Mature Proglottids Research Articles

Comparative Morphologic and Morphometric Study on the Developmental Aspects of In Vitro and In Vivo Reared Echino-coccus granulosus Sensu Stricto Using Differential Interference Contrast (DIC)/Nomarski and Phase Contrast Microscopy

Echinococcus granulosus is a zoonotic parasite with worldwide distribution. The present study focused on comparative morphologic and morphometric observations on the developmental aspects of whole body, more special the reproductive structures of in vitro reared adult worms (RAW) and in vivo reared adult worms in definitive host (AWIDH) using differential interference contrast (DIC)/Nomarski, phase contrast and routine optical microscopy. A total number of 10 in vitro and 10 in vivo reared adult worms of E. granulosus sensu stricto, G1 strain were selected. The worms were processed by Formaldehyde-Alcohol-Azocarmine-Lactophenol (FAAL). The details of morphological factors and reproductive structures of each worm including 25 biometrical parameters were studied by routine optical, phase contrast and Nomarski microscopy. The details of the samples were photographed, measured and analyzed. The fine structures of the parasite including the details of cirrus sac and developmental stages in different strobila were more obvious observing by Nomarski microscopy. The morphometric characters in the RAW and AWIDH showed that length of immature proglottid, length of mature proglottid, length of suckers are larger in RAW than AWIDH worms with statistical difference. Characters in E. granulosus of RAW and AWIDH showed that total number of segments, number of mature segments and the total number of testes were greater in RAW than AWIDH worms; while only the number of mature segments was statistically different is two groups. Application of DIC/Nomarski and phase contrast microscopy together with morphometric criteria are useful means for comparing the developmental aspects of in vitro and in vivo reared adults of E. granulosus.

Ultrastructural observations on the tegumental surface of Polyonchobothrium clarias Woodland, 1925 (Cestoda: Bothriocephalidae), infecting the catfish Clarias gariepinus in Egypt.

The fine structure of the tegument of mature proglottids in Polyonchobothrium clarias, Woodland, 1925, family: Bothriocephalidae, a cestode parasite of the cat fish Clarias gariepinus was studied using transmission electron microscopy.The ultrastructural observations of the tegument revealed that it consists of distal cytoplasm connected with underlying perikarya by cytoplasmic bridges. The distal cytoplasm differs in thickness between the different regions of P. clarias and lies on the basal lamina below which there are two layers of muscles, circular and longitudinal bundles. The main characteristic inclusion in the distal cytoplasm is the presence of electron-dense bodies and vesicles of variable size, shape and density. The tegument perikarya lies beneath the surface musculature.Three different types of microtriches varying in shape and size have been observed on the tegumental surface of the mature proglottids of P. clarias, filiform, blade-like spiniform and digitiform microtriches. Multiple functions of such structures; the amplification of the surface area for digestion, absorption, excretion, movement, attachment to the intestinal mucosa of their hosts and external protection. The types and distribution of microtriches are considered to be of systematic and phylogenetic importance.

Morphological and phylogenetical analysis reveals that a new tapeworm species (Cestoda: Hymenolepididae) from whooper swan belongs to Cloacotaenia not Hymenolepis

During a helminthological study of waterfowl in China, a new species (Cloacotaenia cygnimorbus sp. nov.) of hymenolepidid cestodes (tapeworm) was found in the small intestine of whooper swan (Cygnus cygnus, Linnaeus, 1758). The rudimentary rostellum and four unarmed muscular suckers, proglottids with distinct craspedote and three spherical testes were coincident with the characters of Cloacotaenia or Hymenolepis, but phylogenetic analysis of 28S rRNA and cox1 gene revealed that the new species is Cloacotaenia rather than Hymenolepis. Its morphology was also clearly differentiated from C. megalops in the arrangement of its testes in a triangle instead of in line and the cirrus unarmed rather than spined. Compared with C. megalops, the new species has more elongated neck, much larger mature proglottids and much smaller testes, cirrus sac, ovary, vitellarium and uterine proglottid. In addition, it infected the host intestine not the cloacae. Phylogenetic analysis of cox1 gene of the new species shows that it had a level of sequence variation (10.52–23.06%) with the sequences of C. megalops. The considerable morphological and molecular differences between those two parasites support C. cygnimorbus sp. nov. as a new species.

