Influence of variation in water temperature on survival,growth and yield of Pacific white shrimp Litopenaeus vannamei in inland ponds for low‐salinity culture

There is considerable interest in the culture of whiteleg shrimp (Litopenaeus vannamei) in inland low‐salinity water in Alabama and other states in the Sunbelt region of the US. However, the growing season is truncated as compared with tropical or subtropical areas where this species is typically cultured, and temperature is thought to be a major factor influencing shrimp production in the US. This study, conducted at Greene Prairie Aquafarm located in west‐central Alabama, considered water temperature patterns on a shrimp farm in different ponds and different years; and sought possible effects of bottom water temperature in ponds on variation in shrimp survival, growth and production. Water temperature at 1.2 m depth in 22 ponds and air temperature were monitored at 1‐hr intervals during the 2012, 2013, 2014 and 2015 growing seasons. Records of stocking rates, survival rates and production were provided by the farm owner. Correlation analysis and linear mixed model analysis of variance were used. Results showed that hourly water temperatures differed among ponds. The range of water temperature in each pond explained 41% of the variance in average final weight of shrimp harvested from each pond. In conclusion, the results suggest that variation in water temperature patterns has considerable influence on shrimp growth and survival in ponds.     

对虾内陆养殖的现状、存在的问题及其展望

文章综述了目前对虾内陆养殖的主要品种、养殖方式和发展现状,并对其优点和存在的问题进行了分析。内陆地下咸水的离子组成比例失调是目前对虾内陆养殖遇到的最大的障碍,文章详述了地下咸水的成因和分布,介绍了有关水体离子浓度和比值对对虾生理生态学影响的研究现状。最后讨论了克服内陆对虾养殖存在的问题并使之成为可持续发展的产业的途径。     

Water Temperature in Inland,Low-Salinity Shrimp Ponds in Alabama

Water temperature in eight ponds and air temperatures were monitored at 2-h intervals during the 2010 growing season at an inland, low-salinity shrimp farm in Alabama. There was a high correlation (P < 0.01) between mean daily air and water temperatures; pond water usually averaged 3° to 4°C warmer than air. Monthly mean water temperatures among eight ponds differed by 3.40°C in May and by 2.83°C in September, but there was less than 1°C difference among ponds in June, July, and August. Differences in temperature among ponds were not related to pond water surface:volume ratio, but in July and September there was a negative correlation (P < 0.05) with increasing aeration rate. Negative correlations (P < 0.05) between average water temperature over the entire culture period and survival and production of Pacific white shrimp, Litopeneaus vannamei, possibly resulted from variation in crop duration and were not causal. Nevertheless, differences in water temperature among ponds in May and September were great enough to have possibly caused differential shrimp survival and production among ponds.     

Histological alterations in gills of shrimp Litopenaeus vannamei in low‐salinity waters under different stocking densities: Potential relationship with nitrogen compounds

Two experimental modules with different stocking densities (M1 = 70 and M2 = 120 shrimp /m²) were examined weekly over a culture cycle in tanks with low‐salinity water (1.9 g/L) and zero water exchange. Results showed survival rates of 87.7 and 11.9% in M1 and M2, respectively. Water temperature, pH, dissolved oxygen, electrical conductivity and chlorophyll a were not significantly (p > .05) different between modules. In contrast, the concentrations of nitrogen compounds were significantly (p < .05) different between modules, except nitrite‐N (M2 were 2.31 ± 1.38 mg/L N‐TAN, 0.18 ± 0.49 mg/L N‐NO₂^? and 6.83 ± 6.52 mg/L N‐NO₃^?; in M1: 0.97 ± 0.73 mg/L N‐TAN, 0.05 ± 0.21 mg/L N‐NO₂^? and 0.63 ± 0.70 mg/L N‐NO₃^?). When waters of both modules reached higher levels of ammonia and nitrite, histological alterations were observed in gills. The histological alterations index (HAI) was higher in M2 (5‐112) than in M1 (2‐22).     

