Important discovery at Grahamstown institute not just another fishy tale

By Guy Rogers Environment & Tourism Editor

A NEW species of fish has been identified in the SA Institute for Aquatic Biodiversity collection in Grahamstown.

The discovery of the creature, a species of the venomous, little-known waspfish, means great kudos for the institute.

The SAIAB’s fish collection is already recognised as an “ichthyological Mecca” and the most important in the world in terms of the fishes of the western Indian Ocean. It contains about 2 000 marine and 1 000 freshwater species.

The discovery also signalled again how little we knew about the creatures of the deep sea, the institute’s curator emeritus, Dr Phil Heemstra, said yesterday.

The new species was caught in July 1994 in a lobster trap off the northern KwaZulu Natal coast. The fishermen were not carrying sophisticated depth measurement equipment, but it was estimated the traps were lying 150-300m down.

A Durban marine biologist had seen the fish, recognised it as “something unusual”, and sent it down to the SAIAB, Heemstra explained.

Identified there as a member of a species of waspfish which normally occurs in Japanese waters, it was preserved and archived as an interesting find.

But visiting US researcher Dr Stuart Poss, one of the world’s leading authorities on venomous fishes like the scorpion, stone, lion and waspfish as well as the related but non-venomous velvet and horse fish and coral crouchers, recognised it as far more significant than that.

Following up a hunch after he spotted it last month on the computer catalogue of the institute’s collection, he located the specimen – and confirmed that it was indeed a completely new species. Its dimensions are different and an X-ray showed that its skeletal structure is different too.

Reference to the one photograph taken of it shortly after it was pulled out of the sea and still had some colour showed that its colours are not the same either as the Japanese species. Poss left earlier this week for the US, where he will officially write up his findings.

The newcomer will then be included in an up-coming book on the fishes of the western Indian Ocean.

Heemstra explained some of the excitement and complexities surrounding the discovery.

“Waspfish usually occur on rocky reefs and the habitat there is so deep and rugged it makes sampling very difficult. It’s too deep for scuba diving and unsuitable for trawling because of the danger of losing the trawl. Line fishermen at this depth would be using unsuitably large hooks and we don’t know if it would take a hook anyway.”

What is known is that waspfish and their relatives make strong use of camouflage and feed on crabs, prawns and small fish. They have venomous dorsal fins and a jab from one of these fins will at the least be “very painful”. There is no record of human fatalities, but this could be because so few people had come into contact with them.

He said the institute was very excited because identifying a new fish “is the first step towards learning more about it, and being able to protect it”. A German submersible called Jago, which can go to a depth of 400m, was custom-built and then contracted by the institute to research the coelacanth off South Africa’s north-eastern shores.

This kind of vessel would be ideal to probe possible further populations of the new waspfish. Some thought had been put into re-contracting the Jago or even building our own submersible, but costs were prohibitive and funding must be found, Heemstra said.