Haemonchus placei and Haemonchus contortus are distinct species based on mtDNA evidence.
نویسندگان
چکیده
Debates continue over the extent to which the parasitic trichostrongylids Haemonchus placei and Haemonchus contortus hybridise in nature, and whether they deserve species status. Mitochondrial ND4 gene sequences from individuals of each putative species collected from populations around the United States indicate that the two species are highly differentiated at the mtDNA level. Furthermore, there was no evidence of introgressive hybridisation occurring in wild populations.
منابع مشابه
Description of Haemonchus placei (Place, 1893) (Nematoda, Trichostrongylidae, Haemonchinae), identification and intra-specific morphologic variability.
Haemonchus placei in cattle has never been completely described, possibly due to great morphological similarity with small ruminants Haemonchus contortus. It is newly described on one isolate from Argentina. It has clear distinct morphological features from sheep and goats Haemonchus contortus and presents only two female morphotypes (linguiform and knobbed) instead of three recorded in H. cont...
متن کاملIn vitro activity of Brazilian strains of the predatory fungi Arthrobotrys spp. on free-living nematodes and infective larvae of Haemonchus placei.
In vitro tests were carried out to assess the activity of 26 Brazilian isolates of predatory fungi of the genus Arthrobotrys on a free-living nematode (Panagrellus sp.) and on infective larvae of Haemonchus placei, a parasitic gastrointestinal nematode of cattle. The results showed that the free-living nematode Panagrellus sp. was the most preyed upon, compared to H. placei, for all the fungal ...
متن کاملThe presence of benzimidazole resistance mutations in Haemonchus placei from US cattle.
Haemonchus populations were collected from cattle from mid-western and eastern Southern US (four and six populations, respectively) to determine the relative prevalence of Haemonchus contortus and Haemonchus placei and the frequency of the three isotype-1 β-tubulin polymorphisms associated with benzimidazole resistance. A minimum of 32 individual adult worms were genotyped at position 24 of the...
متن کاملStudies on Haemonchus contortus. II. The effect of abomasal nematodes on subsequent challenge with H. contortus.
Fifty-thousand infective larvae of Trichostrongylus axei dosed to 7-9-month-old Merinos protected them against a subsequent challenge with 50 000 infective larvae of Haemonchus contortus. Protection varied with the period between an initial dosage of T. axei and challenge with H. contortus as follows: After 90 days it was more than 80% effective in more than 80% of sheep; at 119 and 180 days th...
متن کاملMicroclimatic effect on vertical migration of Haemonchus contortus and Haemonchus placei third-stage larvae on irrigated Kikuyu pasture.
The influence of microclimate on numbers of third-state larvae of haemonchus contortus and Haemonchus placei in four strata of irrigated Kikuyu pasture was assessed. On 36 different, interspersed days three replicates of pasture samples were collected on three occasions per day from 1990-1992 for larval recovery and the log10 mean counts of the larvae recovered were analysed by use of ANOVA mod...
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ورودعنوان ژورنال:
- International journal for parasitology
دوره 27 11 شماره
صفحات -
تاریخ انتشار 1997