Neotropical Monogenoidea. 40. Protorhinoxenus prochilodi gen. n., sp. n. (Monogenoidea: Ancyrocephalinae), parasite of prochilodus lineatus (Characiformes: Prochilodontidae) from south Brazil

The monotypic Protorhinoxenus gen. n. is proposed to accommodate a species with the following characteristics: 1) tubular sclerotised vagina, 2) vaginal pore dextrolateral, 3) ventral and dorsal anchors with undifferentiated elongate shaft and base (representing approximately 2/3 of the length of anchor), and 4) superficial and deep roots of ventral and dorsal anchors lacking. Protorhinoxenus prochilodi sp. n. is described from the gills of Prochilodus lineatus (Valenciennes) of the Represa Capivari-Cachoeira, Municipality of Campina Grande do Sul, metropolitan area of Curitiba, Paraná. Specimens of other probable new species of Protorhinoxenus are reported from Prochilodus lineatus of the Rio Paranapanema, Municipality of Salto Grande, S?o Paulo; Hoplias spp. of the Rio Dois de Fevereiro, Municipality of Antonina, Paraná, and the Rio Piraquara, metropolitan area of Curitiba, Parana; Leporinus elongatus Valenciennes of the Rio Tibagi, Municipality of Jataizinho, Parana; and Schizodon fasciatum Agassiz of the Rio Solim?es, island of Marchantaria, near Manaus, Amazonas. Protorhinoxenus appears to be a sister group of Rhinoxenus Kritsky, Boeger et Thatcher, 1988 based on the following apparent synapomorphies: 1) ventral and dorsal anchors lacking superficial and deep roots, 2) ventral and dorsal anchors with elongate shaft, and 3) male copulatory organ with counterclockwise rings.     

Gyrodactylus bohemicus sp. n. (Monogenea: Gyrodactylidae) from Oncorhynchus mykiss (Walbaum) and Salvelinus fontinalis (Mitchill) (Clupeiformes: Salmonidae) in Czechoslovakia.

Gyrodactylus bohemicus sp. n (Gyrodactylidae: Monogenea) is described from the fins, skin and gill filaments of Oncorhynchus mykiss (Walbaum) and Salvelinus fontinalis (Mitchill) (Clupeiformes: Salmonidae) from a trout farm in Czechoslovakia. G. bohemicus sp. n. is most closely related to G. thymalli Zitnan, 1960 and G. magnus Konovalov, 1967 in the shape of the anchors, the ventral and the dorsal bar, but can be distinguished from both these species by the shape of the marginal hook proper.     

Mormyrogyrodactylus gemini gen. et sp. n. (Monogenea: Gyrodactylidae), a new gyrodactylid from Marcusenius macrolepidotus (Mormyridae) from South Africa

Mormyrogyrodactylus gemini gen. et sp. n. (Gyrodactylidea: Gyrodactylidae), a viviparous monogenean is described from the skin and fins of Marcusenius macrolepidotus (Peters) from South Africa. This new genus is unique in having a large cup-shaped cirrus armed with one large needle-like spine and numerous small hair-like spinelets. A peduncular bar is present. The haptor is clearly demarcated from the body and situated on a small pedicle. The haptor has one pair of large anchors, a ventral bar complex, a small dorsal bar and 16 evenly spaced marginal hooks. The ventral bar complex consists of three parts: an inverted U-shaped piece with two semi-attached bars, each bar consisting of a base and an extension. An accessory inverted T-shaped sclerite is present on the posterior rim of the haptor. Mormyrogyrodactylus is the fifth genus of the Gyrodactylidae to be described from Africa.     

Two new species of protogyrodactylus (Monogenoidea: Dactylogyridae) from the gills of Gerres nigri (Teleostei: Gerreidae) from Senegal

Protogyrodactylus ethiopicus sp. n. and P. kritskyi sp. n. are described from the gills of Gerres nigri Günther (Gerreidae, Perciformes) captured from the estuary of the Sine-Saloum River (Senegal, West Africa). These new species differ from previously described species within the genus by a mid- or dextro-ventral vaginal opening (dextral in all other species). They are part of a morphological species group within Protogyrodactylus Johnston et Tiegs, 1922 that has the tip of the superficial root of the ventral anchor resembling a hook and two anterior projections on the anterior margin of the ventral bar. Protogyrodactylus ethiopicus differs from the remaining species in this group mainly by the morphology of the base of the male copulatory organ (MCO), which is disk-shaped, and the shape of the anterior projections of the ventral bar (round in the new species and relatively elongate in the other species of the group). The other new species, P. kritskyi, differs from all others in the same morphological group in having a MCO with a greatly expanded base that bears a heel-like subterminal sclerotization.     

