Induced spawning and embryonic development of striped murrel Channa striata (Bloch, 1793) under indoor conditions using salmon gonadotropin releasing hormone analogue (sGnRHa)

Abstract

Ten successful trials on induced breeding of the striped murrel Channa striata (Bloch, 1793) under indoor conditions were carried out during July-August 2019. Brooders reared in cement tanks,(males weighing  in the range of 290-700 g and females 220-600 g), were used in a set of 2:2 male to female ratio for induced breeding with salmon gonadotropin releasing hormone anologue (sGnRHa) and dopamine antagonist commercial formulation. Each brooder set was kept in an FRP tank (13’x3’x14’’) along with submerged macrophyte Hydrilla verticillata, which was sparsely spread all around the tank. Maturity of brooders was screened on the basis of secondary sexual traits. The brooders were given hormonal injection after 6 h of acclimatisation under indoor conditions @ 1 ml kg^-1 body weight (containing sGnRHa 20 µg ml^-1 and domperidone 10 µg ml^-1) to both the sexes. Natural spawning occurred in all ten sets within 21.5+3.2 h (17-26 h) of injection. In all the tanks, two separate egg masses were observed with 30-95% fertilisation. Approximately 0.14 million eggs were scooped out from the tanks and reared in round plastic tanks (70 l) for hatching, where hatching occurred within 17-26 h post-fertilisation (hpf) with hatching rates of 50.76 to 93.18% at 28+2^oC. The embryonic development was recorded under a stereo-zoom microscope in live condition under controlled temperature conditions and described with digital images. The study revealed that induced breeding of C. striata can be undertaken in FRP tanks under indoor conditions for mass-scale seed production, which will provide a platform for diversification of this high valued fish species for large scale farming practices in ponds as well a new species for culture in recirculatory aquaculture system (RAS) and biofloc technology (BFT).

Keywords: Channa striata, Embryonic development, sGnRH, Striped murrel, Induced breeding