Características Morfológicas de Ovarios y Ovocitos de Nutrias (Myocastor coypus) en Condiciones de Criadero

the aim of this work was to study the morphological characteristics of ovaries and oocytes of the otter (myocastor coypus, coypu) in different seasons and stages of the estrous cycle. the otter (mc) is a rodent native to south america and is widely used in the fur industry. twenty females with a mean weight of 4996.2 g were sacrificed, vaginal swabs or colpocytology were collected and the time of the estrous cycle was determined. eleven were slaughtered in winter, of which 7 were in anestrus, 1 in proestrus, and 3 in diestrus; of the 9 slaughtered in summer, 1 was in anestrus, 1 in proestrus and 7 in diestrus. each ovary was transported to the laboratory in a solution of sterile isotonic sodium chloride at 37° c. the ovaries were weighed and measured and crumbled into petry dishes with two no.28 needles, under a stereoscopic microscope. oocytes were identified, washed in phosphate buffered saline solution (pbs) and were characterized as a, b and c. the results of mean and standard deviation of the weights of the ovaries were: 0.304 g (0.062), length 9.05 mm (0.19) and 5.05 mm wide (0.69). we performed the analysis of variance for the condition of oocytes and found no statistically significant differences associated with the station or estrus status on the status of the oocytes (p <0.05). regarding the number of corpora lutea, fisher′s test was used, with significant differences between stages of estrous cycle (diestrus vs. anestrus) with f=20.57 (p = 0.0001) between seasons (summer vs. winter) with f = 72.21 (p = 0.0000) and interaction between the stages and stations with an f = 10.29 (p = 0.0018).