On the specific distinctness of the ovine and bovine 'Strains' of Haemonchus contortus (Rudolphi) Cobb (Nematoda: Trichostronglidae).

1954 ◽  
Vol 2 (2) ◽  
pp. 275 ◽  
Author(s):  
FHS Roberts ◽  
H Newton-Turner ◽  
M McKevett
Keyword(s):  
Haemonchus Contortus ◽  
Tail Length ◽  
Distinct Species ◽  
Infective Larvae ◽  
Genital Cone ◽  
Total Length ◽  
Different Types ◽  
Parent Female ◽  
Two Populations ◽  
Haemonchus Placei

The investigations reported in this paper were undertaken to determine whether Haemonchus contortus from sheep and H. contortus from cattle are identical or different species. The length of the spicules and the distances from the hooks to the tips of the spicules were found to be significantly greater in males from cattle. Differences were also seen in the shape and dimensions of the appendage of the genital cone in males from the two hosts, but these were not constant. A study of adult females showed at least 14 different types of vulva1 process. In the majority (88.9 per cent.) of females from sheep there was a long, linguiform process, whereas in the majority (93.5 per cent.) of females from cattle the process was short and rounded. In experimental infestations, despite a change of host, these two types maintained their characteristics in accordance with the host of origin. The progeny of single females from sheep and cattle, respectively, gave a distribution of types similar to that of natural infestations in these hosts. The infective larvae from the two hosts were found to be visually distinct. Measurements showed significant differences in total length, tail length, and in the ratio of total length to tail length, larvae from cattle having the greater measurements and smaller ratio. A change of host did not alter these difference and no association was apparent between the type of larva and the type of vulva1 process in the parent female. In an experiment to test the ability of the two populations to interbreed, mixed sheep and cattle larvae were given to the same host. The subsequent generation of larvae could be classified into sheep and cattle types without any difficulty and there was no evidence of any intermediate types. Evidence of this reluctance to interbreed was also seen under conditions favouring cross-infestation in the field, when both types of larvae maintain their respective characteristics. In accordance with the above findings and as there is also evidence of some degree of host specificity, it is concluded that the populations in sheep and cattle represent distinct species. The name Haemonchus contortus (Rud. 1803) is retained for the species defined in this paper as occurring in sheep and the name Haemonchus placei (Place 1893) is proposed for the species occurring in cattle.

scholarly journals Differentiation of Haemonchus placei from Haemonchus contortus by PCR and by morphometrics of adult parasites and third stage larvae

2014 ◽  
Vol 23 (4) ◽  
pp. 495-500 ◽  
Author(s):  
Michelle Cardoso dos Santos ◽  
Mônica Regina Vendrame Amarante ◽  
Maria Regina Lucas da Silva ◽  
Alessandro Francisco Talamini do Amarante
Keyword(s):  
Haemonchus Contortus ◽  
Tail Length ◽  
Pcr Analysis ◽  
Correct Identification ◽  
Specific Primer ◽  
Male Adult ◽  
Domestic Ruminants ◽  
Third Stage ◽  
Species Specific ◽  
Haemonchus Placei

Molecular and morphological methods were evaluated to distinguish between Haemonchus contortus and Haemonchus placei species. A total of 141 H. contortus and 89 H. placei male adult specimens collected from artificially infected lambs were identified individually by PCR analysis, using a species-specific primer pair. These PCR results were used as gold standard for Haemonchus spp. identification. Haemonchus placei presented higher mean spicule and barb lengths than H. contortus (P<0.05). However, some measurements overlapped. For this reason, a discriminate function did not allow the correct identification of 13 H. contortus and one H. placei specimen. The sheath tail length of the third stage larvae (L3), which comprises the distance between the tip of the larval tail and the end of the sheath tail, were measured. Only three of the 485 H. placei larvae (0.619%) had a sheath tail shorter than 85 µm, while only four of the 500 H. contortus larvae (0.8%) presented a sheath tail longer than 85 µm. The results indicated that 6.09% of the male adult specimens would be misclassified based on the discriminate function, while only 0.71% of infective larvae would be misclassified. Therefore, identification of L3 can be used as the first method to indicate the presence of H. placei and/or H. contortus in a population of domestic ruminants.

Haemonchus placei and Haemonchus contortus are distinct species based on mtDNA evidence

1997 ◽  
Vol 27 (11) ◽  
pp. 1383-1387 ◽  
Author(s):  
Michael S. Blouin ◽  
Charles A. Yowell ◽  
Charles H. Courtney ◽  
John B. Dame
Keyword(s):  
Haemonchus Contortus ◽  
Distinct Species ◽  
Haemonchus Placei

scholarly journals PERKEMBANGAN DAN GAMBARAN ANATOMIS LARVA INFEKTIF (L3) Haemonchus contortus YANG DIBIAKKAN DENGAN VERMICULLITE (Development and Anatomical Description of Infektive Larvae (L3) Haemonchus contortus Cultured with Vermicullite)