Evaluation of dynamic developmental processes and the molecular basis of the high body fat percentage of different proglottid types of Moniezia expansa

BackgroundMoniezia expansa (Cyclophyllidea: Anoplocephalidae) is a large species of tapeworm that occurs in sheep and cattle and inhabits the small intestine, causing diarrhea and weight declines, leading to stockbreeding losses. Interestingly, the body fat percentage of M. expansa, which lacks the ability to synthesize fatty acids, is as high as 78% (dry weight) and all of the proglottids of M. expansa exhibit a dynamic developmental process from top to bottom. The aim of this paper is to identify the molecular basis of this high body fat percentage, the dynamic expression of developmental genes and their expression regulation patterns.ResultsFrom 12 different proglottids (four sections: scolex and neck, immature, mature and gravid with three replicates), 13,874 transcripts and 680 differentially expressed genes (DEGs) were obtained. The gene expression patterns of the scolex and neck and immature proglottids were very similar, while those of the mature and gravid proglottids differed greatly. In addition, 13 lipid transport-related proteins were found in the DEGs, and the expression levels showed an increasing trend in the four proglottid types. Furthermore, it was shown that 33 homeobox genes, 9 of which were DEGs, had the highest expression in the scolex and neck section. The functional enrichment results of the DEGs were predominantly indicative of development-related processes, and there were also some signal transduction and metabolism results. The most striking result was the finding of Wnt signaling pathways, which appeared multiple times. Furthermore, the weighted gene co-expression networks were divided into 12 modules, of which the brown module was enriched with many development-related genes.ConclusionsWe hypothesize that M. expansa uses lipid transport-associated proteins to transport lipids from the host gut to obtain energy to facilitate its high fecundity. In addition, homeobox genes and Wnt signaling pathways play a core role in development and regeneration. The results promote research on the cell differentiation involved in the continuous growth and extension of body structures.

Spirometra decipiens (Cestoda: Diphyllobothriidae) Collected in A Heavily Infected Stray Cat from the Republic of Korea.

Morphological and molecular characteristics of spirometrid tapeworms, Spirometra decipiens, were studied, which were recovered from a heavily infected stray cat road-killed in Eumseong-gun, Chungcheongbuk-do (Province), the Republic of Korea (=Korea). A total of 134 scolices and many broken immature and mature proglottids of Spirometra tapeworms were collected from the small intestine of the cat. Morphological observations were based on 116 specimens. The scolex was 22.8–32.6 mm (27.4 mm in average) in length and small spoon-shape with 2 distinct bothria. The uterus was coiled 3–4 times, the end of the uterus was ball-shaped, and the vaginal aperture shaped as a crescent moon was closer to the cirrus aperture than to the uterine aperture. PCR amplification and direct sequencing of the cox1 target fragment (377 bp in length and corresponding to positions 769–1,146 bp of the cox1 gene) were performed using total genomic DNA extracted from 134 specimens. The cox1 sequences (377 bp) of the specimens showed 99.0% similarity to the reference sequence of S. decipiens and 89.3% similarity to the reference sequence of S. erinaceieuropaei. In the present study, we report a stray cat heavily infected with S. decipiens identified by mitochondrial cox1 sequence analysis and morphological examinations of the adult worms.

