不同单养及混养海水实验围隔水化学的研究

１９９５年６～１０月和１９９６年６～８月对不同单养和混养海水实验围隔的水化学研究结果表明：围隔中盐度、总氮、总磷和化学耗氧量（ＣＯＤ）在雨季前逐渐升高,进入雨季后降低;投饵养殖时围隔中磷浓度较低氮浓度较高,其中混养中国对虾和台湾红罗非鱼的围隔活性磷（ＰＯ４－Ｐ）浓度相对较高,混养对虾与菲律宾蛤仔的围隔氨氮（ＮＨ３－Ｎ）浓度较高,投铒兼酌情施肥养殖时围隔中氮浓度较低磷浓度较高,其中混养中国对虾与缢蛏     

不同单养的混养海水实验围隔浮游生物的研究

１９９５年６～１０月和１９９６年６～８月对中国对虾养及其与台湾红非鲫、菲律宾蛤仔、海湾扇贝或缢蛏的不同混养实验围隔浮游生物的研究结果表明,养管理措施和放养种类对围隔浮游生物种类和生物量都会产生一定影响,其中前者往往具主要作用。投饵养殖时围隔浮游植物以２０μｍ以下的种类为主,生物量较低,其中混养台湾红非鲫的围隔叶绿素ａ（Ｃｈｌ－ａ）相对较高,混养菲律宾蛤仔的围隔Ｃｈｌ－ａ较低;在投饵的基础上施肥后甲     

对虾池不同综合养殖系统效率和效益的比较研究

利用５０个５．０×５．０×１．８ｍ陆基围隔研究了中国对虾与台湾红罗非鱼、海湾扇贝和缢蛏投饵或施肥混养及鲈鱼与中国对虾和台湾红罗非鱼混养最佳结构的生态效率、生产效果和经济效益。结果表明,几种综合养殖系统最佳结构下各种养殖对象对Ｎ的绝对利用率由高至低依次为：鲈鱼－对虾－罗非鱼（３０．９１％）＞对虾－海湾扇贝（２１．０９％）＞对虾－罗非鱼施肥混养（２０．１２％）＞对虾－罗非鱼投饵混养（１７．８１％）＞对虾－缢蛏（１６．９３％）＞单养对虾（１１．５２％）;对Ｐ的绝对利用率由高至低依次为：对虾－缢蛏（１６．０８％）＞鲈鱼－对虾－罗非鱼（１２．８３％）＞对虾－罗非鱼投饵混养（１２．６３％）＞单养对虾（１０．８８％）＞对虾－海湾扇贝（６．０１％）＞对虾－罗非鱼施肥混养（４．０４％）;其产出投入比由高至低依次为：对虾－罗非鱼投饵混养（１．９９）＞对虾－罗非鱼施肥混养（１．９８）＞对虾－海湾扇贝（１．５３）＞单养对虾（１．３８）＞鲈鱼－对虾－罗非鱼（１．３０）＞对虾－缢蛏（１．２３）。     

不同单养和混养海水实验围隔浮游生物的研究

1995年6～10月和1996年6～8月对中国对虾单养及其与台湾红非鲫、菲律宾蛤仔、海湾扇贝或缢蛏的不同混养实验围隔浮游生物的研究结果表明:养殖管理措施和放养种类对围隔浮游生物种类和生物量都会产生一定影响,其中前者往往具主要作用。投饵养殖时围隔浮游植物以20μm以下的种类为主,生物量较低,其中混养台湾红非鲫的围隔叶绿素a(Chl-a)相对较高,混养菲律宾蛤仔的围隔Chl-a较低;在投饵的基础上施肥后甲藻等鞭毛藻类易大量发生成为优势种,浮游植物生物量较单纯投饵时有所升高,但单养和混养对围隔Chl-a的影响不明显。非鲫捕食往往导致大型桡足类在浮游动物生物量中的比例下降,贝类则通过食物竞争同时使桡足类生物量降低和种类小型化,由于非鲫与海产贝类的食物灶存在一定分化,二者混养至少对贝类有利,因此鱼虾贝混养应较鱼虾混养或虾贝混养效果更好。     

