Methods of Improving the Overwintering Survival Rate of Large-sized River Crab Oviposita

Abstract

A method for increasing the overwintering survival rate of large river egg-carrying crabs is characterized by including the following steps: firstly, determining a river crab culture pond for selecting river crab parents; secondly, changing the type of feed for river crabs at least ten days earlier, namely replacing animal baits with vegetable feed; thirdly, after the water temperature of a mating pond falls to 12 DEG C or below, putting female crabs into the mating pond for temporary culture for at least 6 days, and then putting male crabs into the mating pond for mating; fourthly, 9-15 days later, draining water in the mating pond, fishing out the male crabs, removing dead crabs, erecting shelters for the egg-carrying crabs and filling water for overwintering, or putting the egg-carrying crabs in another mating pond with the shelters, and keeping the normal temperature of the water for overwintering. By the method, the overwintering survival rate of the large egg-carrying crabs can be effectively increased, cost of river crab fries is reduced, adverse selection of the river crabs is reversed, and germplasm and growth standard of the river crabs are improved.

Description

technical field [0001] The invention relates to an aquatic breeding technology, in particular to a river crab nursery technology, in particular to a method for improving the overwintering survival rate of large-scale river crabs with ovipositors. Background technique [0002] At present, in the process of raising crab seedlings, due to the large amount of eggs in large-scale (150g) crabs, the overwintering survival rate of egg-bearing crabs is very low (generally 30-40%). The survival rate of egg-bearing crabs is not guaranteed. Therefore, river crab nursery farms generally use river crab parents with smaller specifications (less than 125g) to ensure the survival rate of egg-bearing crabs (generally above 90%) and reduce production costs. The phenomenon of adverse selection in which small-scale river crabs are selected as parents to reproduce offspring among the cultivated river crabs, the direct result is that the germplasm gradually degenerates, and the cultivated river cr...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to solve the problem of low overwintering survival rate of large-scale (more than 150 grams) oviposit crabs, and to invent a method that can improve the overwintering survival rate of large-scale river crab oviposit crabs, so as to prevent the phenomenon of reverse selection in the offspring of small-scale oviposit crabs. happened

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