Water Management to Control Clam Shrimp,Cyzicus morsie in Walleye,Stizostedion vitreum,Production Ponds

Clam shrimp, Cyzicus morsie , can occur in hatchery ponds in such dense numbers that they interfere with production of fish. Hatchery ponds are frequently left dry during the fall and winter and are filed in spring or early summer, simulating the vernal pools where clam shrimp naturally occur. Ponds left dry over winter and ponds that were full over winter, but were drained and dried for a period of time immediately prior to stocking, had the highest numbers of clam shrimp (P = 0.001). Few or no clam shrimp were collected in ponds that were full over winter and were not dried in the spring. High turbidities were observed in ponds with high numbers of clam shrimp; however, clam shrimp were not the only cause of turbidity. The largest number of walleye were produced in ponds which contained few or no clam shrimp. Clam shrimp were controlled by preventing hatchery pond substrate from drying during winter and early spring; however, the absence of drying may cause other problems that interfere with fish production.     

Co-occurrence of white shrimp, Litopenaeus vannamei, mortalities and microcystin toxin in a southeastern USA shrimp facility

Various freshwater and marine algal toxins are known to affect plants, fishes, mammals, and invertebrates. During recent mortality events in Texas white shrimp aquaculture ponds, water and shrimp tissue samples were analyzed for cyanobacterial toxins and found to contain microcystin-LR. Cyanoprokaryota dominated the phytoplankton assemblage in water from the affected pond, particularly Microcystis aeruginosa and Anabaena sp. Water samples from the affected pond also contained high levels of microcystin-LR (45 μg/l), whereas adjacent ponds had a diatom-green algal assemblage and no measurable toxin. Unialgal isolates of M. aeruginosa from the affected pond produced microcystin-LR. Free microcystin-LR concentrations in dead shrimp hepatopancreas determined by HPLC were 55 μg/g total shrimp weight, whereas shrimp hepatopancreas from the adjacent pond without shrimp mortalities had no measurable toxin. Muscle toxin concentration was below 0.1 μg/g.     

Carbon and nitrogen budgets in shrimp ponds of extensive mixed shrimp–mangrove forestry farms in the Mekong delta,Vietnam

Mass balance estimates of carbon and nitrogen flux through two extensive shrimp ponds in the Mekong delta, Vietnam, were constructed to identify major sources and sinks of organic matter potentially available for shrimp production. Nutrient transformations in the sediments were measured to further assess rates of decomposition and burial and quality of organic matter. Tidal exchange was the major pathway for inputs and outputs of carbon and nitrogen in both ponds, with net primary production, nitrogen fixation and precipitation being minor inputs. No fertilizers or artificial feeds were added to either pond. The nutrient budgets identified burial and respiration as the next most important outputs after tidal exchange losses of particulate and dissolved carbon and nitrogen. There was no measurable denitrification in either pond, and volatilization was negligible. Mineralization efficiency of carbon in the water column was high (> 100%) in pond 23 reflecting rapid respiration rates; efficiency was lower (36%) in pond 12 waters. Mineralization efficiency of sediment nutrients averaged 34% for C and 41% for N in the pond with a higher annual shrimp yield (pond 12); lower mineralization efficiencies (11% for C, 10% for N) were calculated for the lower yield pond (pond 23). High burial efficiencies for both C (66–89%) and N (59–90%) in the sediments of both ponds suggest that little organic matter was shunted into biological production. Conversion efficiency for shrimp averaged 16% for C and 24% for N from pond 12, and 6% for C and 18% for N from pond 23. The high quantity but low quality of organic matter entering the ponds coupled with other factors, such as poor water quality, limits shrimp productivity. On average, nutrient outputs were greater than inputs in both ponds. This imbalance partly explains why shrimp yields are declining in these ponds.     

