| Abstract: | Breeding colonies of squirrel monkeys in zoos are often a mix of Saimiri taxa, which leads to the possibility of hybridization, loss of classification features, and possible reduction of fertility among hybrids. Two zoos, Potawatomi and Brookfield, were used to assess chromosomal composition of colonies. Chromosomes were analyzed from lymphocyte cultures and animals were classified into cytogenetic types. At both zoos there was a predominance of Peruvian types, but hybrids (Peruvian/Colombian) at Potawatomi and (Peruvian/Colombian and Peruvian/Guyanan) at Brookfield were also identified. Analysis of the Brookfield lineage (three generations) revealed karyotypic Peruvians derived from hybrid parents. The Gothic versus Roman arch of periocular white hair shows intermediate or quite variable expression in hybrids and offspring derived from hybrids. Given the relative length of both pericentric inversions and the segments distal to each, a detectable reduction in fertility is predicted when compared with similar-sized inversions in humans. Somatic segregation of inversion heterozygotes, which would reconstitute homozygosity and elevate fertility, was not detected. |
