Simulated Pond Research Articles

Changes in ventilation, metabolism, and behaviour, but not bradycardia, contribute to hypoxia survival in two species of Amazonian armoured catfish

Amazonian armoured catfishes exhibit substantial cardiac hypoxia tolerance, but little is known concerning organismal cardiorespiratory, metabolic, and behavioural responses to low oxygen levels. This study assessed the general mechanisms used by two species of armoured catfish, Glyptoperichthyes gibbceps and Liposarcus pardalis, to survive the frequent periods of hypoxia encountered in the Amazon River. The gill ventilation rate (fv) and heart rate (fh) were studied under controlled hypoxia in aquaria and under natural hypoxia in a simulated pond. Glyptoperichthyes gibbceps were fitted with radiotelemetry tags and held in field cages to study their habits of depth selection and air breathing. When denied aerial respiration under hypoxia in aquaria, G. gibbceps increased fv, but neither they nor L. pardalis exhibited alterations in fh. An increase in fvwas initially observed in G. gibbceps during pond hypoxia before aerial respiration was initiated and fvdeclined. Glyptoperichthyes gibbceps were hyperglycaemic under normoxia, and extremely large increases in plasma glucose and lactate concentrations were observed under hypoxia. Field studies confirmed their nocturnal behaviour and showed that air breathing increased at night, regardless of dissolved oxygen concentration. Our results show that armoured catfishes preferentially up-regulate fvand anaerobic metabolism and exhibit no bradycardia during hypoxia.

Removal of 85Sr, 134Cs, and 57Co Radionuclides from Acidic and Neutral Waste Solutions by Metal Doped Antimony Silicates

Antimony silicates doped with a metal, (M)x,ySb2-xSi2-yO7 (M=W, Ti, Nb), were studied for the removal of the key radionuclides 85Sr, 134Cs, and 57Co from nuclear waste solutions. Emphasis was given to the removal of radionuclides from acidic effluents for which no efficient commercial exchangers are available. Initial screening tests showed that the undoped antimony silicates (Sb:Si molar ratio ∼1:1) are highly selective for 85Sr. Distribution coefficients (KD) of 35,500 mL g−1 were obtained in 0.1-M HNO3. The antimony silicates also have high or reasonable selectivity for 57Co, 59Fe, and 241Am; but the selectivity for 134Cs is low. An attempt to increase the selectivity for 134Cs was conducted by doping the antimony silicate with Ti4+, Nb5+, or W6+. Best results were obtained with a material doped with tungsten, which resulted in an almost ten-fold increase in cesium selectivity in acid. The pyrochlore structure of the materials was also expected to have an effect in creating cesium selectivity. The granular antimony silicate doped with tungsten performed very well in column tests, and high-breakthrough capacities were observed for 85Sr (>17,000 BV with 1% breakthrough) and 134Cs (5,000 BV) in 0.1-M HNO3, and for 57Co (5,200 BV) and 85Sr (11,000 BV) in neutral simulated pond water. In general, the performance of the metal doped antimony silicates was considerably better than that of commercial materials such as a zeolite, a sodium titanate, and a silicotitanate, which function effectively only in neutral or alkaline conditions and were tested in parallel for reference.

Cadmium induced adaptive responses of certain biogeochemical cycling bacteria in an aquatic system

The population growth of some biogeochemical cycling bacteria (heterotrophic bacteria (HB), ammonifying bacteria (AB), ammonia oxidizing bacteria (AOB), denitrifying bacteria (DNB) and cellulose decomposing bacteria (CDB)), as well as ammonification, and denitrification rates were determined in simulated pond systems treated with full doses (FDs) and split doses (SDs) of cadmium. Reductions in bacterial density and nitrogen activity rates were more severe for the FD and SD followed by a slight recovery in both. Among the test groups, reductions were maximal in the AOB and DNB and lowest for the CDB populations, suggesting that the latter had greater potential for cadmium resistance. Bicarbonate alkalinity of water was found to exert a profound influence in counteracting cadmium stress in the system, as strong negative correlations between this parameter and bacterial mass were evident in the SD treatment. Though the aquatic microbial populations were greatly altered by cadmium stress, the normal operating range of the system was restored at a later time with the CDB population showing higher degree of adaptive responses.

