Showing papers in "Journal of the Helminthological Society of Washington in 1991"

Ultrastructure of the intestinal epithelium, lumen, and associated bacteria in Heterorhabditis bacteriophora

Abstract: Heterorhabditis bacteriophora is an obligate parasit e of insect s that contains the bacterial symbiont , Xenorhabdus luminescens, in its intestinal lumen. Ultrastructural observations were made of the intestinal epithelium, lumen, and associate d bacteria. The oligocytous intestine of the infective juvenile of//, bacteriophora has junctional complexes that delineat e the boundaries of cells forming the intestinal lumen. Fine structure of the intestinal cells includes microvilli on the apical membrane s bordered by a dense matrix of vesicular endoplasmic reticulum and accumulations of variably stained electron-dens e granules within each cell. Rod-shape d bacterial cells occur singly or en masse in the lumen of the intestine. Some bacteri a appear to undergo autolysi s or show interaction with the lumen contents.

Protozoan, helminth, and arthropod parasites of the spotted chorus frog, Pseudacris clarkii (Anura: Hylidae), from north-central Texas

Abstract: Thirty-nine juvenile and adult spotted chorus frogs, Pseudacris clarkii, were collected from 3 counties of north-central Texas and examined for parasites . Thirty-three (85%) of the P. clarkii were found to be infected with 1 or more parasites , including Hexamita intestinalis Dujardin, 1841, Tritrichomonas augusta Alexeieff, 1911, Opalina sp. Purkinje and Valentin, 1840, Nyctotherus cordiformis Ehrenberg, 1838, Myxidium serotinum Kudo and Sprague, 1940, Cylindrotaenia americana Jewell , 1916, Cosmocercoides variabilis (Harwood, 1930) Travassos , 1931, and Hannemania sp. Oudemans , 1911. All represen t new host records for the respective parasites . In addition, a summar y of the 36 species of amphibians and reptiles reported to be hosts of Cylindrotaenia americana is presented .

The proliferative tetrathyridium of Mesocestoides vogae sp. n. (Cestoda)

Abstract: The name Mesocestoides vogae sp. n. is proposed for the species of asexually proliferative tetra- thyridium described by Specht and Voge (1965) and now in popular use in many laboratories in the world. A number of developmental differences are cited that make the tentative identification of this species as Meso- cestoides corti Hoeppli, 1925, by Specht and Voge difficult to accept. Until further data become available which demonstrate its adult stage and definitive host, a different name should be used for this metacestode species.

Helminths of the Wood Frog, Rana sylvatica, and Spring Peeper, Pseudacris c. crucifer, from Southern Michigan

Abstract: Eight helminth species (3 Trematoda, 5 Nematoda) were found in 100 wood frogs, Rana syl- vatica LeConte, and 5 helminth species (1 Trematoda, 4 Nematoda) were found in 88 northern spring peepers, Pseudacris c. crucifer (Wied-Neuwied), collected from southern lower Michigan in spring 1989 and 1990. Of the species identified, Oswaldocruzia pipiens and Hae- matoloechus parviplexus had the highest prevalence and mean intensity in wood frogs, respectively. Glypthel- mins pennsylvaniensis had the highest prevalence and mean intensity in spring peepers. Michigan is a new locality record for G. pennsylvaniensis, Cosmocercoides dukae, O. pipiens, and Rhabdias ranae.

A Redescription of Ostertagia bison is (Nematoda: Trichostrongyloidea) and a Key to Species of Ostertagiinae with a Tapering Lateral Synlophe from Domestic Ruminants in North America

Abstract: Ostertagia bisonis Chapin, 1925, is an abomasal worm of the American buffalo, Bison bison, and other ruminants including cattle in which it can cause clinical nematodiasis. This report describes characteristics of O. bisonis, especially details of the synlophe and esophagus, that are necessary for constructing a key to the species of medium stomach worms (Ostertagiinae) parasitic in domestic ruminants in North America. The synlophe of O. bisonis is most similar to the single ridge tapering lateral synlophe of Ostertagia ostertagi. Ducts of the subventral glands of the esophagus empty anterior to the cervical papillae and the esophageal-intestinal valve is more than twice as long as wide. We follow earlier workers in considering Ostertagia orloffi Sankin, 1930, a synonym of O. bisonis. Ostertagia bisonis may have more generalized characters than any other species with a tapering lateral synlophe that are parasites of domestic ruminants in North America, but polarization of some characters cannot be considered reliable until additional outgroups are studied.

Some digeneans (Trematoda) of the green turtle, Chelonia mydas (Testudines: Cheloniidae) from Puerto Rico.

Abstract: The Caribbean Aquatic Animal Health Project and the Caribbean Stranding Network attempted to rehabilitat e a moribund green turtle, an endangere d marine species , from Puert o Rico. The animal died and a necropsy was performed in an attempt to determine the cause of death. Several species of digeneans were found: a single spirorchid, Learedius learedi; 2 pronocephalids , Pyelosomum cochelear and Glyphicephalus lobatus, recorded for the first time in green turtles of Puert o Rico; a single angiodictyid, Deutcrobaris proteus, which represent s a new locality record for the Caribbean; and 3 microscaphidiids , Angiodictyum parallellum and Octangium sagitta, which represen t new locality records for the Caribbean and Atlantic Ocean, respectively, and Polyangium linguatula, a new locality record for Puert o Rico.