强降雨对粤西凡纳滨对虾养殖池塘微生物群落的影响

于强台风"莫拉菲"环流云系带来的持续强降雨天气前后(2009年7月14日和7月28日),对广东省茂名市电白县凡纳滨对虾半集约化养殖土池的水样和泥样进行调查,研究施用微生态制剂和未施用微生态制剂的虾池水体及底泥中的异养细菌、弧菌和芽孢杆菌的变化情况,并利用BIOLOGECO微板对水体和底泥的微生物群落代谢变化进行探讨。结果发现,定期施用微生态制剂的虾池水体和底泥中的细菌数量和微生物群落功能在强降雨前后基本保持稳定;未施用微生态制剂的虾池在强降雨后,水体的弧菌数升高,Simpson指数和McIntosh指数显著降低(P0.05),水体和底泥微生物群落对碳源的利用率变化明显。研究结果表明,与施用微生态制剂的虾池相比较,未施用微生态制剂的虾池在强降雨后,水体及沉积物环境波动变化明显,强降雨对其水域环境产生很大的影响。因此建议在对虾养殖过程中定期施用微生态制剂,并针对恶劣天气采取有效措施,以稳定虾池水体及沉积物的微生物生态。     

Grow-out of sandfish Holothuria scabra in ponds shows that co-culture with shrimp Litopenaeus stylirostris is not viable

We examined the potential for producing the large numbers of sandfish (Holothuria scabra) needed for restocking programmes by co-culturing juveniles with the shrimp Litopenaeus stylirostris in earthen ponds. Our experiments in hapas within shrimp ponds were designed to detect any deleterious effects of sandfish on shrimp, and vice versa. These experiments showed that a high stocking density of juvenile sandfish had no significant effects on growth and survival of shrimp. However, survival and growth of sandfish reared with shrimp for 3 weeks were significantly lower than for sandfish reared alone. Increased stocking density of shrimp also had a significant negative effect on survival and/or growth of sandfish. A grow-out trial of juvenile sandfish in 0.2-ha earthen ponds stocked with 20 shrimp post-larvae m^− 2, and densities of sandfish between 0.8 and 1.6 individuals m^− 2, confirmed that co-culture is not viable. All sandfish reared in co-culture were dead or moribund after a month. However, sandfish stocked alone into 0.2-ha earthen ponds survived well and grew to mean weights of ∼ 400 g within 12 months without addition of food. The grow-out trial demonstrated that there is potential for profitable pond farming of sandfish in monoculture. Further research is now needed to identify the optimal size of juveniles, stocking densities and pond management regimes.     

Effect of Water Exchange Rate on Waste Production in Semi-Intensive Shrimp Ponds During the Cold Season in New Caledonia

An experiment was conducted in six earthen ponds with 20 shrimp/m² ( Litopenaeus stylirostris ) during the cold season in New Caledonia to determine the effect of water exchange rate on characteristics of effluents and pond sediment. The nitrogen budget was established, taking into account the different forms of nitrogen in the water, sediment, feed, and shrimp. Mean water exchange rates ranged from 10 to 23% per day. Increasing water exchange rate did not cause any significant change in the average quality of the rearing environment (water and sediment) during the whole growout period. However, the results showed that increasing exchange rates boosted primary productivity. Compounds produced by the mineralisation and metabolism of organic matter (feces, uneaten feed) were exported as particulate, rather than soluble matter. The nitrogen budget showed that the amount of exported wastes from the pond into the coastal environment was only 40–50% of nitrogen inputs due to nitrogen accumulation in the pond sediments and/or release to the atmosphere. The highest accumulation of dry material, as well as the highest Δ N (concentration of total N at the end of rearing - concentration of total N before rearing), was observed in ponds with the highest WER.     

The effects of variation in feed protein level on the culture of white shrimp, Litopenaeus vannamei (Boone) in low-water exchange experimental ponds

The present study was conducted to evaluate the effect of varying dietary protein level on pond water quality and production parameters of white shrimp Litopenaeus vannamei (Boone). Experimental units consisted of nine 400‐m² earthen ponds with a low water exchange. Two treatments were tested: treatment HP consisted of shrimp fed a high‐protein diet (40%) during the whole grow‐out, and treatment LP consisted of the use of a low‐protein diet for the complete farming period. No differences on any of the water quality parameters were observed among treatments. Excellent survival (over 85%) and feed conversion ratios (around 1.6), and acceptable growth (over 12 g) and biomass (from 1721 to 1793 kg ha^?1) were recorded in all experimental ponds. No significant differences in any of the production parameters were found among treatment groups.     

