Growth, survival and fillet composition of paddlefish, Polyodon spathula (Walbaum) fed commercial trout or catfish feeds

Paddlefish are gaining increasing acceptance as an aquaculture species worldwide. Commercial trout feeds, containing high protein and lipid levels, are currently used in intensive culture; however, nutritional requirements of paddlefish are not currently known. A study was conducted examining the effects on growth, survival and fillet composition of juvenile paddlefish when fed commercial feeds differing in protein and lipid levels. Paddlefish larvae were first stocked in 14.0 m³ round tanks and fed trout starter feeds for 43 days until trained to accept a 1.6 mm pellet. Paddlefish juveniles of mean weight (±SE) 20±0.27 g were randomly stocked into six0.02 ha ponds at 12 500 ha^?1 and fed floating commercial trout or catfish (lower protein and lipid) feeds, twice daily (08:00 and 15:30 hours) for 92–97 days. At harvest, there were no significant differences in final weight, percent survival, specific growth rate , relative growth and feed conversion ratio between treatments, which averaged 223.6 g, 96.2%, 2.5% day^?1, 10.2 and 1.98 respectively. Surface feeding activity index was significantly higher in ponds supplied with catfish feed than in ponds supplied with trout feeds. Relative pellet buoyancy was not a factor in feeding activity. Fulton's condition factor averaged0.238, was not significantly different, and was similar to a reported value for extensively cultured paddlefish (zooplanktivore). There was no significant difference in liver somatic index between treatments, which averaged 1.91%. Percent protein and moisture of fillets averaged 14.9% and 80.9%, respectively, and were not significantly different between treatments. However, lipid content of fillets was significantly higher in paddlefish fed the trout feed (4.45%), compared with paddlefish fed the catfish feed (2.42%). Fillet lipid content for both treatments was higher than reported values for extensively cultured paddlefish. Percent abdominal fat was significantly higher (0.82%) in paddlefish fed the trout feed compared with paddlefish fed the catfish feed (0.52%). Results from this study indicate that paddlefish can be fed a commercial catfish feed labeled to contain 32% protein and 4.5% lipid without adverse effects on growth, survival and fillet composition, lowering production costs.     

主要养殖鲟鱼的生物学及养殖前景

鲟鱼是世界上最古老的鱼类之一,现存鲟鱼种数有２５～２６种。由于多年的酷渔滥捕和生态环境恶化,鲟鱼资源日益衰退。１９９０年世界鲟鱼产量为２万ｙ,１９９３年下降到１万ｔ。本文作者综述了鲟鱼类的起源、地理分布、生态习性和生物学特性,分析和讨论了开展鲟鱼养殖应注意的问题及鲟鱼的养殖前景。     

鱼类耗氧率测试装置的设计

本文论述了鱼类耗氧率测试装置的结构设计,讨论了平均体质量（156±3.36）g匙吻鲟（Polyodon spathula）幼鱼耗氧率与窒息点的测试方法。在结构设计中,尺寸参数的选择确保了鱼类耗氧率、窒息点测试过程中流入呼吸室的水流均匀,水样采样准确;方便了测试过程中对鱼类行为生物学的观察,呼吸室中没有空气气泡干涉,提高了测试数据的准确性。实测结果表明,匙吻鲟幼鱼耗氧率的最高值为（0.528±0.035）mg.g-1.h-1,最低值为（0.197±0.028）mg.g-1.h-1,窒息点为3.468 mg.L-1。     

匙吻鲟的生物学特性、成鱼养殖技术及消化系统的解剖

匙吻鲟原产北美,吻长,呈扁平状;体表光滑无鳞,背部黑蓝灰色,常有斑点分布;体侧有赭色点状斑,腹部白色;口大眼小,前额高于口部;鳃耙密而细长,鳃盖骨大而向后延至腹鳍,尾鳍分叉,尾柄披有梗节状的甲鳞。匙吻鲟幼鱼具有很高的观赏价值,成鱼可制作出鱼子酱,具有很高的经济价值。本文通过对匙吻鲟的生物学、成鱼的养殖及消化系统的研究,使能够更好的了解匙吻鲟的生长、生活及摄食条件,以便使更多的人了解匙吻鲟的市场价值与潜力,便于进行大规模的推广。     

鲟形目鱼类和渔业

本文论述了国内外鲟形目鱼类和渔业.包括三部分:1.鲟形目的种类和分布:2.鲟形目的生物学特征;3.世界上鲟鱼和白鲟渔业,并着重讨论该鱼类资源在我国的开发和利用.     

放养在胜利水库中的匙吻鲟的生长

在黑龙江省青冈县胜利水库放牧式养殖了匙吻鲟（Polyodon spathula）,同时调查了水库的水质及浮游动物的种类组成和生物量,并随机设置挂网,不定期调查捕获匙吻鲟的生长状况。结果发现：该水库水质符合渔业水质标准（GB11607—89）,浮游生物的生物量较高。放养的匙吻鲟生长良好,当年可超过越冬规格;日平均增重3．31％,体长增长1．17％,结果表明：匙吻鲟适于在北方湖泊、水库等具备越冬条件的水体进行放牧式养殖。     

匙吻鲟肌肉与软骨营养成分分析

分析了匙吻鲟肌肉和软骨常规营养成分(蛋白质、脂肪、水分、灰分、钙和磷)的含量,对蛋白质的17种氨基酸和主要微量元素进行测定。结果表明:匙吻鲟肌肉组织中水分含量为76.50%,粗蛋白含量为15.40%,脂肪含量为5.50%,灰分为1.01%,氨基酸含量最高为谷氨酸,含量最低的为色氨酸;软骨中钠、钾和钙含量比较高,氨基酸含量前3位的是甘氨酸、谷氨酸和亮氨酸,排在最后的是色氨酸和胱氨酸。     

匙吻鲟引进中国20年概述

对我国引进匙吻鲟(Polyodon spathula)20年来,从匙吻鲟的起源、引种、生物学特性、人工繁殖、苗种培育、成鱼养殖、市场需求7个方面作了简要地叙述。     

越冬对匙吻鲟体型的影响研究

选择300尾健康匙吻鲟(均重479.21±42.36 g)进行90天的不投饵越冬试验,在越冬前后分别测定其体重、体长、全长、体高、体厚、吻长、吻宽,分析各体型指标在越冬前后的变化。结果显示：匙吻鲟在越冬后体重、体厚和肥满度显著降低(P＜0.05),其中体重比越冬前降低了9.7%,体长与体厚的比值显著提高(P＜0.05),而其体长、全长、体高、吻长和吻宽在越冬前后没有显著差异(P＞0.05);越冬前三维图集中度较越冬后高,且出现明显迁移,体重的标准化使得越冬前后3个指标的三维图更加分散,但没有发生明显迁移。这些结果说明,匙吻鲟在越冬期间消耗自身的贮能物质为鱼体提供能量,导致越冬后体重显著低于越冬前,匙吻鲟越冬后体厚显著降低、体长与体厚比值显著提高、肥满度显著下降。 三维图分析和多元逐步回归方程分析表明匙吻鲟体型变化主要是由越冬后体重下降引起的。     

匙吻鲟含肉率及肌肉营养成分分析

测定了10尾匙吻鲟(Polyodon spathula)含肉率、肌肉营养成分及其氨基酸含量,并对其营养价值进行了评价。结果显示:匙吻鲟含肉率达62.72%;鱼鲜肉中蛋白质含量为15.55%,脂肪为11.06%,灰分为1.28%,水分为72.08%,无氮浸出物为0.43%;17种氨基酸总含量为15.04%(鲜样),8种人体必需氨基酸总含量为5.37%。