Taenia Saginata in Third-Generation Capsule Endoscopy

A 60-year-old woman presented with chronic abdominal pain and iron deficiency anemia (hemoglobin, 9.8 g/dL; ferritin, 8 μg/L). The patient was white, born in France, and had never traveled outside France. Initial endoscopic evaluation, with gastroscopy and colonoscopy, was normal. Gastroduodenal biopsies were also normal. Small bowel capsule endoscopy (Pillcam SB-III, Medtronic, Dublin, Ireland) diagnosed a Taenia saginata infection. The worm was found from the proximal jejunum, where young immature proglottids consisting of a chain of small segments wider than long were visible (Figure A). Then, the segments grow and stretch out gradually to become mature proglottids (Figure B). This Taenia was extended until the terminal ileum with gradual appearance of gravid proglottids, measuring about 20 mm long and 6 mm wide (Figure C and D). Mature and gravid proglottids are the reproductive structures of this hermaphrodite parasite; with inside male and female structures. On our images, some of these sexual structures are visible, in particular on the last gravid proglottids, with multiple lateral uterine branches (Figure C, blue arrow) and uterus (Figure D, black arrow). The parasite was visible on 75% of the transit time in the small bowel, estimating a size of 2–3 m. The prognosis was favorable after eradication of the Taenia by a single dose of praziquantel. On the Visual Diagnosis of Human Taeniasis by Capsule EndoscopyClinical Gastroenterology and HepatologyVol. 16Issue 7PreviewLe Mouel et al1 recently identified a case of human taeniasis caused by Taenia saginata by means of third-generation capsule endoscopy. The authors of the article provide 4 illustrative images of the tapeworm and, specifically, gravid proglottids containing a branched uterus are shown. Because after endoscopy no additional confirmatory diagnostic method is specified, we reckon that the images of this branched uterus were meaningful enough for the specific tapeworm identification. Capsule endoscopy is a diagnostic method with high sensitivity. Full-Text PDF

Đặc điểm hình thái học và sinh học phân tử của loài sán dây chủ yếu gây tác hại trên chó tại một số tỉnh Đồng bằng sông Cửu Long

The study was conducted to identify the most common cestodes species which mostly affect dogs in some provinces of the Mekong Delta (An Giang, Dong Thap, Soc Trang, Kien Giang). There were 882 dogs examined for tapeworm infection by Skrjabin comprehensive method. The tapeworm samples were described based on the morphological and molecular features. The morphological features of tapeworm were identified for their properties such as scolex, neck, mature proglottid, gravid proglottid and egg. The genome sequences of tapeworm strains were obtained from the database resources of the National Center for Biotechnology Information (USA). The results showed that the infection rate of parasitic tapeworms in dogs was at 26,3%. The five species were Dipylidium caninum, Spirometra mansoni, Taenia pisiformis, Taenia hydatigena, and Diphylobothrium latum. Amongst them, Dipylidium caninum was the most common tapeworm species determined in this study with highest infection rate. The DNA sequencing indicated 96% of homologous gene sets of the American tapeworm Dipylidium caninum on the National Center for Biotechnology Information with the registration code AF023120.1

A New Species ofCatenotaenia(Cestoda: Catenotaeniidae) fromPygeretmus pumilioKerr, 1792 from the Gobi of Mongolia

From 1999 through 2012, a total of 541 individual rodents (jerboas of the family Dipodidae) were collected from several habitat types, primarily from the Gobi region of Mongolia, and were examined for helminth and protistan parasites. Of those rodents, 25 were identified as Pygeretmus pumilio Kerr, 1792 (Rodentia: Dipodidae), whereas 516 were other species of jerboa from the provinces of Dornogobi, Dundgobi, Omnogobi, Ovorhangai, Bayanhongor, Gobi Altai, and Hovd. During our field work, we collected several cestodes; some of which represented undescribed species, and these new species occurred in 40% of P. pumilio from four separate collecting localities. We designate this new species as Catenotaenia tuyae n. sp. (Cyclophyllidea: Catenotaeniidae), which is characterized by having relatively long and narrow gravid proglottids and an ovary in mature segments that is located antiporally in the anterior portion of the mature proglottids. In addition, the position and the ratio of the genital pore toward the anterior end of the proglottids are unique and the ovary is elongate, being confined to the antiporal part of the mature proglottid. These morphological features serve to differentiate Catenotaenia tuyae from all other species in the genus included in the phylogenetic analysis and are supported by molecular phylogenetic evidence using the 28S ribosomal RNA gene. The intensity of C. tuyae infection in Pygeretmus ranged from 1 to 3 individual cestodes per infected host.

