Observations on the embryonic and post-embryonic development of Diploscapter orientalis (nematoda : Rhabditida)

Abstract

Diploscapter orientalis reproduces parthenogenetically. The eggs are elongate, measuring 45-55 x 20-30 µm with blunt spines on their surface. Most eggs are laid in the single cell stage. Hatching takes about 13-17 h from the time of oviposition. The newly hatched juveniles lack labial hooks which develop later in the second stage juveniles. The genital primordium in the early juvenile stage is oriented obliquely to the longitudinal axis. In late stages the germinal nuclei shift to the two ends while the somatic ones remain in the centre of primordium. The division of primordial nuclei is restricted to the periods of moulting but becomes continuous after the third moult. The life cycle from egg to adult is completed in 4-6 days.