Distribution of Ground Water Suitable for Use in Saline-Water Aquaculture in Central and West-Central Alabama

Production of shrimp in inland ponds supplied by water from saline aquifers is a potential new aquaculture industry in Alabama. Examination of 2,527 well records of the Geological Survey of Alabama and the United States Geological Survey and samples from 35 wells revealed 238 wells with chloride concentration of 125 mg/L chloride or more in 11 counties of central and west-central Alabama. Chloride concentrations varied from 136 mg/L to 94,000 mg/L. The highest chloride concentrations were from wells in Washington, Choctaw, and Clarke Counties. However, 83% of the saline-water wells in Dallas, Hale, Greene, Marengo, Wilcox, and Sumter Counties were supplied by aquifers of the Eutaw, Gordo, McShan, and undifferentiated Eutaw-McShan formations. Water from these wells had an average and standard deviation of 1,238 ± 615 mg/L chloride. Based on the frequency of saline-water wells, the number of wells with chloride concentrations above 700 mg/L (about 2 ppt salinity), and well depths, it was concluded that Hale, Greene, Marengo, and Sumter Counties have the greatest potential for saline-water aquaculture. Contour maps for chloride concentrations and depths of wells in these four counties were prepared to better delineate this potential water source for aquaculture. There were, however, areas in Lowndes, Tuscaloosa, and Wilcox Counties with saline ground water suitable for inland aquaculture.     

Supplementation of sodium chloride in diets to improve the meat quality of Pacific white shrimp,Litopenaeus vannamei,reared in low‐salinity water

To investigate the effect of dietary sodium chloride (NaCl) on meat quality of white shrimp (Litopenaeus vannamei) reared in low‐salinity (2 g L^?1) water, shrimp were distributed into four groups (treatments T‐1, T‐2, T‐3 and control) with three replicates. All shrimps were completely randomised stocked into 12 tanks at an initial density of 40 shrimps per tank. Diets for the control, T‐1, T‐2 and T‐3 groups consisted of the basal diet supplemented with 0 g kg^?1, 10 g kg^?1, 20 g kg^?1 and 40 g kg^?1 of NaCl respectively. After 50 days, shrimps in T‐3 showed significantly better (P < 0.05) moisture, crude protein and ash than those of the control and T‐1. Higher muscle Na content was observed (P < 0.05) in T‐3 than that of the control. Significant increases (P < 0.05) in contents of inosinic acid, total free amino acid (TFAA) and essential free amino acid (EFAA) were also found in T‐3. Texture assays showed significant differences (P < 0.05) in hardness, adhesiveness and springiness between group T‐3 as compared with those of T‐1 and control. It indicated that dietary supplementation of NaCl appeared to be a promising practice to improve meat quality of white shrimp reared in low‐salinity waters.     

Supplementation of potassium, magnesium and sodium chloride in practical diets for the Pacific white shrimp, Litopenaeus vannamei, reared in low salinity waters

The culture of Litopenaeus vannamei in inland low salinity waters is currently being practiced in various countries around the world. These environments are often deficient in key ions essential for normal physiological function, including potassium (K⁺) and magnesium (Mg²⁺). Farmers have sometimes been able to counteract ionic deficiencies in the water profile by adding mineral salts containing sources of K⁺ and Mg²⁺. The purpose of this study was to explore the possibility of correcting deficiencies of K⁺ and Mg²⁺ in the water profile with dietary supplementation of these minerals. Two separate 7‐week experiments were conducted in 4.0 g⁻¹ artificial low salinity water to evaluate the effects of mineral supplements (K⁺, Mg²⁺ and NaCl) to diets of L. vannamei reared in low salinity waters. In trial 1 seven diets were formulated (10 g NaCl kg⁻¹, 20 g NaCl kg⁻¹, 150 mg kg⁻¹ Mg²⁺, 300 mg kg⁻¹ Mg²⁺, 5 g K⁺ kg⁻¹, 10 g K⁺ kg⁻¹, and a basal diet to serve as a control). Minerals were added in the form of purified potassium chloride (KCl), magnesium chloride (MgCl₂·6H₂O) and NaCl. Trial 2 evaluated the use of a coating agent for the Mg²⁺ and NaCl treatments, while a K⁺ amino acid complex was utilized in the K⁺ treatments to reduce mineral leaching. Trial 2 was performed using similar treatment levels as trial 1. Shrimp survival and growth were assessed in both experiments. Results from trial 1 indicated no significant differences in survival, growth or percent weight gain. Results from trial 2 revealed no significant differences in survival and growth in the NaCl and Mg²⁺ treatments. However, significant differences in growth (P < 0.05) were observed when using the 10 g K⁺ kg⁻¹ treatment, suggesting that dietary supplementation of a K⁺ amino acid complex may help improve growth of the species in low salinity waters.     

