Australian scientists have recently completed an ambitious 18 month project that has resulted in more than 100 new species of sharks and rays being named and described for the very first time. The results of this study have increased the number of such species in these Australian waters by a third, and boosted the total in the world by about 10 percent.
The new species include two of Australia’s largest freshwater animals, the northern river shark and the northern freshwater whipray, both of which can grow to 6 ½ feet in length. There is also the Maugean skate, whose ancestors swum in the waters off southern Australia over 80 million years ago, according to the fossil record. This species is now endangered, occurring only in the vicinity of Bathurst and Macquarie harbors, off the southwestern tip of the island of Tasmania.
Team leader for the study, Commonwealth Scientific and Industrial Research Organization’s (CSIRO) Dr. Peter Last said that analysis of DNA sequences were used to clarify the identity of closely-related species.
“Additional taxonomic information like this is critical to managing sharks and rays, which reproduce relatively slowly and are extremely vulnerable to overfishing and other human impacts,” Last said. “Their populations are also sensitive to small-scale events and can be an indicator of environmental change.”
Another shark identified as a result of the CSIRO study was a critically endangered gulpher shark, now known as the southern dogfish. It is found only in a small area of the ocean off southern Australia.
The full results of the study will be published in 2009, in a revised edition of Dr. Last’s book Sharks and Rays of Australia, co-authored with his CSIRO colleague Dr. John Stevens. Meanwhile, specimens of many of the new species have been included in the Australian National Fish Collection in CSIRO Hobart, which holds the largest number of preserved sharks and rays in the Southern Hemisphere.