Zhongyujing 種魚經, also called Yangyujing 養魚經 or Yujing 魚經, is a short text on fish farming written during the Ming period 明 (1368-1644) by Huang Shengzeng 黃省曾 (1490-1540), courtesy name Mianzhi 勉之, style Wuyue Shanren 五嶽山人, from Wuxian 吳縣 (Suzhou), Jiangsu.
Huang's book is the oldest surviving book specializing on fish farming. The Han-period 漢 (206 BCE-220 CE) book Tao Zhugong yangyu fa 陶朱公養魚法, allegedly written by Fan Li 范蠡 during the Spring and Autumn period 春秋 (770-5th cent. BCE), is only surviving in fragments quoted in the Qimin yaoshu 齊民要術.
The book consists of three parts, namely larvae and young fish (Zhong 種), feeding (Fa 法 "Methods"), and species, types and names of fishes (Jianghai zhupin 江海諸品).
The first part describes the rearing of fish. It records fishing and breeding methods of natural fry, as well as the feeding habits of black carp (qingyu 青魚, Mylopharyngodon piceus) and grass carp (caoyu 草魚, Ctenopharyngodon idella), and matters needing attention in the breeding of silver carp (lianyu 鰱魚, Hypophthalmichthys molitrix) fingerlings. The record of mullet (ziyu 鯔魚, Mugil cephalus) farming at the seaside of Songjiang 松江 is the earliest record of mullet farming in China.
The second part describes how to feed and farm fish. For the construction of fish ponds, a set of effective methods is necessary. The author recommends that two ponds were made use of to be able to change the water, separate large from small fish, or to separate sick breed from healthy one. The water in the pool should not be too deep, as it would be deficient in oxygen, and low water temperature was not conducive to the growth of fish. However, the pond should be somewhat deeper towards the north so that the fish could make use of different temperature zones. The pond environment should meet the needs of fish growth, with artificial islands facilitating the natural movements of the fish, and surrounding trees giving shelter. For the prevention and control of diseases, the author recommends to sieve out excrements. The inflow of limewater was to be avoided. The regular and will-planned feeding process was important for the growth of any species. Water plants among the food should be avoided, in order to prevent the entrainment of fish enemies.
There were many different editions of the text, and it is found in many series, like Jujia biyong 居家必備, Yimen guangdu 夷門廣牘, Mingshi xueshan 明世學山, Bailing xueshan 百陵學山, Wenfang qishu 文房奇書, Guang baichuan xuehai 廣百川學海 or Congshu jicheng chubian 集成叢書初編. Is is also part of Huang's collection Nongpu sishu 農圃四書.