Fight or flight: agonistic interactions between females of Acanthogonatus centralis Goloboff 1995 (Araneae, Mygalomorphae)

FERRETTI NELSON; COPPERI SOFÍA; POMPOZZI GABRIEL

TURKISH JOURNAL OF ZOOLOGY

TUBITAK SCIENTIFIC & TECHNICAL RESEARCH COUNCIL TURKEY

Año: 2014 vol. 38 p. 354 - 360

1300-0179

One hundred and thirty two encounters using a resident (R) ? intruder (I) paradigm between females Acanthogonatus centralis were investigated in order to study its intrasexual interactions and aggressiveness. Also, we examined the effect of presumed increased hunger levels on the incidence of killing and cannibalism. We selected three groups with different satiation levels: medium group (M), low group (L) and high group (H). Interactions took place in 79.54% of the trials. Aggression by lunges or bites was observed in 21.96% of encounters. Spiders made foreleg vibration and touched the silk functioning as aggression-attenuating mechanism. Other general behaviors observed comprehend threat behavior and hug behavior. We found significant differences between charges and retreats in the following treatments: M(R) - M(I), L(R) - L(I), H(R) - H(I) and H(R) - M(I). During encounters we observed 9 cases of cannibalism between females. Interactions are predominantly non-aggressive, at least in the resident-intruder paradigm. Intraspecific predation was not a response to presumed increased hunger. Future approaches of agonistic behavior and cannibalism should include analyses of diet characteristics during more extended time and of experience in determining the outcome of encounters between adult females.