Paddlewheel Effects on Shrimp Growth, Production and Crop Value in Commercial Earthen Ponds

The effects of continuous paddlewheel operation on shrimp growth, yield and crop value were studied in Hawaii. Six 0.4 ha earthen ponds were stocked with Penaeus vannamei at 25 postlarvae/m². Three ponds served as controls with no mechanical aeration or mixing. Each of the other three ponds had two 1 hp paddlewheel aerators (3.7 kw/ha) running continuously throughout the five month trial (29 April-8 October 1986). All other management factors were applied uniformly.
Daily water temperature and use were significantly different between treatments. Paddlewheel ponds had lower water temperatures (28.3 vs. 28.5 C) and lower water use (0.8% exchange per day vs. 2.2% exchange per day) than control ponds.
Faster shrimp growth in paddlewheel ponds was evident in week 8. At week 14, mean shrimp body weights and growth rates were significantly greater. Shrimp at harvest were 21.2 ± 2.6 g in paddlewheel ponds versus 15.3 ± 2.6 g in control ponds. Mean shrimp production was 2,852 ± 222 kg/ha in paddlewheel ponds compared to only 2,061 ± 558 kg/ha in controls. Mean crop value was $13,719 per pond per crop for paddlewheel ponds versus $9,111 for control ponds. Hence, paddlewheels afforded an increase of 42% in net crop value after subtracting purchase and operating costs.     

Evaluation of shrimp polyculture system in Thailand based on stable carbon and nitrogen isotope ratios

ABSTRACT: To quantify the contribution by cocultured animals to waste assimilation in an intensive shrimp farm in Thailand, the food web structures of the macrobenthos in a reservoir pond, a shrimp culture pond and water treatment ponds were examined using the stable C and N isotope ratio technique. Seawater for aquaculture was drawn from a creek, and stored in a reservoir pond, used for farming the banana prawn Fenneropenaeus merguiensis in culture ponds, and then recycled through treatment ponds where the green mussel Perna viridis was cultured to remove organic wastes discharged from the farming. The clam worm Nereididae sp. and the mud creeper Cerithideopsilla cingulata in the culture pond had δ ¹³C values of −21.0‰ and −18.4‰, respectively, suggesting that shrimp feed (mean δ ¹³C = −20.7‰) was the main food source for these species. The δ ¹³C analysis also suggested that sediments (−23.7‰) in the reservoir pond and particulate organic matter (POM) (−24.0‰) and/or sediments (−25.0‰) in the treatment pond supplied carbon for most macrobenthic animals. However, green mussels in the treatment pond had a mean δ ¹³C value of −20.5‰, suggesting that shrimp feed was the main food source for this species.     

Changes in the Concentration of Nutrients and Other Chemical Properties of Shrimp Pond Soils as a Function of Pond Use

Several soil nutrients, pH, organic carbon, and total soluble salts from the upper 10 cm of soil samples from 72 shrimp ponds in Texas were analyzed. Large increases in sediment concentrations of C, N, Mg, K, Na, Fe, Mn, Zn, Cu, B, nitrate, and water-soluble salts was observed after one production cycle, followed by an asymptotic increase in older ponds. An approximately linear increase in soil concentration of S and P with pond age was observed. The pH showed a marked decrease in ponds that had been used for one production cycle, but stabilized in older ponds. No correlation between Ca and growing cycle was observed. Calculated recovery rates for elements supplied in feed were less than 10% in several cases and 15% for P. No measurable negative effect on shrimp production by the increase of elemental concentrations was measured.     

Effect of Different Feeding Levels of Plant‐ingredient‐based Feed on Fillet Fatty Acid Profile,Carcass Trait,and Sensory Characteristics of Indian Major Carps in Earthen Pond Polyculture

The objective of the present study was to evaluate the effect of plant‐ingredient‐based feeds on fillet fatty acid profiles, proximate composition, carcass traits, and sensory characteristics of three Indian major carps (IMCs), Catla catla, Labeo rohita, and Cirrhinus mrigala, when fed at different levels of their body weight. An experimental feed was prepared with only plant ingredients. The IMCs were fed twice daily at 1.0, 1.5, 2.0, and 2.5% of their body weight for 150 d in 0.06‐ha earthen pond polyculture systems. The maximum growth and best feed utilization was achieved with feeding at 2% of fish biomass in the ponds. Fillet yield and lipid recovery increased significantly (P < 0.05), with increasing feeding level up to 2% of body weight and plateaued thereafter. In fillets, eicosapentaenoic acid (20:5n‐3) and docosahexaenoic acid (22:6n‐3) concentration increased with increasing feeding levels. Carcass traits, sensory characteristics, and consumer acceptance of IMC fillets were not influenced by feeding plant‐ingredient‐based feeds at different feeding rates.     