A new species of the genus Gyrodactylus Nordmann, 1832 (Monogenea) from Gobio gobio (L.)

Gyrodactylus dykovae sp. n. (Monogenea: Gyrodactylidae) is described from the fins of the freshwater fish, Gobio gobio (L.) (Cyprinidae), from the Rokytná River near Moravsky Krumlov, Czechoslovakia. This species is most related to G. gobii Shulman, 1953 from which it differs by possessing more robust anchors with considerably larger shaft and by the morphology of the hook proper of marginal hooks.     

Annulotrematoides bryconi sp. n. (Monogenea: Dactylogyridae) parasitic on Brycon cephalus (Osteichthyes: Characidae) from Brazil

Annulotrematoides bryconi sp. n. is described and illustrated from specimens collected from gills of characiform fish, Brycon cephalus (Günther, 1869), in pisciculture ponds from Pirassununga, S?o Paulo, Brazil. Diagnostic characters of the new species are the tegument of trunk showing annulations, except on the cephalic regiona, and copulatory complex comprising sclerotized male copulatory organ coiled in 1 1/2 rings. This is the first record of monogeneans parasitic on the gills of B. cephalus.     

Three new species of Gyrodactylus (Monogenoidea) from Varicorhinus capoeta gracilis (Keyserling) from the River Lenkoranka.

Three new species of Gyrodactylus Nordmann, 1832 are described from Varicorhinus capoeta gracilis (Keyserling) from the River Lenkoranka (Azebaijan SSR) as follows: G. varicorhini sp. n., G. capoetai sp.n. and G. mikailovi sp.n.     

Two new species of Gyrodactylus (Monogenoidea) from Schizothorax intermedius McClelland from the River Kafirnigan.

Two new species of Gyrodactylus, namely G. kafirniganensis sp. n. and G. hemivicinus sp. n., are described from the fins and nostrils ofSchizothorax intermedius from the River Kafirnigan (Tajik SSR).     

Two new species of Myliocotyle (Monogenea: Monocotylidae) from the gills of Aetomylaeus maculatus and A. nichofii (Elasmobranchii: Myliobatidae) from Sarawak, Borneo, Malaysia

Myliocotyle borneoensis sp. n. and M. multicrista sp. n. (Monocotylidae: Heterocotylinae) are described from the gills of the mottled eagle ray, Aetomylaeus maculatus (Gray), and the banded eagle ray A. nichofii (Bloch et Schneider) (Myliobatidae), respectively, collected from the northern coast of Malaysian Borneo. These are the first monogeneans to be described on elasmobranchs from Borneo. The formerly monotypic Myliocotyle (for M. pteromylaei) was distinguished from other monocotylids by the distribution and morphology of the eight sclerotised dorsal haptoral accessory structures and the morphology of the male copulatory organ. However, we have determined that M. pteromylaei has ten structures on the dorsal surface of the haptor. Myliocotyle borneoensis is distinguished from M. pteromylaei by the morphology of the male copulatory organ and its accessory piece. Myliocotyle multicrista has 12 sclerotised dorsal haptoral accessory structures and a male copulatory organ with two accessory pieces. Additional sclerotised ridges across the ventral surfaces of each loculus (except the posterior-most pair) are also present in M. multicrista. The diagnosis for Myliocotyle is revised given our discovery of additional dorsal haptoral accessory structures in the type species and to accommodate other new characters of the two new species. Anterior secretions of Myliocotyle are discussed.     

Contribution to the knowledge of Gyrodactylus gurleyi Price, 1937 (Monogenea: Gyrodactylidae)

Gyrodactylus longoacuminatus Zitnan, 1964, forma minor sensu Ergens (1985) was identified as G. gurleyi Price, 1937. Morphological and metrical evaluations of the hard parts of opisthaptor of more than 200 specimens provided data on the variability of this parasite; Cyprinus carpio haematopterus represents its new host. Since the shape of the hard parts of opisthaptor of G. gurleyi is very similar to that of G. longoacuminatus, further detailed studies of the two species will be necessary, particularly of their reaction to the changes of environmental temperature.     

