Redescription of Proteocephalus glanduligerus (Cestoda: Proteocephalidea), a parasite of clariid catfishes in Africa with a unique glandular apical organ

The tapeworm Proteocephalus glanduligerus (Janicki, 1928) Fuhrmann, 1933 (Cestoda: Proteocephalidea), a parasite of clariid catfishes (Clarias spp.) in Africa, is redescribed on the basis of an evaluation of voucher material and newly collected specimens from Clarias gariepinus and C. cf. anguillaris from the Sudan, Ethiopia, and South Africa. The most typical characteristic of P. glanduligerus (previously misspelled as P. glanduligera or P. glanduliger) is the presence of an extremely large glandular apical organ, the size of which is 1.6-3.5 times larger than that of the suckers. In addition, other morphological characteristics unreported in previous accounts are provided, such as an unusual position of osmoregulatory canals (situated close to each other, with the dorsal canal latero-ventral to testes), the presence of a vaginal sphincter, several (usually 3-5) uterine pores, and eggs with paired lateral auricular swellings (extensions) of the outer envelope.     

A new genus and species of proteocephalidean (Cestoda) from Clarias catfishes (Siluriformes: Clariidae) in Africa

A new proteocephalidean cestode is described from 2 catfishes, Clarias gariepinus (type host) and C. cf. anguillaris (Siluriformes: Clariidae), from Ethiopia (type locality), Sudan, Tanzania, and Zimbabwe, and a new genus, Barsonella, is proposed to accommodate it. The genus belongs to the Proteocephalinae because its genital organs (testes, ovary, vitellarium, and uterus) are situated in the medulla. Barsonella lafoni, the type and only species of the new genus, is characterized mainly by the possession of an additional opening of each sucker; circular musculature on the anterior margin of suckers, serving as a sphincter; a small thin-walled glandular apical organ; absence of well-developed osmoregulatory canals in mature, pregravid, and gravid proglottids; and a large strobila, up to 173 mm long and 3.2 mm wide. Species of Marsypocephalus Wedl, 1861 (Marsypocephalinae), other large-sized proteocephalidean tapeworms occurring sympatrically in African catfishes (Clarias and Heterobranchus) and also possessing a sphincter-like, circular musculature on the anterior part of suckers, differ from B. lafoni in the absence of an additional sucker opening and glandular apical organ, the cortical position of the testes, well-developed osmoregulatory canals throughout the strobila, and a large cirrus sac. Proteocephalus glanduligerus (Janicki, 1928), another cestode parasitic in Clarias spp. in Africa, is much smaller than B. lafoni (maximum length 15 mm), has suckers without additional opening and circular musculature on the suckers, a large-sized glandular organ, much larger than suckers, and well-developed osmoregulatory canals. Comparison of partial sequences of the 28S rRNA gene for 7 samples of B. lafoni from 2 different hosts and 4 localities in Ethiopia, Sudan, and Tanzania has shown a very low genetic variability. In a limited phylogenetic analysis, B. lafoni formed a clade with Corallobothrium solidum Fritsch, 1886 (Proteocephalidae: Corallobothriinae), an African electric catfish parasite. This clade was the sister group of almost all Neotropical taxa from pimelodid and other catfishes.     

Pterobothrioides,a new genus of tapeworms (Cestoda: Trypanorhyncha: Pterobothriidae) from dasyatid stingrays in the Eastern Atlantic and Pacific Oceans

