El sistema excretor de la raya mariposa Gymnura micrura (Pisces: Rajiformes)

Abstract

THE GENERAL MORPHOLOGY OF THE UROGENITAL SYSTEM OF THE BUTTERFLY RAY GYMNURA MICRURA (BLOCH & SCHNEIDER) IS DESCRIBED WITH EMPHASIS IN THE KIDNEYS AND ITS DUCTS. THE GONADS, ASSOCIATED TO THE EPIGONAL ORGANS ARE PAIRED, WITH TENDENCY TO DEVELOP MORE THAT OF THE LEFT SIDE. LIKEWISE, THE REPRODUCTIVE DUCTS ARE PAIRED. THE KIDNEYS ARE FLAT, TRIANGULAR AND MULTILOBULAR, AND ARE PLACED IN THE ROOF OF THE POSTERIOR PART OF THE VISCERAL CAVITY. FROM THE KIDNEYS THE URINARY ACCESSORY DUCTS ARISE, AND OPEN INTO THE CLOACA BY MEANS OF TWO URINARY PAPILLAE IN FEMALES, AND BY MEANS OF THE ONLY UROGENITAL PAPILLA IN MALES.