蛇鳄龟稚龟摄食行为初探

为研究光照、饥饿、饵料规格和驯食等对蛇鳄龟(Chelydra serpentina)稚龟摄食行为的影响,用全长(1.80±0.25)cm的尼罗罗非鱼(Oreochromis niloticus)(A)、全长(0.96±0.07)cm的尼罗罗非鱼(B)、全长(0.96±0.12)cm的红罗非鱼hybirds tilapia(C)3种活体饵料对蛇鳄龟稚龟[(8.74±1.16)g]进行了饲喂试验。试验结果显示:主动搜寻捕食是蛇鳄龟稚龟的主要摄食方式;光照对其摄食量有极显著影响(P0.01);饥饿程度与捕食频率显著相关(P0.05),但对捕食成功率无统计学影响(P0.05);蛇鳄龟倾向于捕食大规格饵料,但过度饥饿会降低这种偏好的程度;从小驯食不同颜色的饵料(B和C)会影响稚龟对饵料颜色的选择。结果表明,视觉是稚龟捕食行为中的主要感觉系统,获取最大净收益是稚龟的捕食策略,驯食影响它对饵料颜色的选择则是典型的食物印记。饥饿状态会影响蛇鳄龟对饵料的选择性,过度饥饿使之更多地表现为随机捕食。     

鳄龟人工饲养

白须公(Mystus numerus)在分类上属鲶形目(Siluriformes),鱼尝 科,鱼尝 属。是一种亚广盐性鱼类,原产地为马来西亚、缅甸、印尼等东南亚地区。在马来西亚白须公分布于河口受潮汐影响的河段直至上游的缓流水域,也可常见于湖泊和水坝。白须公具有适应性强、易繁殖、生活习性广、抗病力强等特     

大棚水泥池循环水南美白对虾饲养试验

采用封闭式大棚水泥池循环水养殖模式进行南美白对虾高产饲养试验。2001年在如东实验点将9000m^2闲置养鳗池改造成循环水养殖系统，4月25日放苗，到8月9日开始起捕出售，平均每平方米产量达1．02kg。     

鳄龟人工养殖技术

鳄龟原产北美洲和中美洲,以其体壮多肉而闻名于世,故又叫肉龟,具有出肉率高、营养丰富、生长速度快、经济价值高等特点。其出肉率居龟类之首,达８５％～８９％,是一般龟的２倍,鳄龟年平均增重５５０～１１００克,是一般龟的数倍。一、生活习性鳄龟在３～４５℃水温...     

鳄龟的人工饲养技术

鳄龟(Chelydra serpentina),原产于北美,分类上属龟鳖目(Testudinata),曲颈龟亚目(Cryptodira)鳄龟科(Chelydridae),1997年开始引进我国,进入驯养和繁殖。鳄龟的饲养环境条件简单,对温度适应力强,抗病力强,生长速度快。由于鳄龟控温养殖年净增重可达1000-1500克,出肉率高达85％-90％,故又叫肉龟,是龟类中珍稀极品,具有肉质细腻、味道鲜美、营养价值高等特点,被众多的水产养殖者看好,养殖前景十分广阔。     

鳄龟人工养殖技术

鳄龟原产于北美洲和中美洲,又叫小鳄鱼龟,近年引入我国进行人工饲养获得成功,以其体壮多肉而闻名于世,故又叫肉龟,是龟类中的珍稀品,具有出肉率高、营养丰富、生长速度快、经济价值高等特点。其出肉率居龟类之首,达85%～89%。鳄龟年平均增重550～1100克,是一般龟的数倍,鳄龟肉细酥鲜美,且无异味,滋补作用十分明显,可通脉助阳、补阴血、益精气,久病后精血亏虚、疲劳乏力、久瘫痿弱、虚痨咳嗽均有显效,适合产后进补、贫血失眠和脑力衰退者食用。龟板有消肿作用,适合癌肿引起的阴虚、血虚体症。龟血、龟头也都有一定的药用价值。1生活习性鳄龟…     

