Species In Ponds Research Articles

Effects of salinity on the reproductive performance of Apocyclops royi (Copepoda, Cyclopoida)

The cyclopoid copepod Apocyclops royi is a dominant species in inland saline ponds and estuarine areas in southern Taiwan. Although it is an ideal live prey candidate for larval fish feed because of its short life cycle, small body size, and easy maintenance, the ecology of the species is poorly documented. In this study, we conducted a series of individual and population experiments to investigate the effects of salinity on the reproductive performance of A. royi. In the population experiments, 8 ovigerous females were cultivated in an 800-mL culture medium at designated salinities (0, 5, 10, 15, 20, 25, 30, and 35) for 14days, after which the population growth, composition of different developmental stages, and clutch size of adult females were quantified. Subsequently, individual experiments were conducted to test the salinity effects (0, 10, 20, and 30) on the nauplii and clutch production of 12 pairs of copepods over 14days. The results showed that salinity significantly affected the reproduction of A. royi, and that 20 was the optimal salinity for attaining their highest productivity. In the population experiments, significantly lower population growth rates were obtained at the extreme salinity treatments (0 and 5, and 30 and 35). However, a reduced clutch size was revealed only at salinities 0 and 5. In the individual experiments, a significantly lower nauplii and clutch production was found at salinities 0 and 30. Salinity had varying influences on A. royi across its different developmental stages. Our findings revealed the reproductive patterns of A. royi under different salinity conditions and indicated how salinity may affect A. royi in their natural habitat. The results offer a crucial recommendation on the manipulated processes for larval feeding in marine and brackish aquaculture hatcheries.

Performance of macrophyte indicators to eutrophication pressure in ponds

Aquatic macrophytes in ponds are considered as reliable indicators for detecting eutrophication pressure. In this study, the spatial distribution of total phosphorus (TP) and the ratio between transparency and water depth (ZSD/ZM) were characterized in Lake Baiyangdian, north China. Total P and ZSD/ZM were adopted to represent eutrophication pressure. The macrophyte indicators including richness of different species, diversity/evenness, biomass, and relative abundance for submerged/emergent (RAsub/eme) and sensitive/tolerant submerged species (RAsen/tol), were measured for each of the 38 ponds in the study area. Results showed that except richness of emergent and floating-leaved species, other macrophyte indicators were significantly correlated with TP and ZSD/ZM. Among them, evenness, biomass, RAsub/eme and RAsen/tol were selected to evaluate pond status because of their stronger response to TP. To evaluate the status for each pond, a scoring system was created by integrating TP and the four selected macrophyte indicators. We suggest that, control of external pollution sources and internal pollution sources, especially surface runoff from cropland reclamation and intensive use of fish feed from aquaculture, should be the focus of local managers. Inferred from the response of submerged species abundance to light availability, the value of ZSD/ZM should be no less than 0.52 to restore submerged species in eutrophic ponds.

Parametric linear hybrid automata for complex environmental systems modeling

Environmental systems, whether they be weather patterns or predator-prey relationships, are dependent on a number of different variables, each directly or indirectly affecting the system at large. Since not all of these factors are known, these systems take on non-linear dynamics, making it difficult to accurately predict meaningful behavioral trends far into the future. However, such dynamics do not warrant complete ignorance of different efforts to understand and model close approximations of these systems. Towards this end, we have applied a logical modeling approach to model and analyze the behavioral trends and systematic trajectories that these systems exhibit without delving into their quantification. This approach, formalized by Rene Thomas for discrete logical modeling of Biological Regulatory Networks (BRNs) and further extended in our previous studies as parametric biological linear hybrid automata (Bio-LHA), has been previously employed for the analyses of different molecular regulatory interactions occurring across various cells and microbial species. As relationships between different interacting components of a system can be simplified as positive or negative influences, we can employ the Bio-LHA framework to represent different components of the environmental system as positive or negative feedbacks. In the present study, we highlight the benefits of hybrid (discrete/continuous) modeling which lead to refinements among the fore-casted behaviors in order to find out which ones are actually possible. We have taken two case studies: an interaction of three microbial species in a freshwater pond, and a more complex atmospheric system, to show the applications of the Bio-LHA methodology for the timed hybrid modeling of environmental systems. Results show that the approach using the Bio-LHA is a viable method for behavioral modeling of complex environmental systems by finding timing constraints while keeping the complexity of the model at a minimum.