海水养殖实验围隔中海洋原甲藻水华的发生及其影响

研究发现在ＰＯ４－Ｐ浓度较高且静滞的围隔水体中海洋原甲藻易大量发生形成水华；发生水华后围隔水呈棕红色，浮游植物生物量，叶绿素α，初级生产力，水呼吸，ＣＯＤ和ＰＯＣ等都显著升高，溶解氧和透明度随海洋原甲藻的昼夜垂直迁移表现出相应的昼夜变化；发生水华的围隔内中国对虾和台湾红尼罗罗非鱼尚能存活和生长。但体色暗红，海湾扇贝则全部死记，表明海洋原甲藻水华对海立贝类的危害较鱼类和虾类更为严重。     

海水养殖池塘溶氧平衡的实验研究↑（*）

采用围隔实验法,研究了施肥养殖台湾红罗非鱼（Ｏｒｅｏｃｈｒｏｍｉｓｍｏｓａｍｂｉｃｕｓ×Ｏ．ｎｉｌｏｔｉｃｕｓ）和投饵养殖中国对虾（Ｐｅｎａｅｕｓｃｈｉｎｅｎｓｉｓ）的海水池塘中溶氧的昼夜平衡。测定了浮游植物光合作用产氧量、水柱呼吸耗氧量和底泥呼吸耗氧量;用估测模型计算鱼、虾呼吸耗氧量及用差减法估计大气扩散作用引起的得氧或失氧。结果表明：在海水池塘溶氧的收入中,浮游植物光合作用产氧占９０％以上,大气扩散溶入低于１０％;在海水池塘溶氧的支出中,水呼吸耗率约占６２．４８％,鱼、虾呼吸耗氧约占１８．１８％,底泥呼吸耗氧约占１９．３５％。且施肥鱼池和投饵虾池的溶氧平衡状况不同     

中国对虾与罗非鱼施肥混养的基础研究↑（*）

用４个海水池塘陆基围隔（５ｍ×５ｍ），进行了封闭式施肥混养中国对虾（Ｐｅｎａｅｕｓｃｈｉｎｅｎｓｉｓ）与台湾红罗非鱼（Ｏｒｅｏｃｈｒｏｍｉｓｍｏｓａｍｂｉｃｕｓ×Ｏ．ｎｉｌｏｔｉｃｕｓ）的基础研究。结果表明，在不同密度条件下，对虾成活率４５．０％～８６．７％（平均６６４．２％），产量为７５．７～１１１．８ｋｇ／ｈｍ２（５７ｄ），生产力为０．１９／ｍ２·ｄ。池塘对中国对虾的负荷力为１７０．０ｋｇ／ｈｍ２。其中某些围隔对虾死亡较多的原因是负荷量超过了负荷力，发生饵料缺乏和自残。在限定罗非鱼放养量（８×１０３尾／ｈｍ２）的条件下，鱼虾最适放养尾数配比为１∶３，中国对虾（体长５．５５ｃｍ）的最适放养量为２４×１０３尾／ｈｍ２左右。     

鲈-中国对虾-罗非鱼混养的实验研究

1996年 5～ 10月在 1.7hm2 池塘中设 6个 5.0m× 5.0m× 2 .0m陆基围隔 ,研究了鲈 (Lateolabraxjaponicus)、中国对虾 (Penaeuschinensis)和台湾红罗非鱼 (Oreochromismossambicus×O .niloticus)投饵混养的养殖模式。鲈和罗非鱼放养在围隔内的浮式网箱中 ,对虾散放在围隔中 ;鲈在围隔中设 3个放养密度 ,分别为 0 .76、1.52和 2 .2 8尾 /m2 ;对虾 ( 2 .2 8尾 /m2 )和罗非鱼 ( 0 .2 4尾 /m2 )均为单一密度 ,每个处理 2个重复。给鲈投喂冻杂鱼 ,对虾不投喂。实验结果表明 ,鲈出塘体重 ( 2 14.2～ 34 8.3g)和成活率 ( 2 6.3%～ 10 0 .0 % )随放养密度的增加而减少 ,净产量为 174 3.3～ 2 4 68.7kg/hm2 ,生产力为 3.2 6g/d·m2 ,负荷力 2 50 0～2 80 0kg/hm2 。鲈的密度为 1.52尾 /m2 时 ,对虾的出塘体长 ( 10 .2 5cm )、产量 ( 58.35kg/hm2 )和成活率( 17.55% )最高 ,生产力为 0 .4 3g/d·m2 。鲈的适宜放养密度为 38尾 /m2 ,与对虾和罗非鱼的适宜数量比为 1∶( 3～ 4 )∶0 .2 4。还讨论了 3种生物调节水质的生态作用。     

