Days In Ponds Research Articles

Ectoparasite infestation and survival rate of pacific white shrimp (Litopenaeus vannamei) that immunized with crude protein Zoothamnium penaei in intensive ponds

The aim of research was to determine ectoparasite infestation and survival rate of L. vannamei immunized with Zoothamnium penaei crude protein in intensive ponds. This research was an experimental study to determine the effect of using feed and added crude protein Z. penaei to L. vannamei. The sample used was 10,000 (PL-11) L. vannamei. The collected data of ectoparasite infestatiton were analyzed by descriptive and variance analysis. There was a significant difference between the pacific white shrimp immunized with crude protein Z. penaei on the 1th, 30th, 60th and 90th days of maintenance (p< 0.05). The highest ectoparasite infestation occurred in L. vannamei aged 60 days, and 30 days respectively. An increase of ectoparasites infestation occurred on shrimp aged 30 to 60 days in the ponds, though there was no significant difference (P> 0.05). On 90 days of maintenance, there was an increase of ectoparasites infestation and it was significantly different from the infestations in shrimp aged 60 days in ponds (p<0.005). The survival rate of pacific white shrimp immunized with crude protein was the age of 90 days in the pond (79%). crude protein Z. penaei could suppress ectoparasite infestation and vannamei shrimp mortality in intensive ponds.

Seepage characteristics of three-layered landfill cover system constituting fly-ash under extreme ponding condition

A multi-layered final cover system is constructed over the landfill after it reaches its full capacity to minimize water ingress into the underlying hazardous waste. Three layered landfill cover are designed for areas experiencing very humid climatic conditions. Under the effects of climate change, the occurrences of extreme rainfall events become more frequent and this has resulted in catastrophic floods and hence extreme ponding. This study investigates the seepage characteristics of three-layered capillary barrier cover systems under an extreme ponding condition of 1.5 m water head, through detailed laboratory column tests and finite-element seepage analysis. Four 1.2 m-tall columns having different configurations (C1–C4) were studied. Fly ash (FA) was used to amend the surface and barrier layers in columns C2 and C4, in line with the novel concept of “waste protect waste”. Spatiotemporal variations of volumetric water content of the four columns were monitored for three years continuously. With FA amendment in the surface layer and an inclusion of a 0.01 m thick geosynthetic clay liner between the drainage and barrier layers, the onset of basal percolation was significantly delayed until 700 days of ponding, compared to 115 days without FA amendment. Capillary flow dominated the gravitational flow and perched water table was formed as waterfront advanced from the drainage to barrier layers. Further seepage analysis considering a realistic humid climate boundary condition showed that all four configurations were successful in preventing basal percolation for 800 days.

The correlation between ectoparasite infestation and the total plate count of Vibrio sp. in pacific white shrimp (Litopenaeus vannamei) in ponds

Ectoparasite infestation and Vibrio sp. bacterial infection are a major factor causing the death of pacific white shrimp (Litopenaeus vannamei), which can cause an increased mortality rate up to 100% only three days after infection, especially in hatcheries. Ectoparasites that are often found in shrimp culture include Zoothamnium sp., Epistylis sp. and Vorticella sp. Meanwhile, the vibrio bacteria that are often found in the same setting are Vibrio alginolitycus, Vibrio harveyii, Vibrio parahaemoliticus and Vibrio fulvinicus. The aim of this research was to analyze the correlation between ectoparasite infestation and the total plate count of Vibrio sp. in white shrimp (Litopenaeus vannamei) during a culture of up to 90 days in ponds. The method used in the research study was an experimental design with a sampling time spaced out over 0, 30, 60 and 90 days. The results showed that the ectoparasites found to be infecting the white shrimp were Zoothamnium sp. and Vorticella sp. with the lowest number of ectoparasites being 4 individuals found on the 90th day. The highest number was 63 parasites on the 60th day. The lowest Vibrio sp. total plate count was 2.9 × 104 CFU/g and the highest was 5.55 x 104 CFU/g.

