ẢNH HƯỞNG CỦA LHRHa VÀ NHIỆT ĐỘ NƯỚC ĐẾN SINH SẢN CỦA CÁ TỲ BÀ BƯỚM HỔ (Sewellia lineolata)

Abstract

The aim of the study is to contribute in building the artificial breeding process of Tiger hillstream loaches. This study consisted of two experiments. In the experiment 1, fish were injected LHRHa (Luteinizing Hormone-Releasing Hormone analog) with doses of 50 µg, 100 µg, 150 µg and 200 µg combined with 10mg Domperidone/kg of body weight of fish as four treatments NT1.1, NT1.2, NT1.3, NT1.4 respectively and a control treamment (ĐC1) in which fish were not injected. In the experiment 2, the water heat increasing method was used to stimulate spawning of fish, with three treatments as ĐC2 (water temperature was kept at 23ºC), NT2.1 (water temperature was increased from 23ºC to 26ºC) and NT2.2 (water temperature was increased from 23ºC to 29ºC). The results of the experiment 1 showed that there was no spawning of fish in ĐC1. The effective time of hormone in NT1.4 (6.44 hours) was shortest and significantly different from others (p < 0.05) but there was no difference of this between NT1.1 and NT1.2 (p > 0.05). The spawning rate of fish (45,56%) was highest in NT1.3 and NT1.4 and significantly differed from NT1.1 and NT1.2 (p < 0.05). There was no difference of the fertilization rate and hatching rate of eggs between treatments (p > 0,05). The results of the experiment 2 showed that there was no spawning of fish in ĐC2 while fish in NT2.1 and N2.2 spawned with the spawning rate of 40.00 ± 6.67% and 43.3 ± 8.82% respectively. The effective time of hormone, spawning rate of fish, fertilization rate and hatching rate of eggs were not different between NT2.1 and N2.2 (p > 0,05).