对虾养殖池塘混养罗非鱼对底质有机负荷的作用

采用18个36 m2的围隔进行对虾单养和对虾–罗非鱼混养实验,利用N、S、P综合相对污染指数对单养和混养围隔底质有机负荷进行研究。实验分为6组,每组3个围隔。各围隔放养体长为(0.45±0.01)cm的凡纳滨对虾3 000尾,放养体重为(201±25)g的罗非鱼分别为0(Ⅵ组)、4(Ⅰ组)、8(Ⅱ组)、12(Ⅲ组)、18(Ⅳ组)和24尾(Ⅴ组),放养对虾1个月后再放养罗非鱼。实验期间各围隔均不进行水交换,实验周期为70 d。结果表明,各围隔底质中N、P、S呈现显著上升趋势,但对虾-罗非鱼混养围隔底质中N、P、S的积累量均小于对虾单养围隔。其中,Ⅲ组的N、P、S增长率最小。各组围隔相对污染指数排列如下:Ⅵ(10.78)Ⅴ(8.30)Ⅰ(7.68)Ⅳ(7.40)Ⅱ(6.09)Ⅲ(4.12),其中Ⅲ组的相对污染指数显著小于Ⅵ组(P0.05)。Ⅲ组为本实验的效果最佳组,即混养最佳配比为凡纳滨对虾8.3×105尾/hm2、罗非鱼3 320尾/hm2,罗非鱼均重为(201±25)g/尾。本研究可为对虾–罗非鱼混养中选定合适的养殖容量提供参考。     

静水海水池塘投饵养殖非鲫的鱼产力和负荷力

用８个３ｍ×８ｍ的实验围隔，研究了静水海水池塘对投饵养殖台湾红非鲫的鱼产力和负荷力。放养量为０．６７、１．００、１．３３、１．６７尾／ｍ＾２四个水平。每日投喂颗粒饲料４次，投饵量以鱼体重的３％为基础，再根据鱼的摄食情况加以调整，以１．５ｈ内吃完为准。     

对虾养殖实验围隔中的固氮作用及其氮输入

１９９７年６～１０月,以乙炔还原法进行了不同放养模式下对虾养殖实验中生物固氮作用的测定。结果表明,各围隔中,对虾单养（Ｙ－４）和对虾＋海湾扇贝（Ｙ－５）的固氮作用较高,均值分别为２．６２μｇＮ／（Ｌ·ｈｒ）和２．６５μｇＮ／（Ｌ·ｈｒ）;对虾＋罗非鱼＋缢蛏（Ｔ－５）的最低,为１．５３μｇＮ／（Ｌ·ｈｒ）,对虾＋缢蛏（Ｙ－６）和对虾＋罗非鱼（Ｙ－７）的分别为２．３０μｇＮ／（Ｌ·ｈｒ）和１．８９μｇＮ／（Ｌ·ｈｒ）。各围隔中固氮速率较高与水体有效氮含量较低及有效氮磷比值不高有关。水层固氮蓝藻主要为蓝球藻（Ｃｈｒｏｃｏｃｕｓ）和念珠藻（Ｎｏｓｔｏｃ）。估算各围隔实验期间固氮作用输入分别为Ｙ－４∶１７．７２ｇ;Ｙ－５∶１９．６３ｇ;Ｙ－６∶９．０５ｇ;Ｙ－７∶１０．５９ｇ;Ｔ－５∶７．９９ｇ。     

罗氏沼虾亲虾培育技术

利用对虾人工繁殖基地进行罗氏沼虾人工育苗。试验中采用偏低温、大水体、高水位、伴养水葫芦和鳙鱼、多种饵料组合、交叉投喂等技术培育亲虾。这些技术具有推广价值。     

Effects of zooplankton refuge on the growth of tilapia (<Emphasis Type="Italic">Oreochromis niloticus</Emphasis>) and plankton dynamics in pond

