Most cited article - PubMed ID 9516993
Scolex morphology of Proteocephalus tapeworms (Cestoda: Proteocephalidae), parasites of freshwater fish in the Palaearctic Region
Proteocephalidean tapeworms form a diverse group of parasites currently known from 315 valid species. Most of the diversity of adult proteocephalideans can be found in freshwater fishes (predominantly catfishes), a large proportion infects reptiles, but only a few infect amphibians, and a single species has been found to parasitize possums. Although they have a cosmopolitan distribution, a large proportion of taxa are exclusively found in South America. We analyzed the largest proteocephalidean cestode molecular dataset to date comprising more than 100 species (30 new), including representatives from 54 genera (80%) and all subfamilies, thus significantly improving upon previous works to develop a molecular phylogeny for the group. The Old World origin of proteocephalideans is confirmed, with their more recent expansion in South America. The earliest diverging lineages are composed of Acanthotaeniinae and Gangesiinae but most of the presently recognized subfamilies (and genera) appear not to be monophyletic; a deep systematic reorganization of the order is thus needed and the present subfamilial system should be abandoned. The main characters on which the classical systematics of the group has been built, such as scolex morphology or relative position of genital organs in relation to the longitudinal musculature, are of limited value, as demonstrated by the very weak support for morphologically-defined subfamilies. However, new characters, such as the pattern of uterus development, relative ovary size, and egg structure have been identified, which may be useful in defining phylogenetically well-supported subgroups. A strongly supported lineage infecting various snakes from a wide geographical distribution was found. Although several improvements over previous works regarding phylogenetic resolution and taxon coverage were achieved in this study, the major polytomy in our tree, composed largely of siluriform parasites from the Neotropics, remained unresolved and possibly reflects a rapid radiation. The genus Spasskyellina Freze, 1965 is resurrected for three species of Monticellia bearing spinitriches on the margins of their suckers.
- Keywords
- Eucestoda, Proteocephalidae, Spasskyellina, host-parasite associations, molecular phylogeny, systematics,
- Publication type
- Journal Article MeSH
Two new species of bothriocephalidean tapeworms, Bothriocephalus australis n. sp. from the flatheads Platycephalus bassensis Cuvier (type host) and P. aurimaculatus Knapp off southern Australia and B. celineae n. sp. from a hybrid serranid Cephalopholis aurantia (Val.) x C. spiloparaea (Val.) from off New Caledonia, are described. B. australis is unique in the possession of the combination of the three characters: an elongate, obliquely situated cirrus-sac; a wide genital atrium surrounded by chromophilic cells; and a well-developed apical disc. B. celineae is typified by the presence of a low number of testes per segment (14-26), forming one or two incomplete longitudinal bands on each side of segment, and the small size of the strobila (total length 24 mm) which consists of less than 100 segments.
- MeSH
- Cestoda anatomy & histology classification isolation & purification MeSH
- Chordata parasitology MeSH
- Bass parasitology MeSH
- Testis anatomy & histology MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Australia MeSH
- New Caledonia MeSH
The tapeworm order Bothriocephalidea Kuchta, Scholz, Brabec & Bray, 2008 (Platyhelminthes: Eucestoda), which has until recently formed part of the suppressed order Pseudophyllidea, is revised. Four new genera, namely Andycestus n. g. [type- and only species A. abyssmus (Thomas, 1953) n. comb.], Plicocestus n. g. [type- and only species P. janickii (Markowski, 1971) n. comb.] (both Bothriocephalidae), Mesoechinophallus n. g. [type-species M. hyperogliphe (Tkachev, 1979) n. comb.; other species M. major (Takao, 1986) n. comb. (Echinophallidae)] and Kimocestus n. g. [type- and only species K. ceratias (Tkachev, 1979) n. comb.] (Triaenophoridae) are proposed. Parabothriocephaloides Yamaguti, 1934, Penetrocephalus Rao, 1960 and Tetracampos Wedl, 1861 are resurrected as valid genera, whereas Alloptychobothrium Yamaguti, 1968 (newly synonymised with Plicatobothrium Cable & Michaelis, 1967), Capooria Malhotra, 1985 and Coelobothrium Dollfus, 1970 (syns of Bothriocephalus Rudolphi 1808), Fissurobothrium Roitman, 1965 (syn. of Bathybothrium Lühe, 1902), Paratelemerus Gulyaev, Korotaeva & Kurochkin, 1989 (syn. of Parabothriocephaloides Yamaguti, 1934) and Tetrapapillocephalus Protasova & Mordvinova, 1986 (syn. of Oncodiscus Yamaguti, 1934) are considered to be invalid. A recently erected genus, Dactylobothrium Srivastav, Khare & Jadhav, 2006, and its type- and only species, D. choprai Srivastav, Khare & Jadhav, 2006, are considered to be unrecognisable, because their descriptions contain a number of obvious errors and also indicate that a mixture of several taxa, probably of at least two cestode orders, were studied. Parabothriocephaloides wangi nom. nov. is proposed for Parabothriocephalus psenopsis Wang, Liu & Yang, 2004 from Psenopsis anomala in China in order to avoid a secondary homonymy. All 46 genera considered to be valid are revised, with their generic diagnoses amended on the basis of a critical examination of extensive museum and newly collected specimens. Despite apparent paraphyly or polyphyly of some bothriocephalidean families, especially the Triaenophoridae, the current classification restricted to four families, proposed by Bray et al. (1994), namely the Bothriocephalidae, Echinophallidae, Philobythiidae and Triaenophoridae, is provisionally retained with slight modifications until more molecular data on most genera are available. Keys to families and genera are provided.