鳄龟人工养殖技术

鳄龟原产北美洲和中美洲,因其体壮多肉故又叫肉龟,是龟类中的珍稀极品,具有出肉率高、营养丰富、生长快、经济价值高等特点,其出肉率居龟类之首,达８５％～８９％,是一般龟的２倍,鳄龟年平均增重５５０～１１００ｇ,是一般龟的数倍。１　生活习性鳄龟在３～４５℃水温中均能生活,２８～３１℃生长最快,１５℃以下冬眠,在－５℃冰层下不会被冻死,１℃以上可安全过冬,鳄龟喜栖安静环境,食性较杂,喜食水中小动物和水草,在岸上也吃死、活动物、鲜嫩草叶及花果类。人工饲养的饲料有小鱼虾、螺、蚌、昆虫、蚯蚓、蚕蛹、蝇蛆、黄粉…     

杂交条纹鲈苗种小水泥池培育技术试验

用地上露天小水泥池8个．进行杂交条纹鲈苗种培育试验．放养313龄水花30000尾．通过天然饵料、藻粉投喂以及适当水质管理措施．经32天培育，共培育3．5～4．6cm体长的鱼种4336尾．最高成活率为19．1％，最低为6％，平均为14．5％。     

鳄龟养殖生产操作规程（二）

四、亲本培育 1．龟池建设 稚龟经过半年多的养殖，到翌年4～5月份气温稳定在20℃以上时，可从温室内移到室外水泥池养殖。池大小40～60m^2／个为宜，由水池和陆地组成。水池由砖和水泥砌成，池底平滑，池壁平整、光滑，具一定的坡度，池中设有深水区、浅水区。池深50～80cm，水深30～50cm，根据龟个体大小而定，原则为龟小水浅、龟大水深。陆地占总面积20％～30％，供龟休息、活动及作饵料台，     

微卫星标记分析乌龟养殖群体的遗传多样性

利用8个微卫星标记对7个乌龟养殖群体进行了遗传多样性和遗传结构的检测。结果显示,7个养殖群体都表现出较高的多态性,8个位点共检测出130个等位基因,范围在9～26,平均16.25;其多态信息含量(PIC)范围为0.57～0.92,平均值为0.71;观测杂合度(HO)和期望杂合度(HE)分别为0.30～0.87和0.60～0.93。分子变异方差分析(AMOVA)结果表明,遗传变异5.91%来自群体间,84.29%来自群体内部,两两群体间FST值在0.0143～0.1127,其中57.14%的两两群体间无分化,42.86%的两两群体间出现了中等程度的分化。哈迪-温伯格平衡检测表明,8个位点中有5个位点显著或极显著的偏离了哈迪-温伯格平衡,推测各群体中出现了近交繁殖的现象。7群体间遗传距离为0.1066～0.6468,UPGMA聚类分析表明,湖北荆州群体单独聚为一支,其余6个群体聚为另一支。另外,7个群体都存在特有等位基因,提示群体间等位基因扩散受到一定程度的限制,同时在育种上,可以作为亲本选育的一个重要参考指标。     

墨瑞鳕大棚水泥池养殖技术试验

为调整上海郊区的水产养殖结构,开发水产新品种,提升养殖效益,2021年在上海市郊某合作社开展了墨瑞鳕(Maccullochella peelii)大棚水泥池养殖试验。试验采用2口大棚水泥池,投放经标粗培育的平均体质量为150 g/尾的墨瑞鳕大规格鱼种,放养密度为25尾/m²,全程投喂粗蛋白质质量分数43%的海水鱼膨化饲料。经过13个月养殖,共收获墨瑞鳕商品鱼9 576 kg(单位产量13.3 kg/m³,平均规格696.2 g/尾),饲料系数为1.58,单位产值为1 030元/m³。墨瑞鳕大棚水泥池养殖试验成功,对水产养殖结构调优具有一定的借鉴作用。     

Effect of three different oil cake-based diets on pond production performance of silver barb, Puntius gonionotus (Bleeker)