The effectiveness of a commercial microbial product in poorly prepared tiger shrimp, Penaeus monodon (Fabricius), ponds

The efficacy of a commercial microbial product was tested in commercial tiger shrimp, Penaeus monodon (Fabricius), ponds for one culture period in Kuala Selangor, Malaysia. Four ponds with replicates for treatment and control were used. The pond bottom was dried but the organic sludge was not removed as normally practised in pond preparation. The ponds were stocked with 15 post‐larvae at the rate of 31.m^?2. Physical, chemical and biological parameters of the pond were analysed every 2 weeks during the culture period. Water quality parameters remained within the optimum range for shrimp culture except for ammonia‐nitrogen being significantly higher in control ponds and silica in treated ponds. Benthic organisms were not found in any of the ponds. The average counts of different bacteria were not significantly higher in treated ponds than control. Because of poor health, the shrimp were harvested earlier (72 days) than the usual 120 days. An average of 875.60 ± 67.00 kg shrimp ha^?1 was obtained in treated ponds with a feed conversion ratio (FCR) of 1.57 ± 0.10 and survival rate of 42.35 ± 5.37% compared with 719.50 ± 130.94 kg shrimp ha^?1, 2.99 ± 0.70 and 21.25 ± 3.26%, respectively, in control ponds. Neither the microbial product nor the frequent water exchange was effective in overcoming the problems caused by the poor pond bottom.     

On-farm evaluation of three different hatchery sources of Pacific white shrimp (Litopenaeus vannamei) cultured in on-levee tanks in low-salinity waters of west Alabama

ABSTRACT

Shrimp farmers in Alabama who produce the Pacific white shrimp, Litopenaeus vannamei, have recently reported abnormally low survival at harvest. Farmers have hypothesized that this phenomenon may be due to disease, toxic algae, shrimp source, or reduced shrimp robustness in later stages of production. To compare performance of shrimp from different sources, postlarvae were obtained from three different hatcheries and stocked on the same day in on-levee tank systems (TS) on two farms (Farm 1-TS; Farm 2-TS1; Farm 2-TS2). Following 104 days of culture on Farm 2-TS1 and Farm 2-TS2, there were no differences in survival (72.8%–91.2%) or final weight (19.8–24.6 g). At Farm 1-TS following 107 days of culture, there were differences in survival from shrimp sourced from one hatchery (40.5%) compared to the other two hatcheries (61.0%–69.8%). Results demonstrated acceptable growth performance and survival from all hatchery sources.     

溶藻细菌控藻作用及其在对虾养殖池塘中的应用前景

浮游微藻与养殖池塘的水质及对虾的健康状况密切相关,控制有害微藻的过度繁殖,维持优良的藻相对于养殖水环境的稳定、减少对虾疾病的发生具有重要意义。文章对浮游微藻与对虾养殖的关系及溶藻细菌的研究进展进行了概述,分析了溶藻细菌在对虾养殖中的应用前景,提出了利用溶藻细菌控制对虾养殖池塘有害微藻的研发思路。     

对虾海水高密度养殖后期水质因子的昼夜变化规律

2008年7月5～6日,对广东汕尾红海湾对虾养殖场养殖87～88d的海水高密度半封闭养殖虾池水质进行每4h监测分析,旨在了解养殖后期昼夜水质变化状况,为合理和即时调控养殖后期水质提供相关理论数据。结果显示,24h内水质指标除化学需氧量（COD）和无机氮（DIN）基本稳定外,其他因子均有较大波动。其中氨氮（NH4＋-N）在3：00达到高峰,5：00落至低谷,9：00又达到高峰;亚硝酸盐氮（NO2--N）的变化却相反,在3：00落至低谷,5：00达到高峰,9：00又落至低谷;pH和溶解氧（DO）均在5：00降至最低,13：00上升到最高。结果表明,3：00～9：00是虾池水质变动的关键时期,应留意水质变化,适时采取合理增氧措施并投洒相应水质调节剂以提高ρ（DO）,减少NH4＋-N和NO2--N产生及降低其毒性。     

对虾微量元素研究进展

微量元素作为多种酶的辅助因子或结构成分,参与机体多种新陈代谢过程,在维持动物健康和正常生理功能中发挥着极其重要的作用。动物对微量元素营养需求极少,但缺乏、过量或摄入不平衡都会对动物机体生长代谢、免疫、繁殖等带来严重不良影响。本文较详细、系统地总结了国内外关于微量元素在对虾生长代谢、免疫、疾病预防、性腺发育等方面的作用,以及对虾对无机和有机微量元素的吸收、转运和代谢机理,为今后开展对虾优质配合饲料研发提供理论依据。     

