Morphology of the genital organs of Amazonian marmosets
(Callibella humilis and Mico marcai)
1. Primates. 2. Marmosets. 3. Callitrichidae. 4. Reproduction
This study examined the morphology of the male genital organs in four male specimens of C. humilis and two females of M. marcai, all in the wild. This is the first study to describe the morphology of the male genital organs in C. humilis and presents the first description of the anatomy and histology of the internal genital organs in M. marcai. C. humilis exhibited particular characteristics, such as the laterally flattened body of the penis and keratinized spines on the penile glans. The testicles were relatively small compared to body size. Regarding the females of M. marcai, ovoid-shaped ovaries and histological characteristics indicative of the early luteal phase were observed. The uterine tubes and uterus exhibited similar characteristics to other primate species, while the vagina had a non-keratinized stratified squamous epithelium. Measurement of reproductive hormones is recommended to understand the changes in the internal genital organs throughout the reproductive cycle of M. marcai females. These results, which include detailed knowledge of reproductive morphology, can contribute to comparative studies of primate reproductive ecology, serving as a key component in the development of management strategies for captive and wild populations.