两种罗非鱼主要生物学性状及杂交F_1代生长性能的研究

测量了荷那龙罗非鱼(O.hornorum)和橙色莫桑比克罗非鱼(O.mossambicus)的主要生物学性状。结果得出:①2种罗非鱼通过外形能够清楚区分,荷那龙罗非鱼体色暗黑,有纵纹,体型呈纺锤型;莫桑比克罗非鱼体色橙色,无纵纹,体型呈长梭型。②2种罗非鱼最小性成熟年龄均为6个月,最小体长荷那龙罗非鱼为8·64cm,莫桑比克罗非鱼为6·60cm,绝对繁殖力前者为810粒,后者为702。③水温16~32℃时,荷那龙罗非鱼(体重10·40~116·28g)耗氧率在0·07~0·61mg/(g·h)之间,橙色莫桑比克罗非鱼(体重18·98~102·53g)耗氧率范围是0·06~0·43mg/(g·h)。水温24℃时,前者溶氧临界窒息点是0·33~0·55mg/L,后者是0·24~0·31mg/L。④两罗非鱼均属于耐盐性较强的鱼类,荷那龙罗非鱼的MLS-96(96h半致死盐度)为21·56,莫桑比克罗非鱼为22·29。⑤荷那龙罗非鱼的低温致死范围是9·5~15·1℃,莫桑比克罗非鱼的低温致死范围为8·0~9·9℃。前者对低温的耐受较差。⑥两罗非鱼的杂交F1代,雄性率高,养殖性能较好,具有推广价值。

Studies on the Principal Biological Characteristics of Oreochromis hornorum,Oreochromis mossambicus and the Growth Performance of Hybrid F1

The principal biology characteristics of O.hornorum and O.mossambicus were studied. The results showed that: ①two species could be distinguished clearly, the O.hornorum was dark with longitudinal striation, body shape was spindle. And O.mossambicus was orange without longitudinal striation, body shape was dolicho-shuttle. ②the minimal maturity age of them were both six months, their minimal maturity body-length were 8.64 cm and 6.60 cm, respectively, absolute fecundity were 810 for the former and 702 for the latter. ③when the water temperature ranged between 16 ℃ and 32 ℃, the oxygen consumption rates of O.hornorum (weight 10.40～116.28 g) were 0.07～0.61 mg/(g·h), while that of O.mossambicus (weight 18.98～102.53 g) were 0.06～0.43 mg/(g·h). The asphyxiation points were 0.33～0.55 mg/L for the former, 0.31～0.45 mg/L for the latter at 24 ℃. ④The MLS-96 (median lethal salinity-96 hours) values were 21.56 for O.hornorum and 22.29 for O.mossambicus. They all could withstand high salinity. ⑤The lethal temperatures were 5.1～9.51 ℃ for O.hornorum and 9.9～8.0 ℃ for O.mossambicus. Tolerance to lowest temperatures of the former was not good. ⑥Their hybrid F1 was worthy of being spread with high percentage of male offspring and better growth performance.