<< Previous Issue | June 1991 | Next Issue >> | ||
Quick DipsTuatara SexReproduction is a long, slow process for the tuatara, as Dr Alison Cree of Otago University's Zoology Department has discovered. In male lizards, testosterone levels rise over a one to three month period during the mating season. This increase is associated with sperm production. In male tuatara, the testosterone level is elevated for almost half a year. Female lizards which lay eggs usually produce at least one clutch of eggs a year. Female tuatara breed on average once every four years. This is because egg yolk production takes on average three years to complete. Once the egg is fertilised, the egg shell takes up to eight months to develop. This is three times as long as for any other known reptile. Tuatara reproduction has been described as primitive, but a more correct term is specialised," says Cree. "The prolonged reproductive cycle in both the male and the female is a specialisation for the cool maritime environment in which most tuatara live." Linda Gray, Otago University |
||
<< Previous Issue | June 1991 | Next Issue >>
All contents of this site copyright © 1990-2007 Webcentre Ltd. All Rights Reserved |