Showing papers on "Digenea published in 1993"

The life-cycle and morphology of Sanguinicola inermis Plehn, 1905 (Digenea: Sanguinicolidae)

Abstract: The life-cycle and morphology of Sanguinicola inermis in laboratory infected common carp Cyprinus carpio and Lymnaea peregra at 20°C are described. Furcocercous cercariae develop from two generations of sporocysts within four to five weeks and directly infect a cyprinid definitive host. Post-penetration larvae migrate to the blood circulatory system of the fish and mature into adults which release eggs into the blood by 30 days post-exposure. Eggs reaching the gills mature and liberate miracidia within seven days. The miracidia emigrate through host tissue to the water, where they locate and penetrate a snail host. A detailed description of the developmental stages is given and the surface structure of the cercaria, the oral muscular organ of the adult and the vitelline membrane of the egg are described for the first time.

Homogeneity of sperm structure in six species of schistosomes (digenea, platyhelminthes)

Abstract: L'ultrastructure du spermatozoide est decrite chez six especes de schistosomes: Schistosoma curassoni, S. rodhaini, S. intercalatum, S. bovis, S. margrebowiei, and S. mansoni. La structure du spermatozoide est homogene chez les schistosomes, mais tres differente de celle des autres Digenea

The life-cycle of Helicometra gibsoni n. sp. (Digenea: Opecoelidae)

Abstract: The life-cycle of Helicometra gibsoni n. sp., an opecoelid trematode of marine fishes, is elucidated and the life-history stages are described. Natural infections with the cercariae, which are typically opecoelid in many respects but characterised by having very long, extensile tails, were found in the intertidal snail Anachis terpsichore collected from the Lawson's Bay Coast, Bay of Bengal. Metacercariae were found in the thoracic muscles of the shooting shrimp Alphaeus malabaricus as prominent, reddish-brown, oval cysts. Laboratory experiments demonstrated that 14 days are required for the development of cercaria into the infective metacercarial stage in shrimps. Natural infections with the adult fluke were found in Scorpaenopsis cirrhosus. Therapon jarbua served as an experimental host. Fourteen-day-old metacercariae fed to T. jarbua developed into egg-producing adults in 40–43 days. Intra-specific variations noted in the flukes obtained from natural and experimental infections are presented. H. fasciata of Madhavi (1975) is regarded as a synonym of H. gibsoni.

Bathymonorchis polyipni (Reimer, 1985) n. g., n. comb. (Digenea: Monorchiidae) from bathypelagic fishes of the eastern mid-Atlantic Ocean

Abstract: The new genus Bathymonorchis is defined and differentiated from the genera Monorchis and Allolasiotocus. B. polyipni (Reimer) n. comb., previously attributed to Monorchis, is described from Neoscopelus macrolepidotus and Polymetme corythaeola from the Atlantic off the coast of NW Africa. The new genus is characterised by its single vitelline field, multilobate ovary, spinous blind portion of Looss' organ, lack of external seminal vesicle, testicular position and uterine configuration.

L'ultrastructure de la protonéphridie chez les Monogènes. Ses implications pour la phylogénie du groupe

Abstract: SUMMARY The small protonephridial capillaries and flame buibs of Trematoda Aspidogastrea, Digenea, Monogenea Polyopisthocotylea and Monopisthocotylea have a longitudinal septate junction which is absent in Udonella, Amphilinidea, Gyrocotylidea and Eucestoda. Capillaries of most species of the first group possess lamellae whereas those of the second group (except Udonella) possess short microvilli. External leptotriches are well developed in the first, but absent or weakiy developed in the second group. In the monopisthocotylean monogenean Anoplodiscus, the septate junction of the capillaries is rudimentary, probably due to secondary reduction. The ultrastructural findings and DNA studies do not support the view that Monogenea and Cestoda form a taxon with an origin different from that of the other groups of parasitic Platyhelminthes. Gyrocotyle is a cestode, as indicated by the ultrastructure of the protonephridia and DNA sequencing.

A new zoogonid cercaria (Trematoda: Digenea) from the Florida horse conch, Pleuroploca gigantea in the Northwestern Gulf of Mexico

Abstract: A seventh known species of larval zoogonid is reported, which was found parasitizing the gonad and digestive gland of the large carnivorous gastropod mollusc Pleuroploca gigantea collected in the Gulf of Mexico southeast of Galveston, Texas. Descriptions of the sporocyst and cercarial stages are given. The larva is assigned the temporary designation of "zoogonid Cercaria A" until further information concerning its life cycle and specific identity becomes available. The morphology of the cercaria most nearly resembles that of the cercaria of Zoogonoides viviparus (Olsson, 1868) Odhner, 1902, from which it differs by its lack of a prepharynx and lack of anterolateral indentations in the stylet. Other differences are in body size, host species, and host geographic range.