First Record of Raillietina celebensis (Cestoda: Cyclophyllidea) in South America: Redescription and Phylogeny.

Raillietina celebensis is a cestode that parasitizes the small intestine of rats and humans. Here, we detail the morphology and morphometry of R. celebensis based on specimens collected from Rattus norvegicus in the municipality of São Gonçalo, state of Rio de Janeiro, Brazil, by light and confocal scanning laser microscopies and also report the results of molecular phylogenetic analyses to determine its relationships within the family Davaineidae. Analysis of the number and size of testes, number and shape of rostellar hooks, cirrus sac length, capsules and eggs per capsule, and morphology of the mature proglottid allowed concluding that the present specimens constitute a new record of R. celebensis in South America. Our genetic and phylogenetic analyses, based on the partial small subunit 18S rRNA gene, revealed R. celebensis to be in the family Davaineidae within the genus Raillietina, in agreement with the morphological taxonomy. Phylogenetic trees obtained by neighbor-joining and maximum likelihood methods demonstrated R. celebensis as a unique taxonomic unit, and also demonstrated some taxonomic inconsistences. The incorporation of Brazilian R. celebensis sequences derived from mammals in the phylogeny of davaineids is consistent with the assertion that neither Raillietina nor Fuhrmannetta can be supported as distinct genera.

Molecular analysis of a novel species, Gangesia punjabensis (Family: Proteocephalidae, Subfamily: Gangesiinae) infecting an Indian freshwater cat fish, Wallago attu evidencing species complex.

In the present study, from August 2015 to July 2016, a total of 159 specimens of Wallago attu Bloch and Scheider, 1801 vern. mully were collected from the Ropar wetland, Punjab, India and were examined for the presence of intestinal tapeworms. The infection rate was 12.5%, out of which, two fishes were heavily infected with a proteocephalidean cestode belonging to the genus Gangesia in the month of February. Gangesia punjabensis sp. nov. was identified and described on the basis of morphology and partial amplification of LSUrDNA (28S rDNA). The histopathogenesis caused by these parasites have also been studied in histological sections. About 9-35 number of worms were collected from a single host. The length of worms ranged from 6.0 to 6.2cm. The strobila consisted of an armed scolex, neck, immature proglottids (approximately 90 in number) and mature proglottids (approximately 7 in number) and gravid proglottids were not detected. Analysis of 28S large subunit (LSU) rDNA sequence of the isolate of G. punjabensis n. sp. demonstrated maximum similarity of 99% with G. bengalensis, 98% with G. vachai, 97% with G. macrones. The phylogenetic tree based on the final edited alignment (822bp) with Neighbour-Joining showed the highest bootstrap value of 100 and placed G. punjabensis n. sp. with G. bengalensis and G. macrones in the same clade showing them to be a species complex. The intestinal mucosal lining exhibited blister formation, haemorrhagia and inflammation due to the presence of deeply embedded scolices. Histopathology caused was evident due to disruption of villous surface and cellular infiltration. This is the first report of cestodes belonging to the genus Gangesia from Ropar wetland, Punjab, India.

Two new cestode species of Tetragonocephalum Shipley & Hornell, 1905 (Lecanicephalidea, Tetragonocephalidae) from Himantura randalli Last, Manjaji-Matsumoto & Moore (Myliobatiformes, Dasyatidae) from the Gulf of Oman.

