CAPE TOWN — It is 75 years since the enigmatic coelacanth was rediscovered off the South African coast, but no one has yet seen how the fish, which give birth to live young, mate. The fish, found off the Eastern Cape coast in 1938, are basically the same as 400-million-year-old fossils of the same species. In December 1938, a fisherman asked Dr Majorie Courtenay-Latimer, who worked at the East London museum, to look at his catch. One “steel-blue fish, the loveliest I had ever seen” stood out, she said later. She preserved the fish, and it was later identified by Professor J.L.B. Smith as a coelacanth. The fish are also found off Kosi Bay in Northern KwaZulu-Natal. Dr Kerry Sink, marine programme manager at the SA Biodiversity Institute, said it is expensive and difficult to track down living coelacanths to study in the wild. The fish, which occur in groups of about 13, live at depths of 100 to 700 metres and are relatively scarce. The specialised gas to allow divers to venture that deep costs about R3 per breath. If they want to go still deeper, a mini-submarine and a support vessel are needed. There are coelacanths in the iSimangaliso Wetland Park, one of only two World Heritage sites in the Indian Ocean. “We are preparing to tag the park’s population to get an idea of their numbers,” said Sink. The first coelacanth photographed live underwater was named Jessie. She was first filmed in 2001 and has since been seen about 10 times. She is recognised by her unique pattern of white flecks. The first juvenile was seen this year. It was about one metre long, while adults reach between two and three metres. “Three fish seen in the park were possibly pregnant, but they were not seen again,” said Sink. “We don’t know where they go to give birth. They give birth to live young, but no one has ever seen this. “No one has ever seen them mate either,” said Sink, adding that the males have no visible external sex organ, so the whole process is a mystery. • There are two species of coelacanths. The one found off South Africa is called Latimeria chalumnae — the genus refers to Courtenay-Latimer, who first found it and the species name to the Chalumna river near East London near which it was caught. • It is a predator with lobed fins, which can swim upside down. • They look very similar to how they looked 400 million years ago, because they have evolved very slowly.