2016 ◽  
Vol 10 (1) ◽  
pp. 62
Author(s):  
Rahmi Sulastri Mukhtar ◽  
Muhammad Hambal ◽  
Muhammad Hanafiah ◽  
Yudha Fahrimal ◽  
Winaruddin Winaruddin ◽  
...  
Keyword(s):  
Larval Development ◽  
Body Length ◽  
Haemonchus Contortus ◽  
Tail Length ◽  
Total Body Length ◽  
Basic Information ◽  
Infective Larvae ◽  
Body Diameter ◽  
Total Body ◽  
Banda Aceh

This study was aimed at obtaining basic information about bioecology of Haemonchus contortus, related to larval development and anatomical description of infective larvae (L3). In this study, the ova of Haemonchus contortus were harvested out of the intestines of goats, those were slaughtered in municipal slaughterhouse in Kampung Jawa Banda Aceh. The ova of Haemonchus contortus were then cultured using vermiculite as media, and observed daily until the larvae reached 3rd stage larvae. The result revealed that the larvae need 7 days to reach from eggs into infective larvae. Larvae obtained has uniform morphology, with a body diameter of 22 μm, tail length up to 55 μm hyaline, esophagus posterior to the tail of 592 μm, length of esophagus anterior to posterior esophagus 145 μm, and a total body length of larvae 737 μm.

Improved Methods of Obtaining Clean Larvae of Haemonchus contortus

1963 ◽  
Vol 37 (4) ◽  
pp. 251-254 ◽  
Author(s):  
M. G. Christie ◽  
J. E. Patterson
Keyword(s):  
Free Surface ◽  
Surface Area ◽  
Haemonchus Contortus ◽  
Water Repellent ◽  
Optimum Conditions ◽  
Infective Larvae ◽  
Mucous Coat ◽  
Third Stage ◽  
Free Surface Area ◽  
Improved Methods

A pellet of sheep faeces containing eggs of Haemonchus contortus forms an adequate environment for the development of those eggs to third stage infective larvae, provided that it is kept moist. Observation shows a concentration of developing larvae on the external mucous coat of the pellet. These data suggest that optimum conditions for development would occur when pellets are separated one from another and standing on a water repellent surface, thus presenting the maximum free surface area and minimum opportunity for aggregation and hence of over crowding. The best method of recovering the infective larvae would be one that obtained larvae free from contamination without requiring them to expend energy in separating themselves from the contamination.

Studies on resistance of sheep to infestation with Haemonchus contortus and Trichostrongylus spp. and on the immunological reactions of sheep exposed to infestation. I. The preparation of antigens for the complement fixation test and the reactivity of the biochemical fractions of H. contortus

1950 ◽  
Vol 1 (3) ◽  
pp. 285 ◽  
Author(s):  
DF Stewart
Keyword(s):  
Haemonchus Contortus ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Fixation Test ◽  
Mature Adult ◽  
Infective Larvae ◽  
Lipid Fractions ◽  
Significant Difference ◽  
Third Stage ◽  
Free Material

All antigen was developed to detect circulating antibodies by means of the complement fixation test in sheep infested with Haemonchus contortus and Trichostrongylus spp. Extraction of worm material at 100°C. for 10 minutes was found to be the most satisfactory method for the preparation of antigens. Potent antigens were prepared from young adult H. contortus, from third-stage infective larvae, and from the eggs. Old mature adult H. contortus yielded antigens of low potency. No significant difference was found between the potency of antigens prepared from male and female adult H. contortus collected from the same sheep. Both adult Trichostrongylus spp. and third-stage infective larvae consistently yielded antigens of high potency. No significant difference was found in the results obtained with larval or adult H. contortus antigens, adjusted to the same potency and tested with natural H. contortus antisera. H. contortus and Trichostrongylus spp. absorbed the antiserum to each other. It was shown that a lipid was an essential constituent of the boiled antigen in the complement fixation reaction with natural antisera. Lipid-free antigens from H. contortus failed to react with natural antisera. The lipid was not antigenic when injected into rabbits. The carbohydrate fraction of H. contortus did not fix complement in the presence of natural antisera and was not antigenic when injected into rabbits. The lipid fraction of a variety of nematode parasites reacted with natural antisera to H. contortus infestation. Similar lipid fractions of two species of trematodes did not react with natural antisera to H. contortus infestation. Normal saline suspensions of the lipid-free material from a variety of helminths showed a greater degree of specificity when tested with artificially prepared antisera than did the lipid fractions.

Taxonomic status of male salamanders of the Ambystoma jeffersonianum complex from an Ontario population, with the first record of the Jefferson salamander, A. jeffersonianum (Green), from Canada

1976 ◽  
Vol 54 (8) ◽  
pp. 1270-1276 ◽  
Author(s):  
Wayne F. Weller ◽  
W. Gary Sprules
Keyword(s):  
Diploid Species ◽  
Taxonomic Status ◽  
Tail Length ◽  
First Record ◽  
Total Length ◽  
Ambystoma Jeffersonianum ◽  
Morphological Criteria ◽  
G Ratio ◽  
Jefferson Salamander

Nine morphological criteria were used to determine the taxonomic status of the male salamanders of the Ambystoma jeffersonianum complex from a population near Streetsville, Toronto Township, Peel County, Ontario: (a) snout–vent length; (b) ratio of tail length to snout–vent length; (c) internarial width; (d) extent of separation or overlap of the toes of adpressed limbs; (e) total length; (f) ratio of tail length to total length; (g) ratio of internarial width to snout–vent length; (h) colouration of dorsal, lateral, and ventral body surfaces; and, (i) extent and distribution of the bluish spotting. The results indicate that all of these males resemble A. jeffersonianum or A. platineum rather than A. latérale. Since A. platineum males occur very rarely in nature, these Streetsville individuals are logically assigned to A. jeffersonianum. This represents the first record of this species from Canada. Based upon this new distributional datum of A. jeffersonianum and of the two Diploid species from the literature, we suggest that these triploid species may have originated in post-Wisconsin times and subsequently dispersed northward.

