Anatomía sexual de Gambusia regani (Pisces: Poeciliidae)

Abstract

BY MEANS THE STUDY OF THE AKELETON AND SOFT STRUCTURES OF GAMBUSIA REGANI, FORM THE LAGOON OF TAMPAMACHOCO, VERACRUZ, MAIN SEXUAL DIFFERENCES ARE IDENTIFYIED. BESIDES GONADS, THE FEATURE PRODUCIONG MOST OF SUCH DIFFERENCES IS THE FOWARD DISPLACEMENT OF THE MALE ANAL FIN. YHIS IMPLYIES MODIFICATIONS OF SOME HAEMAL ARCHES INTO GONAPOPHYSIS, ANAL FIN PTERYGIOPHORES INTO THE GONACTINOSTAL COMPLEX, THE DEVELOPMENT OF THE LIGASTYLE, AND THE DIVISION OF THE SWIM BLADDER IN TWO LONG CAUDAL LOBES. IT IS NOTABLE THE DIFFERECE IN THE MUSCULATURE OF THE ANAL FIN, THAT MOVES THE GONOPODIUM. WHILE THE URINARY SYSTEM SHOWS A TOTAL INDEPENDENCE FROM EACH SIDES , THE GONADS FUSE TOGETHER, AND GROW MAINLY IN THE RIGTH SIDE OF THE VISCERAL CAVITY. UNLIKE OF MOST TELEOSTEAN FISHES, AN UROGENITAL SINUS IS PRESENTED IN FEMALES. THERE IS NO SUPERFETATION.