 Scientists using DNA have catalogued and described 100 new species of sharks and rays in Australian waters, which they said on Thursday would help conservation of the marine animals and aid in climate change monitoring. More than 90 of the newly named species were identified by scientists in a 1994 book "Sharks and Rays of Australia" but remained scientifically undescribed. One rare species of carpet shark catalogued was found in the belly of another shark. The new names and descriptions will now feature in a revised 2009 edition of the book by Australia's peak scientific body. The Commonwealth Scientific & Industrial Research Organization (CSIRO) said its cataloguing of the new species was critical for the management of sharks and rays, which reproduce slowly and are vulnerable to overfishing. CSIRO scientists said sharks and rays as apex predators play a vital role in the ocean's ecosystem and can be indicators of climate change. "Their populations are sensitive to small-scale events and can be an indicator of environmental change," CSIRO team leader Peter Last said in a statement announcing the cataloguing. Some of the new species named include: * The endangered Maugean Skate shark, closely related to an ancestor from the Gondwanan period in Australia some 80 million years ago, found at the southwest of the island state of Tasmania. It is one of the only skates in the world found in brackish or freshwater and its survival could be affected by climate change, said the scientists. * The critically endangered gulper shark or the Southern Dogfish which is endemic to the continental shelf off southern Australia. * The Northern Freshwater Whipray and the Northern River Shark, which grow to over two meters (six feet) in length, and are among the largest freshwater animals in Australia. Until recently these were confused with similar marine species. Environment group WWF-Australia said the cataloguing of 100 new species of sharks and rays would boost conservation moves to protect the marine animals. "It is a major scientific breakthrough," said WWF-Australia fisheries manager Peter Trott. "We now need to know what changes in management are needed to conserve these animals." Trott said confusion between separate species of sharks and rays meant that new, rare or endangered species may be mistaken for more common species and inadvertently taken by fishermen. "We are literally fishing in the dark when it comes to sharks and rays. In many cases we simply do not know what species we are plucking from Australian waters, Trott said in a statement.