Proteocephalidean Cestode Research Articles

Molecular systematic analysis of the order Proteocephalidea (Eucestoda) based on mitochondrial and nuclear rDNA sequences

Two ribosomal DNA sequences were used to infer phylogenetic relationships among the Eucestoda order Proteocephalidea. A 437 bp portion of the 16S mitochondrial and a 1149 bp 5′ portion of the nuclear large sub-unit rRNA molecule were sequenced for 53 proteocephalidean cestodes (representing nine subfamilies and 22 genera) and for one outgroup species. Parsimony and distance-based analyses of the two databases, alone and combined, failed to support the monophyly of the two traditionally accepted families, of numerous subfamilies (with the exception of the Rudolphielliinae and Othinoscolescinae which were validated in our analysis) and of various genera, including the genus Nomimoscolex (Woodland), Ophiotaenia (La Rue) as well as the type genus Proteocephalus (Weinland). Palaearctic Proteocephalus species nevertheless constituted a well-defined clade. The two genes globally yielded compatible results; however, the nuclear ribosomal gene provided a better resolution of relations among Proteocephalidea.

Révision des cestodes (Monticelliidae) décrits par Woodland (1934) chez Brachyplatystoma filamentosum avec redéfinition des genres Endorchis Woodland, 1934 et Nomimoscolex Woodland, 1934

In 1934, Woodland described three new species of proteocephalidean tapeworms (Monticelliidae) from the Amazonian siluriform fish Brachyplatystoma filamentosum: Endorchis piraeeba (type-species), Nomimoscolex piraeeba (type-species) and Amphoteromorphus piraeeba. Examination of Woodland's type-material and its comparison with newly collected specimens from the same host close to the type-localities revealed inaccuracies in Woodland's diagnoses of these taxa. The main problems concern the scolex of E. piraeeba, the gravid proglottis of N. piraeeba and aspects of the anatomy of A. piraeeba. In our revision, we establish that: (1) the scolex assigned by Woodland to E. piraeeba belongs to N. piraeeba, and the actual scolex of E. piraeeba is characterised by bi-lobed suckers; (2) the gravid proglottis figured by Woodland does not belong to N. piraeeba, differing in particular, in the presence of paramuscular vitelline follicles and the cirrus-pouch length/proglottis width ratio; and (3) the cross-section assigned by Woodland to A. piraeeba belongs to N. piraeeba.

Spasskyellina mandi n. sp. (Proteocephalidea:Monticelliidae), parasite of Pimelodus ornatus Kner, 1857 (Pisces:Pimelodidae) of the Paraná River, Paraná, Brazil.

Spasskyellina mandi n. sp. (Proteocephalidea: Monticelliidae) is described from the Siluriform fish Pimelodus ornatus Kner, 1857, caught in the Paraná River, Paraná, Brazil. The new species differs from other species of the same genus mainly by a fewer number of testes and by a larger osmoregulatory canal. This is the second species of proteocephalidean cestode collected in P. ornatus.

Structure and diversity of endoparasitic infracommunities and the trophic level of Pseudoplatystoma corruscans and Schizodon borelli (Osteichthyes) of the high Paraná River.

One hundred and ten specimens of Pseudoplatystoma corruscans (Pimelodidae) and 582 specimens of Schizodon borelli (Anostomidae) collected in the high Paraná River were analyzed. On necropsy 74% of P. corruscans were found to be parasitized; proteocephalidean cestodes presented the greatest number. With regard to S. borelli, the percentage of parasitism reached 19.42% and the nematode Cucullanus pinnai was the most abundant. The absence of correlation between the endoparasitic diversity and the standard length of the two host species indicates that each one presents homogeneity in alimentary behaviour during all its life time, permiting the uniform recruitment of the same species of endoparasites during all its ontogenetic development. Independence of diversity values in relation to sex of P. corruscans and S. borelli evidences that the ecological relationships are similar between males and females in these species. Both host's infrapopulations presented a typical overdispersed pattern of distribution with isolationist characteristics.

Proteocephalidean Cestodes in the Freshwater Fish Cichla monoculus from the Paran� River, Brazil

A redescription of Proteocephalus macrophallus and P. microscopicus found in “Tucunaré”, Cichla monoculus Spix 1831 of the Paraná River, is provided, since previously only incomplete taxonomic data were available.

Uma nova espécie de cestóide proteocefalídeo, Monticellia belavistensis, sp.n., parasita de Pterodoras granulosus (Valenciennes) (Pisces, Doradidae), do reservatório de Itaipu e rio Paraná, Paraná, Brasil

In the present paper the authors describe and illustrate a new species of proteocephalidean cestode, Monticellia belavistensis, sp.n., parasite of a freshwater siluriform fish (thorny catfish). Pterodoras granulosus (Valenciennes, 1833), from the Itaipu Reservoir and Parana River, in the region of Porto Rico. This is the first reference of a proteocephalid in this host. The values of prevalence and mean intensity of infection are given and the life cycle is discussed.