The original description of the genus Tetragonocephalum was published more than one hundred years ago but its taxonomic status was clarified only recently. To date, approximately 30 nominal species of this genus have been described, mostly from the northern Indian Ocean, but nearly half of them are invalid and only 14 species are recognized as valid. In the present study two new species of Tetragonocephalum are described from the spiral intestine of Himantura randalli from off Jod, on the northern coast of the Gulf of Oman. Tetragonocephalum sabae sp. n. is distinguishable from the valid species of Tetragonocephalum based on number of proglottids (43−53), number of testes (42−50), and size of scolex (401−453×328−455), acetabula (87−109×72−116), mature proglottids (802−1,333×226−336), cirrus sac (92−160×103−154), and eggs (16−19×11−13). Tetragonocephalum salarii sp. n. can be distinguished from Tetragonocephalum sabae sp. n. and all other valid species of Tetragonocephalum based on number of proglottids (77−86). Furthermore, it differs from its congeners based on a combination of some characteristics, including the number of mature (3−7) and gravid (18−20) proglottids, the number of testes (30−38), and the size of acetabula (84−111×80−96), mature proglottids (497−833×334−403), gravid proglottids (1,036−1,482×440−575), testes (20−34×31−50), ovary (123−215×210−278), and eggs (24−45×13−21).

Cerebral and non-cerebral coenurosis: on the genotypic and phenotypic diversity of Taenia multiceps.

We characterised the causative agents of cerebral and non-cerebral coenurosis in livestock by determining the mitochondrial genotypes and morphological phenotypes of 52 Taenia multiceps isolates from a wide geographical range in Europe, Africa, and western Asia. Three studies were conducted: (1) a morphological comparison of the rostellar hooks of cerebral and non-cerebral cysts of sheep and goats, (2) a morphological comparison of adult worms experimentally produced in dogs, and (3) a molecular analysis of three partial mitochondrial genes (nad1, cox1, and 12S rRNA) of the same isolates. No significant morphological or genetic differences were associated with the species of the intermediate host. Adult parasites originating from cerebral and non-cerebral cysts differed morphologically, e.g. the shape of the small hooks and the distribution of the testes in the mature proglottids. The phylogenetic analysis of the mitochondrial haplotypes produced three distinct clusters: one cluster including both cerebral isolates from Greece and non-cerebral isolates from tropical and subtropical countries, and two clusters including cerebral isolates from Greece. The majority of the non-cerebral specimens clustered together but did not form a monophyletic group. No monophyletic groups were observed based on geography, although specimens from the same region tended to cluster. The clustering indicates high intraspecific diversity. The phylogenetic analysis suggests that all variants of T. multiceps can cause cerebral coenurosis in sheep (which may be the ancestral phenotype), and some variants, predominantly from one genetic cluster, acquired the additional capacity to produce non-cerebral forms in goats and more rarely in sheep.

Description and life-cycle of Taenia lynciscapreoli sp. n. (Cestoda, Cyclophyllidea).

A new species of tapeworm, Taenia lynciscapreoli sp. n. (Cestoda, Cyclophyllidea), is described from the Eurasian lynx (Lynx lynx), the main definitive host, and the roe deer (Capreolus capreolus and Capreolus pygargus), the main intermediate hosts, from Finland and Russia (Siberia and the Russian Far East). The new species was found once also in the wolf (Canis lupus) and the Eurasian elk/moose (Alces alces), representing accidental definitive and intermediate hosts, respectively. The conspecificity of adult specimens and metacestodes of Taenia lynciscapreoli sp. n. in various host species and regions, and their distinction from related species of Taenia, was confirmed by partial nucleotide sequences of the mitochondrial cytochrome c oxidase subunit 1 gene. Morphologically, Taenia lynciscapreoli sp. n. can be separated unambiguously from all other species of Taenia by the shape of its large rostellar hooks, particularly the characteristically short, wide and strongly curved blade. If the large rostellar hooks are missing, Taenia lynciscapreoli may be separated from related species by a combination of morphological features of mature proglottids. It is suggested that Taenia lynciscapreoli has been present in published materials concerning the tapeworms of Lynx lynx and Lynx pardinus in Europe, but has been misidentified as Taenia pisiformis (Bloch, 1780). Taenia lynciscapreoli sp. n. has not been found in lynx outside the range of roe deer, suggesting a transmission pathway based on a specific predator–prey relationship. The present study applies a novel, simple approach to compare qualitative interspecific differences in the shape of rostellar hooks.

