Microsatellite DNA markers for tuatara (Sphenodon spp.)

Tuatara (Sphenodon punctatus and S. guntheri) are the last surviving members of the reptilian order, Sphenodontia (Benton 1993). The distribution of tuatara has declined severely since human arrival approximately 1000 years ago, being once extensive throughout New Zealand, but now restricted to 34 offshore islands in New Zealand, and zoological collections world-wide. Sphenodon guntheri occurs naturally only on North Brother Island with around 300 adults (Thompson et al. 1990). Sphenodon punctatus is present in 11 island groups and is managed as two distinct genetic groups (Cook Strait and northern groups, Daugherty et al. 1990; Cree and Butler 1993). The phylogenetic distinctiveness and limited distribution of the tuatara have made them a target for illegal trade (P. Younger pers. comm.) and the dramatic, recent contraction in their range has made the study of their biology essential for conservation purposes. Ecological studies of the tuatara are difficult owing to a range of life history characteristics. In particular, tuatara mature late (13– 20 years), have a slow reproductive cycle (4 to 5 years, Cree 1994), and a long life span (>100 years, Robb 1977). Therefore, we have isolated and characterised six microsatellite loci in Cook Strait Sphenodon punctatus, and have tested these loci for amplification in populations of S. guntheri and northern and Cook Strait S. punctatus