A cytochemical study of the nervous system of the proteocephalidean cestode, Proteocephalus pollanicola

Marks N. J., Halton D. W., Shaw C. and Johnston C. F. 1993. A cytochemical study of the nervous system of the proteocephalidean cestode, Proteocephalus pollanicola. International Journal for Parasitology 23: 617–625. The localization and distribution of cholinergic, serotoninergic and peptidergic nerve elements in the proteocephalidean tapeworm, Proteocephalus pollanicola, have been investigated by enzyme histochemistry, and by an indirect immunofluorescence technique interfaced with confocal scanning laser microscopy. Cholinesterase (ChE) activity was localized in the major components of the central nervous system (CNS) and the peripheral nervous system (PNS), including the innervation of the reproductive structures of the worm. Serotoninergic (5-HT) nerves were found in the paired cerebral ganglia, transverse commissure and in the 10 longitudinal nerve cords. Antisera to 17 mammalian regulatory peptides and the invertebrate peptide FMRFamide have been used to explore the peptidergic nervous system of the worm. The most extensive immunostaining occurred with antisera raised to members of the neuropeptide Y superfamily, namely neuropeptide Y (NPY), peptide YY (PYY) and pancreatic polypeptide (PP). In all cases, intense immunoreactivity was found in numerous cell bodies and fibres of both the CNS and PNS, including the innervation of the reproductive apparatus. FMRFamide antisera stained the same structures to a comparable degree as those raised to the NPY superfamily. Cholinergic and peptidergic elements were much more prevalent within the CNS, while the serotoninergic nerve fibres tended to dominate in the PNS. The overlap obtained in staining patterns for the peptidergic and cholinergic components suggests that there may be a certain amount of co-localization of peptides with small-molecule transmitter substances in the same neurone. Weak staining for the tachykinin, substance P and for calcitonin gene-related peptide (CGRP) was confined to the major longitudinal nerve cords.

Distribution and immunochemical characteristics of neuropeptide F (NPF) ( Moniezia expansa)—immunoreactivity in Proteocephalus pollanicola (Cestoda: proteocephalidea)

1. Using immunocytochemical techniques and confocal scanning laser microscopy, the proteocephalidean cestode, Proteocephalus pollanicola from Lough Neagh pollan ( Coregonus autumnalis) was examined for the presence of the native platyhelminth neuropeptide, neuropeptide F (NPF). 2. An antiserum specific for whole-molecule NPF(1–39) ( Moniezia expansa) did not immunostain nerve processes in P. pollanicola. A C-terminally-directed NPF(30–39) ( M. expansa) antiserum immunostained nerve fibres and cell bodies of both the central and peripheral nervous systems, including innervation associated with the female reproductive system. 3. The pattern of immunoreactivity was identical to that obtained using antisera to the C-terminal region of mammalian NPY-superfamily peptides and the invertebrate neuropeptide, FMRFamide. 4. Under radioimmunoassay conditions, only the C-terminally-directed NPF antiserum cross-reacted with the P. pollanicola peptide and detected 58.74 ng g wet weight of NPF-IR in extracts of the worm. 5. Chromatographic characterisation of P. pollanicola NPF-immunoreactivity indicated an apparent molecular weight of 4400–4700 Da, similar to that of NPF ( M. expansa). 6. Further analytical HPLC characterisation identified two molecular forms of P. pollanicola NPF-immunoreactivity, both of which had different retention times from those of NPF ( M. expansa) and NPF ( Artioposthia triangulata). 7. These data suggest that P. pollanicola possesses a neuropeptide which is homologous in its C-terminal region to NPF ( M. expansa) but diners in its mid- to N-terminal region.

Megathylacus travassosi sp. n. e Nomimoscolex sudobim Woodland, 1935 (Cestoda - Proteocephalidea) parasitos de Pseudoplatystoma corruscans (Agassiz, 1829) (Siluriformes - Pimelodidae ) do reservatório de Itaipu e Rio Paraná, PR, Brasil)

It is described Megathylacus travassosi sp. n., parasite of Pseudoplatystoma corrusccans (Agassiz,1829), a pimelodid fish caught in Itaipu reservoir and Parana river, Brazil. Nomimoscolex sudobim Woodland, 1935 is redescribed and for the first time referred parasitising P. corruscans. The list of proteocephalid cestodes of genus Pseudoplatystoma Bleeker, 1862, with its geographic distribution is given.