Effects of zooplankton refuge on the growth of tilapia (Oreochromis niloticus) and plankton dynamics in pond were assessed by using 12 land-based experimental enclosures (7 m× 4 m) in a saline–alkaline pond. There were 4 treatments resulting from a combination of 2 stocking densities of tilapia (5 and 10 kg per enclosure) and 2 enclosure types (refuge and nonrefuge). Each treatment had three replicates. In the enclosures with refuge, all fish were excluded from a water column ¼ of the enclosure’s size with a polyethylene net (1.5 cm mesh size). Our field experiment showed that the individual gain in weight of tilapia increased 6.4 times with refuge treatment at the stocking density of 5 kg per enclosure than that in nonrefuge treatment. But at the stocking density of 10 kg per enclosure, the individual fish weight in all enclosures decreased due to the excessive density of fish stocking. Our results also showed that the refuge significantly increased the rotifer biomass and phytoplankton diversity and decreased the phytoplankton biomass (P < 0.05), but the copepod biomass was not affected by the refuge.     

Optimization of Phosphorus Fertilizer in Supplemental Feed‐Fed Based Nile Tilapia (Oreochromis niloticus) Ponds

An experiment was conducted in earthen ponds at the Asian Institute of Technology, Thailand to determine different phosphorus fertilizer dose effects on Nile tilapia production, water quality variables, nutrient utilization and cost‐benefit under supplemental feeding. Five phosphorus fertilization rates were used as treatments e.g. 100%, 75%, 50%, 25% and 0% of 7 kg P ha week^?1. Nitrogen fertilization rate was fixed at 28 kg N ha week^?1 for all the treatments. Sex‐reversed Nile tilapia were stocked at 3 fish m^?2, and 30% CP floating feed fed at 50% satiation feeding rate. Nutrient budget showed higher phosphorus fertilizer input resulted in higher phosphorus sink in the sediment. Mean weight, mean weight gain, daily weight gain and net yield were not significantly different among treatments (P > 0.05). Total Kjeldahl nitrogen, total phosphorus and soluble reactive phosphorus were significantly different among treatments. Economic analysis showed phosphorus fertilization resulted in positive net returns. Though the gross income was not affected by different fertilization rates, significantly lowest cost was found in the treatment using 25% phosphorus fertilizer. It can be concluded from the research that 25% phosphorus fertilization might be used as an alternative strategy of Nile tilapia pond culture in terms of economic return and nutrient loss in sediment.     

对虾池的放养密度对浮游生物群落的影响

于１９９８年７￣９月在山东海阳养虾场运用陆基围隔实验生态学方法,研究了对虾与罗非鱼在五种放养密度下浮游生物群落的变动情况。结果表明;可能浮游动物的摄食对浮游植物产生影响,二者数量的消长在大多数围隔都呈负相关;纤毛虫的数量与浮游植物的总生物量呈负相关;随着养殖密度的增加,浮游植物生物量减少,而浮游动物却有所增加,前者的优势类群由硅藻变为甲藻、蓝藻和隐藻。后者的在组成中镖水蚤数量减少而剑水蚤、无节幼体、轮虫和原生动物等小型种类有所增加;纤毛虫在高密度围隔中大量繁殖,说明水质已逐渐恶化。     

Evaluation of Nile tilapia pond management strategies in Egypt

Five pond management strategies for Nile tilapia Oreochromis niloticus L. production were evaluated in 0.1‐ha earthen ponds in Egypt during a 145‐day production cycle. Pond management strategies developed by the Pond Dynamics/Aquaculture Collaborative Research Support Programme (PD/A CRSP) were compared with a traditional and a modified Egyptian pond management strategy. Young‐of‐year Nile (mixed‐sex or sex‐reversed) tilapia were stocked into ponds at 20 000 fish ha^?1. Sex‐reversed tilapia were stocked into chemical fertilization, organic fertilization plus formulated feed and feed only treatment ponds, whereas mixed‐sex tilapia were stocked into organic fertilization plus formulated feed and chemical plus organic fertilization plus formulated feed treatment ponds. Nile tilapia yields ranged from 1274 to 2929 kg ha^?1. Nile tilapia yields in organic fertilization plus formulated feed treatments were significantly greater than the yield from chemical fertilization ponds. PD/A CRSP pond management strategies did not produce significantly greater Nile tilapia yields than the traditional Egyptian system, but a larger percentage of harvested tilapia in the organic fertilization plus feed treatments were classified in the first and second class size categories compared with the traditional Egyptian system. Organic fertilization plus formulated feed pond management strategies had the highest net returns, average rate of return on capital and the highest margin between average price and break‐even prices to cover total variable costs or total costs.     

