Observaciones morfofuncionales en el riñón del lobo marino de un pelo Otaria flavescens

Abstract

Morphofunctional observations on the kidney of the South American Sea Lion Otaria flavescens
The functional morphology of the kidney of Otaria flavescens is studied using resin uretral injection, corrosion casts and histological methods. The kidney is reniculated. There is no renal pelvis but a renal hilus in the ventral face where the renal artery entries and the venous system and ureter emerge. The ureter gives rise to cephalic and caudal branches which in turn branch off reaching each renicular calix. Renicular number was found to be 345 I 50 being 9% of them double ones. Medullary to cortical thickness ratio (5.8 and 4.7 for pups and adults, respectively) and the renicular relative medullary thickness (6.8 +/- 2.2) show that the kidney of the sea lion shares common morphological features with other marine marnmals and desert rodents.