Response Analysis Of Urban Vaname (Litopenaeus Vannamei) Which Is Exposed to Crude Protein Zoothamniumpenaei Oral and Maintained In Ponds

ABSTRACTThe objectives of this study were immune response, specific growth rate and survival rate of shrimp vaname (Litopenaeus vannamei) in ponds. The research method used was experimental to know the effect of feed use and added crude protein Zoothamnium penaei on vaname shrimp (Lithopenaeus vannamei) in pond. The sample used is shrimp vaname (Lithopenaeus vannamei) as much as 10,000 heads of juvenile stadia. The food used is commercial feed added crude protein Zoothamnium penaei with a dose of 150 μl / head, which is given 7 times every 7 days interval from the age of 1 day up to Shrimp aged 56 days in ponds. The results showed that there was an increase of immune response (increase of THC and DHC) due to feeding added by Zoothamnium penaei crude. The highest total of Haemocytes (THC) occurred in commercial-fed shrimp and added crude protein ie 56,58 x 106 cell / ml, And the lowest in shrimp shrimp that is not given its crude protein 23.57 x 106 cells / ml. Similarly, the highest Differential Haemosite Count (DHC) also occurred in shrimps fed commercial and added crude protein, 26.57% aged 60 days in ponds and 14.99% low on shrimp not given 90 day crude protein in ponds . Results of parasite shrimp infestation examination exposed with crude protein showed that the highest Zoothamnium penaei infestation was obtained in shrimp fed with artificial feed and not added crude protein Zoothamnium penaei that is 63,35% in shrimp age 90 days. While the shrimp were given artificial feed and added crude protein Zoothamnium penaei infestation Zoothamnium penaei highest of 14.27% in 90 days old shrimp.The highest specific rate of vaname shrimp growth also occurred in shrimp fed commercial and added crude protein Zoothamnium penaei highest of 53.46% and the lowest 16.15% in shrimps aged 90 days in ponds. The highest shrimp life occurrence occurred in commercial vaname shrimp and added crude protein Zoothamnium penaei age of 90 days which has a higher tendency than shrimp that is not given crude protein that is 72% and 21%. The addition of Zoothamnium crude protein to commercial feed as immunostimulant material may enhance immune response, specific growth and shelf life of 30, 60 and 90 days old shrimp in ponds, so that it can be developed as an immunostimulant material.Keyword: Litopenaeus Vannamei, Zoothamnium penaei, udang vanamei

Rainwater harvesting options for rice–maize cropping system in rainfed uplands through root-zone water balance simulation

A root-zone water balance model was used to simulate the soil moisture storage of maize (Zea mays L.) and rice (Oryza sativa L.) fields in rainfed uplands of eastern India. The simulation study revealed that short duration (95 days) rice fields in uplands remained under ponding condition for a period of 32 days during the entire growing season. Based on the ponding depth requirement in rice fields (50 mm), excess ponding was found for seven days only out of the 32 days of ponding. In contrast, the maize field under similar length of growing season (95 days) and topographic condition could produce harvestable runoff for 23 days. Furthermore, the rice crop was to remain under moisture stress for eight days during its mid-season stage, whereas the maize was found to be without stress during entire growing season. Before sowing of winter crops, the soil moisture in the seeding zone was determined to be depleted below germination soil moisture for 18 and 19 years out of 30 years of simulation in rice and maize fields, respectively. This implies that a second crop, following withdrawal of monsoon, is not possible without pre-sowing irrigation in three out of five years in rainfed uplands. Thus, complete substitution of rice by maize in uplands would create a better scope for rainwater harvesting. Alternatively, partial replacement of rice could be a viable option for meeting both rice demand of the people and harvesting of adequate rainwater for supplemental irrigation to crops in rainy and winter seasons.

Conducta alimenticia, supervivencia y crecimiento de juveniles silvestres de Graus nigra Philippi, 1887 en cautiverio (Perciformes: Kyphosidae)

Wild juveniles of Graus nigra were collected and acclimated for 30 days in ponds with open- water flow and ambient temperature; the specimens were given a formulated feed. Fish individuals were separated into six groups that were studied for 196 days. The average survival was 80%. The total length increased an average of 93.3% for large individuals (groups 4, 5, 6) and 125% for small ones (groups 1, 2, 3). The total weight showed an average increase of 434% for large fishes (groups 4, 5, 6) and 707% for small ones (groups 1, 2, 3). Graus nigra was found to tolerate captivity and handling, with a relatively high survival rate, making it an attractive species for aquaculture in Chile.