Interactions between the intestinal cestode Polyonchobothrium clarias (Pseudophyllidea: Ptychobothriidae) from the African sharptooth catfish Clarias gariepinus and heavy metal pollutants in an aquatic environment in Egypt.

In an aquatic environment, there is a profound and inverse relationship between environmental quality and disease status of fish. Parasites are one of the most serious limiting factors in aquaculture. Therefore, the present investigation was carried out during the period of February-December 2014 to determine the parasitic infections in the African sharptooth catfish Clarias gariepinus, relative to the capability of internal parasites to accumulate heavy metals. Up to 100 catfish were examined for gastrointestinal helminths and 38% of fish were found to be infected with the cestode Polyonchobothrium clarias. The morphology of this parasite species, based on light and scanning electron microscopy, revealed that the adult worm was characterized by a rectangular scolex measuring 0.43-0.58 (0.49±0.1)mm long and 0.15-0.21 (0.19±0.1)mm wide, with a flat to slightly raised rostellum armed with a crown with two semicircles each bearing 13-15 hooks, followed by immature, mature and gravid proglottids which were about 29-55 (45), 16-30 (24) and 15-39 (28) in number, respectively. The mature proglottid contained a single set of genitalia in which medullary testes measured 0.09-0.13 (0.11±0.01)mm long and 0.05-0.08 (0.06±0.01)mm wide; a bi-lobed ovary was situated near the posterior margin of the proglottid, extending laterally up to the longitudinal excretory canals; the tubular uterus arose from the ootype up to the anterior margin of the proglottid; and vitelline follicles were cortical. The greater portion of the gravid proglottid was occupied by a uterus filled with unoperculate and embryonated eggs. Chemical analysis confirmed that the concentrations of heavy metals (Zn, Cu, Mn, Cd, Ni and Pb) accumulated in P. clarias were higher than in fish tissues and values recommended by FAO/WHO, with the exception of Zn, which was found to be higher in fish kidneys than in the cestode. This supports the hypothesis that cestodes of fish can be regarded as useful bioindicators when evaluating the environmental pollution of aquatic ecosystems by heavy metals.

Studies on pseudophyllidean cestode genus Ptychobothrium loennberg, 1889 (cestoda: ptychobothriidae, luhe, 1902) from freshwater fish Mastacembelus armatus (lacepede, 1800)

The present study deals with description of a new species of Pseudophyllidean Cestode genus Ptychobothrium, Loennberg,1889 collected from intestine of freshwater fish, Mastacembelus armatus (Lacepede, 1800) at Mahur, Dist. Nanded M.S. India during February, 2011 to January, 2013. Ptychobothrium vitellaris Sp.Nov. comes closer to all known species of genus Ptychobothrium, Loennberg, 1889 in general topography of organs but differs due to sessile Scolex, paired bothria, apical disk at anterior end of scolex, Neck absent, Mature Proglottids broader than long, Cirrus pouch pyriform, Testes 40-45 in numbers, Ovary bilobed and Vitellaria follicular.

Functional ultrastructure of the parenchymatic capsules of the cestode Thysanotaenia congolensis (Cyclophyllidea, Anoplocephalidae, Inermicapsiferinae).

