The wild stock of the Mekong giant catfish are going to be driven to extinction if the hydropower dams planned for construction in the Mekong River get the go ahead, says a report recently released by the WWF (World Wildlife Fund)

The report, which was titled “River of Giants: Giant Fish of the Mekong”, writes on four of these giant catfish which make their home in the Mekong. They rank in the top 10 of biggest freshwater fish in the entire world. The Mekong River’s Giant freshwater stingray can be half the length of a bus, and weigh in at somewhere around 1,300 pounds and currently holds the title for world’s biggest freshwater fish. However, the Mekong giant catfish, now listed as critically endangered, ranks third being almost 10 feet long and weighs in at around 771 pounds.

The hydropower dam which is supposed to be constructed on the Mekong River at Sayabouly Province, northern Laos, is a serious threat to the survival of the wild stock of this magnificent catfish.

“A fish the size of a Mekong giant catfish cannot swim across a large barrier like the Sayabouly dam to reach its spawning grounds upstream,” explained the Director of WWF’s Greater Mekong Program, Dekila Chungyalpa, “Building this and other dams will lead to the collapse of the wild population of this iconic species.”

One can only hope that they put a stopper in this plan to dam up their home, and cause strife for this majestic animal.

Chinese ichthyologists Yang, Chen and Yang have described three new species of snow trout in a paper[1] published in the journal Zootaxa[2]. All three species have been described from material previously identified as one single species, Schizothorax griseus. True trouts belong to the Salmoninae subfamily in the Salmonidae family, but snow trouts are members of the family Cyprinidae.

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cypriniformes
Family: Cyprinidae
Genus: Schizothorax

New species: Schizothorax beipanensis

Schizothorax heterophysallidos

Schizothorax nudiventris

Schizothorax beipanensis

Schizothorax beipanensis is found in southern China where it inhabits the Beipan River drainage, a part of the Pearl River drainage. It has been encountered in both slow-flowing deep pools and fast-flowing rivers with clear water and over a wide range of different bottom substrate, from mud and sand to rocks, boulders and pebbles.

Schizothorax beipanensis differs from its close relatives by having well-developed upper and lower lips (the lower lip is actually tri-lobed), no horny sheath on the lower jaw, and a continuous postlabial groove with a minute median lobe.

Schizothorax heterophysallidos

Just like Schizothorax beipanensis, the snow trout Schizothorax heterophysallidos is found in the Pearl River drainage in southern China, but it lives in the river drainage of Nanpan, not Beipan. Schizothorax heterophysallidos lives in small streams where the bottom consists of sand and pebbles.

The name heterophysallidos is derived from the unusual swim bladder of this fish; physallis is the Greek word for bladder and heteros means different. In addition to the swim bladder (the posterior chamber of the air bladder is three to six times longer than the anterior chamber), Schizothorax heterophysallidos can be recognized on its well-developed and trilobed lower lip, thin upper lip, and blunt snout. It has a continuous postlabial groove with a minute median lobe and the last unbranched dorsal-fin ray has a strong lower part. In mature specimens, the abdomen lacks scales.

Schizothorax nudiventris

Schizothorax nudiventris also lives in southern China, but in the upper parts of the Mekong River drainage. The Mekong basin is one of the richest areas of biodiversity in the world. More than 1200 species of fish have been identified here and the number is believed to increase as the area becomes more thoroughly explored by science.

Schizothorax nudiventris has a well-developed and trilobed lower lip, thin upper lip, blunt snout, and continuous postlabial groove. The body is decorated with irregular black spots on the sides, and the last one-quarter of the last unbranched dorsal-fin ray is soft. In mature specimens, the abdomen has no scales, and it is this feature that has given the fish its name nudiventris. Nudus is the Latin word for naked, while venter means abdomen.