Two new species of pterobothriid trypanorhynch cestodes representing a new genus are described from dasyatid stingrays taken in Pacific coastal waters off Mexico and Costa Rica and from Atlantic waters off Senegal, West Africa. Pterobothrioides carvajali n. g., n. sp. is described from Dasyatis longus (Garman) from Pacific coastal waters off Mexico and Costa Rica. P. petterae n. g., n. sp. is described from Gymnura altavela (Linnaeus) from Atlantic coastal waters off West Africa. Both species resemble other pterobothriids in their possession of four pedicellate bothridia in a cruciform arrangement, elongated scolex and bulbs, heteroacanthous armature with five hooks per principal row, one or more intercalary rows and a band consisting of irregular files of microhooks on the external tentacular surface. Both new species are unique in the possession of a simple chainette of hooks in addition to a band of microhooks in the tentacle armature. The chainette hooks of P. carvajali are robust, rose-thorn-shaped hooks with large rounded bases. The chainette of P. petterae consists of smaller uncinate hooks that are most distinct in the basal region of the tentacle armature and progressively decrease in size until they become almost indistinguishable from the band microhooks in the distal metabasal region. A new genus, Pterobothrioides, is proposed to accommodate these two new species, combining a chainette, considered characteristic of poeciloacanths, with the band of hooks characteristic of atypical heteroacanths. It is suggested that through changes in hook number and arrangement the typical heteroacanths, having bands of hooks, evolved into poeciloacanths with chainettes and that clades are now apparent in the family Pterobothriidae.     

Redescription of Cystidicoloides fischeri based on specimens from piranhas in Brazil, and erection of a new genus (Nematoda: Cystidicolidae)

The cystidicolid nematode Cystidicoloides fischeri (Travassos, Artigas and Pereira, 1928) is redescribed from specimens collected from the stomach of the San Francisco piranha, Pygocentrus piraya (Cuvier), and the white piranha, Serrasalmus brandtii (Lütken) (both Characidae, Characiformes) (new host records), from the Três Marias Reservoir, Upper S?o Francisco River, Minas Gerais state, Brazil. The morphology of this type species of Cystidicoloides Skinker, 1931, studied with both light and scanning electron microscopy, is characterized by some taxonomically important, previously unreported features, such as the presence of a cephalic cuticular collarette, subdorsal and subventral cephalic spikes, cuticular tooth-like elevations inside the prostom, deirids, area rugosa, and details in the structure of the cephalic end. Heliconema izecksohni Fabio, 1982 is transferred to Cystidicoloides as C. izecksohni (Fabio, 1982) n. comb. Cystidicoloides uniseriata Valovaya and Valter, 1988 is considered a species inquirenda with uncertain generic appurtenance. The presence of subdorsal and subventral cephalic spikes and the collarette are characteristic of Cystidicoloides, comprising only species parasitizing Neotropical fishes. The species from salmonids in the Holarctic, hitherto reported mostly as Cystidicoloides ephemeridarum (Linstow, 1872), belongs to a different, newly erected genus, for which the name Salmonema n. gen. (type species S. ephemeridarum) is now proposed. Cystidicoloides prevosti (Choquette, 1951) is transferred to Salmonema as S. prevosti (Choquette, 1951) n. comb. Sterliadochona ssavini Skryabin, 1948 and Sterliadochona Skryabin, 1948 are considered as species inquirenda and a genus inquirendum, respectively. A key to species of Cystidicoloides is provided.     

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.     

Two new species of Nomimoscolex (Cestoda: Proteocephalidea,Monticelliidae) from Gymnotus carapo (Pisces: Gymnotiformes) in Argentina

Nomimoscolex guillermoi n. sp. and N. dechambrieri n. sp. are described from the gymnotiform fish Gymnotus carapo from Argentina. The new species are placed into Nomimoscolex based on the cortical position of the vitelline follicles, and medullary position of the testes, ovary, and uterus. Both species were compared to the 13 species considered valid in the genus. The combination of features distinguishing N. guillermoi from N. dechambrieri is (1) the position of the vagina to cirrus pouch (anterior or posterior vs always anterior respectively), (2) the total number of testes (41-85 vs 108-130 respectively), (3) the distribution of the vitelline follicles (arranged in dorso-lateral and ventro-lateral bands vs lateral bands respectively), (4) the length of the uteroduct (ending 58% vs 35% from posterior margin of mature proglottis respectively), and (5) the presence of gland cells in the scolex (unicellular glands in the apical region and the external margin of suckers vs the presence of unicellular glands in the apex and other grouped in a cluster medially to the suckers respectively).     