Pond macroinvertebrates of the Presidential Estate of Castelporziano (Rome): a review of ecological aspects and selecting indicator taxa for conservation

Macroinvertebrates of 49 (27 temporary and 22 permanent) ponds located in the Presidential Estate of Castelporziano (Rome) were studied from 1989 to 2004 to investigate their community ecology and to provide a first estimation of their conservation value. More than 300 taxa (about 70 % identified to species) were collected. The main environmental factors influencing the number of species in the study ponds were hydroperiod length, depth, surface area, dissolved oxygen concentration and macrophyte species richness and abundances. Permanent biotopes generally hosted higher number of taxa than temporary ones. Some taxa were exclusive or more abundant in a pond type. Functional organization (functional feeding groups, habits and resistance to desiccation) of the community appeared similar in the two pond types but differed among mesohabitats. Up to date, about 62 % of the taxa collected have an unknown status with respect to their distribution in Italy (common, rare, threatened and vulnerable). We identified 50 target species with peculiar ecological requirements and/or geographical distribution to promote effective practical basis for pond conservation in Italy. The distribution of rare, vulnerable or threatened species within the ponds studied suggests that the two pond types and all mesohabitats therein should be considered for the sampling procedure to obtain a correct evaluation of pond conservation.

Hatching phenology of Odonata species inhabiting temporary and permanent water bodies (Odonata: Lestidae, Aeshnidae, Libellulidae)

The hatching phenology of 15 Odonata species was studied under seminatural conditions to find out how the hatching modes of typical species of summer dry temporary waters (vernal ponds) differ from those of species inhabiting both permanent and temporary waters. We attempt to answer the following questions. (1) Do vernal pond species hatch earlier in the year than congeneric permanent water species? (2) Can hatching in vernal pond species be delayed under unsuitable environmental conditions, like drought? (3) Can eggs of vernal pond species survive for more than one year? Larvae of vernal pond species, Aeshna affinis, Lestes barbarus, L. dryas and Sympetrum flaveolum, hatched significantly earlier than their permanent water counterparts A. mixta, L. sponsa, L. virens, L. viridis, S. danae, S. depressiusculum, S. meridionale, S. sanguineum, S. striolatum and S. vulgatum. Only one vernal pond species, L. macrostigma, did not show this early hatching. In both vernal pond and permanent water species hatching ...

Spatial distribution, temporal variation and specificity of microhabitat of Tropisternus species (Coleoptera: Hydrophilidae) in permanent ponds.

The spatial distribution and temporal variation of 11 species of Tropisternus were analyzed in two permanent ponds located in the province of Corrientes, Argentina. Samples were collected every 15 days, between October 2010 and March 2011. The species recorded were Tropisternus collaris (Fabricius), Tropisternus ovalis Castelnau, Tropisternus laevis (Sturm), Tropisternus lateralis limbatus (Brullé), Tropisternus longispina Fernández & Bachmann, Tropisternus carinispina Orchymont, Tropisternus bourmeisteri Fernández & Bachmann, Tropisternus apicipalpis (Chevrolat), Tropisternus dilatatus Bruch, Tropisternus obesus Bruch, and Tropisternus ignoratus Knisch. The first four were present in higher proportions than the remaining during most of the study period. The spatial distribution of individuals was mostly related to the homogeneity or heterogeneity of the ecosystem in relation to microhabitats with aquatic vegetation: In ponds with different microhabitats, individuals were mainly aggregated, whereas in ponds with homogenous features, individuals were randomly distributed. However, when species were analyzed individually, the spatial distribution and the use of microhabitat by each species were different with respect to preference and behavior.

얕은 연못에서 담수 어류의 열성 스트레스 저감을 위한 피난처 개발 및 수질환경 조사 연구

The purpose of this study evaluates the water quality of artificial deep pool (ADP) during the late spring and summer. we monitored the water quality, as pH, dissolved oxygen (DO), temperature and conductivity at two stations (St. 1. open water, St. 2. in the ADP). The water quality in the ADP is very stable, and temperature and DO are lower than the open water (average value; temperature 1.4~3.2°C, DO 2.4~3.6 mg/L). In particular, daily variation of temperature in the open water showed above 4°C, but ADP remained stable. The water quality was analyzed using two-way analysis of variance (ANOVA). The results of the analysis showed difference about temperature, pH, DO, conductivity (two-way ANOVA, p<0.05). The ADP has created an aqua environment in thermal and DO gradients by depth. About 1.2 m, Temperature and DO were sharply decreased. The Rhodeus uyekii is dominant species in pond of this study. The ADP offers optimum water temperature (16.5~18.5°C) to the Rhodeus uyekii about spawning. Consequently, the ADP offers stable habitat than open water for fish and aquatic organisms during the summer. It is also a good shelter for fish from a thermal stress.