One of the three iso-nitrogenous (30% crude protein) and iso-energetic (15.0 MJ kg⁻¹ diet) oil cake-based diets (groundnut, D-1; soybean, D-2 and mustard, D-3) was fed to the fingerlings (6.61 ± 0.06 g) of silver barb ( Puntius gonionotus ) for 120 days in triplicate fertilized ponds (0.04 ha) with a stocking density of 9000 fish ha⁻¹. Fish were fed at 10% of their body weight for the first month, followed by 3% in the second and 2.5% in the third and fourth months of the culture period. The fish fed diets D-1, D-2 and D-3 grew from initial weights of 6.67, 6.67 and 6.50 g to 320.23, 298.23 and 305.13 g respectively. No significant variation ( P >0.05) was found in the growth and nutrient utilization of fish fed different dietary treatments. Net profits of Indian Rupees 67 385, 59 535 and 65 790 ha⁻¹ were obtained in fish fed D-1, D-2 and D-3, respectively, within 120 days of culture. The results of this study suggest the possibility of the use of mustard oil cake as a dietary protein source for pond culture of silver barb in addition to groundnut and soybean oil cakes without compromising the growth, nutrient utilization, production performance and economics of culture of this fish.     

Indicator taxa for the conservation of pond invertebrate diversity

• 1. Ponds are a valuable resource for the conservation of freshwater biodiversity, but are often extremely numerous in a given area, making assessment of the conservation value of individual sites potentially time consuming.
• 2. The use of indicator taxa, the species richness of which is representative of total site species richness, may provide one way to improve the efficiency of survey work. However, such indicators are poorly developed for freshwater systems.
• 3. A data set was used describing the occurrence of macroinvertebrate taxa in ponds in Oxfordshire, UK, to assess the extent to which variation in the species richness of selected taxa most consistently represented variation in all other taxa.
• 4. Coenagriidae (Odonata) and Limnephilidae (Trichoptera) reflected the variation in species richness of other taxa most consistently, with Coenagriidae showing the best overall performance as an indicator taxon.
• 5. For both suggested indicator taxa, selection of sites based solely on the presence of at least one species of indicator would represent over 95% of all species recorded across all sites.
• 6. Further investigation in different geographical regions is necessary to establish whether these relationships are consistent over a wider area.

Copyright © 2003 John Wiley & Sons, Ltd.     

Shrimp pond zooplankton dynamics and the efficiency of sampling effort

The abundance and species composition of zooplankton assemblages were examined in a commercial Penaeus monodon (Fabricius) aquaculture pond in subtropical Australia. Numbers and biomass of zooplankton in the surface tows (142 µm mesh) varied from 2080 L^?1 (2466 µg L^?1) to < 1 L^?1 (15 µg L^?1). Peak zooplankton abundance and biomass occurred at the beginning of the shrimp farm season. The small copepod Oithona australis Nishida was dominant during these peaks in abundance although other species were common, including small, low‐salinity copepods in the first year and larger marine copepods in the second year. Irrespective of taxa or size, zooplankton abundance declined rapidly after the stocking of P. monodon postlarvae, indicating high levels of non‐selective predation. For the remainder of the grow‐out season, mean zooplankton abundance was below 1 L^?1 in the first season and below 3 L^?1 in the second season. The factors that maintain the abundance of these zooplankton assemblages at these relatively low levels are poorly understood but may include a deterioration pond water quality. At these lower levels of abundance, the copepods Acartia pacifica Steuer and Acartia sinjiensis Mori were relatively common during the middle phase of the production season, with barnacle nauplii increasing in abundance during the later stages of the grow‐out season. Analysis of fixed effects showed that there were significant differences in total zooplankton abundance between farm production seasons and occasion within season, and time (day or night). Analysis of random effects demonstrated that the dominant source of variation, in total zooplankton abundance, was day‐to‐day changes within sampling occasions. The complexity of temporal and spatial patterns in the abundance, distribution and composition of zooplankton assemblages in shrimp ponds presents significant challenges in designing sampling programmes that accurately quantify temporal or spatial trends. Our results have shown that sampling for more than four consecutive days, at more than one site, is necessary to accurately assess such trends.     