Proglottids from adult Thysanotaenia congolensis from naturally infected black rats Rattus rattus from Santiago Island, Cape Verde, were examined by transmission electron microscopy (TEM). The uterus in mature proglottids is composed of an ephemeral transverse tube or sac that breaks down, releasing eggs into the parenchyma where they are sequestered in groups and encapsulated by parenchymatous layers. In gravid proglottids, eggs accumulate in groups of 6-12 at the distal end of sac-like uterine ducts. As eggs accumulate, the end of the uterine ducts expands until it pinches off, releasing groups of eggs into the parenchyma surrounded by remnants of uterine epithelium. These epithelium-bound groups of eggs remain in the parenchyma until they are encapsulated with several parenchymatous layers, forming parenchymatic egg capsules, typical for mature and gravid proglottids of Inermicapsiferinae. The parenchymatic capsules originate from the medullary parenchyma of immature proglottids, which undergoes differentiation into the three layers of gravid proglottids: (1) an outer connective tissue layer composed of long delicate filaments of unknown chemical nature embedded in a granular extracellular matrix; (2) a middle layer appearing as an accumulation of large closely packed PAS-positive mucous goblets that are intensely metachromatic after toluidine blue staining and (3) an inner compact layer composed of lipid-containing cells, muscle cells with elongated muscle fibres and cells of various sizes and shapes forming or containing calcareous corpuscles. The mature hexacanths of T. congolensis are surrounded by reduced oncospheral envelopes consisting of remnants of a very thin membranous layer of degenerating embryophore with long, irregularly shaped cytoplasmic processes and by remnants of uterine epithelium extending as numerous apical microlamellae into the parenchymatic capsule lumen.

Fine structure of the uterus in tapeworm Tetrabothrius erostris (Cestoda: Tetrabothriidea).

The uterine organization in Tetrabothrius erostris (Tetrabothriidea) was investigated by the methods of transmission and scanning electron microscopy. In sexually mature proglottids, the uterine wall consists of a syncytial epithelium (1.4-2.5 μm thick, except in regions containing nuclei). The ribosomes, mitochondria and numerous cisternae of granular endoplasmic reticulum with concentric or parallel profiles with electron lucent material are observed in the epithelium. The uterine wall is characterized by the abundance of lipid droplets that are localized inside the long protrusions of the uterine epithelium (called fungiform papillae) up to 15-17μm and in the surrounding medullary parenchyma. The protrusions with lipid droplets in the proximal ends of the uterus are located closely to each other. A basal matrix (up to 0.6 μm thick) supports the uterine epithelium. The musculature consisting of 1-2 muscle layers is well developed; large myocytons are connected with the myofibrils and have a nucleus that reaches 4μm in size. In gravid proglottids, the epithelium without nuclei is reduced to 0.2-1.6 μm thick. The number of protrusions of the uterine epithelium and lipid droplets in the epithelial layer decreases. Sparse small muscle bundles underlay the uterine wall at this stage; the basal matrix is feebly marked. The matrotrophy or the support by nutrition from the parent organism to embryos is discussed for T. erostris which belongs to oligolecital cestodes and possesses numerous lipid droplets in the uterine wall during the development of embryos.

Reports on cestode genus Senga (Dollfus, 1934) (Ptychobothridae, Luhe, 1902) of Mastacembelus armatus from Marathwada region Maharashtra, India

The present investigation deals with biosystematic studies of Pseudophyllidean tapeworm Senga i.e. S. satarensis, S. madhavae, S. mangalbai and S.microrostellata collected from intestine of a Mastacembelus armatus at various places of Marathwada Region (M.S.) India during the period of May, 2012 to Oct., 2013. The worm of present study come closer to all known species of this genus in general topography of organ but differs due to morphometeric measurements and morphological characteristics. The Senga satarensis (Bhure et.al., 2011) comes closer to known species of the genus Senga Dollfus, 1934 in general topography of organ but differs due to taxonomic characters as scolex pear shaped, rostellum bearing 28-30 rostellar hooks, neck absent, testes 175-200 in numbers, cirrus pouch oval, ovary bilobed, vagina runs posteriorly, genital pores oval, vitellaria granular, uterus saccular and egg elongated. The Senga madhavae (Bhure et.al.,2010) comes closer to known species of this genus in general topography of organ but differs due to scolex triangular, rostellum bearing 40-44 rostellar hooks, neck absent, mature proglottids five to six times broader than long, testes 200-220 in numbers, cirrus pouch oval, ovary dumb-bell shaped, genital pores oval in shape, vitellaria granular, uterus saccular and egg elongated. The Senga mangalbai (Bhure et.al.,2011) comes closer to all the known species of this genus in general topography of organ but differs due to scolex conical, hooks 38-42 in numbers, absence of neck, testes 70-80 in numbers, ovary bilobed, each lobe nut shaped and vitellaria granular. The Senga microrostellata (Bhure et.al.,2014) comes closer to all known species of this genus in general topography of organ but differs due to scolex triangular, bothria sessile, rostellum armed with 18-20 hooks which is single circled, absence of neck, mature proglottids 8-9 times broader than long, testes 250-300 in numbers, cirrus pouch elongated, vagina runs posteriorly, ovary dumb-bell shaped, uterus sacular filled with non-operculated eggs and Vitellaria follicular.