Arlenelepis harpiprioni gen. et sp. n. (Cestoda: Dilepididae) from Harpiprion caerulescens (Vieillot) (Aves: Threskiornithidae) in Paraguay

Arlenelepis harpiprioni gen. et sp. n. (Cyclophyllidea, Dilepididae) is described from the plumbeous ibis Harpiprion caerulescens (Vieillot) (Ciconiiformes, Threskiomithidae) in Province Concepción, Paraguay. This cestode is characterised by a very small body (not exceeding 5 mm in length) consisting of about 30 proglottides, musculo-glandular rostellar apparatus, rostellar hooks arranged in two regular rows, few testes (7-10 in number) situated mostly in a post-ovarian group but one testis pre-ovarian, a large oval cirrus sac reaching antiporal osmoregulatory canals, massive cirrus armed with needle-shaped and thorn-shaped spines, long convoluted vagina, and longitudinally elongate sacciform horseshoe-shaped uterus with deep lobes of the medial uterine wall. The new genus is unique among the family Dilepididae in possessing a rhynchus armed with conical spines.     

Heliocotyle ewingi sp. n. (Monogenea: Monocotylidae) from the gills of Myliobatis australis (Myliobatididae) from Tasmania, Australia

Heliocotyle ewingi sp. n. (Monogenea: Monocotylidae) is described from the gills of Myliobatis australis Macleay, 1881 (Myliobatididae) collected from Norfolk Bay near Hobart, Tasmania, Australia. Heliocotyle ewingi can be distinguished readily from the only other species in the genus, Heliocotyle kartasi Neifar, Euzet et Ben Hassine, 1999, by the presence of a single pseudoseptum on each of the peripheral loculi except the posteriormost, eyespots and by the morphology of the male copulatory organ which is a short, straight sclerotised tube which lacks a sclerotised accessory piece. The generic diagnosis is revised to accommodate the new species and the anterior glands are discussed.     

Branchotenthes octohamatus sp. n. (Monogenea: Hexabothriidae) from the gills of the southern fiddler ray, Trygonorrhina fasciata (Rhinobatidae) in South Australia: description of adult and larva

Branchotenthes octohamatus sp. n. (Monogenea: Hexabothriidae) is described from the gills of the southern fiddler ray, Trygonorrhina fasciata Müller et Henle (Elasmobranchii: Rhinobatidae), off Adelaide, South Australia. It is distinguished from the type species, Branchotenthes robinoverstreeti Bullard et Dippenaar, 2003, by producing eggs that are joined end to end forming a chain, in the morphology of the male copulatory organ that has a pronounced constriction in duct diameter between proximal and distal regions, the possession of a thin muscular layer surrounding the proximal part of the male copulatory organ and distal region of the vaginae, and by the absence of a raised process on the shaft of the hamulus. An amended generic diagnosis is provided and the reliability of sperm duct number as a generic character is discussed. The oncomiracidium of B. octohamatus is also described and is the first monogenean to be described with only eight hooklets in the larval haptor. This discovery of eight hooklets may be important for higher-level monogenean evolutionary hypotheses.     

Two new species of the genus Gyrodactylus (Monogenea) from the fins of Leuciscus cephalus (L.)

Gyrodactylus kearni sp. n. and G. lamberti sp. n. (Monogenea: Gyrodactylidae) are described from the fins of the freshwater fish, Leuciscus cephalus (L.) (Cyprinidae), from the Rokytná River and St?pánovicky Brook (basin of the River Danube), Czechoslovakia, G. kearni sp. n. is most related to G. leucisci Zitnan, 1964 in the shape and size of marginal hooks, but can be separated from it in the shape of anchors and ventral bar. G. lamberti sp. n. is most closely related to G. gobii Shulman, 1953 and G. truttae Glser, 1974 in the shape of the complex of anchors, but differs markedly from them in the shape of the hook proper of marginal hooks.     

