Reptilian recovery

SOME 10 kilometres from the din of Lucknow in Uttar Pradesh, India, the gharial - a member of the reptile fam-ily - is getting a second lease of life. More than two decades ago, the Gharial Rehabilitation Centre was set up here in the Kukrail reserve forest area. Its aim: saving this species from certain extinction. It was a small affair in the beginning: one truck of 38 gharial eggs. So far, however, the centre has bred more than 6,500 gharials, released some 2,569 of them into rivers and has sent 184 to different zoos across India.

Called "living fossils" and found in the rivers of northern India, gharials (Gavialis gangeticus) are the sole survivors of a crocodilian family that has been dated to the Mesozoic era - the age of the dinosaurs. Surviving mainly on a diet offish, an adult gharial can grow up to five metres in length and weigh around 700-1,000 kg. The average life expectancy of these reptiles can be as much as 80 years. The females lay about 40-50 eggs every year during April.

In Kukrail, the reptiles are kept in graded tanks. The younger ones have separate tanks. It is crucial that gharials over a year of age be kept in big enclosures to prevent stunted growth.

One to two-year old gharials can eat fish equal to around three per cent of their weight. In their second year, the gharials grow to 90-95 cm in length and can weigh up to two kg.

Newborn gharials emerge from the eggs that are five to six inches in diameter and buried in sand at tempera-tures ranging from 30-32 C after an incubation period of 65-70 days. The females of the species select the nesting site carefully, in their attempts to pro-tect the eggs from predators. A number of trial holes are dug first before the ideal one is chosen. The gharials have a short snout in relation to the body. Newborns have a sharp protrusion, known as the egg tooth, on the tip of the snout. Ghara (pot)-shaped appendage on the snout gives the gharial its name. The ghara, a bony protrusion, is attained by the males upon sexual maturity and is thought to be a secondary sexual organ.

The sex of the gharials is decided by incubation temperature, not by the gene expression. High incubation tempera-ture leads to females and vice versa. This is primarily because this reptile species does not have any sex chromosomes. The state forest department is conducting several studies and experi-ments on gharials in Kukrail.

The centre, say experts, is providing a much-needed boost not only to the gharials, but to the soft-shelled turtle:, and several other rare or extinction-bound reptilian species as well.