重庆山区4种鲟仔、稚、幼鱼生长特性对比研究

Comparison of Growth Characteristics of Postlarvae and Juveniles among Four Species or Hybrids of Sturgeon in Mountainous Area of Chongqing

为有效筛选出适宜重庆山区养殖的鲟鱼品种,将卵黄囊消失的施氏鲟、西杂鲟(西伯利亚鲟♀×施氏鲟♂)、施杂鲟(施氏鲟♀×西伯利亚鲟♂)、大杂交鲟(达氏鳇♀×施氏鲟♂)仔鱼饲养在直径2 m、高0.6 m的蓝色圆形玻璃钢盆中,每盆3000尾,开始时投喂打碎的水蚯蚓,7 d后(全长约3 cm),用微粒饲料与水蚯蚓浆制成软颗粒饲料,阴干后投喂,经15~20 d转食后,投喂鲟鱼专用微粒饲料,养殖84 d后比较分析4种鲟鱼胚后发育时间,形态特征,及仔、稚、幼鱼成活率、生长特性等。试验结果显示:在水温(17.94±0.54)℃、溶解氧质量浓度(8.91±0.32)mg/L、pH(8.09±0.43)的条件下,大杂交鲟、西杂鲟胚后发育时间早于施杂鲟和施氏鲟;4种鲟幼鱼外部形态特征均有区别;西杂鲟成活率最高,为(65.33±2.12)%,显著高于施氏鲟、施杂鲟和大杂交鲟;7日龄后,4种鲟鱼特定生长率随着日龄增加而降低;从生长模型可知,西杂鲟全长生长速度最快,从(0.81±0.34)cm增长至(16.67±1.37)cm,大杂交鲟体质量生长速度较快,西杂鲟次之,但77日龄后西杂鲟体质量生长速度超过大杂交鲟。试验结果表明,西杂鲟在重庆山区山泉水养殖条件下具有明显的生长优势。

In order to effectively screen out suitable sturgeon varieties for breeding in mountainous areas of Chongqing,4 four species or hybrids of postlarvae and juveniles sturgeons including Amur sturgeon Acipenser schrenckii,hybrid sturgeon(A.baerii♀×A.schrenckii♂),hybrid sturgeon(A.schrenckii♀×A.baerii♂)and hybrid sturgeon(Huso dauricus♀×A.schrenckii♂)were raised in a blue circular fiberglass basin with a diameter of 2 m and height of 0.6 m,at stocking density of 3000 fish in each basin for 84 d to compare and analyze their embryonic development time,morphological characteristics,survival rates and growth characteristics.At the beginning,the postlarvae were fed crushed water earthworms,and after 7 d(about 3 cm in total length),soft particle feed made from particle feed and water earthworm slurry and dried in the shade,and after 15 to 20 days of feeding conversion,the juveniles were fed special particle feed for sturgeons for 84 days.The results showed that the post-embryonic development time of Amur sturgeon and the hybrid sturgeon(A.baerii♀×A.schrenckii♂)was earlier than that of hybrid sturgeon(A.schrenckii♀×A.baerii♂)and hybrid sturgeon(H.dauricus♀×A.schrenckii♂)under the test conditions of water temperature(17.94±0.54)℃,dissolved oxygen concentration of(8.91±0.32)mg/L,and pH of 8.09±0.43,with different external morphological characteristics of juvenile sturgeon in four species or hybrids.There was the maximal survival rate in hybrid sturgeon(A.baerii♀×A.schrenckii♂)(65.33±2.12)%,significantly higher than that in hybrid sturgeon(A.schrenckii♀×A.baerii♂),Amur sturgeon and hybrid sturgeon(Huso dauricus♀×A.schrenckii♂).The specific growth rate of four sturgeon species or hybrids were shown to be decreased with increasing age after 7 days old,and the growth model showed that the hybrid sturgeon(A.baerii♀×A.schrenckii♂)had the maximal total length growth rate,from(0.81±0.34)cm to(16.67±1.37)cm,and the hybrid sturgeon(H.dauricus♀×A.schrenckii♂)had better body weight growth rate,followed by hybrid sturgeon(A.baerii♀×A.schrenckii♂),but after 77 days old the hybrid sturgeon(A.baerii♀×A.schrenckii♂)had weight growth rate over that of hybrid sturgeon(Huso dauricus♀×A.schrenckii♂).Through the test,it is first known that the hybrid sturgeon(A.baerii♀×A.schrenckii♂)has obvious growth advantage reared under the mountain spring water conditions in Chongqing.