Response of tilapia yield and economics to varying rates of organic fertilization and season in two Central American countries

The response of Nile tilapia (Oreochromis niloticus) yield to weekly applications of chicken litter at 125, 250, 500 or 1000 kg total solids (T.S.)/ha was determined in Honduras and Panama using a completely randomized design. Tilapia were stocked at 10 000/ha into 0.1-ha (Honduras) and 0.087-ha (Panama) earthen ponds. Each experiment, which lasted approximately 150 days, was performed during the rainy and dry season. Enterprise budgets were developed for each fertilization rate in each country.Gross yield of tilapia (y) increased significantly with chicken litter applications (x) in both countries, and was described by the model y=797.3+2.945x−0.001x² (r²=0.775; n=48). Gross yields ranged from 827–2729 kg/ha in 147 days during the rainy season, and from 1145–2984 kg/ha in 150 days during the dry season. Maximum tilapia gross yields were achieved at 1000 kg T.S./ha week⁻¹ chicken litter in both countries. In Honduras, rainy (1761 kg/ha in 152 days) and dry (1705 kg/ha in 150 days) season mean tilapia gross yields were similar (P=0.05). Dry season (2071 kg/ha in 149 days) mean tilapia gross yield in Panama was significantly greater (P<0.05) than rainy season mean gross yield (1683 kg/ha in 141 days). Rainy season climatic conditions in Panama probably contributed to the lower fish yields. Mean fish gross yield at the cooler, drier Honduras site (1733 kg/ha in 151 days), an upland valley located 580 m above sea level, and at the Panama site (1855 kg/ha in 145 days), a coastal plateau 100 m above sea level, was similar (P=0.05). Mean gross yields were similar in both countries for all but the highest fertilization rate, where the Panama mean yield was significantly greater. This difference was caused by site-specific factors other than nutrient input.The use of chicken litter as an organic fertilizer was profitable in both Honduras and Panama. Net returns to land, labor and management during the 5.5-month production cycle ranged from $ 642 to $ 1724/ha (Honduras) or from −$237 to $313/ha (Panama) for the low to high fertilization rates, respectively. Application of 1000 kg T.S./ha week⁻¹ chicken litter yielded the greatest estimated profit in both countries.     

Combined effects of fertilization rate, manuring and feed pellet application on fish performance and water quality in polyculture ponds

This study analyses the combined effects of organic and inorganic fertilization and of feeding with pellets on fish performance and water quality in a polyculture of common carp. Cyprinus Carpio L., silver carp. Hypophthalmichthys molitrix (Val.), grass carp. Ctenopharyngodon idella (Val.) and hybrid tilapia, Oreochromis niloticus L. x O. aureus Stetndachner. Experiments included six treatments, which are combinations of inorganic fertilisation (daily or fortnightly), manuring (supplied or not), feed pellets (supplied or not) and density of phytoplanktivorous fish species (high-density treatments with 50% more hybrid tilapia and 300% more silver carp than low-density treatments). The effects of the management procedures on fish weight, growth, survival and yield. plankton abundance, water quality, and their complex interactions at the different levels of the natural food web were analysed. The hypothesis that daily fertilization should increase algal production, which in turn should sustain a higher density of phytoplanktivorous fish, proved to be correct within certain limits. Algal reproduction rate was higher under daily fertilization, pointing to better supply of food for herbivorous fish, while algal biomass was similar under both fertilization regimes, pointing to the utilization of that algal food supply. The increased algal food supply sustained a 50% density increase of the omnivorous tilapia, but not the 300% density increase of the grazer silver carp.     

施肥对围隔中浮游纤毛虫种群动态的调控分析

通过不同的施肥处理,对低盐度对虾养殖围隔环境中浮游纤毛虫群落结构动态变化进行了研究,共检测到浮游纤毛虫48种,分属于3纲、11目、37属;其中,寡毛目（Oligotrichida）8种,缘毛目（Peritrichida）7种,腹毛目（Hypotrichida）和盾纤目（Scuticociliatida）均为6种;优势种...