Hyperparasitism by helminths: new records of cestodes and nematodes in proteocephalid cestodes from South American siluriform fishes

Proteocephalid cestode hyperparasites are reported from numerous proteocephalids occurring in pimelodid fishes in different regions of Brazil. In addition, three specimens of a nematode hyperparasite are reported from the proteocephalid cestode Choanoscolex abscissus from the pimelodid fish Pseudoplatystoma corruscans in Brazil. Previous records of cestode and nematode hyperparasites of cestodes are listed, and the possible identities of the Brazilian records are discussed.

Ophiotaenia ecuadorensis n. sp. (Cestoda: Proteocephalidae) from Hyla geographica Spix, 1824 in Ecuador

Ophiotaenia ecuadorensis n. sp. is described from the small intestine of Hyla geographica Spix, 1824 collected in Ecuador. It is compared to all species of Ophiotaenia with equatorial or slightly pre-equatorial genital pores and is most similar to Ophiotaenia olseni, but differs in having an apical organ on the scolex, a shorter strobila, narrower proglottids, fewer and wider testes, and an ovary with expanded anterior lobes in gravid proglottids. Of 16 species of Hyla collected in the summer of 1968 during the course of a study conducted by Dr. William E. Duellman, Museum of Natural History, University of Kansas, on amphibians and reptiles of Ecuador, only 1 of 5 adult Hyla geographica Spix, 1824 was found to harbor a proteocephalid cestode. Other frogs examined and found negative for cestodes included Hyla alboguttata Boulenger, 1882, Hyla bifurca Andersson, 1945, Hyla boans Daudin, 1803, Hyla calcarata Troschel, 1848, Hylafasciata Gunther, 1858, Hyla garbei (Miranda Ribeiro, 1926), Hyla lanciformis (Cope, 1870), Hyla leucophyllata (Beireis, 1783), Hyla marmorata (Laurenti, 1768), Hyla parviceps Boulenger, 1882, Hyla punctata (Schneider, 1799), Hyla reticulata Jimenez de la Espada, 1870, Hyla rondoniae Bokermann, 1963, Hyla rubra Daudin, 1803, and Hyla sarayacuensis Shreve, 1935. This report is based on a single specimen of an unidentified proteocephalid. For a summary of the various proteocephalids of amphibians and reptiles, the reader is referred to the reports of La Rue (1914), Freze (1965) and Brooks (1978). The latter represents a scholarly study on the systematic status of proteocephalid cestodes of amphibians and reptiles in North America and provides a key distinguishing the 19 species. A similar study for proteocephalids of South American amphibians and reptiles has yet to be done. MATERIALS AND METHODS The tapeworm was recovered in situ by autopsy of the host shortly after capture. It was fixed in 10% formalin, stained with Harris' hematoxylin, dehydrated, cleared in beechwood creosote, and mounted in CanReceived 2 July 1985; revised 18 November 1985; accepted 18 November 1985. ada balsam for study. All measurements are in micrometers unless otherwise indicated. Since only a single specimen was available for examination, the mean followed by the range in parentheses is given when feasible. Drawings were made with the aid of a camera lucida and a Leitz microprojector (Figs. 1-3).

Tegument and apical end organ fine structure in the metacestode and adult Proteocephalus ambloplitis

The tegument of plerocercoid and adult P. ambloplitis was examined. Differences in tegument structure existed between these two stages. Plerocercoids of P. ambloplitis lacked extensive vacuolization and unicellular gland cells characteristic of adult tegument. Plerocercoid microtriches were short and conoid; adult microtriches were lenticular with an extended, whip-like shaft. An inclusion, not previously reported from proteocephalid cestodes, is described. Adult tegument had ducts, originating from underlying unicellular glands, extending through the distal cytoplasm and opening to the exterior between microtriches. The apical end organ cavity of P. ambloplitis contained numerous labyrinth-like spherical bodies. These structures appeared to be synthesized and secreted into the end organ by a thin cellular lining of the end organ. This lining was composed of discrete, filamentous cells believed to be modified subtegumental cell bodies. Spherical structures identical to those observed within the end organ cavity occurred within this cellular lining. The spherical bodies may be associated with enzymes necessary for tissue migration by the metacestode.

Some aspects of chromosome cytology in the cestode Acanthotaenia multitesticulata.

The diploid chromosome number of the proteocephalid cestode Acanthotaenia multitesticulata is reported for the first time to be fourteen from mitotic as well as meiotic stages of gametogenesis. A chiasma frequency of 2.42 was found. Variation in chromosome numbers in cestodes with reference to this parasite is discussed from an evolutionary point of view.

