Effects of adding different proportions of the small fish punti (Puntius sophore) and mola (Amblypharyngodon mola) to a polyculture of large carp
Effects of adding different proportions of the small fish punti (Puntius sophore) and mola (Amblypharyngodon mola) to a polyculture of large carp
复制标题
DOI：
10.1111/j.1365-2109.2004.00990.x
复制
发表时间：
2004-01-30
影响因子：
2
通讯作者：
Milstein, A
中科院分区：
文献类型：
--
作者：
Alim, MA;Wahab, MA;Milstein, A
这项试验是在一个项目的框架内进行的，该项目是在孟加拉国的条件下开发一种可行的鱼类混养技术，该技术允许同时生产供农民家庭消费的小型本地鱼类和作为经济作物的大型鲤鱼。本试验的目的是评价不同比例添加punti和mola对大型鲤鱼和环境的影响，以及punti对mola和mola对punti的影响。混养包括大型鲤鱼罗虎、鲶鱼和鲤鱼（作为经济作物鱼），以及小型本地鱼punti和翻车鱼（作为小农家庭的食物）。大型鲤鱼总放养密度为1万条/ h(-1)，种数比为1:1:1。对照组的小鱼总放养密度为0，处理的小鱼总放养密度为3万只雄鱼和翻齿鱼（-1），放养比例为2:1、1:1和1:2。以测试的密度和所有比例放养鲳鱼和翻车鱼是同时获得大型鲤鱼经济作物和小鱼以养活农民家庭的可行办法。在不同比例的小鱼放养中，大鲤鱼的产量有统计学上的边际差异。这些边际差异可以用punti和普通鲤鱼之间以及mola和rohu之间的食物竞争来解释，这些食物竞争的结果取决于放养的小鱼的比例。以1:1的比例放养鲳鱼和翻车鱼会为农民家庭带来更多的小鱼，而最昂贵的大型鲤鱼罗虎的个体尺寸会稍微小一些，但不一定小到足以降低其售价。其中一种小鱼的比例高于另一种（2:1或1:2）将导致家庭消费的翻车鱼较少，而普通鲤鱼的收获则略少，小鱼的收获则较少。由于普通鲤鱼是大型鲤鱼中最便宜的，所以这种小的减少并不一定会对家庭收入产生重大影响。有了这些结果，农民现在就能够重新安排大鲤鱼和小鱼的放养方式，并决定适当的小鱼放养比例，以满足他们的需要。
This experiment was carried out in the framework of a project to develop a viable fish polyculture technology under Bangladeshi conditions that allows simultaneous fish production of small indigenous species for the farmers' family consumption and of large carp species as a cash crop. The objectives of this experiment were to assess the effects of adding punti and mola in different proportions on the large carp and on the environment, and to assess the effects of punti on mola and mola on punti. The polyculture included the large carp rohu, catla and common carp (as cash crop fish), and the small indigenous fish punti and mola (as food for the small-scale farmer family). The total large carp stocking density was 10 000 fish ha(-1), at a species ratio of 1:1:1. The total small fish stocking densities were 0 in the control and 30 000 punti and mola ha(-1) in the treatments, these at rates 2:1, 1:1 and 1:2. Stocking punti and mola at the density and all ratios tested were viable solutions to obtain simultaneously large carp cash crops and small fish to feed the farmer's family. Statistically marginal differences in large carp production were obtained in stocking small fish in the different proportions. These marginal differences could be explained by food competition between punti and common carp and between mola and rohu, which had different outcomes depending on the proportions of the small fish stocked. Stocking punti and mola at a 1:1 ratio would result in more small fish for the farmer's family, while the individual size of rohu, the most expensive large carp, would be somewhat smaller, but not necessarily small enough to decrease its selling price. Stocking one of the small fish in higher proportion than the other (2:1 or 1:2) would result in less mola for the family consumption, while harvesting of common carp would be somewhat lower and of smaller fish. Since common carp is the cheapest of the large carps, this small reduction would not necessarily affect the family income in an important way. With these results, farmers would now be able to reorganize their stocking practices with large carps and small fish and decide the appropriate small fish stocking ratios to meet their needs.