Artificial Reproduction of Zebrafish Dania rerio under Controlled Laboratory Condition

Abstract

The objective of this study was to describe a standard universally accepted artificial culture protocol for zebrafish. Also, developmental stages of embryogenesis were also described. Because Zebrafish are considered as a model organism and are widely used in biomedical research to study human genes and human diseases. Despite this, the artificial reproduction of zebrafish is poorly described, and there is not any standard universally accepted artificial culture protocol. To satisfy the scientist working in the biomedical area, a standard culture method of zebrafish under controlled laboratory conditions must be developed. The present study was conducted at the Aquaria Research unit of Marine Sciences and Technology Faculty of Iskenderun Technical University, Iskenderun Turkey, from March 2018 to October 2018. Spawn traps and gravels are not used for spawning of broodstock. Female and male broodstock were selected from our previously cultured stock, based on their swollen abdomens. Mean body lengths for female and male were 3.34±0.40, 2.97±0.3 cm and the mean weights were 0.38±0.14, 0.25±0.27 g, respectively. First eggs were squeezed from the ovaries then milt was taken from the testes onto the eggs. Fertilisation was done artificially by the dry method. The eggs hatch within 4-5 days at 28±1°C. The mean diameter of eggs and fecundity were measured using a micrometre attached to a microscope. During the experimental studies, the water quality parameters were also maintained at optimum. In the present study, temperature and pH were maintained at 28±1°C, and 7.28 respectively and which were the best for reproduction of zebrafish. Fecundity differed widely between individuals, and the number of eggs ranged from 7 to 110. The average diameter of the eggs ranged from 405± 0,001 to 570 ± 0,001 µm. Mainly seven developmental stages of embryogenesis were described; the zygote, cleavage, blastula, gastrula, segmentation, pharyngula and hatching stages. The results of the present study suggest that with the right artificial culture conditions and proper manual stripping, the required number of eggs and embryos for biomedical research can be easily obtained.