The Gonads of the South American Dolphins, Inia geoffrensis, Pontoporia blainvillei, and Sotalia fluviatilis. Journal of Mammology. rivers near Iquitos, Peru, from Leticia, Colombia, and from Guanare, Venezuela (Peru, Columbia, Venezuela).

Project Details

Date : 1975
Volunteer Name : Richard J. Harrison and Robert L. Brownell, Jr.
Category : ,

Project Description

Abstract: The appearancesof the gonads are described in males and females of 18 Inia geoffrensis, 11 Pontoporia blainvillei, and eight Sotalia fluviatilis from South America. Males of I. geoffrensis become sexually active at a length of about 228 centimeters, females at 175 to 180 centimeters. Length at birth is 76 to 80 centimeters; parturition occurs from about July to September in the upperAmazon.Males of P. blainvillei are still sexually immature at a length of 128.5 centimeters, females become sexually active at a length of 137 centi- meters. Off Uruguay, pregnant females have fetuses 6 centimeters in length in February and 61 centimetersin October. Males of S. fluviatilis are sexually active at a length of 148 centimeters, females at 140 centimeters. Gonad weights and details of corpora lutea and albicantia are given. Corpora albicantia appear to persist as in other cetaceans. The ovaries of I. geoffrensis are relatively bulky with the corpora enclosed in the ovarian substance and not pedunculated as in P. blainvillei and S. fluviatilis in which the right ovary is poorly developed.