Breeding method of new variety of hard-shelled razor clams

1 . A method for breeding a hard-shelled razor clam strain, comprising:

a step (a) comprising:

constructing a plurality of full-sib families of razor clams using a control population of razor clams;

measuring a growth trait and a shell hardness trait for the plurality of full-sib families to obtain a measured result of the growth trait and the shell hardness trait; and

performing a heritability evaluation based on the measured result to obtain a heritability evaluation result;

a step (b) comprising:

during a reproductive season of the razor clams, collecting razor clam individuals from a predetermined sea area to form a base population;

measuring shell hardness of each razor clam individual in the base population using an electronic hardness tester for material mechanics; and

selecting, from the base population, the razor clam individuals having measured shell hardness greater than a predetermined selection threshold as a breeding population;

a step (c) comprising:

washing and sterilizing the breeding population, and then air-drying the breeding population in a ventilated shaded place for 2 to 4 hours; and

inducing spawning of the breeding population by injecting 5-hydroxytryptamine into feet of the breeding population in combination with running-water stimulation to obtain offsprings of the breeding population;

a step (d) comprising:

growing out the offsprings to obtain target individuals of a first-generation hard-shell razor clam strain based on the heritability evaluation result; and

a step (e) comprising:

using target individuals of the first-generation hard-shell razor clam strain as the breeding population, repeating the steps (c) and (d) for 3 to 4 rounds to obtain one or more generations of hard-shell razor clam strains.

2 . The method for breeding of a hard-shelled razor clam strain of claim 1 , wherein the plurality of full-sib families of razor clams is constructed using a nested design method, and the growth trait comprises a shell height, a shell length, a shell width, and a total weight.

3 . The method for breeding of a hard-shelled razor clam strain of claim 1 , wherein

the electronic hardness tester is a mechanical apparatus optimized and applied to perform accurate measurement for the shell hardness trait of the razor clams; and

the step (b) further comprises:

selecting 200 razor clam individuals;

measuring the shell hardness of the 200 razor clam individuals using the electronic hardness tester, and sorting the measured hardness values;

determining a constant-pressure value for the breeding population;

configuring the electronic hardness tester to perform parent screening by testing the 200 razor clam individuals using the constant-pressure value; and

eliminating crushed individuals and retaining individuals having shell hardness greater than the constant-pressure value as the breeding population.

4 . The method for breeding of a hard-shelled razor clam strain of claim 1 , wherein the step (c) further comprises:

randomly selecting 50-100 individuals from the breeding population; and

injecting, using a syringe, 0.1 to 0.2 ml of 5-hydroxytryptamine with 0.02 to 0.04 mmol/L to the foot of each razor clam.

5 . The method for breeding of a hard-shelled razor clam strain of claim 1 , wherein in the step (e), the one or more generations of hard-shell razor clam strains includes two or three generations hard-shell razor clam strains.

6 . The method for breeding of a hard-shelled razor clam strain of claim 1 , wherein the step (c) further comprises:

randomly selecting 50-100 individuals from the breeding population;

injecting, using a syringe, 0.1 to 0.2 ml of 5-hydroxytryptamine with 0.02 to 0.04 mmol/L to the foot of each razor clam; and

using 0.05 mmol/L EDTA solution as a stimulating substance for the running-water stimulation.