Age and egg-sac loss determine maternal behaviour and locomotor activity of wolf spiders (Araneae, Lycosidae)

Fanny Ruhland (1) , Violette Chiara (1) , Marie Trabalon (1)

1 EthoS - Ethologie animale et humaine

Wolf spiders’ (Lycosidae) maternal behaviour includes a specific phase called “egg brooding” which consists of guarding and carrying an egg-sac throughout the incubation period. The transport of an egg-sac can restrict mothers’ exploratory and locomotor activity, in particular when foraging. The present study details the ontogeny of maternal behaviour and assesses the influence of age of egg-sac (or embryos’ developmental stage) on vagrant wolf spider Pardosa saltans females’ exploration and locomotion. We observed these spiders’ maternal behaviour in the laboratory and evaluated their locomotor activity using a digital activity recording device. Our subjects were virgin females (without egg-sac) and first time mothers (with her egg-sac) who were divided into three groups. The first group of mothers were tested on the day the egg-sac was built (day 0), and the females of the other two groups were tested 10 or 15 days after they had built their egg-sac. We evaluated the effects of the presence and the loss of egg-sac on mothers’ activity. Pardosa saltans females’ behaviour depended on mothers’ physiological state and/or age of egg-sac (developmental stage of embryos). Virgin females’ behaviour was not modified by the presence of an egg-sac in their environment. Mothers’ reactions to the presence, the loss and the recovery of their egg-sac varied during the maternal cycle. Maternal behaviour changed with age of egg-sac, but the levels of locomotor activity of mothers with egg-sacs was similar to those of virgin females. Loss of egg-sac modified the maternal behaviour and locomotor activity of all mothers; these modifications were greater on “day 15” when embryos had emerged from eggs. All mothers were able to retrieve their egg-sacs and to re-attach them to their spinnerets.

Keywords: Pardosa saltans; arachnids; mobility; development status; maternal care

Domains: Life Sciences [q-bio]; Animal biology; Invertebrate Zoology; Life Sciences [q-bio]; Neurons and Cognition [q-bio.NC]; Psychology and behavior; Life Sciences [q-bio]; Neurons and Cognition [q-bio.NC]; Cognitive Sciences; Life Sciences [q-bio]

Fanny Ruhland, Violette Chiara, Marie Trabalon. Age and egg-sac loss determine maternal behaviour and locomotor activity of wolf spiders (Araneae, Lycosidae). Behavioural Processes, 2016, 132, pp.57-65. ⟨10.1016/j.beproc.2016.09.011⟩. ⟨hal-01375498⟩