Origin identification method by multiple trace elemental analysis of short-neck clams produced in Japan, China, and the Republic of Korea

The correlations among the contents of trace elements in the shells of short-neck clams collected from Japan, China, and the Republic of Korea were examined. Origin-specific elemental content patterns were seen in clams originating from Japan, China, and the Republic of Korea. The crushed shells were decomposed with nitric acid–hydrogen peroxide, and the concentrations of ten elements (Li, V, Mn, Co, As, Rb, Mo, Ba, Pb, and U) in the shells were measured by inductively coupled plasma mass spectrometry. Some of the metal concentrations in the samples displayed clear geographical trends. The average concentration of Pb in Japanese clam shells was one-half to one-quarter that seen in Chinese or Korean clams. Average concentrations of As, Rb, and Ba in shells of Japanese origin were one-half those observed in Chinese or Korean clams. Linear discriminant analysis was applied to these analytical data, and four discriminant models were constructed. These discriminant models were able to distinguish the geographic origins of short-neck clams with 80.0–100 % accuracy. In particular, clams of Japanese origin were classified correctly ≥90 % of the time. Therefore, the trace elemental analysis of a short-neck clam shell is useful for identifying the country of origin of the clam.     

A 13C/12C Tracer Study of the Utilization of Presented Feed by a Commercially Important Shrimp Penaeus vannamei in a Pond Growout System1

A study of added feed utilization by pond grown shrimp was done using seven feeds with different ¹3C/¹²C ratios, as expressed by δ¹³C. The pond shrimp did not track the δ¹³C value of the feed to the extent that tank grown shrimp did. For the seven pond experiments the δ¹³C data indicate that the added feed supplied between 23 and 47% of the growth carbon. This implies that between 53 and 77% of the growth is due to the grazing on pond biota. It is suggested that this experimental approach can be used to evaluate the relative contribution of presented dried feeds versus natural productivity in ponds as an aid to developing pond management strategies and optimum feeds.     

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.     

Evaluation of floating cages as an experimental tool for marine shrimp culture studies under practical earthen pond conditions

The New Caledonia blue shrimp Litopenaeus stylirostris is commercially produced under semi-intensive rearing conditions. The size of the farming earthen ponds (5–10 ha) and the subsequent production constraints make it difficult to use them as experimental units for random experiments. Moreover, since every pond has its own characteristics, ponds' effects cannot be ruled out, thus making it hard to define true replicates.In order to design future experiments under conditions resembling those used in production, we evaluated the possible use of floating cages as experimental units with the aim of assessing treatment effects with a reasonable statistical power. To this end, two sets of floating cages were placed respectively in two different ponds in a commercial farm. In both cases the zootechnical conditions in the cages were similar in post-larvae origin, management, and diet and feeding regime.The aim of the study was to evaluate on a technical basis the possibility of rearing shrimps in floating cages set up in earthen ponds and to assess this method from a statistical standpoint. Shrimps reared in and outside the cages showed comparable growth and survival rates. The variability in the zootechnical parameters between cages, expressed as the estimated coefficient of variation (CV) for survival rate, total final biomass (g), final body weight (g), daily increment in body weight (g day^− 1) and FCR were 11.0, 13.7, 4.4, 5.4, and 7.0%, respectively. On the basis of these figures, we calculated for a given statistical power (80%) the number of replicates (cages) that would be required to reveal significant differences between two treatments, at a 5% level of significance. We found that for expected differences of 20% from the control mean, 3 and 6 floating cages per treatment would be reasonable to determine statistical differences for growth parameters and survival rate, respectively. Moreover, we showed a significant pond effect in regard to survival and growth between the two sets of cages. These results illustrated the within-farm variability among the ponds, and confirmed that the specific characteristics of each pond from the same farm make it difficult to use the ponds themselves as experimental units.The study demonstrates that rearing in floating cages is an economical, powerful and sensitive experimental tool for shrimp culture studies specifically carried out under conditions close to semi-intensive production.     