Pond-to-pond variability in post-larval shrimp, Litopenaeus vannamei, survival and growth in inland low-salinity waters of west Alabama

Despite the recent success of Alabama shrimp farmers in culturing the Pacific white shrimp, Litopenaeus vannamei , in inland low-salinity waters there is large variability in growth and survival among ponds. Farmers suspect that high mortality occurs during the first weeks of culture following stocking of postlarvae (PL). In order to determine the effect of pond ionic composition on PL growth and survival, three trials were carried out at a shrimp farm. Trials 1 and 2 evaluated PL growth and survival over 21- and 28-day periods, respectively, using static water from different production ponds. Trial 3 evaluated growth and survival over 7, 14, 21 and 28 days using water from one production pond. Results suggest that initial mortality (8–10%) is attributed to the acclimation process and occurs immediately following stocking. Pond-to-pond variations in ionic profiles could be a contributing factor but are not likely the major reason for variable 'survival'. Mortalities after stocking appear to occur quickly as there were no differences in survival from 7 to 28 days post stock. Variable survival is likely due to a combination of reasons including environmental factors, but is largely due to poor handling of PL and stocking errors that produce perceived reductions in survival.     

Effects of ammonia on growth and molting of Litopenaeus vannamei postlarvae reared under two salinity levels

ABSTRACT

Litopenaeus vannamei postlarvae were exposed to 0, 6, 13, and 19 mg/L total ammonia nitrogen (TAN) treatments. After 45 days, shrimp weight and length were lowest under TAN concentrations of 13 and 19 mg/L (P ≤ 0.05). Maximum weight gain was observed in control and 6 mg/L treatments. Mortality was highest (80.55 ± 4.80%) under 19 mg/L reared in 35 ppt salinity. Average intermolt periods of PLs exposed to 0, 6, 13, and 19 mg/L TAN were 11.5 ± 0.7, 10.8 ± 1.3, 9.4 ± 1.0, and 8.7 ± 0.6 days under 35 ppt and 11.1 ± 0.5, 10.7 ± 0.6, 10.1 ± 0.5, and 9.5 ± 0.2 days under 45 ppt salinity. Although TAN increased postlarvae molting frequency, its negative effects on the shrimp growth and survival of PLs was directly linked to its concentration and exposure duration. Higher salinity reduces the effects of ammonia and increases the survival.     

Hydrology of inland brackishwater shrimp ponds in Chachoengsao, Thailand

This study focuses on a new trend in shrimp aquaculture, the development of brackishwater ponds for Penaeus monodon culture in inland freshwater areas of Thailand’s Central Plain. Water balances were calculated for ponds and reservoirs at an inland shrimp farm in Chachoengsao, Thailand, between May and July 1999. Regulated inflow and outflow were the largest water fluxes, averaging 0.94 and 0.70 cm/day. Other daily average water gains were rainfall (0.52 cm/day) and runoff (1.7 cm/day), and other water losses were evaporation (0.31 cm/day) and seepage (0.52 cm/day). Over an entire crop cycle, of average length 109 days, average water inputs were: initial pond filling (84 cm); regulated inflow (103 cm); rainfall (57 cm); and runoff (3 cm). Average outputs were: regulated outflow (76 cm); seepage (57 cm); evaporation (34 cm); and draining at harvest (87 cm). The main feature of note in the water balance is the large volume of regulated outflow. All regulated outflow and most (82%) of the pondwater drained at harvest went directly to the irrigation canal system. Such large volumes of discharge could have serious environmental implications because small inland waterways have low assimilative capacity and pond effluent is saline. Consumptive water use for 14 inland shrimp ponds and reservoirs averaged 0.83±0.14 cm/day. Consumptive water use was also measured for 11 nearby rice fields, the main land use in the regions where inland shrimp farming is proliferating. Rice paddy water use averaged 0.91±0.17 cm/day. There was no significant difference in the daily consumptive water use of shrimp ponds and rice fields, suggesting that conversion from rice farming to shrimp farming would have little net impact on water availability for irrigation.     

