Scientific breakthrough reveals evidence of ‘human fish’ locked away in cave system
By Shaun Hurrell, Mon, 09/02/2015 – 10:35
How do you find physical evidence of a rare species when most of its habitat (the subterranean waters of limestone cave systems in the Balkans) is inaccessible to humans? The ‘human fish’ is the largest cave animal in the world. Despite this, Proteus anguinus – a blind, entirely-aquatic salamander commonly known as the olm, and endemic to the Dinaric Alps – is incredibly difficult to find.
The answer was recently provided by the Society for Cave Biology (SCB; Društvo za jamsko biologijo) in a project funded by the Critical Ecosystem Partnership Fund (CEPF) when they found the first physical evidence of the species in Montenegro using new techniques to sample its DNA.
In this region, activities such as water extraction, river damming and agriculture have increased the stress on Proteus and other aquatic cave animals. Limestone habitats like cave systems can be intricate and complex, having taken millions of years to form by natural processes. One wrong move can wipe out entire species, so urgent measures need to be taken in order to save them.
Nick-named the ‘human fish’ by locals because of its skin colour, Proteus are listed as Vulnerable on the IUCN Red List of Threatened Species and in some localities the species is already extinct. However the extent of the decline cannot be estimated without an extensive survey of its distribution – in habitat where access is easy for the human fish, but not so easy for human beings. The purpose of the CEPF project was to solve this problem: to test a scientific method that safely, effectively and accurately determines Proteus presence.
SCB, experts in speleological (cave and karst) research, designed a solution based on so-called ‘eDNA’. During the process of skin regeneration, Proteus shed fragments of epidermal cells which are carried away by water. DNA dissolved in water is called environmental DNA (eDNA), and SCB successfully tested and perfected the sensitive and inexpensive technique of identifying Proteus eDNA from samples of water.
After many hours in the field and thousands of water samples, the team have discovered new localities of Proteus in Montenegro and in Bosnia and Hercegovina. This ground-breaking research will give SCB and partners the evidence to appeal and counsel the nature conservation authorities in Montenegro to start all necessary legal actions to protect Proteus in their territories, and to guide the management planning of authorities in Bosnia and Hercegovina.