Effects of temperature and relative humidity on development and survival of the free-living stages of Trichostrongylus colubriformis, T. rugatus and T. vitrinus.

Temperatures of 4 and 10 degrees C reduced the rate of hatching of eggs and the development of the pre-infective stages of T. colubriformis and T. rugatus, but not T.

Comparison of the effects of infection with Trichostrongylus colubriformis, T. vitrinus and T. rugatus in merino lambs.

Groups of six worm-free merino lambs were infected with 100,000 larvae of T. colubriformis, T. vitrinus, T.

The effects on merino lambs of chronic infection with Trichostrongylus rugatus.

Four groups of six 5-month-old merino lambs were exposed to infection with 12,000 larvae of Trichostrongylus rugatus per week and one group was killed at each of 3, 6, 9 and 12 weeks. Numbers of adult worms increased in an approximately linear manner throughout the experiment; the percentage of larvae developing to adults remained between 35 and 25% throughout the course of the experiment. Sub-total villus atrophy was evident in the anterior small intestine of each group of infected sheep and significant reductions occurred in the plasma concentrations of albumin and phosphate.

Genetic characterization of three species of Onchocerca at 23 enzyme loci.

The technique of allozyme electrophoresis was applied to species of Onchocerca from cattle to increase the number of enzyme loci established and therefore provide a genetic basis for a rational species-level taxonomy. Twenty-three enzyme loci were established and provided unequivocal genetic evidence for the taxonomic validity of Onchocerca gibsoni, O. gutturosa and O.

Host-parasite associations of Eimeria spp. (Apicomplexa:Eimeriidae) in kangaroos and wallabies of the genus Macropus (Marsupialia:Macropodidae).

Faecal samples from 514 kangaroos and wallabies representing 12 species of the genus Macropus were examined for oocysts of Eimeria spp. Six species of Eimeria were redescribed from their type hosts, and on the basis of finding homologous oocysts in the faeces of other Macropus spp., host ranges for these coccidia were extended.

Identification of life cycle stages of the nematode Echinocephalus overstreeti by allozyme electrophoresis.

Data presented in this study highlight the potential of allozyme electrophoresis in providing unequivocal genetic evidence for the identification of life cycle stages, particularly where species have complex life cycles. Adults of the nematode Echinocephalus overstreeti parasitize the elasmobranch Heterodontus portusjacksoni. The putative larval form which is morphologically dissimilar is found in two species of marine molluscs, Chlamys bifrons and Pecten albus.

Behavioral effects of prenatal exposure to caffeine in rats.

For the first ten days of gestation, rats received daily intraperitoneal injections of 10-40 mg/kg of caffeine. Open field behavior of their fostered offspring was observed 61, 145 and 188 days after birth. While there were no obvious physical effects of the prenatal experience, at 61 days caffeine exposure led to an increase in the number of times seen walking for males only and increased ambulation (distance travelled) for both sexes.

Parasites and associated pathology of the swamp wallaby, Wallabia bicolor (Marsupialia).

Thirty-five swamp wallabies from Victoria, New South Wales and Queensland, Australia were examined for parasites. Thirty-nine species of nematodes, five species of cestodes and eight species of arthropods were found. Wallabies from Queensland and northern New South Wales had a less diverse helminth fauna (23 species) than did wallabies from southern New South Wales and Victoria (32 species).

Biochemical differentiation in bile duct cestodes and their marsupial hosts.

Isozyme electrophoresis was used to assess possible cospeciation of parasites (cestodes of the Progamotaenia festiva complex) and their hosts (Australian diprotodont marsupials) and to compare the extent of interspecific genetic diversity of the parasites and their hosts. On the basis of morphology, there are three species in the complex, although electrophoresis revealed 14 distinct genetic types, most of which were host specific, although there were three cases of apparent host switching. The evolutionary relationships among the parasites were only partially concordant with those among the hosts.

Development of villus atrophy in the small intestine of sheep infected with Trichostrongylus rugatus.

Pairs of sheep infected with 120 000 larvae of Trichostrongylus rugatus were killed at intervals from 2 to 56 days after infection (DAI). Worms were located in tunnels in the epithelium of villi or upper intestinal crypts at all stages of development. Villus atrophy developed progressively until 16 DAI, when surface microtopography, characterised by subtotal villus atrophy, stabilised.

Morphogenesis of Trichostrongylus rugatus and distribution during development in sheep.

Morphogenesis of Trichostrongylus rugatus was examined in 16 sheep experimentally-infected with 120 000 third-stage larvae and killed 2, 4, 6, 8, 10, 12, 16 and 20 days later (DAI). Third stage larvae moulted between Days 4 and 6, and fourth stage larvae moulted on Day 10 after infection. Four sheep first passed eggs in the faeces between Days 16 and 18 after infection.

The trichostrongyloid parasites of sheep in South Australia and their regional distribution.

The species of trichostrongyloid nematodes present in 376 sheep from different agricultural regions of the state of South Australia were determined. Parasites encountered in the abomasum were Teladorsagia circumcincta, T. trifurcata, T.

[Peramelistrongylus Mawson, 1960 and Profilarinema n. gen., trichostrongyloid nematodes apparently transitional between the Strongyloidea and the atypical genus Filarinema Mönnig, 1929 (author's transl)].

Peramelistrongylus skedastos Mawson, 1960, type species of the genus Peramelistrongylus Mawson, 1960 is redescribed. Also described is Profilarinema hemsleyi n. gen.

[Description of Zaglonema zaglossi n. gen., n. sp., and Z., ewersi, n. sp., (Nematoda: Trichostrongyloidea) parasitic in the intestine of Zaglossus bruynii in New Guinea (author's transl)].

The new genus Zaglonema is characterised by the presence of primitive cephalic features, a poorly developed synlophe, the presence of a cervical groove, extra branches of the dorsal ray, short spicules and the absence of a spike on the tail of the female. Many of these features distinguish the new genus from the 3 other genera of Trichostrongyloid Nematodes occurring in Monotremes. The new genus appears to have some affinities with the genus Mackerrastrongylus which occurs in perameloid marsupials.