Effects of Low Levels of Salinity on Production Characteristics of Fingerling Channel Catfish Reared from Fry

Abstract Two production trials were conducted to determine the effects of low levels of salinity on production characteristics of fingerling channel catfish Ictalurus punctatus reared from fry under simulated nursery pond conditions. In each trial, fry were stocked into 10,000-L earthen-bottom pools at salinities of 0, 1, 2, or 4 g NaCl/L and reared for 170-d to produce fingerling catfish. At termination, selected production characteristics (weight, length, total yield, percent survival, feed conversion ratio, and feed consumption) were determined. In both trials, final weight and length of fish was greatest at a salinity of 1 g/L. Total yields of fish reared at salinities of 0, 1, or 2 g/L were not significantly different; however, yield was reduced at a salinity of 4 g/L. Survival and feed conversion ratio were not significantly affected by salinity levels tested. The total amount of feed fed to fish reared at a salinity of 4 g/L was significantly less than that fed to fish reared at salinities of 0 and...

Responses of phosphate solubilizing bacteria to qualitatively different fertilization in simulated and natural fish ponds

The growth of phosphate solubilizing bacteria (PSB) was examined inresponse to pond fertilization with poultry dropping (PD) (12,500 kgha−1 y−1), cattle manure (CM) (25,000 kg ha−1 y−1), inorganic fertilizer (IF) consisting of urea (10.83 kg ha−1 y−1) and single super phosphate (43.52 kg ha−1 y−1) and inorganic-organic mixed fertilizers (PD:CM:IF − 1:1:1) in simulated fish ponds under alluvial and laterite soil conditions as well as in natural pondslocated in alluvial soil zone. The high correlation between dissolved oxygenand density of PSB implied the contribution of the latter in the aerobicorganic decomposition. The PSB were maximal in the PD, and minimal in theIF treatments. The distribution pattern of PSB was related to theautochthonous C/N ratio and the N/P ratios of water. Relatively low C/N ratios caused greater abundance of PSB. Increased fish production in PD treatments was clearly due to increased primary productivity and higher zooplankton abundance resulting from nutrient-grazing-detritus-microbial-food chain complex pathways.

Microhabitat Choice of Tadpoles of Seven Anuran Species.

The habitat choice of tadpoles of seven anuran species with respect to light and dark phases was studied using a choice tank with a simulated pond edge. In each trial, which lasted for 12 hrs, twenty freshly collected tadpoles (Gosner stage 32-38) of a given species were used. After introducing tadpoles into the choice tank, their number at the surface, up the water column, and on the substrate was recorded at half-hour intervals. Four trials each for day and night were conducted for each species. Tadpoles of Rana curtipes, Rana cyanophlyctis, and Rana temporalis, which possess a ventral mouth, predominantly occupied the substrate zone, whereas those of Bufo melanostictus, Polypedates maculatus, and Rana tigrina, which have an antero-ventral mouth, utilized both substrate and column zones but with a clear preference for the substrate zone. Within the substrate zone, the number of tadpoles of B. melanostictus, P. maculatus, R. temporalis, and R. tigrina was greater at night than in the daytime, whereas the opposite was true for R. curtipes. Of these five species response for day-night changes was prominent in P. maculatus. It is unclear whether variation in the number of tadpoles with respect to day and night is due to changes in the light intensity or temperature or oxygen levels. The tadpoles of R. cyanophlyctis did not show any response to day-night changes. On the other hand, the tadpoles of Microhyla ornata, which possess an antero-dorsally placed and highly simplified mouth (devoid of teeth) preferred the surface (64%) and column (28%) zones in both light and dark phases. The tadpoles of M. ornata are not easily spotted despite their surface occupancy due to their transparent appearance. The present study shows the existence of diversity in the microhabitat choice of the anuran tadpoles that correlates well with their morphological characteristics.

