Silurus biwaensis

Silurus biwaensis

Silurus biwaensis ( Japanese: Biwako o'namazu ,ビワコオオナマズ, English:. Giant Lake Biwa Catfish ) is a large, endemic only in Japanese Lake Biwa catfish species occurring.

Dissemination

Silurus biwaensis occurs exclusively in Lake Biwa, in the lives of Silurus lithophilus a second endemic catfish species.

Description

This catfish is similar to the European catfish. He has an elongated cylindrical body and reaches up to 118 centimeters in length and 17 kilograms in weight. The back is black, white belly. The head makes a little less than a quarter of the standard length. The lower jaw is considerably longer than the upper jaw. The single Bartel couple on the lower jaw is relatively short and fine, the barbels on the upper jaw reaching in adult animals, the pectoral fins not reaching these in young animals but. The dorsal fin has four to six rays. The pectoral fins have a hard jet and 13 to 15 soft rays, the pelvic fins a hard and nine to twelve soft rays. The anal fin has 71-83 soft rays. In the upper lobe of the caudal fin with six to seven rays is longer than the lower seven to nine. The gills Reuse has the upper arc two or three, at the bottom nine to twelve spines. There are 14 to 16 Branchiostegalstrahlen present.

Way of life

Little is known about the life of Silurus biwaensis. He eats fish and lives on the bottom of the lake waters. S. biwaensis is the largest predatory fish in Lake Biwa. Using a telemetric methods they tried to explain the migratory behavior of the species. Here it was found that the fish are more or less spatial fidelity and usually stay close to their spawning grounds. Other studies showed that the subpopulations of the lake hardly mix.

Relationship with people

Some fishermen are of the opinion that the fish were able to predict earthquakes, by changing their behavior in a forthcoming earthquake. In Japanese mythology, it is believed even that earthquakes are caused by the movements of a giant Biwa catfish below the earth's crust.