Sexual dimorphism in Chaetophractus vellerosus based on the pelvic girdle morphometry

SQUARCIA , S.,; CIRONE, G.,; CASANAVE, E. B.

Facultad de Ciencias Veterinarias Universidad Nacional de La Plata, ARGENTINA

Congreso; IX NATIONAL CONGRESS OF MORPHOLOGICAL SCIENCES (9º Congreso Nacional de Ciencias Morfológicas); 2004

Sociedad Argentina de Ciencias Morfológicas

48. SEXUAL DIMORPHISM IN CHAETOPHRACTUS VELLEROSUS BASED ON THE PELVIC GIRDLE MORPHOMETRY Squarcia SM1, Cirone GR1, Casanave EB2. 1,2UNS, Dpto. Biol., Bioq. y Fcia., San Juan 670, Bahía Blanca, 1Cát. Anatomía Comparada, E-mail: squarcia@criba.edu.ar; 2 Cát. Fisiología Animal; 2CONICET. E-mail: casanave@criba.edu.ar A morphological and morphometrical study of the pelvic girdle of Chaetophractus vellerosus was done, with the objective of investigate a possible sexual dimorphism. We used six females and six males, all adults, collected in Bahía Blanca area. Ten pelvic dimensions were measured (maximum length and breadth, dorsoventral and rostrocaudal diameter of the obturator and ileoschiatic foramen, dorsoventral and transversal diameter of the  pelvic aperture and distance between anterior and posterior projections). Two morphological features would be used for discrimination. One is the direction of the posterior projections of the ischium, which support the carapace; they are displaced out in females, while in males they are vertical. Another feature is the orientation of the pubic symphyses, which is caudally displaced in females and rostrally displaced in males. Also, the pelvic girl of females is longer and wider than that of males (p<0.05) and the pelvic aperture is higher and narrowed (p<0.01). So, the pubic symphysis is lower in females. These results are coincident with those previously obtained by us in C. villosus. Subsided by SGCYT (UNS), Project 24/B086. BIOCELL 28(2), 248, 2004