Wetland Loss and Waterbird use of Wetlands in Palwal District, Haryana, India: The Role of Agriculture, Urbanization and Conversion to Fish Ponds

Wetlands in tropical and sub-tropical landscapes are experiencing changes and loss due to urbanization and intensive human use, but there is sparse detailed understanding of how these affect use by wetland-dependent birds. Urbanization and conversion of community wetlands to private fish ponds are occurring rapidly in Haryana state in north India. We conducted a study in Palwal district, Haryana in 2013–2014 to simultaneously understand (i) rates and reasons for wetland loss between 1970s and 2000s, and (ii) relative importance of location (towns/ villages versus those amid agriculture) versus site-specific variables on the winter abundance of 31 waterbird species in these fish ponds. Wetland extent reduced by 52 %, and average wetland size reduced by 42 % between 1970s and 2000s. Expansion of urban areas converted 105 agricultural wetlands to town wetlands. Wetlands of different locations could not be differentiated using waterbird abundance suggesting that wetland conditions have been homogenized, in part due to conversions to fish ponds and in part due to urban expansions. Focal waterbird abundance was affected more due to human activities relative to location or vegetation. A complex combination of current management practices and historical determinants of wetland persistence appear to be driving waterbird use of wetlands in locations like Palwal.

Gene expression variation in duplicate lactate dehydrogenase genes: do ecological species show distinct responses?

Lactate dehydrogenase (LDH) has been shown to play an important role in adaptation of several aquatic species to different habitats. The genomes of Daphnia pulex, a pond species, and Daphnia pulicaria, a lake inhabitant, encode two L-LDH enzymes, LDHA and LDHB. We estimated relative levels of Ldh gene expression in these two closely related species and their hybrids in four environmental settings, each characterized by one of two temperatures (10°C or 20°C), and one of two concentrations of dissolved oxygen (DO; 6.5–7 mg/l or 2–3 mg/l). We found that levels of LdhA expression were 4 to 48 times higher than LdhB expression (p<0.005) in all three groups (the two parental species and hybrids). Moreover, levels of LdhB expression differed significantly (p<0.05) between D. pulex and D. pulicaria, but neither species differed from the hybrid. Consistently higher expression of LdhA relative to LdhB in both species and the hybrid suggests that the two isozymes could be performing different functions. No significant differences in levels of gene expression were observed among the four combinations of temperature and dissolved oxygen (p>0.1). Given that Daphnia dwell in environments characterized by fluctuating conditions with long periods of low dissolved oxygen concentration, we suggest that these species could employ regulated metabolic depression to survive in such environments.

Spatial and temporal organization in three syntopic species of the Scinax ruber group (Anura: Hylidae) in the Atlantic rainforest, southeastern Brazil

Coexistence of anuran species might lead to acoustic interference among communications, especially where species are closely related. This problem might be minimized through resource partitioning. To test this idea, we analysed calling with respect to temporal and physical space usage in three syntopic, closely related species (Scinax cuspidatus, Scinax aff. hayii and Scinax aff. x-signatus) in a temporary pond in the Atlantic rainforest. The chorus attendance of each species resulted from a different combination of factors in the rainy season. Although there was some temporal overlap of daily activity among species, peak activity time differed, particularly between the two species whose calls were most similar. Although all three species tend to aggregate in open microhabitats, their coexistence is apparently facilitated by differential use of vertical strata and organization of calling sites near the sites of conspecifics. Together, these factors apparently reduce acoustic interference among heterospecific calls.

Unravelling the impact of anthropogenic pressure on plant communities in Mediterranean temporary ponds

Identifying the respective role of environmental, landscape and management factors in explaining the patterns in community composition is an important goal in ecology. Using a set of 32 temporary ponds in northern Morocco we studied the respective importance of local (within the pond) and regional (density of ponds in landscape) factors and the impacts of different land uses on the plant species assemblages, separating pond and terrestrial species. The main hypotheses tested were that (1) species assemblages respond to both local and regional environmental factors, (2) anthropogenic pressure has a negative influence on the number of pond species, and that (3) human activities differ in their impact on pond biodiversity. The results showed that (1) local factors explain most of the variation in plant community composition, and (2) land use impacts the communities through changing local environmental conditions, leading to a loss of typical pond species. Aside from recreation, all other activities (grazing, drainage, agriculture and partial urbanisation) significantly reduced the number of pond species. The conservation strategy for rare pond species should focus on maintaining networks of oligotrophic ponds, while allowing only low-impact activities.

