The effect of water temperature on growth parameters of intensively reared juvenile peled Coregonus peled

The effect of water temperature on growth and food intake of juvenile peled Coregonus peled was tested with specimens of initial age 75 days and 230 days posthatching (dph). The 75‐day group (initial body weight 0.6 ± 0.04 g) were reared for 63 days and 230‐day group (initial body weight 13.75 ± 2.93 g) for 42 days at temperatures of 13, 16, 19, 22 and 25°C under 12:12 L:D photoperiod. The optimal temperature range for the 75 dph fish was found to be 19–22°C. The fish reached final mean weight of 9.7 ± 2.5 g at 19°C and 9.0 ± 2.7 g at 22°C. Final mean weight of 230 dph fish did not differ significantly among temperature groups. Mortality increased at higher temperatures, with the critical temperature of 25°C for both age groups. Maximum food intake (19.0 ± 4.7, 18.8 ± 5.2, 18.6 ± 4.6 g kg^?1biomass) was observed in groups reared at temperatures of 19, 22 and 25°C with no significant differences among groups.     

The effect of water oxygen saturation on growth and haematological profile of juvenile peled Coregonus peled (Gmelin)

The effect of varying oxygen saturation regimes on growth and haematological profiles of peled Coregonus peled was investigated on fish of initial age 90 days post hatching. Eighty‐five juveniles per group (initial body weight 3.09 ± 0.80 g) were submitted to a 63‐day experiment with one of four water saturation regimes: normoxia (NORm, 80%–90%), hypoxia (HYPo, 50%–60%), hyperoxia (HYPe, 150%–160%) and intermittent hyperoxia (iHYPe, 150%–160% ‐ 80%–90%). Survival rate in NORm, HYPe and iHYPe ranged from 96.3 ± 2.1% to 97.7 ± 2.7, but survival 87.5 ± 3.0 was significantly lower in the HYPo group. No differences were observed in feed conversion ratio. The highest final body weight of 18.2 ± 4.6 g and a specific growth rate of 2.81 ± 0.01%/day were seen in the NORm group. Significant differences were found in haemoglobin concentration with increased saturation. The fish had lower haemoglobin 55.00 ± 5.72 and 51.35 ± 10.89 g/L in treatments HYPe, iHYPe with compared to the normoxia (64.22 ± 5.78 g/L). Haematocrit was similar in the groups HYPo, NORm and iHYPe (0.55 ± 0.04, 0.58 ± 0.05 and 0.54 ± 0.09) with the exception of HYPe, which was significantly lower (0.48 ± 0.06). Significantly lower count of erythrocyte was observed in iHYPe group (0.88 ± 0.20) with compared to the normoxia (1.06 ± 0.13). The supersaturation level was not associated with effects on growth and survival, and adding oxygen is not recommended for intensive rearing of peled. The results showed normoxia oxygen level to be the most suitable conditions for peled.     

高白鲑的生物学特性及增养殖技术

高白鲑 (ＣｏｒｅｇｏｎｕｓＰｅｌｅｄ)属于鲑科白鲑属鱼类。白鲑属系冷水性鱼类 ,世界上约有30余种 ,广泛分布在北纬 5 0°以北的广大淡水水域 ,是欧洲、北美、亚洲北部的经济鱼类 ,也是重要的增殖、养殖对象 ,其中高白鲑、普通白鲑 (Ｃ .ｌｖａｒｅｔｕｓ)、楚德白鲑 (Ｃ .ｍａｒａｅｕｓ)更受人们亲睐 ,现已移植到美国、法国、波兰、日本等许多国家 ,在人工繁殖及养殖上已取得了显著的成果。 1 998年被移植到新疆赛里木湖。1　白鲑属和高白鲑的生物学特征1 1　白鲑属鱼类的特征鳞片较大 ,具脂鳍 ,一般不具颌骨齿 (如有 ,那么在舌和间颌…     

青海地区高白鲑鱼苗培育试验

高白鲑(Coregonus Peled)为冷水性鱼类,属鲑科(Salmonldae)白鲑属(Coregonus)鱼类,是前苏联的特有品种.     

