An Optimized Experimental Zebrafish Breeding Scheme for Significantly Enhancing Reproductive Efficiency and Service Life

Abstract

Objective To solve the problems of delayed growth and development and insufficient spawning of experimental Zebrafish, so as to improve the reproductive efficiency and service life of experimental Zebrafish.Methods The zebrafish at the age of 2 months after fertilization were divided into two groups. The experimental group was fed with dry commercial diets specifically designed for ornamental fish or frozen adult brine shrimp, while control group was fed with live laval brine shrimp. Within a period of 70 days, the growth performance of the zebrafish was evaluated by measuring body length and weight, and the reproductive performance was assessed by measuring the fecundity and spawning rate. Zebrafish with apparent goiter disease were fed with dry commercial diets, and the inhibitory effect of the pellets on this disease was evaluated by measuring the diameter of the thyroid enlargement lesion. The three feeding methods were combined, and the feeding plan was optimized. The actual effects of the plan on zebrafish rearing were validated through reproductive performance tests.Results Starting from 60 days post-fertilization (dpf) until 111 dpf, the body length and weight of the dry commercial diets feed group gradually surpassed those of control group (all P<0.000 1). From 60 dpf to 96 dpf, the growth trend in body length of the adult brine shrimp group was similar to that of control group, but the female fish in the adult brine shrimp group had significantly higher body weight than the female fish in control group at 75-82 dpf (P<0.000 1). Compared to control group, there was a significant difference in body color between males and females in the adult brine shrimp group, and at 75 dpf, gender could be accurately distinguished by body color differences. Furthermore, the spawning rate of the zebrafish in the adult brine shrimp group at 3 months of age was significantly higher than that of control group (94.44% vs. 27.78%, P<0.05). Additionally, after feeding with the dry commercial diets for 130 days, all thyroid enlargement lesions in the experimental zebrafish disappeared. Based on the above results, the three feeding methods were combined and the feeding plan for zebrafish older than 2 months of age was optimized as follows: feed live brine shrimp in the morning, and alternate between dry commercial diets and adult brine shrimp in the afternoon. This feeding plan lasts until the age of 12 months. The spawning rate of Zebrafish can maintan 70%, and the spawning amount can reach (233.6±3.95) eggs. The fertilization rate and hatching rate were 97.47% and 90.24%, respectively, both significantly higher than those of control group (P<0.001, or P=0.01).Conclusion Compared to live brine shrimp feed, the dry commercial diets feed significantly improves the growth performance of zebrafish and has a therapeutic effect on thyroid enlargement disease. On the other hand, adult brine shrimp feed significantly enhances the early reproductive performance of zebrafish. The optimized feeding plan successfully improves the spawning efficiency of laboratory zebrafish, prolonging their reproductive lifespan and better supporting relevant scientific research.

Keywords

• zebrafish
• breeding scheme
• reproduction
• growth