Kinetics of exsheathment of infective ovine and bovine strongylid larvae in vivo and in vitro

Parasitology ◽  
2002 ◽  
Vol 125 (1) ◽  
pp. 65-70 ◽  
Author(s):  
H. HERTZBERG ◽  
U. HUWYLER ◽  
L. KOHLER ◽  
St REHBEIN ◽  
M. WANNER
Keyword(s):  
Haemonchus Contortus ◽  
Buffer System ◽  
Bicarbonate Concentration ◽  
Infective Larvae ◽  
Nylon Mesh ◽  
Mesh Bags ◽  
Sheep Rumen ◽  
Kinetics Of

The aim of the study was to investigate the longitudinal changes of exsheathment of ovine and bovine 3rd-stage strongylid larvae in an artificial rumen (RUSITEC) and to compare the results with in vivo data obtained from rumen-fistulated sheep. Infective larvae were incubated in nylon mesh bags in the sheep rumen or the RUSITEC apparatus for periods of 1, 6 and 12 h, respectively. The 12 h exsheathment rates in the rumen and the RUSITEC apparatus (in parentheses) were as follows: Haemonchus contortus: 100% (100%), Ostertagia circumcincta: 100% (76%), O. leptospicularis: 100% (100%), O. ostertagi: 53% (59%), Trichostrongylus axei: 100% (100%), T. colubriformis: 37% (36%), Cooperia curticei: 94% (76%), C. oncophora: 95% (89%), Nematodirus filicollis: 0% (N.D.), N. spathiger: 11% (15%), N. battus: 7% (5%), Oesophagostomum venulosum: 17% (9%), Chabertia ovina: 7% (2%), Dictyocaulus filaria: 1% (N.D.). Larvae of Nematodirus spp. and T. colubriformis showed a quick rise of the exsheathment rate 2 h after transfer into the abomasum. These results confirm that exsheathment generally occurs in the part of the gastrointestinal tract immediately anterior to the habitat of the adult parasite. The overall similar course of exsheathment in both systems indicates that the essential stimuli for exsheathment were generated and maintained under in vitro conditions of the artificial rumen. In both systems, the bicarbonate concentration and the pH reflected a similar status of the H2CO3/HCO buffer system, which is known to provide the essential stimuli for larval exsheathment of the abomasal species. These results give evidence that the RUSITEC system represents a valid system for studying the kinetics of exsheathment of strongylid nematodes under in vitro conditions. For 7 of the species investigated the obtained results represent the first data on larval exsheathment in vivo and in vitro.

Studies on resistance of sheep to infestation with Haemonchus contortus and Trichostrongylus spp. and on the immunological reactions of sheep exposed to infestation. III. The antibody response to infestation with Trichostrongylus spp.

1950 ◽  
Vol 1 (4) ◽  
pp. 413 ◽  
Author(s):  
DF Stewart
Keyword(s):  
Antibody Response ◽  
Haemonchus Contortus ◽  
Complement Fixation Test ◽  
Complement Fixation ◽  
Immunological Response ◽  
Serological Response ◽  
Apparent Effect ◽  
Relative Resistance ◽  
Infective Larvae ◽  
Immunological Reactions

In infestation of sheep with Trichostrongylus spp., both the intake of larvae and infestation with adult worms stimulated the production of antibodies. The character of the antibody response in infestation with Trichostrongylus spp. thus differed from that caused by Haemonchus contortus. Sera of sheep dying from infestation with Trichostrongylus spp. were negative to the complement fixation test. It was found that older sheep responded serologically earlier and more vigorously to infestation with Trichostrongylus spp. than did young sheep. Subsequent doses of larvae of Trichostrongylus spp. elicited a more rapid and grester serological response, even in young sheep, than an initial dose of larvae. Previous infestation with H. contortus did not result in resistance to Trichostrongylus spp., whereas previous infestation with Trichostrongylus spp. heightened the resistance of sheep to subsequent infestation with the same species. It is concluded that the relative resistance of older sheep to Trichostrongylus spp. is due, a t least in part, to an earlier immunological response which is strengthened by subsequent doses of larvae. When infective larvae of Trichostrongylus spp. were superimposed upon an existing infestation of the same species, the egg count declined ;apidly and the development of the superimposed larvae resisted Doses of infective larvae of Trichostrongylus spp. had no apparent effect on the egg counts of sheep infested with H. contortus.

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