Reproductive activities impair immunocompetence in Physocyclus dugesi (Araneae: Pholcidae)

CALBACHO ROSA, LUCIA; MORENO, MIGUEL; LANZ, HUMBERTO; PERETTI, ALFREDO VICENTE; CORDOBA-AGUILAR, ALEJANDRO

JOURNAL OF ARACHNOLOGY

AMER ARACHNOLOGICAL SOC

Año: 2012 p. 18 - 22

0161-8202

When host organisms mount an immune response, they incur energetic costs. Theory predicts that these costsresult in trade-offs between investment in life history traits (such as growth and reproduction) and investment in immuneresponse. Recent empirical work investigating whether immune ability is impaired during sexual activity in invertebratesdoes not uniformly support this prediction. Here, we use lytic activity to test for trade-offs between immune ability andreproductive events in three experiments with the pholcid spider Physocyclus dugesi (Simon 1893). First, we test whethermales or females have their immune response negatively affected after mating; second, we assess whether ovipositionbehavior affects immune response; and third, we investigate whether sexual aggression by females affects immune response.We compare reproductive and non-reproductive spiders? immune response. Our results suggest a down-regulation ofimmune response following mating, oviposition, and aggression. This supports the notion that immunocompetence iscompeting for a resource with sexual activities. We discuss reasons why such costs arise in P. dugesi.