虾池浮游微藻与养殖水环境调控的研究概况

在对虾养殖过程中,虾池中的浮游微藻群落结构和对虾的健康养殖有着密切关系,一些有益微藻能调节水体溶氧量（DO）和酸碱度（pH）,吸收氨氮（NH4-N）和亚硝氮（NO2-N）等有害物质,有效地调控养殖环境。但一些能分泌毒素的微藻也会给对虾的健康生长带来危害。数量和生物量占微藻总量比例均较高的浮游微藻优势种对整个虾池微藻群落结构的稳定起着重要作用,主导着微藻群落的功能发挥。不同养殖模式、养殖季节、养殖地域以及养殖阶段虾池中浮游微藻的优势种类分布、多样性等群落特征有差异。浮游微藻群落中优势种的变动规律和虾池中各种环境因子的动态密切相关,环境因子的变动会影响浮游微藻群落结构的变动。文章综述了对虾养殖生产实践中浮游微藻群落结构和生态调控特征的研究概况,并对在养殖中构建优良微藻藻相的方法进行了探讨。     

老化虾池生态系中几类主要细菌的季节变化特征

对青岛市老化虾池生态系中几类主要细菌的季节变化情况进行了研究，结果表明，虾池水体中的异养菌总数在放苗前和养成前期均较低，从养成中期开始逐渐增高，7、8月份菌量达到最高，养成末期逐渐有所下降，总变化幅度为10^3-10^5cells/ml；弧菌数和硝酸盐还原菌数在养殖中、后期增长速度高于其他种类，在总菌中所占比例增大；沉积环境中的3类细菌的数量均比同期水体中的菌量高1-2个数量级，养殖后期和末期菌量仍保持在较高水平，硝酸盐还原菌在总菌量中占较高比例。因此认为，现有老化虾池微生物群落的演变不利于对虾的生长，应对微生态平衡进行人工调控。     

3种微生物制剂调控工厂化对虾养殖水质的研究

研究了地衣芽孢杆菌(Bacillus licheniformis,BL)、荚膜红假单胞菌(Rhodopseudomonas capsulate,RC)和乳酸杆菌(Lactobacillusspp.,LB)对凡纳滨对虾(Litopenaeus vannamei)工厂化养殖水质的影响。结果表明,施用不同微生物制剂组合,其作用效果各不相同。各组微生物制剂均能降低水体中氨氮,地衣芽孢杆菌 荚膜红假单胞菌(G1)组、地衣芽孢杆菌 荚膜红假单胞菌(G2)和地衣芽孢杆菌 乳酸杆菌(G3)组NH4 的相对降解率为62%、63%和65%;前21d,G2组降低NH4 效果最明显,相对降解率为79%。在降低NO2-方面,G1组的效果较好,相对降解率为46%;但各处理组对于PO34-、COD均无显著效果。相对而言,G1组改善养殖水质的效果最好。实验中微生物制剂的不同施用频率对水质的净化没有明显的差别。各项水质指标均随养殖时间的推移呈现不断上升的趋势。     

Effect of water exchange on effluent and sediment characteristics and on partial nitrogen budget in semi-intensive shrimp ponds in New Caledonia

An experiment was conducted in six earthen ponds with 20 shrimps m^?2Litopenaeus stylirostris (Stimpson) during the warm season in New Caledonia to study the dynamics of wastes in relation with water exchange rate (WER). The nitrogen budget was established, taking into account the different forms of nitrogen in the water, sediment, feed and shrimp. Data from a wide range of treatments applied in unreplicated ponds were treated using regression analysis to establish the relationship between WER and partial nitrogen budget, sediment characteristics and shrimp performance. To compare effluent quality between treatments during the season, data were analysed using the non‐parametric sign test. The water outflow was characterized by a decrease in the concentrations of N‐mineral forms (TAN, NO₂^?–NO₃^?), an increase in the concentration of organic soluble and sestonic organic forms (expressed in terms of particulate nitrogen, particulate organic carbon, chlorophyll a) compared with the water inflow. Increasing WER increased the amount of exported wastes and mainly in the organic forms and TAN can be considered as negligible. The nitrogen budget showed that 19–46% of nitrogen input (feed+water) was exported into the coastal environment. The results showed that the quality of the sediment decreased as WER decreased. The potential negative impact of the developing industry in New Caledonia on the costal environment could be partially reduced in a first step by decreasing WER. However, if applied in the farms, this practice should be linked to a close survey of the evolution of sediment quality.