A mechanistic study of corrosion inhibiting admixtures

PurposeThis research aims to unravel the role of salt contamination and corrosion inhibiting admixtures in the processes of cement hydration and rebar corrosion.Design/methodology/approachMortar samples were prepared with NaCl and one of three corrosion inhibitors, sodium nitrite, disodium β‐glycerophosphate, or N,N′‐dimethylethanolamine, admixed. After 28 days curing, all steel‐mortar samples were ponded with 3 percent NaCl solution and electrochemical impedance spectroscopy (EIS) measurements were conducted periodically during the first 48 days. After 60 days of ponding by 3 percent NaCl solution, field‐emission scanning electron microscopy (FESEM) analyses were conducted on the fracture surface of the steel‐mortar sample.FindingsThe FESEM results revealed that admixing chlorides and inhibitors in fresh mortar changed the morphology and cement hydration product of hardener mortar at the steel‐mortar interface. The EIS data indicated that all inhibitors increased the polarization resistance of steel, implying reduced corrosion rate of the steel over 48‐day exposures to salt ponding. 0.05 M N,N′‐dimethylethanolamine was the most effective corrosion inhibitor, followed by 0.5 M sodium nitrite; whereas 0.05 M disodium β‐glycerophosphate was a slower and less capable corrosion inhibitor. The admixing of inhibitors in fresh mortar consistently increased the capacitance and decreased the electrical resistance of hardened mortar. The effect of sodium nitrite inhibitor on the resistance of steel mortar interfacial film compensated that of corrosive NaCl by participating to the formation of a protective ferric oxide film.Originality/valueThe results reported shed light on the complex role of admixed salt and corrosion inhibitors in cement hydration and their implications on the durability of steel‐reinforced concrete.

Effect of periphyton on growth performance of grey mullet, Mugil cephalus (Linn.), in inland saline groundwater ponds

Summary The present study attempts to assess the potential of artificial substrates to enhance fish production in inland saline groundwater ponds through periphyton production. Grey mullet, Mugil cephalus, was cultured for 100 days in ponds with substrate (treatment ponds) and without substrate (control ponds). To enhance the surface area, bamboo poles were used as substrate. The periphyton population, pigment concentration and hydrobiological characteristics of pond water were monitored. The studies revealed little difference in most of the water quality parameters observed in the two treatments. However, turbidity (27.0 ± 0.1–35.0 ± 0.1 Nephalo Turbidity Unit (NTU)), chlorophyll ‘a’ (6.6 ± 0.6–7.6 ± 0.6 μg L−1), plankton population (phytoplankton 8.4 × 103–9.4 ×103 numbers L−1; zooplankton 4.0 × 103–5.1 × 103 numbers L−1) and NH4–N (2.0 ± 0.2–2.3 ± 0.1 mg L−1) were high in the treatment with no additional substrate; however, in the treatment with substrate the total Kjeldahl nitrogen (9.8 ± 0.8–10.8 ± 0.7 mg L−1) and o-PO4 (0.1 ± 0.01–0.1 mg L−1) remained significantly (P < 0.05) higher. Highest periphyton biomass in terms of dry matter (DM) (0.8 ± 0.01–1.4 ±0.01 mg cm−2), ash free DM (0.4 ± 0.0–0.6 ± 0.01 mg cm−2), chlorophyll ‘a’ (3.1 ± 0.2–8.1 ± 0.8 μg cm−2) and pheophytin ‘a’ (1.9 ± 0.4–3.9 ± 0.5 μg cm−2) was observed at 50 cm depth in ponds provided with additional substrate. Fifteen plankton genera showing periphytic affinity colonized the bamboo substrates. Fish growth (mean fish weight 524.3 ± 8.7 g and SGR 2.5 ± 0.1) was significantly (P < 0.05) higher in ponds provided with additional substrate compared with control ponds (387.2 ± 6.0). Length–weight relationship (LWR) (W = cLn) also showed that the exponential value (‘n’) of length was high in substrate-supported ponds (n = 2.36) in comparison with controls (n = 1.09). These studies suggest that a periphyton-supported aquaculture system can be used successfully for the culture of herbivorous brackishwater fish species like M. cephalus in inland saline groundwaters and thus could contribute to the development of sound and sustainable aquaculture technology.