Comparison of microbial community structures in intensive and extensive shrimp culture ponds and a mangrove area in Thailand

ABSTRACT:   A pelagic bacterial community structure was examined in experimental intensive shrimp culture ponds that have a shrimp–mangrove complex aquaculture system, an extensive shrimp culture pond and a mangrove area in Thailand by denaturant gradient gel electrophoresis analysis of polymerase chain reaction amplified partial 16S rRNA genes. Bacterial community structure in the intensive shrimp culture ponds was distinguishable from that of the mangrove area. In the extensive shrimp culture pond, the bacterial community structure resembled that in the mangrove area, but bacterial abundance was as great as that in the intensive shrimp culture ponds. Among the intensive shrimp culture ponds, the bacterial community structure was different between a closed culture system and a shrimp–mangrove complex culture system. Moreover, the bacterial community structure in mangrove planted ponds was close to those in the intensive shrimp culture ponds when shrimp culture was conducted, but it was close to those in the mangrove areas without shrimp culture. These results suggest that intensive shrimp culture with shrimp feed input affects the bacterial community structures in pond water.     

Feeding Channel Catfish, Ictalurus punctatus, Diets Amended with Refined Marine Fish Oil Elevates Omega-3 Highly Unsaturated Fatty Acids in Fillets

Channel catfish, Ictalurus punctatus, 88.4 ± 2.6 g/fish, were fed a basal diet amended with 4% of three processed menhaden, Brevoortia tyrannus, oils. These were compared with basal diets amended with 4% corn oil or 4% canola oil. Three replicate aquaria of nine fish each were fed assigned diets twice daily. At 6 wk, fish were group weighed, fillets were collected for sensory evaluation, fatty acid analysis by gas chromatography (GC). In a second study, catfish, 118.8 ± 3.2 g/fish, were stocked into fifteen 0.04‐ha earthen ponds and fed once daily for 16 wk one of four diets containing 2 or 4% of either catfish offal oil or refined (RF) menhaden oil. At harvest, fillets were saved for sensory evaluation and fatty acid analysis. Results showed no significant (P > 0.05) differences among treatments for aquarium study and pond study variables such as weight gain, fillet proximate analysis, or pond production. GC analysis showed that levels of omega‐3 (n‐3) highly unsaturated fatty acids (HUFA) in fillet lipid were significantly (P < 0.05) elevated for fish fed menhaden oil diets. Sensory evaluation revealed that fillets from fish fed RF menhaden oil had satisfactory flavor and could be a source of n‐3 HUFA for humans.     

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.     

Effects of Pond Renovation on White River Crayfish,Procambarus acutus acutus Production

Abstract

The effects of renovation on the production of white river crayfish, Procambarus acutus acutus were evaluated in ten 0.1-ha earthen ponds. The bottoms and levees of five ponds were reshaped with heavy equipment prior to planting sorghum-Sudan grass forage during the de-watered phase of the culture cycle. Five non-renovated ponds served as a control. The mean total length (TL) of the crayfish harvested from renovated ponds was significantly larger than those crayfish harvested from non-renovated ponds. The renovated pond harvest contained an estimated 43.2% carryover crayfish (>95 mm TL) in comparison to 7.6% in the harvest from non-renovated ponds. By weight, carryover crayfish constituted an estimated 69.3% of the harvest from renovated ponds, compared to 21.0% from non-renovated ponds. No difference was observed in the harvest between treatments; however, the low proportion of young-of-the-year crayfish in the renovated pond harvest may adversely impact future production.     

Chemical and Physical Properties of Shrimp Pond Bottom Soils in Ecuador

Chemical and physical analyses were conducted on bottom soil samples from 74 brackish-water ponds representing 40 shrimp farms in Ecuador. Most ponds had soils with pH > 6 and total carbon concentrations < 2.5%. Carbon was mostly in organic form, for the average concentration of carbonate carbon was 0.06%. The C: N ratio was 8 to 10 in soils with < 2.5% carbon. In ponds built in former mangrove areas, soil carbon was > 2.5% and C: N ratios were 25 to 30. Ponds soils in former mangrove areas also tended to be high in total sulfur and low in pH. Lack of correlation between carbon and sulfur in mangrove soils suggested that most of the sulfur was inorganic and presumably in sulfides. Soils containing above 0.4% free carbonate (as equivalent CaCO₃) had pH values > 7. Although carbonate concentration was a major factor controlling soil pH, calcium hardness of pond waters was strongly influenced by salinity (and calcium) in the water supply. Total phosphorus concentrations averaged 898 mg/kg, and dilute acid extractable phosphorus usually accounted for 25–35% of the total. Concentrations of major cations and minor elements varied greatly in soils and exhibited ranges of up to three orders of magnitude. Contrary to opinions of shrimp producers, many pond soils in Ecuador are not acidic and few soils have a high organic matter content. Proper use of soil and water testing could greatly improve the efficiency of liming and other soil management practices.