Reproduction, growth, and development

This chapter provides an overview of reproductive physiology, pre- and postnatal development, and growth in common marmosets. Marmosets display a unique set of reproductive and developmental traits, including production of litters, typically twice a year, making them the most fertile anthropoid primates. Associated with this high fertility is a relatively high rate of pregnancy loss, perhaps reflecting a marked sensitivity to stressors. Litter mates develop in an unusual uterine environment that includes shared placentation resulting in hematopoietic chimerism. Associated with their small size, marmosets have a fast maturation rate, initiating puberty at 9-10 months of age and completing physical growth prior to 2 years of age. Growth patterns in captive marmosets are affected by factors that may impair growth, such as failure to thrive associated with poor birth condition or parental abuse and early life occurrence of inflammatory bowel diseases. In the last decade, there has been an increase in altered growth patterns in the opposite direction as well, with early life obesity being relatively common in many colonies. The etiology of this pediatric obesity is still poorly understood, but its sequelae are those commonly associated with obesity, including metabolic dysfunction and cardiovascular problems.