Sexual Dimorphism with Respect to the Macro-Morphometric Investigations of the Forebrain and Cerebellum of the Grasscutter (Thryonomys swinderianus)
Ibrahim,N. D. G
This study was carried out to record the morphometric parameters of the brain of male and female grasscutters. Ten healthy grasscutters (5 males and 5 females) were used in this study. The mean brain weights were 9.80 + 0.50 g and 10.27 + 0.45 g for males and females respectively. The olfactory bulb mean weight was 0.57 + 0.05 g for males and 0.43 + 0.10 g for females. The cerebral and cerebellar mean lengths of 3.14 + 0.04 cm and 1.34 + 0.04 cm for males, 6.26 + 0.10 cm and 3.80 + 0.32 cm for females were observed. The cerebrum, cerebellum and olfactory bulb account for 70 %, 12 % and 6 % of the total brain weight in males and 64 %, 13 % and 4 % in the females respectively. The mean brain lengths were 5.63 + 0.07 cm and 6.26 + 0.1 cm for males and females respectively. There were significant differences in the body and olfactory bulb weights and also, in the whole brain and cerebral lengths between the males and females. In our present research, the ratios of 0.01 for males and 0.006 for females were observed. This suggests a relatively low brain weight in the ruminants. The olfactory bulb in the male is larger than that in the females. Females in turn have longer brain dimension than the males. Cerebellum has no sex variation both in weight and in length.