A new species of Mathevotaenia (Cestoda: Anoplocephalidae) and other tapeworms from marsupials in Argentina

Cestodes are reported from Didelphis albiventris Lund, 1840 and Micoureus cinereus Temminck, 1824 (Marsupialia: Didelphidae) in Argentina. These include a new species of Mathevotaenia Akhumyan, 1946 (Cestoda: Anoplocephalata) as well as M. bivittata (Janicki, 1904) and an unknown hymenolepidid cestode. Mathevotaenia argentinensis n. sp. is characterized by a relatively narrow strobila, 18-37 mm in total length and 1.0-1.5 mm in maximum width, 135-163 craspedote proglottids, 19-27 testes, and a muscular genital atrium. This species differs from M. didelphidis (Rudolphi, 1819) in the disposition of the genital ducts between the excretory canals and in the entrance of the vagina into the genital atrium posterior to the cirrus pouch; from M. paraguayae Schmidt and Martin, 1978 in the disposition of the genital ducts, absence of a seminal receptacle, and presence of an armed cirrus; and from M. boliviana Sawada and Harada, 1986 and M. pennsylvanica Chandler and Melvin, 1951 in the presence of an armed cirrus. Linstowiines appear to be the dominant cestodes in New World marsupials, with M. bivittata representing the most prevalent and widely distributed species. The hymenolepidid is the first record of this family in Neotropical marsupials.     

Redescription of Diesingium lomentaceum (Diesing, 1850) (Cestoda: Trypanorhyncha)

Ardeirhynchus spiralis (Rudolphi, 1809) n. g., n. comb. (syns Echinorhynchus spiralis, Prosthorhynchus spiralis and Plagiorhynchus spiralis), a parasite of herons (Ciconiiformes: Ardeidae), is redescribed on the basis of the holotype from Ixobrychus minutus and specimens from Ardeola ralloides (new host record) in Bulgaria. A. spiralis is a member of the family Polymorphidae and not of the Plagiorhynchidae in which it was previously classified. Ardeirhynchus n. g. is distinguished from the most morphologically similar genus, Arhythmorhynchus Lühe, 1911, by the position of the male genital system, which occupies the posterior 1/8-1/6 part of the trunk, the distribution of hypodermal nuclei in groups in the anterior part and in lateral rows along the length of the posterior part of the trunk, a considerably shorter neck, minute trunk spines and a terminal genital pore.     

Checklist of tapeworms (Platyhelminthes,Cestoda) of vertebrates in Finland

A checklist of tapeworms (Cestoda) of vertebrates (fishes, birds and mammals) in Finland is presented, based on published observations, specimens deposited in the collections of the Finnish Museum of Natural History (Helsinki) and the Zoological Museum of the University of Turku, and additional specimens identified by the present author. The checklist includes 170 tapeworm species from 151 host species, comprising 447 parasite species/host species combinations. Thirty of the tapeworm species and 96 of the parasite/host species combinations have not been previously reported from Finland. The total number of tapeworm species in Finland (170 spp.) is significantly lower than the corresponding figure for the Iberian Peninsula (257 spp.), Slovakia (225 spp.) and Poland (279 spp.). The difference between Finland and the other three regions is particularly pronounced for anseriform, podicipediform, charadriiform and passeriform birds, reflecting inadequate and/or biased sampling of these birds in Finland. It is predicted that there are actually ca. 270 species of tapeworms in Finland, assuming that true number of bird tapeworms in Finland corresponds to that in other European countries with more comprehensive knowledge of the local tapeworm fauna. The other main pattern emerging from the present data is the seemingly unexplained absence in (northern) Fennoscandia of several mammalian tapeworms that otherwise have extensive distributions in the Holarctic region or in Eurasia, including the northern regions. Previously unknown type specimens, that is, the holotype of Bothrimonus nylandicus Schneider, 1902 (a junior synonym of Diplocotyle olrikii Krabbe, 1874) (MZH 127096) and the syntypes of Caryophyllaeides fennica (Schneider, 1902) (MZH 127097) were located in the collections of the Finnish Museum of Natural History.     