Evaluation of Decapsulated Artemia Cysts in Hatchery Diets for Channel Catfish Ictalurus punctatus Fry and Effects on Subsequent Fingerling Production

Abstract.— Two 10‐d hatchery growth trials were conducted to determine if differences in growth, body composition, and survival existed among catfish fry Ictalurus punctatus fed a diet of 100% catfish‐starter (CS) or CS in combination with decapsulated Artemia cysts (DAC) at 25%, 50%, or 75% of diet weight. A 120–d production trial was undertaken immediately following the first hatchery trial to evaluate the effects of diet on production characteristics (survival, length, weight, feed conversion ratio, and total yield) of fingerling catfish produced from hatchery‐raised fry. Fry fed diets containing DAC weighed 61–98% more (P < 0.05) than fry fed only CS. The size differential of DAC‐fed fry was maintained through 120 d of growth in simulated nursery ponds (0.001‐ha earthen‐bottom pools). The increased growth of fry fed DAC might have been related to differences in dietary lipid content, amino acid composition, or digestibility of CS and DAC. Body weights of fingerlings produced under simulated production conditions from fry fed hatchery diets containing 50% and 75% DAC were 17% and 25% higher, respectively, 130 d post‐hatch, than fingerlings produced from fry fed only CS. In addition, the total yield of fingerlings produced from fry fed 75% DAC was 17% greater that that of fingerlings produced from fry fed only CS. The increased performance of fingerlings produced from DAC‐fed fry could have resulted from their larger size at stocking, since larger fry might be capable of capturing natural food organisms and ingesting prepared diets more effectively than smaller fish. CS‐DAC diet combinations could be used to increase weight gain of hatchery‐raised fry if the cost‐benefit ratio of adding DAC to the standard hatchery diet warrants its use.

Enhancement of the fertilizer value of rock phosphate engineered through phosphate-solubilizing bacteria

Increasingly high costs of chemical fertilizers are major problems to the fish farmers of India. This was the main stimulus for searching for an alternative, naturally-occurring, dependable, biodegradable, phosphatic fertilizer. Phosphate-solubilizing bacteria (PSB) and solubilization of Mussoorie phosphate rock (MPR) were examined in simulated fish ponds using four treatments: (a) addition of compost of straw, waterhyacinth and cattle manure; (b) exogenous introduction of PSB, compost and MPR; (c) compost and MPR; and (d) bacteria-free compost, PSB and MPR. Exogenous introduction of PSB with the compost resulted in the highest concentrations of different species of phosphate in water or sediments among all treatments. This was attributable to the combined effects of the PSB population of both exogenous and compost origin with short generation time. The relationship between the phosphorus level of water and PSB population was expressed in exponential equations in all but compost treatment without MPR. The results of stepwise multiple regression analysis indicated that the MPR-leached phosphate was strongly influenced by PSB, followed by alkaline phosphatase in all treatments, except that treated only with compost.

Adaptive phenotypic plasticity in timing of metamorphosis in the common frog Rana temporaria

