Older than dinosaurs: last South African coelacanths threatened by oil exploration

Just 30 of the prehistoric fish known to exist, raising fears oil wells will push it to extinction

Tony Carnie in Durban

Fri 17 Aug 2018 11.29 BSTLast modified on Mon 20 Aug 2018 09.52 BST

Bright blue, older than dinosaurs and weighing as much as an average-sized man, coelacanths are the most endangered fish in South Africa and among the rarest in the world.

Barely 30 of these critically-endangered fish are known to exist off the east coast of South Africa, raising concern that a new oil exploration venture in the area could jeopardise their future.

Coelacanths, whose shape has remained almost unchanged for 420m years, captured world attention when the first living specimen was caught off the port city of East London in 1938. This discovery was followed by the subsequent capture of several more off the Comoros islands in the early 1950s, confirming that coelacanths were definitely not extinct.

December 2000 brought further excitement when divers found a small coelacanth colony in underwater canyons near South Africa’s Sodwana Bay, adjacent to the iSimangaliso wetland park and world heritage site.

Now the Rome-based energy group Eni plans to drill several deep-water oil wells in a 400km long exploration block known as Block ER236.

Dr Andrew Venter, the chief executive of Wildtrust, one of several conservation groups lobbying for a significant expansion of South Africa’s protected ocean areas, said: “The Deepwater Horizon oil spill in the Gulf of Mexico in 2010 decimated fish populations – so if we had an oil spill off iSimangaliso it is very likely it could wipe out these coelacanths.”

The Sodwana coelacanths are about 40km from the northern boundary of the Eni exploration area and nearly 200km north of the first drilling sites, but Venter said oil spills spread far and swiftly.

His concerns have been echoed by the coelacanth expert Prof Mike Bruton, who said the fish are specialist creatures, sensitive to environmental disturbance.

Continued  

Still Capable of Adapting: Genetic Diversity of 'Living Fossil' Coelacanths

ScienceDaily (June 14, 2012) — The morphology of coelacanths has not fundamentally changed since the Devonian age, that is, for about 400 million years. Nevertheless, these animals known as living fossils are able to genetically adapt to their environment.

This is described by PD Dr. Kathrin Lampert from the RUB's Department of Animal Ecology, Evolution and Biodiversity along with colleagues from Würzburg, Bremen, Kiel and Dar es Salaam (Tanzania) in the journal Current Biology. "Coelacanths are rare and extremely endangered. Understanding the genetic diversity of these animals could help make preservation schemes against their extinction more effective" says the biologist.

Different populations in Africa studied

Previous genetic studies focused mainly on the biological relationships of coelacanths to lungfish and and vertebrates. In order to assess whether the fish are still able to adapt to new environmental conditions, however, you have to know the genetic diversity within the species. For this purpose, the research team examined 71 specimens from various sites on the east coast of Africa. The researchers analysed genetic markers from the nucleus and from the mitochondria, the powerhouses of the cells.

Continued:  http://www.sciencedaily.com/releases/2012/06/120614094115.htm

Skull Confirms Older Origin for 'Living Fossil' Fish

A group of ancient fish, called coelacanths, have changed so little over time they are known as "living fossils." Now, the remains of a skull found in the Yunnan Province of China, confirms these creatures have been around, largely unchanged, for more than 400 million years.

Once thought to have died out at roughly the time the dinosaurs disappeared, the first living coelacanth was discovered in a fishing net in 1938 off the eastern coast of South Africa. Since then, others have turned up elsewhere along the coasts of the Indian Ocean. 

While it's clear their history goes way back, the fossils they left behind have been scarce so far. A lower jawbone, more than 400 million years old and discovered in Australia, hinted at the earliest known emergence of coelacanths whose appearance matched the two species alive today. This small fossil has been described as the oldest coelacanth, but the authors of the recent research write that it offers so little information that it cannot be reliably placed within the fishes' family tree.

The newest fossil evidence, the remains of a skull, date back to almost the same time and contain more definitive features that indicate both it and the Australian fossil were "modern" coelacanths, according to the study researchers writing in the April 10 issue of the journal Nature Communications.

Read on:  http://www.livescience.com/19602-living-fossil-fish-coelacanth.html