Dowel bars corrosion in concrete pavement

To study the effectiveness of sealants in reducing chlorides and water intrusion into pavement joint openings, nine 122 × 91 × 20 cm concrete slabs were fabricated. One slab was cast without a joint and was used as a control, two were cast with non-sealed joints, and the other six were cast with joints that were sealed, after the slabs were cured, with either type A (low modulus silicone) or type B (polyurethane) sealant, which are one-component rigid pavement joint sealants. Three dowel bars, used for load transfer, were installed below the joint at the mid-thickness of each slab. Two types of dowels were used: epoxy-coated and uncoated. A joint and crack beneath it were formed at the middle of the slab to simulate field conditions. To accelerate dowel bar corrosion and to examine pavement joint sealant effectiveness in abating chloride intrusion, the slabs were exposed to alternate ponding cycles of 6% sodium chloride solution (3 days of ponding and 4 days of drying). The corrosion progress was monitored by measuring corrosion current density using a three-electrode linear polarization device. Also, chloride contamination was measured by collecting powdered concrete samples from each slab at four different depths to determine the chloride concentration profile. The corrosion current density and chloride contents over a period of 18 months were analyzed. The results show that the unjointed slab has a higher resistance to chloride penetration, followed by jointed slabs sealed with type A sealant, then jointed slabs sealed with type B sealant. In addition, the performance of epoxy-coated dowel bars in abating corrosion was better than that of uncoated dowels.Key words: sealant, rigid pavement, concrete, chloride intrusion, corrosion, dowels.

Functional mechanisms of an inducible defence in tadpoles: morphology and behaviour influence mortality risk from predation

Abstract In many amphibian larvae a suite of morphological and behavioural characters varies together in an induced defence against predators, but it remains unclear which features are functionally related to defence. We independently manipulated behaviour and morphology in tadpoles of Hyla versicolor and assessed their consequences for swimming performance and predator escape. Data on burst swimming showed that tadpoles which accelerated rapidly were elongate, with shallow bodies and tails. Predator escape was measured by exposing tadpoles to predators (larval Anax dragonflies or larval Ambystoma salamanders) and recording time until death. Tadpoles were first reared for 30 days in ponds containing either caged Anax or no predators; individuals responded to predators by developing large brightly coloured tails and short bodies. We placed tadpoles of both morphological phenotypes into plastic tubs, and manipulated their behaviour using food and chemical cues from predators. Mortality risk experienced by the predator-induced phenotype was about half that of the no-predator phenotype, and risk increased with time spent swimming. An interaction between morphology and behaviour arose because increasing activity caused higher risk for tadpoles with deep tail fins but not shallow tail fins.

Dowel bars corrosion in concrete pavement

To study the effectiveness of sealants in reducing chlorides and water intrusion into pavement joint openings, nine 122 × 91 × 20 cm concrete slabs were fabricated. One slab was cast without a joint and was used as a control, two were cast with non-sealed joints, and the other six were cast with joints that were sealed, after the slabs were cured, with either type A (low modulus silicone) or type B (polyurethane) sealant, which are one-component rigid pavement joint sealants. Three dowel bars, used for load transfer, were installed below the joint at the mid-thickness of each slab. Two types of dowels were used: epoxy-coated and uncoated. A joint and crack beneath it were formed at the middle of the slab to simulate field conditions. To accelerate dowel bar corrosion and to examine pavement joint sealant effectiveness in abating chloride intrusion, the slabs were exposed to alternate ponding cycles of 6% sodium chloride solution (3 days of ponding and 4 days of drying). The corrosion progress was monitored by measuring corrosion current density using a three-electrode linear polarization device. Also, chloride contamination was measured by collecting powdered concrete samples from each slab at four different depths to determine the chloride concentration profile. The corrosion current density and chloride contents over a period of 18 months were analyzed. The results show that the unjointed slab has a higher resistance to chloride penetration, followed by jointed slabs sealed with type A sealant, then jointed slabs sealed with type B sealant. In addition, the performance of epoxy-coated dowel bars in abating corrosion was better than that of uncoated dowels.Key words: sealant, rigid pavement, concrete, chloride intrusion, corrosion, dowels.

Effects of Clam Shrimp on Production of Walleye and Northern Pike, and a Review of Clam Shrimp Control Strategies

The dynamics of clam shrimp, Caenestheriella belfragei, populations in fish culture ponds were studied to evaluate their effect on yield of fingerling northern pike, Esox lucius, or walleye, Stizostedion vitreum. The studies were carried out on twenty-three 0.64-ha ponds during the culture season for northern pike and on 19 of the same ponds during the season for walleye. Ponds were filled between April 26 and May 12, 1992. The ponds were drained after 3 to 4 weeks to harvest the pike, then refilled after 0 to 4 days (mean = 1.5 days) to raise walleye. Adult clam shrimp were observed in 12 of the 23 ponds during northern pike culture and in 10 of the 19 ponds during walleye culture. Northern pike were cultured up to 29 days in ponds with clam shrimp, while pike were cultured a maximum of 22 days in ponds without clam shrimp. Survival and yield (fishha) of northern pike were significantly (P < 0.05) lower in ponds with clam shrimp, compared with survival and yield in ponds without clam shrimp. Similar differences, although not significant, were seen in walleye culture ponds. Northern pike and walleye were cultured longer in ponds with clam shrimp, implying that fish growth is reduced in culture ponds with clam shrimp. The majority of large clam shrimp found during the walleye culture season were most probably hatched during northern pike culture. When used in tandem to raise northern pike and walleye, ponds should be thoroughly dried between culture periods to prevent development of clam shrimp during the walleye culture.

