一种双层鱼类选育苗种池塘养殖网箱

A double layers pond aquaculture cage for family breeding of Luciobarbus capito fry and fingerling

摘要:

为了解决现有网箱养殖中放养苗种需要前期培育、清洗更换网箱工作强度大的问题，研发出一种双层鱼类苗种池塘养殖网箱。双层网箱呈长方形，箱体网衣由上层大网目和下层小网目组成，两种网衣高度均为1 m，鱼苗在下层小网目 (0.42 mm) 水体中培育，随着鱼苗生长逐渐升高水位，苗种在上层大网目 (0.6 cm) 和下层小网目合围的水体中养殖。结果显示，双层网箱可以进行大鳞鲃鱼苗到鱼种的连续养殖，漂浮网箱适合大规格鱼苗 (全长>2.0 cm) 到鱼种的养殖。双层网箱养殖大鳞鲃1龄鱼种的全长、体长、增重率和特定生长率均显著高于漂浮网箱养殖的鱼种。3个月养殖期间，双层网箱不需要更换清洗网箱，漂浮网箱需要更换清洗网箱5次。结果表明，双层网箱大鳞鲃1龄鱼种的养殖效果显著优于漂浮网箱，并且养殖管理工作强度显著降低。为了验证双层网箱苗种选育的养殖效果，以大鳞鲃耐盐碱选育家系为养殖对象，分别在3个660 m²的池塘中平行安装6个相同规格的网箱，进行从鱼苗到1龄鱼种的池塘养殖。在双层网箱养殖条件下，大鳞鲃选育家系1龄鱼种体长为13.87~16.07 cm，体重为34.71~42.07 g，与池塘养殖条件下的1龄鱼种规格相似，并且6个家系呈现出不同的生长性状。研究表明，在池塘中进行多个双层网箱养殖，可为鱼类选育苗种提供相同的养殖条件和准确的生长数据。双层网箱可为鱼类选育苗种提供一种池塘养殖方式。

Abstract:

Cage aquaculture originated in China and then spread throughout the world gradually. In the late 1970s, there was a new development in the methods and species of cage aquaculture in freshwater cages in China. Floating cage is the most widely used aquaculture method. Floating cage require a minimum size of stocking fry, which must be cultivated to a suitable size before they can be cultured in the cage. In addition, with the growth of the fish, it is necessary to replace the cage with a larger mesh in time. After the cage is in the water for a period of time, it can easily be blocked by algae adhesion. In order to solve the problem that fry in the existing cage culture needs early cultivation and high frequency of cleaning and replacement of floating cage and fixed cage when experimental fish are cultivated, a double layer submerged cage was developed for the breeding aquaculture of fry and fingerling in the pond. The cage net was composed of an upper large mesh size (0.6 cm) and a lower small mesh size (0.42 mm). The fry was cultivated in the lower small mesh net, whereas the fingerling was cultivated in the enclosed space of the upper large mesh net and the lower small mesh net with a gradual increase of water. Through the comparison between double layers cage and floating cage in pond aquaculture, the results showed that the fry and fingerling could be continuously cultured in a double layers cage, while the large-scale fry (full length >2.0 cm) and fingerling could be cultured in a floating cage. The total length, body length, body weight, weight gain and specific growth rate of fingerling fish cultured in double layers cages were significantly higher than those in floating cages (P<0.05). During the three-month breeding period, the double layers cage did not need to be replaced and cleaned, and the floating cage was to be replaced five times and cleaned six times. The results showed that the culture effect of the first-year-old fish in the double layers cage was significantly better than that in the floating cage, and the intensity of culture management was significantly reduced. To verify the breeding effect of this system, six double layers cages with the same specifications were installed in a 660 m² pond in parallel. The saline-alkali tolerant breeding families of Luciobarbus capito were selected as breeding objects, and culturing from fry to fingerling was completed without replacing or cleaning the cage. The body length was 13.87-16.07 cm, and the weight was 34.71-42.07 g, which was a similar size to the one-year-old L. capito obtained under pond aquaculture conditions. Moreover, six families showed different growth characteristics (P<0.05). The research showed that the same breeding conditions and accurate growth data can be provided for the fish family selection by the double layers cage aquaculture in the pond. The double layers cage can provide a pond aquaculture method for fish selective breeding.