Non-chromatographic speciation of inorganic arsenic by atomic fluorescence spectrometry with flow injection hydride generation with a tetrahydroborate-form anion-exchanger

Two reaction conditions, with different HCl andl-cysteine concentrations, allow determination of both species in real tap, well, pond, and seawater samples down to 15 ng L−1.

Pond area and distance from continuous forests affect amphibian egg distributions in urban green spaces: A case study in Sapporo, Japan

We examined factors that affect egg distributions of amphibians, which are currently declining globally, in urban areas. We counted the number of egg masses of two amphibian species (Hynobius retardatus and Rana pirica) in ponds in urban green spaces during two years (2011 and 2012) and investigated the effects of local and landscape factors on them. Forest area in green spaces and pond area had positive effects, and distance from continuous forests in the suburbs and the rate of pond shore protection had negative effects on the number of eggs. Among these factors, distance from continuous forests and pond area had strong effects on egg distributions. These results suggest the importance of water habitat size and the need for colonization by amphibians from surrounding continuous forests. To conserve urban amphibian assemblages, the preservation of ponds with sufficient area and continuous forests close to urban habitats would be important.

Diurnal habitat segregation by tadpoles in two temporary ponds in an Atlantic Rainforest remnant, Northeastern Brazil

Tadpoles are found in diverse aquatic habitats, where they share resources in various dimensions. Tadpole assemblages were studied in two temporary ponds in Atlantic Rainforest. Our aim was to analyze the temporal and spatial distribution patterns and their correlation with abiotic factors. Tadpoles were sampled weekly using nets, from March to December 2008. Samples were collected during the day and at night, and taken near the shore and in the centre of the ponds. Samples in inshore and pond centres were taken from both areas with and without aquatic vegetation. The assemblage consisted of 15 species in pond A and 12 species in pond B. The majority of species was accidental, and used the pond continuously. The assemblage was predominantly diurnal, which may be related to greater activity rate. In pond A the tadpoles primarily used the centre of ponds, whereas in pond B tadpoles primarily used shore areas. However, some populations showed preferences for particular environments. In pond A, environmental heterogeneity in the centre had the greatest influence on tadpole abundance. Our data suggest that temporal distribution facilitated the coexistence of different species of tadpoles in the pond but this conclusion is tentative and requires verification. Hence, more data needs to be collected so that we can propose effective area management plans.

Egg Size Versus Clutch Size: Variation and Trade-off in Reproductive Output of Rana dalmatina and R. temporaria in a Pond near Bonn (Germany)

The common frog (R. temporaria) is a widespread and abundant species of woodland and agricultural landscapes in Europe and north-west Asia. In contrast, the distribution of the agile frog (R. dalmatina) is rather scattered and restricted mainly to deciduous and mixed forests in western, central and south-eastern Europe. Within their overlapping range, both species often breed in the same ponds. Although ecology of these brown frog species is well known in parts, many aspects of their biology possibly explaining niche differentiation and large and small scale distribution remain uncertain. Interspecific variation in reproductive output may be one key factor explaining local differences in their abundance and dispersal ability. Our study compares the reproductive output of both species in a single pond near Bonn (Germany) using data on egg size (diameter, egg mass), clutch size, body size, age, and body condition.

How can we conserve cold stenotherm communities in warming Alpine ponds?

Freshwater biodiversity has shown to be highly vulnerable to climate warming, alpine cold stenotherm populations being especially at risk of getting extinct. This paper aims at identifying the environmental factors favouring cold stenotherm species in alpine ponds. This information is required to provide management recommendations for habitats restoration or creation, needed for the mitigation of the effects of climate warming on alpine freshwater biodiversity. Cold stenotherm species richness as well as total (i.e. stenotherm and eurytherm) richness were analyzed for aquatic plants, Coleoptera and Odonata in 26 subalpine and alpine ponds from Switzerland and were related to environmental factors ecologically relevant for pond biodiversity. Our results confirmed that the set of environmental variables governing pond biodiversity in alpine or subalpine ponds is specific to altitude. Altitude and macrophyte presence were important drivers of cold stenotherm and total species richness, whereas connectivity did not show any significant relation. Therefore, the management of pond biodiversity has to be ‘altitude-specific’. Nevertheless, cold stenotherm species from the investigated alpine ponds do not show some specific requirements if compared to the other species inhabiting these ponds. Therefore, both total and cold stenotherm species richness could be favoured by the same management measures.

Replication of white spot syndrome virus (WSSV) in the polychaete Dendronereis spp.

