Description and developmental biology of Plectus zelli n. sp. (nematoda : Araeolaimida)

Abstract

Plectus zelli n. sp. is described and illustrated. It is closely related to P. opisthocirculus Andrassy, 1952 and P. inquirendus Andrassy, 1958, and also to P. sambesii Micolctzky, 1916. It has L = 0.57-0.83 mm, a = 18-26, b = 3.5-5.0, c = 8-13, V = 45-56; a continuous lip region, cephalic setae not reaching the apex of the cephalic region and paired lateral alae. P. zelli n. sp. reproduces by parthenogenesis, its embryonation time varies from 18-20 h. The first stage juveniles have paired primordia each of which form one sexual branch. The flexure in the ovary is formed at the time of the fouruh and final moulting. The total duration of life cycle from egg to adult is 7 to 9 days at 28 ± 2 °C.