Variations in cerebellar morphology of the Atlantic stingray, Dasyatis sabina

The cerebellar corpus of the Atlantic stingray consists of an anterior lobe which is divided into rostral and caudal lobules, and a posterior lobe. The long axis of the posterior lobe and rostral lobule of the anterior lobe both lie along the midline, whereas the orientation of the caudal lobule varies. We examined this variation in 127 animals. In 52% the long axis of the caudal lobule lay on the right of the midline, in 21% it was on the left, and in 27% across the midline. While this distribution is not random, it is not related to size or sex. It is proposed that the observed variation is the reflection of variation in the cerebellar developmental program.