Distinguishing morphological features of the third larval stage of ovine Trichostrongylus spp.

摘要: In this paper we describe a procedure that enables the identification of species infective third stage (L(3)) Trichostrongylus larvae. Lambs were infected with putatively monospecific infections three commonly found in New Zealand (T. axei, T. colubriformis and vitrinus) Teladorsagia (Ostertagia) circumcincta. After recovering L(3) from faecal cultures, lambs slaughtered adult male worms recovered examined for spicule morphology to verify identification. morphological features measurement their length. Further exsheathed under high power optics observe posterior (tubercles). The has three-tubercle structure whereas vitrinus single tubercle axei none. However, tails circumcincta also lack tubercles thus cannot be readily distinguished them on feature. range lengths spp. (600-858 microm) (700-914 overlap considerably. shape anterior end these two differs combination length provides an indication proportion culture. A number, overall L(3), can used differentiate nematode populations colubriformis,