The use of morphometric characters to discriminate specimens of laboratory-reared and wild populations of Gyrodactylus salaris and G. thymalli (Monogenea)

Gyrodactylus thymalli Zitnan, 1960 and G. salaris Malmberg, 1957 have an indistinguishable ribosomal internal transcribed spacer (ITS) DNA sequence, but exhibit surprisingly high levels of intra- and interspecific sequence variation of the mitochondrial cytochrome oxidase I (CO1) gene. To test whether different populations of these reportedly very similar species could be discriminated using morphometric methods, we examined the morphometry of four different populations representing different mitochondrial clades. Twenty five point-to-point measurements, including five new characters of the attachment hooks, were recorded from three Norwegian laboratory populations (G. salaris from the Rivers Lierelva and Rauma, and G. thymalli from the River Rena), and from one wild population of G. thymalli from the River Test, UK. The Norwegian populations were kept under identical environmental conditions to control for the influence of temperature on the haptoral attachment hooks. Data were subsequently subjected to univariate and linear stepwise discriminant analyses. The model generated by the linear stepwise discriminant analysis used 18 of the 25 original variables, the first two roots accounting for 96.6% of the total variation between specimens. The hamulus shaft length accounts for 66.7% of the overall correct classification efficiency. Based on morphometry, all specimens were assigned to the correct species. Apart from three specimens of G. salaris from the River Lierelva population which were misclassified as belonging to the G. salaris Rauma population, all specimens were assigned to the correct population. Thus, populations of Gyrodactylus identified by mtDNA can also be discriminated using morphometric landmark distances.     

Lamellodiscus (Monogenea: Diplectanidae) parasites of Dentex macrophthalmus (Teleostei: Sparidae) from the North Atlantic coast of Africa, with a redescription of L. dentexi Aljoshkina, 1984, and description of three new species

Lamellodiscus dentexi Aljoshkina, 1984, a gill parasite of Dentex macrophthalmus (Bloch), is redescribed based on new material from the northwest coast of Africa (Senegal and Morocco). Three new species of Lamellodiscus Johnston et Tiegs, 1922 from D. macrophthalmus are described, Lamellodiscus toguebayei sp. n., L. vicinus sp. n., and L. triacies sp. n., all belonging to the "ignoratus" group. They can be distinguished from all other species of this group by the size and shape of male copulatory organ and sclerotised parts of the haptor. Considering the peculiar morphology of the male copulatory organ (long and thin tube) we propose to put together L. dentexi, L. virgula Euzet et Oliver, 1967 and L. obeliae Oliver, 1973 to form the "elongatus" type within the "elegans" group.     

Dendromonocotyle colorni sp. n. (Monogenea: Monocotylidae) from the skin of Himantura uarnak (Dasyatididae) from Israel and a new host record for D. octodiscus from the Bahamas

Dendromonocotyle colorni sp. n. (Monogenea: Monocotylidae) is described from the dorsal skin surface of two specimens of Himantura uarnak (Forssk?l) kept at the Eilat Underwater Observatory in Israel. Dendromonocotyle colorni is distinguished from the other eight species in the genus by the morphology of the terminal papillar sclerite on the haptor, the distal portion of the male copulatory organ and the morphology of the vagina. The development of the male copulatory organ is detailed for D. colorni and the adaptations of species of Dendromonocotyle to life on the dorsal skin surface of rays are discussed. Dendromonocotyle octodiscus Hargis, 1955 was identified from the dorsal skin surface of the southern stingray Dasyatis americana Hildebrand et Schroeder off Bimini, Bahamas and represents a new host record.     

Acolpenteron australe sp. n. (Dactylogyridae:Dactylogyrinae), a new species from the ureters of Percichthys trucha (Perciformes:Percichthyidae) in Patagonia (Argentina)

Acolpenceron australe sp. n. (Dactylogyridae, Dactylogyrinae) is described from ureters and renal tubules of Percichthys trucha (Cuvier et Valenciennes) (Perciformes, Percichthyidae) from Andean Patagonian lakes. The new species has a haptor with 14 hooks, with shanks comprised of two subunits. It has overlapped intercaecal gonads, male copulatory organ as a sclerotized tube with one counterclockwise coil and a J-shaped accessory piece. It differs from the other species of Acolpenteron by having a non-forked accessory piece. This is the first monogenean species described from a percichthyid host in South America.