Note on digenetic trematodes parasitic in fishes near shallow sea in guangdong province,china i.cryptogonimidae and haploporidae (digenea)

Abstract: This paper reports two new species and one new genus of the members belonging to Di-genea, all specimens from fishes of the family Mugilidae collected from the coast waters ofHuidong County, Guangdong Province. Of the two species, one belongs to the new genus ofsubfamily Tubanguiinae, Cryptogonimidae and the other to the genus Saccocoelioides, Haplo- poridae. Measurements are in millimeters. All the type specimens are deposited in the Ichthy-ological Lab, Department of Biology, Zhongshan University. Tandemorchis gen. nov. Generic diagnosis Body small, ovoid in shape, spinulate with one pair of eyespots. Oralsucker terminal, followed by a developed pharynx. Oesophagus short. Caeca long sac--shapedor short sac--shaped, reaching to the posterior area of the middle part of body or the front ofthe posterior testis. Acetabulum absent. Testes double, tandem, existed in longitudinal axisof the body. Seminal vesicle oval--shaped, located on the ventral side of the anterior testis.Genital pore situated near the intestinal bifurcation. Ovary located between two testes.Laurer's canal present. Vitellaria distributed in each side of ovary. Uterus containsa feweggs. Full embryonated eggs contain miracidia with eyespots. Excretory vesicle V--shaped,stems reaching nearly to eyespots. Parasitic in intestine of marine fishes. Genotype: Tandemorchis yuedongensis. The new genus differs distinctly from genus Tubanguia Srivastava, 1935 in having eye-spots. no prepharynx, much shorter caeca, different disposition of the oral sucker and vitel-laria. etc. Tandemorchis yuedongensis sp. nov. (fig. 1 and 2) Hosts Migil macrolepis Smith. Location Intestine. Locality Huangfu Town, Huidong County (22°41′N, 114°55′E). Date January 8, 1990. Type specimens Holotype N901;Paratypes N902,N903. Body ovoid to elliptical, covered with cuticular spines. Total length 0. 3225 --0. 3295(0. 3250), maximum width 0. 2250--0. 2475 (0. 2450 ). Two eyespots located in each side ofpharynx. Left 0. 0150×0. 0150, right 0. 0175×0. 0145. Oral sucker terminal, 0. 0450--0. 0495×0. 0490--0. 0525 (0. 0475×0. 0500). Prepharynx absent. Pharynx oval in shape,0. 0225-- 0. 0260×0. 0245 -- 0. 0275 (0. 0250×0. 0250). Oesophagus 0. 0050 -- 0. 0085(0. 0075). Caeca long sac--shaped, reaching to the posterior area of the middle part of body orthe front of the posterior testis. Testes double and tandem. Anterior testis 0. 0850--0. 0895×0. 0725 -- 0. 0790 (0. 0875×0. 0775); posterior one 0. 0625--0. 0675×0. 0800--0. 0850(0. 0650×0. 0825). Seminal vesicle oval in shape, situated on the ventral side of the anteriortestis, 0. 0525 --0. 0575×0. 0500--0. 0550(0. 0550×0. 0525). Male genital pore opening inde-pendently in genital atrium located near the intestinal bifurcation. Ovary elliptical, 0. 0400 ---0. 0450×0. 0300--0. 0355 (0. 0425×0. 0325), located between the testes. Seminal receptacleovoid--shaped, existed on the left side of the posterior testis, 0. 0325 -- 0. 0375×0. 0530---0. 0575 (0. 0350×0. 0550). Laurer's canal present. Vitellaria distributed in each side of ovary.Uterine coils chiefly between genital pore and ovarian complex. Metraterm opens separatelyfrom the male aperture. Egg ovoid in shape, 10--15 in numbers in uterus, 0. 0275--0. 0300× 0. 0400--0. 0425 (0. 0280×0. 0420). Fully embryonated eggs contain miracidia with eyespots.Excretory vesicle V--shaped, arms reaching to near eyespots. Saccocoelioides huidongensis sp. nov. (fig. 3 and 4) Hosts Mugil parvus (Oshima). Location Intestine. Locality Dazhou Town, Huidong County (22°42' N, 114°54' E). Date September 5,1990. Type specimens Holotype S905; Paratype S906 7. Body 0. 675--0. 080 (0. 074) in length with breadth 0. 170--0. 175(0. 1725). Body elon-gate, covered with spines. Oral sucker terminal, 0. 0975 -- 0. 1150×0. 0900 -- 0. 1175, fol-lowed by prepharynx, 0. 0225--0. 0250. Pharynx ovoid in shape, 0. 0725--0. 0950×0. 0700-0. 1000. Oesophagus short, with developed muscular tissue, 0. 0152 -- 0. 0175. Caeca sac-shaped, reaching to front level of ovary. Acetabulum developed, 0. 0950--0. 1500×0. 0925-0.