: Trypanorhyncha), with the description of Zygorhynchus borneensis n. sp

Tetrarhynchobothrium tenuicolle Diesing, 1850 is redescribed from the type-specimens collected from Raja clavata Linnaeus in the Adriatic Sea. T. striatum (Wagener, 1854) is redescribed from voucher specimens from the type host, Myliobatis aquila Linnaeus, from the type-locality, off Naples, Italy. The two species are very similar in tentacular armature, but are provisionally maintained as independent species, since the armature of T. tenuicolle cannot be fully described and because all available specimens of T. striatum are immature, limiting comparisons of potential differences in segment anatomy. T. setiense Dollfus, 1969 is treated as a synonym of T. striatum. Zygorhynchus borneensis n. sp. is described from Himantura uarnacoides (Bleeker) and H. pastinacoides (Bleeker) off Sabah, Malaysia. The new species is distinguished from its congeners by the very small hooks present in the basal region and by the presence of a uterine pore. The metabasal tentacular armature of Didymorhynchus southwelli Beveridge & Campbell, 1988, described for the first time, is homeoacanthous and homeomorphous in form. However, it has a basal swelling with hook rows originating on the bothrial surface and terminating on the antibothrial surface of the tentacle.     

Two new species of Echinobothrium van Beneden, 1849 (Cestoda: Diphyllidea) from the Persian Gulf

Two new species of diphyllidean cestodes are described from the Persian Gulf, Echinobothrium persiense n. sp. from Rhinobatos punctifer Compagno & Randall and Echinobothrium hormozganiense n. sp. from Mustelus mosis Hemprich & Ehrenberg. E. persiense is the first record of a species of Echinobothrium van Beneden, 1849 from R. punctifer and these two new species increase the number of diphyllideans known from the Persian Gulf from one to three. The number of apical hooks of E. persiense (hook formula: {5-6 6/5 5-6}) is distinct from all other species in the genus except for E. affine Diesing, 1863, E. harfordi McVicar, 1976, E. bonasum Williams & Campbell, 1980, E. fautleyae Tyler & Caira, 1999, E. syrtense (Neifar, Tyler & Euzet, 2001) Tyler, 2006 (emend), E. chisholmae Jones & Beveridge, 2001, E. tetabuanense Ivanov & Caira, 2012, E. sematanense Ivanov & Caira, 2012 and E. weipaense Ivanov & Caira, 2012. Echinobothrium persiense can be distinguished from all other species of the genus with 11 apical hooks by a combination of the following features: armed cephalic peduncle, testes arranged in a single column, lateral hooklets arranged in two groups, U-shaped ovary, cephalic peduncle length (124-181 μm), genital pore and cirrus-sac position, and by having 10-14 spines per row on the cephalic peduncle. Echinobothrium hormozganiense has a hook formula of {12-15 16/15 12-15} and is similar to E. musteli Pintner, 1889, E. notoguidoi Ivanov, 1997 and E. diamanti Ivanov & Lipshitz, 2006 by possessing additional spines between the rostellum and the bothria. It differs from E. musteli by having an H-shaped ovary and lateral hooklets arranged in two lateral groups, and the number of spines per row on the cephalic peduncle (18-21) readily differentiates it from E. notoguidoi (24-26) and E. diamanti (95-118). With these two new species, Echinobothrium van Beneden, 1849 now includes 45 valid species.     

Bathygrillotia n. g. (Cestoda: Trypanorhyncha), with redescriptions of B. rowei (Campbell, 1977) n. comb. and B. kovalevae (Palm, 1995) n. comb.

Bathygrillotia n. g. (Cestoda: Trypanorhyncha) is erected for B. rowei (Campbell, 1977) n. comb. and B. kovalevae (Palm, 1995) n. comb. The new genus is based on the possession of two bothria, an atypical, heteroacanthous, heteromorphous armature with longitudinal files of hooks on the external surface of the tentacle associated with each principal row, each consisting of a large anterior hook followed by two smaller hooks. Bathygrillotia is allocated to the Lacistorhynchoidea Guiart, 1927 and its relationships with Grillotia Guiart, 1927 are discussed.