有益微生物的应用对海水对虾养殖池塘中细菌数量动态变化的影响

2001年5~7月,在深圳东海岸水产公司南澳半封闭式斑节对虾Penaeus monodom精养基地,进行了有益微生物的应用对虾塘总异养细菌和弧菌数量影响的调查研究。结果表明,对虾养成过程中,施用有益微生物的实验组虾塘水体中总异养细菌和弧菌数量明显较未施用的对照组虾塘低,但各虾塘水体中总异养细菌和弧菌数量的变化特征基本相同,即在养殖前期,虾塘水体中总异养细菌和弧菌数量均较稳定,并处于相对较低的水平;而在养殖中、后期,总异养细菌和弧菌数量均急剧升高,尤以对照组虾塘的升幅最大,其弧菌数量甚至超过100×102CFU.mL-1的对虾发病之弧菌数量临界值。实验组与对照组虾塘中表层沉积物中,总异养细菌和弧菌数量差异不大,总异养细菌和弧菌数量变化特征也基本相同,但实验组与对照组之间有所差异,其中实验组表现为双峰型的变化特征,峰值出现在养殖前期或中期和养殖将结束时;对照组则呈单峰型变化,峰值均出现在养殖中期。有益微生物的应用对虾塘水体中总异养细菌和弧菌数量的抑制效果较对沉积环境中的效果明显。     

池塘精养南美白对虾高产高效规模化养殖试验报告

在沿黄低洼盐碱地鱼池进行了规模化精养南美白对虾高产高效试验，报道了离子调节、池水藻相控制、水质保护剂使用等全套技术。面积5010亩，总产1375t，平均体长13cm，成活率68．8％，亩均利润6510元，饲料系数1．5。投入产出比1：2．46。     

新疆主要渔区池塘水质环境现状及评价

对新疆主要渔区池塘水源水和养殖水的质量现状和污染特征进行了研究,测定了总大肠菌群、汞、镉、铅、铬、砷、铜、锌、氟化物、挥发性酚、甲基对硫磷、马拉硫磷、乐果、六六六(丙体)、滴滴涕(ο,ρ'-DDT、ρ,ρ'-DDT、ρ,ρ'-DDD、ρ,ρ'-DDE)15个项目。结果表明:两种水质的合格率较高,水源水为90%,养殖水为70%。水源水中主要污染物为总大肠菌群,养殖水中主要污染物为总大肠菌群和氟化物。在此基础上,采用综合污染指数对水质进行了评价。结果显示,新疆池塘水源水和养殖水均为尚清洁,综合污染指数分别为0.54和0.92。不同种类水源水综合污染指数从低到高依次为地下水<湖水<河水<水库水;不同区域养殖水综合污染指数从低到高依次为东疆<南疆<北疆。     

耕水机在罗非鱼精养池塘的应用效果分析

选择两组罗非鱼(Tilapia)精养池塘作为研究对象,通过设置实验塘和对照塘的方法,研究耕水机的使用对精养池塘水质变化情况和养殖效果的影响.结果表明:与对照池塘相比,实验池塘的水质稳定,池水化学耗氧量的平均值降低了1.56 mg/L,总悬浮物的平均含量下降了24.3028 mg/L,总氨氮的平均浓度下降了0.2418 ...     

土池循环水养鳗模式的初步研究

应用循环水处理技术建立鳗鲡土池健康养殖模式,主要通过对补给水源进行过滤消毒及对排出水进行无害化处理,调节鱼池中的藻类密度和有机物质含量,来达到调控水质、控制疾病、节约用水并实现无公害养殖的目的.循环系统启用30d以后,NH4 -N去除率稳定在50%以上,而NO2--N、高锰酸盐指数值的变化不明显.经过112d养殖,试验鱼平均规格达406.0g(2.5p),存塘重量达7847.17 kg,存塘密度达113.73 kg/hm2,增重倍数达5.1倍.试验结果表明:循环水养殖模式可有效控制池塘水质环境的变化,保持藻相稳定,有利水环境的稳定,促进鳗鱼生长,减少疾病发生.