A new genus and two new species of Aporhynchidae (Cestoda: Trypanorhyncha) from catsharks (Carcharhiniformes: Scyliorhinidae) off Taiwan

New collections of cestodes from the spiral intestines of catsharks (Carcharhiniformes: Scyliorhinidae) off Taiwan have led to the discovery of a new genus and 2 new species of trypanorhynchs. These taxa are relatively unique among trypanorhynchs in their lack of all elements of the rhyncheal apparatus. The new genus, Nakayacestus n. gen., is considered to belong with Aporhynchus in the Aporhynchidae. In addition to lacking the rhyncheal apparatus, these 2 genera share circum-medullary vitelline follicles, post-ovarian testes, and complex terminal genitalia consisting of accessory, external, and internal seminal vesicles. The 2 genera differ conspicuously in spinithrix configuration; whereas both species of Nakayacestus n. gen. bear scolex spinitriches that are bifid, trifid, or pectinate, species of Aporhynchus either lack scolex spinitriches entirely or possess spathulate spinitriches. The configuration of the bothria of the 2 genera also differ conspicuously. Whereas the bothria of Aporhynchus are sessile and generally do not extend beyond the lateral margins of the cephalic peduncle, those of Nakayacestus bear only a tenuous connection with the scolex proper, being conspicuously free both anteriorly and posteriorly and extending conspicuously beyond the cephalic peduncle. Futhermore, the boundary between the scolex and the strobila of members of the new genus is clearly delineated, whereas this distinction is ill-defined in species of Aporhynchus. Nakayacestus takahashii n. sp., the type of the new genus, was collected from the Broadmouth catshark, Apristurus macrostomus, and differs from Nakayacestus tanyderus n. sp., collected from the Blacktip sawtail catshark, Galeus sauteri, in being shorter, bearing a longer pedunculus scolecis, an ovary that is more posterior in the proglottid, and fewer post-ovarian testes. Furthermore, the 2 new species differ conspicuously from one another in the configuration of their scolex spinitriches.     

A new genus and two new species of dactylogyrid monogeneans from gills of Neotropical catfishes (Siluriformes: Doradidae and Loricariidae)

A new genus of dactylogyrid monogeneans (Ancyrocephalinae), Paracosmetocleithrum n. gen., is erected to accommodate P. trachydorasi n. sp. from Trachydoras paraguayensis (Siluriformes: Doradidae) in the Upper Paraná River basin, Brazil. The new genus differs from Neotropical dactylogyrids in the presence of a well-developed ornamentation in the middle portion of the ventral bar, and a sclerotized patch on the surface of the dorsal bar with an inconspicuous medial process that possesses two submedial projections arising from the tapered ends of this patch. In addition, Demidospermus rhinelepisi n. sp. is described from Rhinelepis aspera (Siluriformes: Loricariidae). The new species, which is the fifth species of the genus described from loricariids, can be differentiated from congeners by the possession of a sclerotized patch attached to the middle portion of the ventral bar, and by morphology of the accessory piece, which presents broad ends, tapering in the centre, rounded proximal end, distal end folding on both sides with folds extending to approximately ¾ of the accessory piece length. Molecular data on both new species are also provided and species composition of Demidospermus, recently revealed as polyphyletic by molecular studies including the present one, is discussed.     

Redescription of Electrotaenia Malopteruri (Fritsch, 1886) (Cestoda: Proteocephalidae), a Parasite of Malapterurus Electricus (Siluriformes: Malapteruridae) from Egypt

The proteocephalidean cestode Electrotaenia malopteruri (Fritsch, 1886) (Proteocephalidae: Gangesiinae), the type- and only species of Electrotaenia Nybelin, 1942 and specific to the electric catfish Malapterurus electricus Gmelin (Siluriformes: Malapteruridae), is redescribed on the basis of freshly collected material from the River Nile in Egypt. The validity of Electrotaenia is confirmed and some unique characters of this genus, observed in extensive material from different host specimens from Egypt, Sudan, Sierra Leone and Nigeria are first reported or described in detail. Such details include the internal morphology of a rostellum-like apical organ which is disc-shaped with a flat or slightly concave apex, the structure of the ovary which is follicular to reticulate, the structure of the cirrus-sac, the presence of a medio-dorsal band of muscle fibres, and the morphology of the vagina and eggs.