Immunocompetence costs associated with burrow-digging in a Neotropical wolf spider

SIMO, MIGUEL; AISEMBERG, ANITA; CALBACHO ROSA, LUCIA; ALBIN, ANDREA

Denver

Congreso; 54th Annual Conference of the Animal Behavior Society University of Toronto Scarborough Campus, Canada June 12-16, 2017; 2017

Allocosa senex inhabits sandy coastal areas in Argentina, Brazil and Uruguay. Males build silken burrows in the sand which are mating refuges and breeding nests. Females visit males and mate with those with longer burrows. Burrow digging in this species could be considered energetically expensive due to silk production and deposition. Our aim was to determine if digging behavior affected immune response in males of A. senex. We placed each male in a container of 8.5 diameter and 31.0 cm height (n=29), or in one of similar diameter but of 1.5 cm height that allowed burying but not digging (n=16), with sand as substrate. Forty eight hours later, we estimated immune function through lytic activity measured by changes of optical density of samples of hemolymph of each male and compared the results between the groups. Conversely to our expectations, digging males showed higher immunological responses than males who were prevented from digging (z=-4.22, p=0.006). Accordingly, burrow digging in A. senex is possibly carried out only by males in good body condition and with high immune responses.