Fine structure of the spermatozoon of Proteocephalus longicollis (Cestoda proteocephalidea)

The spermatozoon of the proteocephalid cestode Proteocephalus longicollis (Zeder, 1800) is a very elongate, thread-shaped cell, about 300 μ m long and 0, 1 - 0, 9 pm in diameter, with no differentiation into head, midpiece and tail.The spermatozoon body (Figs. A-K) consists of: (a) two axonemes of the unique “9+1“ pattern, (b) an elongate nucleus, (c) numerous electron-dense, glycogen-like granules of different sizes and shapes and (d) cortical, cytoplasmic microtubules associated with the limiting plasma membrane. The total lack of acrosome and mitochondria is a remarkable and unusual finding which seems to be characteristic for all cestode spermatozoa examined so far.The nucleus of the spermatozoon, narrow and rod-shaped in its anterior part, becomes progressively enlarged and flattened toward the posterior end. The nuclear envelope is relatively thick and composed of two wavy membranes (Figs. G and H). The nucleoplasm is very loose and consists of fine filaments and granules of chromatin.

On Some Proteocephalid Cestodes from Freshwater Fishes in the Sudan

Investigators up to the time of Monticelli (1891), with the exception of Weinland (1858), considered the proteocephalan group of fish cestodes to belong to the genus Taenia. It was Weinland (1858) who removed them from this genus, and erected the genus Proteocephalus for them.Linstow (1891), was the first to point out that the fish species made a closely related group within the genus Taenia on account of certain constantly occurring characters. In the same year, Monticelli pointed out that in these fish “Taenias”, as then known, some showed marked differences from the rest, notably in the cortical position of the testes, and that these justified their separation as the genus Tetracotylus.

On some remarkable new Monticellia-like and other Cestodes from Sudanese Siluroids

1. Those species of Proteocephalid Cestodes in which the testes are situated in the cortex may be described as of the Monticellia type. Of this type there are three conditions : (a) the Monticellia condition in which the testes, uterus, ovary, and vitellaria are all situated in the cortex; (b) the Rudolphiella condition in which the testes and vitellaria alone are in the cortex, the other organs being entirely or almost entirely in the medulla ; and (c) the Marsypocephalus condition in which the testes alone are in the cortex, all other organs being medullary. Fuhrmann's genus Goezeella is synonymous with Monticellia if we ignore the characters of the scolex as features of generic value. 2. The anatomy of two species of Marsypocephalus is described: Marsypocephalus rectangulus Wedl, 1862, and Marsypocephalus heterobranchus, n.sp., from Nile Siluroid fishes. 3. It is concluded that the cortical situation of the testes and other organs is a taxonomic feature of generic value only (as in Pseudophyllidea in the case of the vitellaria) and La Rue's new family of the Monticellidae, created to include Monticellia-like forms, is not accepted. Monticellia, Rudolphiella, and Marsypocephalus are thus regarded as new genera in the Proteocephalidae. 4. The facts that the ‘Corallobothrium’ type of scolex is found in all of the three genera Monticellia (as amended by me and including ‘Goezeella’ siluri, Fuhrmann), Rudolphiella, and Proteocephalus (as amended by me and including ‘Corallobothrium’ solidum, Fritsch), and that in the Caryophyllaeidae, Bothriocephalidae, and Cyclophyllidea (cf. e.g. Taenia solium and Taenia saginata) minor scolex characters are evidently only features of specific value, compel us to delete such genera as Corallobothrium, Choanoscolex, Acanthotaenia, and my own recent genus Gangesia and to regard them as synonyms of Proteocephalus (La Rue's genus ‘Ophiotaenia’, syn. ‘Crepidobothrium’, not being accepted). Fuhrmann's Goezeella siluri becomes Monticellia siluri, and Fritach's Corallobothrium solidum becomes Proteocephalus solidus. The genera of the Proteocephalidae are thus four in number: Proteocephalus , Monticellia, Rudolphiella , and Marsypocep, halus, and these are formally or informally redefined. The two species of Marsypocephalus are diagnosed. 5. The ‘Taenia malopteruri’ of Fritsch, 1886, is not of the Monticellia type, as suggested by La Rue. Its structure is of the usual Proteocephalid type, save that the scolex possesses a rostellum and a broad band of hooklets and is covered with spinelets. It is renamed Proteocephalus malopteruri. 6. A new species of Clestobothrium--Clestobothrium clarias, from Clarias anguillaris Günth-is described. It is of interest, not only as being the third (second ?) species known of the genus, but because it affords one more illustration of the fact that the characters of the scolex cannot be used for diagnoses of genera. For this reason also, Lönnberg's genus Ptychobothrium (1889) becomes synonymous with Diesing's genus Polyonchobothrium (1884).