This study investigated whether WSSV replicates in naturally infected Dendronereis spp., a common polychaete (Nereididae) species in shrimp ponds in Indonesia. To detect WSSV replication, (i) immunohistochemistry (IHC) using a monoclonal antibody against WSSV VP28 protein and (ii) nested RT-PCR using specific primers set for the vp28 gene to detect WSSV-specific mRNA were applied. WSSV immunoreactive-nuclei were detected in the gut epithelium of the polychaete and WSSV mRNA was detected with nested RT-PCR. This, together with the IHC results, confirmed that WSSV could replicate in Dendronereis spp. This is the first report showing that WSSV replicated in a naturally infected non-crustacean host.

Using Environmental DNA to Estimate the Distribution of an Invasive Fish Species in Ponds

Knowledge of the presence of an invasive species is critical to monitoring the sustainability of communities and ecosystems. Environmental DNA (eDNA), DNA fragments that are likely to be bound to organic matters in the water or in shed cells, has been used to monitor the presence of aquatic animals. Using an eDNA-based method, we estimated the presence of the invasive bluegill sunfish, Lepomis macrochirus, in 70 ponds located in seven locales on the Japanese mainland and on surrounding islands. We quantified the concentration of DNA copies in a 1 L water sample using quantitative real-time polymerase chain reaction (qPCR) with a primer/probe set. In addition, we visually observed the bluegill presence in the ponds from the shoreline. We detected bluegill eDNA in all the ponds where bluegills were observed visually and some where bluegills were not observed. Bluegills were also less prevalent on the islands than the mainland, likely owing to limited dispersal and introduction by humans. Our eDNA method simply and rapidly detects the presence of this invasive fish species with less disturbance to the environment during field surveys than traditional methods.

Seasonal nekton assemblages in a flooded coastal freshwater marsh, Southwest Louisiana, USA

Marsh flooding and drying may be key factors affecting seasonal nekton distribution and density because habitat connectivity and water depth can impact nekton accessibility to the marsh surface. Recent studies have characterized freshwater nekton assemblages in marsh ponds; however, a paucity of information exists on the nekton assemblages in freshwater emergent marshes. The principal objectives of this study are to characterize the seasonal nekton assemblage in a freshwater emergent marsh and compare nekton species composition, density, and biomass to that of freshwater marsh ponds. We hypothesize that 1) freshwater emergent marsh has lower taxa richness than freshwater marsh ponds; and 2) freshwater emergent marsh has a lower seasonal density and biomass than freshwater marsh ponds. Mosquitofish Gambusia affinis and least killifish Heterandria formosa were abundant species in both habitats while some abundant species (e.g., banded pygmy sunfish Elassoma zonatum) in freshwater ponds were absent in freshwater emergent marsh. Our data did not support our first and second hypotheses because taxa richness, seasonal density and biomass between freshwater emergent marsh and ponds did not statistically differ. However, freshwater emergent marsh was dry during the summer months and thus supports no fish species during this period. Additional long-term research on the effects of flow regime in the freshwater marsh on nekton assemblages would potentially improve our understanding of nekton habitat requirements.

Phytoplankton assemblage of a solar saltern in Port Fouad, Egypt

The present study is the first investigation of the phytoplankton community in one of Egypt’s saltworks. The phytoplankton composition and distribution in five ponds of increasing salinity were investigated in the solar saltern of Port Fouad. The phytoplankton community consisted of 42 species belonging to cyanobacteria (16), diatoms (12), dinoflagellates (11), Euglenophyceae (2) and Chlorophyceae (1). The number of species decreased significantly and rapidly with increasing salinity, varying between 33 species in the first pond (P1) and one species in the crystallizer pond (P5). Conversely, the total phytoplankton density, except that recorded in P1, increased significantly with rising salinity, fluctuating between 8.7 and 56×105 individuals l−1 in P2 and P5 respectively. In spite of the local variations in climate and nutrient availability, the phytoplankton composition, density and spatial variations along the salinity gradient were, in many respects, very similar to what has been observed in other solar saltworks. The pond with the lowest salinity (P1−< 52gl−1) was characterized by a significant diversity and blooming of diatoms and dinoflagellates. Intermediate salinity ponds (P2 and P3) with salinity∼112–180gl−1 exhibited a decline in both species richness and density, but the stenohaline blue green algae (Synechocystis salina) did flourish. The highly saline concentrating ponds and crystallizers (P4 and P5) with salinity∼223–340gl−1 were characterized by few species, the disappearance of blue green algae and the thriving of the halotolerant green alga Dunaliella salina.