Mating behaviour in ageing Teratorhabditis palmarum (Nematoda: Rhabditida)

Abstract

ABSTRACT Teratorhabditis palmarum Gerber and Giblin-Davis, 1990, a free-living nematode, is able to produce hundreds of thousands of offspring in a short time. Reproduction is the main feature that defines life and, therefore, it plays an important role in determining what kinds of selective parameters play a powerful role in the maturity and evolution of mating systems. In the present study, we estimated the features of mating behaviour of Teratorhabditis using long-time microscopic videography and repeated observations. The mating behaviour of Teratorhabditis could be separated into a series of successive behaviours, including pre-mating (searching and contacting), mating (copulating) and post-mating (enduring). Here, we present the mating behaviour of 2- and 10-day-old virgin males and females. The mean time of the four phases – searching, contacting, copulating and enduring – varied significantly, at 24.6 ± 4.6 min, 36 ± 5.7 min, 31 ± 4.1 min and 10 ± 2.3 min in 2-day-old and 38.2 ± 3.3 min, 44.3 ± 5.0 min, 39 ± 4.3 min and 11 ± 3.2 min in 10-day-old individuals, respectively. Attraction between the sexes was observed, indicating the probable involvement of sex pheromone(s) in mating behaviour. In all age groups of males there was a significant increase in the duration of mating as the females aged. As the mobility of ageing individuals was reduced, this may have directly influenced the durations of the various phases of mating behaviour.