Unpredictable environments are expected to select for adaptive plasticity in traits enabling adjustment of phenotype to prevailing environmental conditions. Common frogs (Rana temporaria) breed frequently in ponds, which dry up before the aquatic larvae have metamorphosed, and consequently, plasticity in timing of metamorphosis in response to pond drying could be adaptive. We investigated the responses of half- and full-sib R. temporaria larvae to simulated pond drying in a factorial experiment to test whether there is adaptive phenotypic plasticity in timing of metamorphosis, and whether this plasticity is genetically determined. As expected under the adaptive hypothesis, we found that larvae exposed to the decreasing water treatment metamorphosed significantly faster than their sibs in the constant water treatments. Furthermore, age and size at metamorphosis were positively correlated in the constant water treatments, but negatively correlated in the decreasing water treatment. However, larvae from decreasing water treatment metamorphosed, on average, at a smaller size as compared to larvae from the constant water treatments, even after controlling for variation in developmental time. Since smaller size at metamorphosis is likely to be related to reduced fitness, this indicates that faster development may trade off with other components of fitness. The results further show that the amount of food received during the four first days of development influenced age and size at metamorphosis, reinforcing the view that early life nutrition may have a significant impact on later life fitness. Although there was a genetic component to developmental rates, we found no evidence for genetic variation in plasticity. In accordance with evidence from other studies, our results suggest existence of adaptive phenotypic plasticity in amphibian development.

On the use of micro-electrodes in fish pond sediments

The surface layer of fish pond sediments is characterized by very high microbial activity. Oxygen uptake by the microbes at the sediment surface leaves little oxygen to penetrate the sediment. In marine and freshwater lake sediments, oxygen only penetrated a few millimeters. In this study, oxygen penetration into the sediment layer in fish ponds and simulated fish ponds was measured with an oxygen micro-electrode. Oxygen profiles determined with micro-electrodes showed that oxygen does not penetrate deeper than 1 mm under quiescent conditions in intensive and semi-intensive fish pond sediments. Sediment oxygen consumption (SOD) at approximately 25°C, calculated from measured oxygen profiles, ranged from 45 to 50 mg O 2/m 2 per h. Change in water temperature and the addition of formaldehyde showed that most of the oxygen consumption in the sediment surface layer is related to biological activity. Redox potential profiles of fish pond sediments measured with a micro-platinum electrode, showed reducing conditions conducive to sulfide formation at 2–4 mm below the sediment surface. Nitrate addition to the overlying water poised redox potential above 300 mV to a sediment depth of about 15 mm. Nitrate thus buffered the sediment–water interface against reducing conditions in the sediment and the possible diffusion of toxic reduced end products to the water.

The uptake of radioisotopes onto clays and other natural materials

The leaching of137Cs and90Sr from Surrey Earth montmorillonite and Silver Hill illite has been studied. Three forms of the clays, calcined and uncalcined and their composites with cement, were leached with four leachants, deionized water, and simulated sea ground and storage pond waters. Results were expressed as the cumulative fraction of activity leached against the square root of time, and used to compute diffusion coefficients. These suggested that all the leaching processes studied were slow (10−22 to 10−18 m2.s−1).

Terrestrial hibernation in the northern cricket frog,Acris crepitans

We used laboratory experiments and field observations to explore overwintering in the northern cricket frog, Acris crepitans, in southern Ohio and Indiana. Cricket frogs died within 24 h when submerged in simulated pond water that was anoxic or hypoxic, but lived 8-10 days when the water was oxygenated initially. Habitat selection experiments indicated that cricket frogs prefer a soil substrate to water as temperature decreases from 8 to 2°C. These data suggested that cricket frogs hibernate terrestrially. However, unlike sympatric hylids, this species does not tolerate extensive freezing: only 2 of 15 individuals survived freezing in the -0.8 to -2.6°C range (duration 24-96 h). Cricket frogs supercooled when dry (mean supercooling point -5.5°C; range from -4.3 to -6.8°C), but were easily inoculated by external ice at temperatures between -0.5 and -0.8°C. Our data suggested that cricket frogs hibernate terrestrially but are not freeze tolerant, are not fossorial, and are incapable of supercooling in the presence of external ice. Thus we hypothesized that cricket frogs must hibernate in terrestrial sites that adequately protect against freezing. Indeed, midwinter surveys revealed cricket frogs hibernating in crayfish burrows and cracks of the pond bank, where wet soils buffered against extensive freezing of the soil.

