ON THE GEOGRAPHICAL DISTRIBUTION OF THE FOUR KINDS OF POND-CULTURED CARPS IN CHINA

The silvery low-eyed carp, spotted big-head carp, black carp, and grass carp, the most popular freshwater pond-cultured fishes in China, have been widely raised since getting success with artificial breeding in 1958. However, their natural geographical distribution is still less known so far. Based on collections and fossil records, the authors present the results of a study on the geo graphical distribution of the four kinds of fishes as follows:Ⅰ. Ancient records, fossil records and present natural habitats.1. Hypophthalmichthys molitrix (Cuv. el Val.), silvery loweyed carp, the earliest records in China were given in poems of "Old Fish-Net" (敞苟), "Pick Green Vegetables" (采绿), and "Great Han Land" (韩奕) of Shijing (诗经), about 827-782 B. C. Fossils: Discovered from Yushe Basin (榆社盆地), Shanxi Province, Pliocene deposits (Haihe River System); Pingluxian County (平陆县), Shanxi Province, Pleistocene diposits (Huanghe River System). Distribution: Aihun (瑷珲), Qiqihare (齐齐哈尔), and Xingkai Lake to the lower reaches of Heilongjiang River; sorthw-ards to Niuzhuang (牛荘) in the Liaohe River and westwards to the Fenhe-Weihe Basin of the Huanghe, Changjiang, and Zhujiang River.2. Aristichthys nobilis (Richardson), spotted big-head carp, first recorded in Shanhaijing (山海经 about 200 B. C.). Fossils: recorded from Sanmenxia, Henan Province, Pleistocene deposits.3. Mylopharyngodon piceus (Richardson),black carp, first record in Jin Dynasty (about 265-289 A. D.), Fossils: collected from the Yushe Basin, Pliocene deposits, Shanxi Province; Pleistocene deposits in Linfen and Sanmenxia, Shanxi and Henan Province; and Holocene deposits in Yichang (宜昌), Hubei Province.4. Ctenopharyngodon idellus (Cuv. et Val.), grass carp, recorded in the earliest ancient Chinese Encyclopeadia, "Erya" (尔雅), some 200 B. C. Fossils: Pliocene deposits in Yushe Basin, Pleistocene deposits in Linfen, and Holocene deposits in Yichang.The records indicate that they mainly distributed in the plain of eastern China, especially in the Huanghe and Changjiang River Valley. The detailed distribution of their habitats have been shown on the map.Ⅱ. Analysis and discussion on the present natural habitats of the four pond-cultured carps.1. The data suggest that they are typical plain fishes of eastern China ranging between about 22-40°N and 104-122°E, never beyond 51°N northwards, 19°N southwards, 104°E westwards, and 140°E eastwards. They mainly live in the Changjing and Huanghe River Basin under 200 metres above the sea livel and can rarely reach an elevation of 500 metres. Their habitats always cover a certain distance in plain region so that the larval, juvenile, and young fishes are able to live in better conditions.2. Their living conditions also suggest that they belong to north warm temperate zone fishes. Their optimum growth temperature is between 24-29℃. They can hardly survive at temperatures below 4 ℃ of above 30℃.3. The fossils of cyprinid fishes have been discovered from Eocene deposits in Hunan Province, just in the middle part of the plain in eastern China. So it is assumed that the current plain fishes of China have evolved from primitive cyprinid fishes during the stage of the monsoon climate while the large rivers and lakes have gradually formed because of getting rising of the Himalayas since Pliocene.4. Because.the lower reaches of Heilongjiang River, Nenjiang River, and the Second Songhuajiang River were all the upper reaches of the ancient Nenliaohe River which flowed into the lower reaches of ancient Huanghe River in Pliocene, they could reach the lower reaches of Heilongjiang River through the ancient Nenliaohe River except the spotted big-head carp.5. During the Glacial Era, the shore sea area along the southeastern China was freshwater low land, the four carps might reach the Zhujiang River southwards at that period, although the Nanling Mountains began to rise and form gradually in the Oligocene Epoch. The silvery low-eyed carp had even reached the northern part of Hainan Island and the lower reaches of Honghe R