Gravitational gradients and blood flow patterns in specialized arboreal (Ahaetulla nasuta) and terrestrial (Crotalus adamanteus) snakes.

Blood pressure and blood flow patterns were recorded from the carotid artery and aortae of a thick-bodied terrestrial snake (Crotalus adamanteus) and a thin-bodied arboreal species (Ahaetulla nasuta) anesthetized with ketamine hydrochloride. Hemodynamic stress induced by rotation resulted in pronounced changes in the blood flow patterns and pressure in C. adamanteus: rotation of A. nasuta produced changes of a similar type, but of a much lower magnitude. The markedly different responses of these two species, the baroreceptor reflexes of which were disrupted, suggest that morphological factors--such as differential gross cardiac displacement, or variation in the interaortic foramen--in addition to physiological factors, are important in determining a snake's ability to withstand hemodynamic stress.