Effects of Selected Water Quality Variables on the Persistence of Tannic Acid and Related Compounds under Simulated Aquaculture Conditions

Tannins have potential commercial applications in aquaculture for the prevention of piscine diseases and off-flavor in fish. Selected water quality variables, such as temperature, pH, dissolved oxygen, light intensity, total hardness and total alkalinity, and available nutrients found in fish ponds were examined for their influence on the fate of gallic acid, methyl gallate, propyl gallate, and tannic acid. It was determined that total hardness and alkalinity were the most effective factors in the dissipation of tannin compounds. High levels of selected water quality variables were significantly different from low levels in their ability to transform tannin compounds. It was also found that natural suspended solids were effective in precipitating 60% of the methyl gallate and 81.3% of the propyl gallate per week from solution. Abiotic processes, such as physical transportation and chemical transformation, affected the fate of tannin compounds in a simulated fish pond. This study may guide the use of tannins as a feed additive or disease treatment in the management of fish-farming problems.

Laboratory Evaluation of a Methyl Anthranilate Bead Formulation on Mallard Feeding Behavior

We applied methyl anthranilate (MA) bead formulation coded JR930413 to bottom sediment in a simulated pond setting to evaluate its repellency to captive mallards (Anas platyrhynchos). We applied JR930413 at a rate of 21.7 kg/ha or 7 bead/cm 2 to bottom sediment. Methyl anthranialte bead formulation JR930413 was effective in reducing time mallards spent in pools (P ≤ 0.01). Application of JR930413 to contaminated waterfowl feeding areas at 21.7 kg/ha could reduce feeding and mortality and warrants further testing in the field.

Modeling the dynamics of double-diffusive scalar fields at various stability conditions

Abstract This paper presents some results of mathematical modeling and numerical computation of the dynamics of the temperature and concentration fields in simulated salt-gradient solar ponds, which are commonly used for collection and long-term storage of solar- and otherwise-generated heat. The pond has been treated as a two-layer, double-diffusive system, infinite in the horizontal plane, initially stably stratified by downward salinity gradient and with a uniform (or stably stratified) temperature distribution, which has been subjected to stratification disturbance by supplying heat from the bottom. The method of simulation employs a two-equation model of turbulence with variable turbulent Prandtl-Schmidt numbers, modified to account for thermal and mass buoyancy. The predictions obtained agree well with several sets of experimental data available in the literature.

Relative status and contribution of sediment phosphorus and nitrogen in carp culture system fertilized with various combinations of rockphosphate

Growth performances of advanced fry of Indian major carps. Labeo rohita (Hamilton). Catla catla (Hamilton) and Cirrhinus mrigala (Hamilton), were examined in simulated pond systems using monthly application of the following fertilizers in six treatments: Mussoorie rockphosphate (MPR) in low (100 kg P2O5 ha−1) and high doses (200 kg P2O5 ha−1), single superphosphate (SSP) (50 kg P2O5 ha−1), single superphosphate mixed with rockphosphate (1:1 by weight: 50 kg P2O5), compost (C) (water hyacinth and cattle manure) and composted rockphosphate (MPR-C). The amount of available P in surface sediment of MPR-C did not differ from that in either the SSP or the MPR + SSP treatment, whereas the total and available N contents differed greatly. There was an inverse relationship between the time to reach phosphate peak of water and the retention time of fertilizer in surface sediments. It is evident that total P of surface sediment was the most significant contributor to fish growth in exclusively MPR treatments, whereas total P and total N of surface sediments are involved in the MPR treatments in combination with compost or SSP.

