A large south east Asian sisorid catfish popular with fishermen and sport anglers may be heading towards extinction due to overfishing for its valuable flesh.
The Goonch or Chien catfish, Bagarius yarrelli, which is said to reach sizes of up to 2m/6'6" and can weigh over over 50kg/110 lbs, is a delicacy in Vietnam and has been so heavily fished that experts now believe the species could be wiped out if fishing pressures are not reduced.
The fish is so valuable to fishermen that they are putting their lives and the environment at risk trying to catch the fish from rocky gorges and underwater crevices in Vietnam's Da River, often in torrential water.
A 45kg Bagarius can sell in a local market for 1 million Vietnam dong (about 34.20) but the average daily wage is just 54p - so the catfish is the equivalent to more than two month's wages. "A single Bagarius can be worth two month's wages..."According to a report from Vietnam News, one fisherman diving into the Gam River - wearing only a pair of swimming goggles - was armed with home-made guns equipped with a barbed "fishgig" in the barrel to spear the fish:
"With nothing more than a sense of where he believes the fish to be hiding, Senh jumps into the gorge and begins his mission with a hope that the current won't be too strong and the tiger catfish won't be down too deep.
"On a successful job, Senh can bring home a fish weighing 45kg and worth one million dong at the market. "Successful" also means he isn't injured or killed."
Extreme fishingOther fishermen are going to even greater lengths to cash-in on the lucrative fishery by setting underwater mines to stun the fish and make them easier to catch.
Pham Bau, a scientist specialising in fish conservation, told Vietnam News: "The use of mines or discharge pulse should be stopped right away. They are uprooting the existence and reproductive abilities of many species that will never be seen in the river again".
Bau says that B. yarrelli is one of several valuable species which are being pushed towards extinction by uncontrolled fishing in the Da River.
He wants the authorities to set up protected areas where the fish breed so that the adults and their offspring can be allowed to reproduce, unthreatened by fishing, and wants endangered fishes to be bred commercially for reintroduction to the river.
However, other experts believe that the funds available for such a project are simply too limited, although initial successful work has been undertaken to breed Bagarius yarrelli in captivity.
Ngo Sy Van of the Institute of Aquatic Research said that he has been breeding the species for three years and believes he can train local farmers to produce the fish in their natural habitat. Van also believes that the commercial farming of the species might help decrease fishing pressures, giving the remaining stocks a fighting chance against the commercial trade for Chien steaks.
The Bagarius genusBagarius yarrelli is a member of the catfish family Sisoridae and was first described by Sykes in 1839 as Bagrus yarrelli.
The species is one of four known Bagarius species, including: B. sutchus, B. rutilus and B. bagarius.
B. rutilus was described by Heok Hee Ng and Maurice Kottelat in 2000 from Laos, Vietnam and China and reaches around 1m in length.
Some fishkeeping writers have claimed that yarrelli is not a valid species, and has been considered a synonym of Bagarius in the past. However, Kottelat regards the species as valid, and it is listed as valid in FishBase, ITIS and Eschmeyer.
You can read more about the genus in this article on Bagarius bagarius.