Bite matters: sexual dimorphism in the mandibular apparatus of a caviomorph rodent (Ctenomys australis).

VASSALLO ALDO IVÁN; BECERRA FEDERICO; MORA MATÍAS SEBASTIÁN; CASINOS PARDOS ADRIÀ

Valencia

Congreso; Annual Main Meeting of the Society for Experimental Biology; 2013

Society for Experimental Biology

The South American rodent Ctenomys uses both forelimbs and incisors for digging. Incisors are also used in aggressive encounters between males, having Ctenomysa polygynous mating system. The effectiveness of a bite, in inflicting physical injury, depends on the robustness of teeth and the force of jaw muscles. The sand dune tuco-tuco, Ctenomys australis (mean body mass 350 and 450 g, in females and males, respectively) digs complex burrows in coastal dunes of Buenos Aires province. We analysed possible sexual dimorphism in the mandibular apparatus of that species assessing allometric trajectories of both sexes. Bite force (BF) at the incisors was measured in vivo using a force transducer, in field trapped individuals [mean BF in males (n=21) 69.5 N; mean BF in females (n=34) 53.5 N; ANOVA p = 0.001]. ANCOVA results (p = 0.39 and p