Determination of phosphorus saturation level in relation to clay content in formulated pond muds

An experiment was conducted to determine the amount of P needed to saturate simulated fish pond sediments, formulated to contain six levels of clay (0, 30, 41, 64, 73 and 81% by weight). A series of cylindrical cement tanks were filled to 20 cm depth with the six sediment types and triple superphosphate (TSP) solution was added to reach P saturation in sediment. Results showed that all sediment types reached constant inorganic-P concentration in the upper 5 cm after 12 weeks of TSP application, and P adsorption capacity of sediment increased with increasing clay content. Sediment P adsorption was slower and not significant ( P > 0·05) below 5 cm depth except in the sediment type containing 0% clay. Regression analysis showed that the rate and adsorption capacity of P in sediment are primarily governed by clay content and its dominant minerals. While organic-P and loosely bound-P are commonly deposited in sediment, most inorganic-P is adsorbed by cations to form cation-P complexes. The linear relationship between cation-P saturation level and the percentage of clay in sediment is highly significant ( r 2 = 0·84, P < 0·001) and, therefore, maximum adsorption capacity of cation-P in pond sediment can be approximated by Y = 0·019 X (where Y represents the 100% saturation level in mg P g −1 soil, and X is the percentage of clay in the sediment). In practice, the level of P saturation in sediment can be approximated by the initial cation-P and clay contents in the top 5 cm of pond mud using the equation: P saturation (%) = initial cation-P (mg g −1 soil) × 100/P adsorption capacity (mg g −1 soil).

The interactive effects of low pH, toxic metals, and DOC on a simulated temporary pond community

The effects of pH, potentially toxic metals, and dissolved organic carbon (DOC) on a freshwater, palustrine wetland assemblage (three amphibian species, one mosquito genus, and 18 genera of algae) were examined in 500 liter outdoor mesocosms. The design was fully factorial and exposure levels were set to represent concentrations that occur naturally in temporary ponds in central Pennsylvania, an acid-impacted region of the USA. Water chemistry was precisely regulated by use of an artificial pond water rather than using stream water or well water with partially unknown composition. Jefferson ( Ambystoma jeffersonianum) and spotted salamanders ( A. maculatum) were negatively impacted by low pH and high metal concentrations. Wood frogs ( Rana sylvatica) were negatively impacted by high DOC and low pH. These negative effects included increased time to metamorphosis and decreased survival and wet body mass at metamorphosis. Mosquito emergence was unaffected by pH, metals, or DOC. All three abiotic factors (metals, pH, and DOC) interacted to determine algal taxonomic composition. Hence, abiotic conditions may determine amphibian reproductive success both directly and indirectly, via effects on algae, since a primary food source of salamanders, zooplankton, are affected by changes in algal composition. These complex interactions should be considered in evaluating the possible toxicity of pond waters to fauna and flora. Until now, pH alone has been considered the primary limiting factor for amphibians breeding in temporary ponds.

The Value of Simulated Pond Communities in Mesocosms for Studies of Amphibian Ecology and Ecotoxicology

We provide a review of literature concerning the use of artificial pond communities in static, outdoor, above-ground tanka (mesocosms) for ecological studies of amphibians. This approach has been widely used to evaluate the interaction of biotic variables, and less often biotic and abiotic variables. Although simulated pond communities offer unusually attractive properties for evaluating the effects of xenobiotics on aquatic ecosystems, this approach has received only limited attention as a potential model system for studying the effects of toxicants on amphibian communities. We provide a summary of results and experimental designs from past studies in order to illustrate the general protocols used and complex interactions between biotic and abiotic variables that can be simulated in artificial pond communities

Use of amorphous zirconium phosphate for the treatment of radioactive waste

Amorphous zirconium phosphates (ZrP) loaded with 137Cs and 90Sr/90Y isotopes are contained in cements and theirleaching behaviour with simulated pond, ground, sea and deionized waters, evaluated. Acceptable compositions of the waste mixes in terms of the proportions of various components and their solid to liquid ratios, are also described. The first paper in this series sought to establish a current commercially available amorphous zirconiuin phosphate (ZrP) as a medium for aqueous nuclear waste treatment. 1 This paper extends this to encapsulation studies.