高白鲑仔鱼规模化培育技术

介绍了在青海省黑泉水库利用库底水进行高白鲑鱼苗规模化培育的情况。在平均水温6.8℃、溶氧7.1 mg/L、水流量8 L/m in的条件下,用卤虫无节幼体作开口饵料,经过45d,培育规格为7~9 mm的480万尾初孵高白鲑仔鱼,平均规格15~18 mm稚鱼450万尾,培育成活率达到94%以上。该培育试验对高白鲑的引种移植和扩大示范推广具有借鉴意义。     

赛里木湖高白鲑的人工繁殖

自1998年春以来,新疆连续3年从俄罗斯引进了高白鲑(Coregonus peled)发眼卵700万粒,孵化后,向新疆高山湖赛里木湖移植3 00余万尾高白鲑稚鱼.通过2年的跟踪观测,高白鲑在赛里木湖生长迅速,性腺发育良好.尤其是1998年春移植的鱼苗至2000年底,捕获的雌性个体平均体重达1390g,体长37.4cm;雄性个体平均体重891g,体长34.4cm.其生长速度比原产地要快得多,并且性腺也提早1～2年达到性成熟.2000年12月至2001年1月,我们在赛里木湖现场捕捞高白鲑进行人工繁殖试验,获得了一些数据和实践经验.     

赛里木湖高白鲑性腺发育观测

高白鲑 (Ｃｏｒｅｇｏｕｎｓｐｅｌｅｄ)属鲑科冷水性鱼类 ,其主要分布在北纬 5 0度以上的河流、湖泊中 ,尤以俄罗斯西伯利亚地区的鄂毕河流域为多。由于该鱼适应性强 ,肉味美 ,易捕捞 ,长势快 ,又是典型的食浮游动物的鱼类 ,早在上世纪 30年代前苏联已将高白鲑作为重要的增养殖开发对象 ,在其境内冷水水域广泛移植和推广。我国黑龙江省于 1985年从日本国引进过高白鲑 ,并在池塘进行过养殖和人工繁殖试验。然而对高白鲑在大型水域引种移植和在天然水域中直接进行人工繁殖在我国尚未进行。 1998年以来新疆连续 3年从俄罗斯引种高白鲑发眼卵 7…     

赛里木湖高白鲑的人工繁殖

自 1998年春以来 ,新疆连续 3年从俄罗斯引进了高白鲑 (Ｃｏｒｅｇｏｎｕｓｐｅｌｅｄ)发眼卵 70 0万粒 ,孵化后 ,向新疆高山湖赛里木湖移植 30 0余万尾高白鲑稚鱼。通过 2年的跟踪观测 ,高白鲑在赛里木湖生长迅速 ,性腺发育良好。尤其是 1998年春移植的鱼苗至 2 0 0 0年底 ,捕获的雌性个体平均体重达 1390ｇ ,体长 37 4ｃｍ ;雄性个体平均体重891ｇ ,体长 34 4ｃｍ。其生长速度比原产地要快得多 ,并且性腺也提早 1～ 2年达到性成熟。 2 0 0 0年12月至 2 0 0 1年 1月 ,我们在赛里木湖现场捕捞高白鲑进行人工繁殖试验 ,获得了一些数据和实践…     

高白鲑稚鱼人工培育比较试验

对高白鲑稚鱼投喂卤虫初孵无节幼体、鸡蛋黄、去壳卤虫卵和配合铒料等4种不同铒料，结果表明摄食卤虫无节幼体的稚鱼生长速度较快，体长、体重生长比分别是2.24和4.63；其次是鸡蛋黄、配合铒料和去壳卤虫卵。以稚鱼在不同投喂频率下的生长速度进行了比较，稚鱼生长速度表现出随每天的投喂次数的增加而加快的趋势。     