A new combination and a new species of onchobothriid tapeworm (Cestoda: Tetraphyllidea: Onchobothriidae) from triakid sharks

A new combination and a new species of onchobothriid tapeworm are described from triakid sharks. We found Platybothrium xiamenensis Wang & Yang, 2001 and Erudituncus musteli (Yamaguti, 1952) from Hemitriakis japanica (Müller & Henle). Based on the morphology of the hooks P. xiamenensis is transferred to the genus Erudituncus Healy, Scholz & Caira, 2001. The specimens studied by us differ from the original description in the number of proglottids and testes and in the size of the cirrus-sac. However, we consider them conspecific with E. xiamenensis due to the consistent hook morphology and laciniations in both descriptions and believe the differences reflect intraspecific variation. The type-host of E. xiamenensis was reported as Mustelus griseus Pietschmann. However, in the present study, this parasite was found only in H. japanica and never in M. griseus although many specimens of the latter host were examined. This suggests that the type-host in the original description has probably been misidentified. We found another undescribed species in M. griseus, Calliobothrium shirozame n. sp., which is distinguished from the congeners by having a unique combination of the number of laciniations: four in the cephalic peduncle, six in the immature proglottids and four in the mature proglottids.

The Ocellated Eagle Ray,Aetobatus ocellatus(Myliobatiformes: Myliobatidae), from Borneo and Northern Australia as Host of Four New Species ofHornellobothrium(Cestoda: Lecanicephalidea)

Four new species are described in the lecanicephalidean genus Hornellobothrium from the ocellated eagle ray, Aetobatus ocellatus, from Australia and Indonesian Borneo. The species possess flat, laterally expanded immature proglottids and a small internal, glandular apical organ diagnostic of the genus. To date, only 2 valid species are recognized in the genus: Hornellobothrium cobraformis Shipley & Hornell, 1906 , from " Aetobatus narinari " from Sri Lanka, and Hornellobothrium extensivum Jensen, 2005 , from A. ocellatus , also from Australia. The new species differ from H. cobraformis in the shape of the apical organ and mature proglottids, and from H. extensivum in testes number and scolex dimensions. The new species can be distinguished from one another based on the following combination of features: Hornellobothrium gerdaae n. sp. possesses testes arranged in 2 layers and lacks post-ovarian vitelline follicles; Hornellobothrium iotakotta n. sp. has a single column of 4 testes and lacks spiniform microtriches on the distal bothridial surface; both Hornellobothrium kolossakotta n. sp. and Hornellobothrium najaforme n. sp. possess a single column of 6 testes, but H. najaforme n. sp. is a longer worm with a greater number of laterally expanded immature proglottids. Host associations suggest this genus is potentially limited to A. ocellatus . While reports of up to 9 lecanicephalidean congeners in a single host species exist, they are considered dubious and in need of verification, mainly because of host identification issues. This study demonstrates the presence of at least 5 species of Hornellobothrium in A. ocellatus . Insufficient sampling of this host species across the Indo-Pacific and at each locality may account for the apparent restricted distribution of species of Hornellobothrium.