Living habits and morphological characteristics of Tibetan naked carp

Oxygymnocypris stewartii belongs to the order Cypriniformes, family Cyprinidae, subfamily Schizothorax, and genus Oxygymnocypris stewartii. Commonly known as: Sri Lankan naked carp. English name: Naked schizothoracin.

Endangerment level: Endangered.

The body is slender and slightly flattened on the sides. The head is long and tapered. The muzzle is pointed and long. The mouth is large, terminal, and deeply arc-shaped. The upper lip is more developed; the lower lip is narrow, underdeveloped, and divided into left and right lobes. There are mucous cavities in the chin and cheeks. No need. The eyes are small. The body is naked and scaleless, with only a few irregular scales on the shoulder straps and longitudinal buttock scales. The dorsal fin spines are thick and the trailing edge is deeply serrated. The dorsal fin is located further back; the pectoral fin is short. The dorsal side of the body is blue-grey with dark spots, and the abdomen is silvery white. The back and caudal fins are blue-grey, the ends of the chest, abdomen and anal fins are orange-red, and there are many spots on the back and caudal fins.

It inhabits plateau waters above 3,600 meters above sea level, and mostly lives in the flowing water of major trunk and tributaries in the middle reaches of the river. Due to the high altitude and low annual average water temperature, a special ecological environment is formed. The naked carp is adapted to an environment where precipitation and mountain snow water are the source, and the water flow is relatively clear. Mainly feeds on other fish and aquatic insects.

The naked carp is endemic to my country and is only distributed in the middle reaches of the Yarlung Zangbo River in Tibet. The largest individual can reach over 600 mm and weigh over 3.5 kg.

The distribution of the naked carp is limited, the number is small, the growth rate is slow, and the age of sexual maturity is late. In the past, because Tibetans did not eat fish due to the influence of tradition and religion, the naked carp was able to maintain a certain population for a long time. Since the 1950s, a large number of people from the mainland have moved to Tibet for development, and fishing intensity has continued to increase. The amount of fish caught far exceeds its growth rate, resulting in a sharp decline in the current population.

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