Combined effect of weaning time and co‐feeding duration on growth and survival of peled Coregonus peled (Gmelin) larvae

The study investigated the combined effect of weaning from live feed to a commercial dry pellet at 10, 15, 20, 25 or 30 days posthatching (dph) and co‐feeding for 1, 3 or 6 days on survival and growth of Coregonus peled larvae. Additional groups fed only live Artemia sp. nauplii (ART), and only Biomar LARVIVA ProWean 100 (DRY) were included. A final survival rate of 66.4%–85.5% was observed in groups weaned after 20 dph. Final body weight (BW) and total length (TL) were significantly lower in groups weaned at 10 and 15 dph, regardless of the duration of co‐feeding. Larvae reached 29–37 mg BW and TL of 17.7–19.0 mm in groups weaned at 20, 25 and 30 dph. The recommended minimum duration of feeding with live food, based on these results, is 20 days. Based on the significantly higher yield of larvae weaned after 20 dph irrespective of co‐feeding duration, it can be concluded that abrupt weaning to dry food after 20 days of feeding with live prey can provide adequate production while reducing the effort and costs associated with live feed.     

赛里木湖高白鲑性腺发育观测

高白鲑(Coregouns peled)属鲑科冷水性鱼类,其主要分布在北纬50度以上的河流、湖泊中,尤以俄罗斯西伯利亚地区的鄂毕河流域为多.由于该鱼适应性强,肉味美,易捕捞,长势快,又是典型的食浮游动物的鱼类,早在上世纪30年代前苏联已将高白鲑作为重要的增养殖开发对象,在其境内冷水水域广泛移植和推广.我国黑龙江省于1985年从日本国引进过高白鲑,并在池塘进行过养殖和人工繁殖试验.然而对高白鲑在大型水域引种移植和在天然水域中直接进行人工繁殖在我国尚未进行.1998年以来新疆连续3年从俄罗斯引种高白鲑发眼卵700万粒,经孵化向赛里木湖移植高白鲑鱼苗300万余尾.1998～1999年通过跟踪观测,高白鲑在赛里木湖生长发育良好.为使高白鲑苗种本地化,2000年我们对赛里木湖高白鲑的性腺发育规律进行了观测,以掌握其在赛里木湖水域中性腺成熟度的变化规律,为高白鲑的人工繁殖做好准备,同时作者还对高白鲑在赛里木湖的食性变化进行了观测.     

高白鲑在赛里木湖的生长发育观测

赛里木湖是新疆最大的一个高山封闭湖泊,总面积453ｋｍ2,海拔2072ｍ,最大水深91ｍ;年平均气温05℃,水温在5℃以上有7个月,10℃以上有4个月,最高水温为19℃,湖区封冻期为12月至第二年5月初。水体透明度8～13ｍ,平均ｐＨ为90,溶解氧79～82ｍｇ/Ｌ,离子总量平均为2967ｍｇ/Ｌ,为ＳｍｇⅡ型水。六十年代以前该湖无任何鱼类,六十年代以后先后移植了高体雅罗鱼、贝加尔雅罗鱼、东方欧鳊、湖拟鲤等鱼类,因水温终年较低,抑制了上述鱼类性腺发育,致繁殖能力低弱,至今无商业生产。为了充分利用这一冷水资源,1998年开始进行移植冷水性高白鲑的尝试。高…     

赛里木湖高白鲑繁殖生物学特性研究

1999～2003年对赛里木湖高白鲑(Coregonus peled)繁殖生物学特性进行了研究，结果表明：雄性个体多在1^ 龄达到性成熟，为96．1％；雌性个体1^ 龄达到性成熟的为18．2％，其余多在2^ 龄达到性成熟。其繁殖期为12月下旬到第二年1月份，雄性从9月到第二年1月都有流精个体；雌性绝对怀卵量平均为133360粒，相对怀卵量平均为82粒/g，繁殖期平均卵径为1．70mm。其体长与繁殖力关系方程为：F=0．01401L^4.3948(r=0．857)。体重与繁殖力关系方程为：F=130．121W-64196(r=0．898)。本还系统地描述各期精巢和卵巢的形态结构、特征及周年变化。     