Reproductive Performances of Crossbred and Pure-Strain Channel Catfish Brood Stocks

Pure-strain and interstrain (crossbred) channel catfish Ictalurus punctatus were compared for spawning day, spawning rate (percent of replicate pairs that spawned), fecundity, egg size and hatchability, and survival of offspring. Crossbred fish usually spawned earlier (P < 0.05) than pure-strain channel catfish. As 3-year-olds, crossbred fish had higher spawning rates and fecundity than purebred fish, and their output of juveniles (number surviving 45 days in ponds, per kilogram of female parent) was greater. As 4-year-olds, pure-strain fish improved their performances, and crossbreds lost most of their relative advantages. Brood stock derived from crosses of four strains spawned earlier than those from two-strain F2 crosses, but their surviving offspring were no more numerous. The main value of cross-strain breeding is to produce channel catfish that mature earlier in life and spawn sooner in the season than purebreds. Received July 16, 1982 Accepted March 4, 1983

Field studies of water and salt movement in an irrigated swelling clay soil. I. Infiltration during ponding

Infiltration and deep percolation were measured during ponding of a saline sodic cracking clay soil, commonly used for rice production in the Riverina of New South Wales. Because gypsum may be used to ameliorate this soil for row cropping, the effect of incorporating gypsum into the plough layer was determined. Without gypsum, 292mm water infiltrated in 379 days of ponding, wetting the profile to approximately 2.1 m. In contrast when gypsum was incorporated in the plough layer, 605 mm of water infiltrated in 145 days, and water had penetrated beyond 4.5 m in 57 days. In the latter case, sufficient water percolated below 2.0m to raise the groundwater level by as much as 10m. The infiltration rate for the unameliorated soil was similar to values determined by others; for the ameliorated soil, infiltration behaviour was more like that of non-sodic self-mulching grey or brown clays, and raises questions regarding the amount of deep percolation when rice is grown on such soils.

Reclamation of saline soils at Kerang, Victoria, by ponding and pumping from an aquifer

Large areas of saline soils occur in the irrigation districts near Kerang in north-west Victoria. In the past, reclamation of these soils by leaching from intermittent irrigations has taken several years. The present work demonstrates- 1. The rapid reclamation of 2 1/2 acres of badly salted land by simultaneously ponding (fresh water) on the soil surface andpumping from a sand layer at 24feet. Thus, ten days of ponding and 56 hours of pumping from the aquifer reduced salinity in the top six inches of soil (0-6 in.) from 1.60 per cent NaCl to 0.05 per cent NaCl. Changes in soil p H and exchangeable cations, brought about by leaching and/or the we of gypsum, are reported. 2. The rapid leaching of salt from the surface soil of 2 acres of highly saline country by ponding alone.

Comparative Evaluation of Two Tilapias as Pondfishes in Alabama

Abstract The Java tilapia, Tilapia, mossambica, is a very efficient pondfish. Total production in ponds stocked with brood fish varied with different rates of feeding from 1,477.1 pounds per acre in 168 days to 4,383.9 pounds per acre in 191 days. Total production varied from 771.1 pounds per acre in 123 days in ponds stocked with 4,000 fingerlings to 2,945.7 pounds per acre in 111 days in those stocked with 20,000 fingerlings. The Nile tilapia, Tilapia nilotica, in limited tests with feeding, yielded a maximum of 4,003.7 pounds per acre in 208 days with adult stocking and 2,380 pounds per acre in 113 days with a stocking of 16,000 fingerlings. Combinations of largemouth bass, Micropterus salmoides, and the Java tilapia produced a higher percentage of harvestable-sized tilapia (6 inches or more) and a smaller total production than tilapia used alone. Highest production of harvestable fish was obtained by delaying stocking of bass until August, when many tilapias were too large to be eaten. Tilapias spawne...