Light and electron microscopical study of a bacterial parasite from the cyst nematode, Heterodera glycines.

Abstract: The host range and morphology of a mycelial and endospore-forming bacterium (CNP) that par- asitizes the cyst nematode, Heterodera elachista, differentiates it from 2 related species, Pasteuria penetrans and Pasteuria thornei, parasites of Meloidogyne spp. and Pratylenchus spp., respectively. In cross-inoculation ex- periments with the 3 bacteria, the CNP parasitized the nematodes Heterodera glycines and Globodera rostochiensis but not species in either Meloidogyne or Pratylenchus. The rhomboidal shape of the sporangia of Pasteuria thornei distinguishes this species from the other 2 bacteria, which have cup-shaped sporangia. The results of the cross- inoculation studies and differences in the fine structure of the cup-shaped sporangia suggest that CNP should be assigned to a new species within the genus Pasteuria.

Intensity of Neobenedenia girellae (Monogenea: Capsalidae) on the halfmoon, Medialuna californiensis (Perciformes: Kyphosidae), examined using a new method for detection

Abstract: The intensity and prevalence of infestation of Neobenedenia girellae (Hargis, 1955) Yamaguti , 1963, were examined in the halfmoon, Medialuna californiensis (Steindachner) . The halfmoon is a new host for this parasite, and its presenc e on this fish near Sant a Catalina Island, California, extends its known geographical distribution. Two methods of examination were compared, 1 of which was a far more effective way of detecting non-microscopi c N. girellae. Our results sugges t that female M. californiensis have a significantly higher intensity of infestation than males. There appear s to be no relationshi p between adult host size and intensity of infestation.

Early Development of Larval Taenia polyacantha in Experimental Intermediate Hosts

Abstract: The early larval development and migration route of Taenia po!yacantha were examined using oral inoculation of oncospheres into red-backed voles and Mongolian gerbils. The larvae were recovered in the wall of the small intestine and in the mesenteric lymph nodes by 5 days postinfection (PI) and from the peritoneal cavity after 6 days PI. These results suggest that the larval cestodes developed initially in the wall of the small intestine and the mesenteric lymph nodes, and later migrated to the peritoneal cavity. Although the development of the parasite was quite similar in the 2 host species, pathological changes were different. In Mongolian gerbils, these changes were slight, but in red-backed voles, they were marked and fatal. In addition to oral inoculation, hatched oncospheres were injected intraperitoneally and subcutaneously into red-backed voles, Mongolian gerbils, and AKRlJ mice. Larval development took place at the injection sites in gerbils and mice, but was delayed and abnormal. Some of the parasites in the injection site showed abnormal numerous budding. High pathogenicity was shown after subcutaneous and intraperitoneal injection as well as after oral inoculation.

First report of Ostertagia leptospicularis (Nematoda: Trichostrongyloidea) in calves (Bos taurus) from North America

Abstract: Specimens of Ostertagia leptospicularis were recovered from abomas a of 17 of 23 naturally infected calves in Oregon. Also present were: Ostertagia kolchida, Ostertagia lyrata, and Ostertagia ostertagi. The co-occurrenc e of specific pairs of species (O. leptospicularis: O. kolchida, and O. ostertagi: O. lyrata) support s the hypothesi s of polymorphi c species pairs within the Ostertagiinae . This is the first report of O. leptospicularis and the second of O. kolchida in cattle from North America.

Redescription of Eimeria escomeli (Rastegaieff , 1930) from Myrmecophaga tridactyla, and a First Report from Bolivia

Abstract: Eimeria escomeli (Rastegaieff, 1930) Levine and Becker, 1933, is redescribed from the giant anteater, Myrmecophaga tridactyla (L.), from the departamento de La paz, Bolivia. This is the first report of parasites from M. tridactyla from Bolivia and only the third time that coccidians have been recorded from this host.

Sterol Composition of the Corn Root Lesion Nematode, Pratylenchus agilis , and Corn Root Cultures

Abstract: ,o.BSTRACT: Sterols from mixed stages of the com root lesion nematode, Pratylenchus agilis, and uninfected com root cultures were analyzed by gas chromatography-mass spectrometry. Twenty-eight sterols were identified in P. agilis, including 9 not previously detected in nematodes. The major sterols were 24-ethylcholest-22-enol, 24_ethyJcholesta-5,22-dienol, 24-methy1cholestanol, 24-ethy1cholestanol, isofucostanol, and 24-ethy1cholesterol. The principal corn root sterols were 24-ethylcholesta-5,22-dienol, 24-methylcholesterol, 24-ethylcholesterol, isofucosterol, and cycloartenol. Therefore, the major metabolic transformation of sterols by P. agilis was sat­ uration of the sterol nucleus. In addition, very small amounts of 4a-methylsterols were biosynthesized by P. agilis. The 4-methylation pathway is unique to nematodes and was previously demonstrated only in free-living Rhabditida. The sterol composition of P. agilis is remarkably different from that of other nematodes in its very small relative percentage of cholesterol (0.4% of the total nematode sterol).