The magnitude of community-wide dispersal is central to metacommunity models, yet dispersal is notoriously difficult to quantify in passive and cryptic dispersers such as many freshwater invertebrates. By overcoming the problem of quantifying dispersal rates, colonization rates into new habitats can provide a useful estimate of the magnitude of effective dispersal. Here we study the influence o...

The performance of three genotypes (LL, LR, RR) of tadpoles resulting from the hybrid mating system of Rana lessonae (phenotype L, genotype LL) and Rana esculenta (phenotype E, genotype LR) was determined in artificial ponds. The effects of interspecific competition and pond drying on growth, development, and survival of tadpoles were used to measure the performance of genotypes and the relativ...

The Makoba integrated mariculture pond system project (IMPS) has been on-going since 1998. Except for a period from mid 1999 to 2001, various water quality parameters, namely temperature, salinity, pH, dissolved inorganic nutrients and dissolved oxygen concentration and saturation, have been monitored continuously. In 2002, measurement of sediment oxygen demand (SOD) and consumption of oxygen b...

Larvae of. Culex tarsalis Coquillett and Culiseta inornata Williston are abundant in duck ponds within the San Joaquin freshwater marsh. Culex tarsalis are found year-round and Culiseta inornata are found during the winter months. Each duck pond has an area ofopen water ringed with emergent Scirpus californicus (bulrush) and Typha latifolia and Typha anpstifolia (cattails). Low densities of lar...

Untreated waters from ten farm ponds located in central, north central, southeastern, and southwestern Ohio were examined for numbers of coliforms, enterococci, thermodurics, thermophiles, and psychrophiles. The median population densities per 100 ml water for all ponds were: coliforms, 23; enterococci, 3.6; thermodurics, 6,000; thermophiles, 450; psychrophiles, 1,000. The results indicate that...

The rapid increase in the number of swine has caused pronounced environmental impacts worldwide, especially on water resources. As an aggregate, smallholdings have an important role in South American pork production, contributing to the net diffusion of pollution. Thus, duckweed ponds have been successfully used for swine waste polishing, mainly for nutrient removal. Few studies have been carri...

We experimentally tested whether two similarly sized generalist predators found in different habitats had similar effects on prey community patterns. Notophthalmus viridescens (the red-spotted newt) occurs primarily in temporary ponds, while Enneacanthus obesus (the banded sunfish) is restricted to permanent ponds. Larval anurans are an important prey assemblage found in both kinds of ponds. We...

The present study aimed at evaluating the composition, diversity and short-term temporal fluctuations of zooplankton communities in fish ponds. The study was carried out in two fish ponds, with 180 m(2) of water surface (6 x 30 m) each, located in the Aquiculture Centre of the Pindamonhangaba Fisheries Institute - São Paulo. The study was developed over eight weeks, from February 16 to April 6,...