柴窝堡湖高白鲑生长与移殖效应分析

2004年6月-2007年5月,采集柴窝堡湖高白鲑标本79尾,对其年龄与生长状况及高白鲑在柴窝堡湖移殖效应进行了分析。研究表明：柴窝堡湖高白鲑1龄平均逆算体长L1=11.7cm、2龄平均逆算体长L2=26.1cm;体长与体重的回归方程为W=0．013474L^309069;高白鲑在柴窝堡湖生长正常,能够形成捕捞群体,但由于柴窝堡湖现有的渔业捕捞方式,影响了高白鲑在柴窝堡湖渔业移殖效应。     

赛里木湖高白鲑引种移植效应评价

1998年以来,新疆从俄罗斯引进高白鲑发眼卵1.72×107粒,经孵化后向赛里木湖移植,投放数量共7.575×106尾。经观测,高白鲑在赛里木湖发育良好,生长迅速,现已具有了一定的种群数量。就赛里木湖引种移植高白鲑的效应、前景和存在问题进行评价和探讨。     

高白鲑发眼卵孵化技术探讨

报道了在黑泉水库利用水库库底水进行高白鲑发眼卵大规模孵化情况。孵化水温3~8℃,积温达到364.5~469.1℃.d时破膜孵出稚鱼,孵化率为96%。全过程的观察发现,昼夜水温稳定是提高孵化率的主要因素,在破膜前期保持4℃左右低水温对提高孵化率和保证仔鱼质量起关键作用,在积温达到临界值时适当升温会促使发眼卵集中破膜。     

食盐对高白鲑鱼苗气泡病的治疗效果观察

应用袋装食盐,对感染气泡病的152尾高白鲑鱼苗进行治疗效果试验,并设阳性对照组。食盐治疗组鱼苗在用药后5~8 h鱼头向下、尾向上,水面上打转症状明显减轻,用药后8 d,未查到有气泡病的鱼苗。试验表明,按照500 g/m3的食盐剂量对感染气泡病的鱼苗病样一次给药浸浴即可治愈;对严重感染者间隔2 d再次给药,连用2个疗程具有良好的治疗高白鲑鱼苗气泡病的效果。     

南门峡水库高白鲑移植及生物学观测

2003年6月在南门峡水库投放1.5 cm、0.011 g高白鲑鱼苗1.0万尾,2004年5月再次投放2.0cm、0.02 g的鱼苗8万尾。不投人工饲料。经18个月的生长,平均体长32.4 cm,平均体质量532.6 g,并达到性成熟。高白鲑在青海高原海拔2 769 m的南门峡水库首次移植试验成功。     

Skeletal development and deformities in cultured larval and juvenile seven-band grouper, Epinephelus septemfasciatus (Thunberg)

The seven‐band grouper, Epinephelus septemfasciatus (Thunberg), is currently recognized as a potential new species for aquaculture in Japan. This study describes normal and abnormal skeletal development of the jaw and vertebrae in cultured larvae and early juveniles of E. septemfasciatus. The ontogenetic stages at which skeletal deformities of jaw and vertebra developed were also described for this species. Osteological observations were made using a clearing and staining method for larvae and soft X‐ray photographs for juveniles. A high incidence of skeletal deformities was observed in the jaws and vertebral column during the larval and juvenile stages. Most of the jaw deformities were explained by an abnormal maxilla curvature. Jaw deformities were visually evident from flexion stage after ossification of the deformed elements. Deformities in the vertebral column (mostly lordosis) were observed from the post‐larval stage and became more evident as growth proceeded. The lordosis generally occurred on the positions of the 8–11th vertebra. These types of deformities are compared with those of other species, and possible causative factors of the skeletal deformities are discussed.