Maternal Food-Supply Activity and Its Regulation in Coelotes Terrestris (Araneae, Agelenidae)

Abstract

The funnel-web spider Coelotes terrestris (Agelenidae) displays extended maternal care, especially characterized by a progressive provisioning of the young during a four-eight week gregarious phase. As they grow up, the spiderlings are provided with a increasing amount of prey, which is captured on the web and carried by the mother into the silk tube that represents the nest. This paper is aimed to determine the mechanism that could regulate, throughout the gregarious phase, this food-supply activity. Eleven females were observed, at different times, from one week before egg-laying till one week after the progeny's dispersal. Females' feeding behaviour noticeably changed from the young's emergence onwards. In particular, the prey was less and less handled and the overall time during which the mother kept her prey for herself-Prey Handling Time (PHT)-steadily decreased. Meanwhile, the spiderlings reacted more and more rapidly to the mother's prey catching and carrying, and they stimulated her more and more actively. The mother's prey-supply behaviour was experimentally shown to be modifiable within a short delay. Separating the mother from her brood made her shift her "Prey Handling Time" from a few minutes to more than two hours (i. e. about the level of the pre-emergence PHT). Conversely, reuniting the mother with her brood lead to an equivalent decrease of the PHT. This phenomenon was obtained at four different periods during the gregarious phase. The present study shows that, in this invertebrates species, the maternal provisioning activity is essentially regulated by exogenous factors: i. e. stimulations (that qualitatively and quantitatively variate in the course of time) emanating from the developing progeny.