- MeSH
- Cestoda classification ultrastructure MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
A list and key to the identification of valid species of tapeworms of the Proteocephalus Weinland, 1858 aggregate sensu de Chambrier et al. (2004), i.e. species of the genus occurring in fresh- and brackish-water fishes in the Palaearctic Region, are provided, with data on their hosts and geographical distribution. Instead of 32 taxa listed by Schmidt (1986) and subsequent authors, only the following 14 species are considered to be valid: P. ambiguus (Dujardin, 1845) (type-species); P. cernuae (Gmelin, 1790); P. filicollis (Rudolphi, 1802); P. fluviatilis Bangham, 1925; P. gobiorum Dogiel & Bychowsky, 1939; P. longicollis (Zeder, 1800); P. macrocephalus (Creplin, 1825); P. midoriensis Shimazu, 1990; P. percae (Müller, 1780); P. plecoglossi Yamaguti, 1934; P. sagittus (Grimm, 1872); P. tetrastomus (Rudolphi, 1810); P. thymalli (Annenkova-Chlopina, 1923); and P. torulosus (Batsch, 1786). An analysis of sequences of the nuclear genes (ITS2 and V4 region of 18S rDNA) revealed the following phylogenetic relationships for these taxa: P. torulosus ((P. midoriensis, P. sagittus) (P. fluviatilis (P. filicollis, P. gobiorum, P. macrocephalus)) (P. cernuae, P. plecoglossi, P. tetrastomus ((P. longicollis, P. percae) (P. ambiguus, P. thymalli)))). P. pronini Rusinek, 2001 from grayling Thymallus arcticus nigrescens is synonymised with P. thymalli. P. esocis La Rue, 1911 is apparently invalid but its conspecificity with either P. percae or P. longicollis could not be confirmed due to the absence of the scolex in the holotype and the unavailability of other material for morphological and molecular studies. P. osculatus (Goeze, 1782) has recently been transferred to Glanitaenia de Chambrier, Mariaux, Vaucher & Zehnder, 2004. The validity of the genus is supported by the position of G. osculata within the Proteocephalidea, based on molecular data, as well as its morphology and nature of the definitive host (the European wels Silurus glanis). P. hemispherous Rahemo & Al-Niaeemi, 2001, described from S. glanis in Iraq, is transferred to Postgangesia Akhmerov, 1960 as Postgangesia hemispherous (Rahemo & Al-Niaeemi, 2001) n. comb.
- MeSH
- Cestoda genetics MeSH
- DNA, Helminth chemistry genetics MeSH
- Phylogeny MeSH
- DNA, Ribosomal Spacer chemistry genetics MeSH
- Molecular Sequence Data MeSH
- Polymerase Chain Reaction MeSH
- RNA, Ribosomal, 18S chemistry genetics MeSH
- RNA, Ribosomal, 5.8S chemistry genetics MeSH
- Fishes parasitology MeSH
- Base Sequence MeSH
- Sequence Alignment MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA, Helminth MeSH
- DNA, Ribosomal Spacer MeSH
- RNA, Ribosomal, 18S MeSH
- RNA, Ribosomal, 5.8S MeSH
Microtriches on different parts of the scolex and neck of the gangesiine cestode Silurotaenia siluri (Batsch 1786) were studied. The neodermis of the central frontal scolex part (around the rostellar furrow) bears filamentous microtriches only. The lateral frontal part and the parts between and posterior to the suckers cover filamentous and spine-like microtriches. Within the suckers there are short spine-like microtriches with bases enforced by electron-dense ribs. The proximal neck part bears filamentous and spine-like microtriches, the middle part solitary distributed blade-like and spine-like microtriches among filamentous ones, and the distal part blade-like microtriches. The functions of different types of microtriches are discussed.
- MeSH
- Cestoda ultrastructure MeSH
- Fish Diseases parasitology pathology MeSH
- Intestines parasitology ultrastructure MeSH
- Catfishes parasitology MeSH
- Microscopy, Electron, Transmission methods MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
This paper presents a redescription of the proteocephalidean cestode Proteocephalus sagittus (Grimm, 1872) based on freshly collected specimens from the type-host, the stone loach Barbatula barbatula (L.) (family Balitoridae), from the Czech Republic. This species has recently been synonymised with P. torulosus (Batsch, 1786), a parasite of cyprinid fishes in the Holarctic Region, but it differs in the following characters: (i) scolex morphology (scolex rounded, with more apically situated suckers and lacking longitudinal wrinkles in P. sagittus versus large and club-shaped, with more laterally situated suckers and longitudinal wrinkles in P. torulosus); (ii) position of the vagina (opens anterior to the cirrus-sac in P. sagittus versus overlapping its distal region dorsally in P. torulosus); (iii) length of the cirrus-sac (shorter in P. sagittus); (iv) osmoregulatory canals (more distinct and situated more laterally, but almost indistinguishable and more medial in P. torulosus); and (v) sequences of the partial 18S rRNA (V4 region - 96.9% similarity) and 5.8S-ITS2 genes (65.9% similarity). P. pamirensis Dzhalilov & Ashurova, 1971, a poorly described species from the Tibetan stone loach Noemacheilus stoliczkai[= Tryplophysa stoliczkae (Steindachner)] in Tadjikistan, is synonymised with P. sagittus.
- MeSH
- Cestoda anatomy & histology genetics ultrastructure MeSH
- DNA, Helminth chemistry genetics MeSH
- Cypriniformes parasitology MeSH
- Microscopy, Electron, Scanning MeSH
- Molecular Sequence Data MeSH
- Polymerase Chain Reaction MeSH
- RNA, Ribosomal, 18S chemistry genetics MeSH
- Base Sequence MeSH
- Sequence Alignment MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA, Helminth MeSH
- RNA, Ribosomal, 18S MeSH