The brook silverside (Labidesthes sicculus) was the only atherinid species found in Lake Texorna, Oklahoma, from 1944 to 1953. Inland silversides (Menidia beryllina) were first collected in Lake Texoma in 1953 and had completely replaced Labidesthes by 1955. We conducted comparative studies of feeding mechanics and feeding efficiencies of Labidesthes and Menidia to see if there was a competitive differential between species that could have been a factor in the replacement of Labidesthes by Menidia. Menidia has a protrusible and tube-shaped mouth that is more successful capturing evasive copepod prey than the v-notched mouth of Labidesthes. While both species have similar feeding rates for slow-swimming daphnids, Menidia has higher feeding rates than Labidesthes for cyclopoid and calanoid copepods. Menidia's use of copepod prey is a competitive advantage over Labidesthes in laboratory competition experiments. We hypothesize the same advantage was an important factor in displacing Labidesthes from Lake Texoma.Key words: planktivory, Labidesthes sicculus, Menidia beryllina, Lake Texoma

In laboratory feeding trials, we analyzed the feeding behavior and selectivity of the cichlid, Sarotherodon galilaeum, for zooplankton prey from Lake Kinneret, Israel. The feeding behavior was dependent on fish size . Fish less than 20 mm SL fed on zooplankton as obligate particulate feeders . Fish from 20 to 42 mm SL fed either as particulate feeders or as filter feeders . Fish larger than 62 mm SL fed as obligate filter feeders . Particulate-feeding fish were size selective and had highest feeding electivities for large-sized zooplankton species . Filter-feeding fish had highest feeding electivities for zooplankton species with poor escape ability . In general, S . galilaeum predation pressure would be greatest on Ceriodaphnia reticulata, a large-bodied and easily captured species which is selected by both particulate-feeding and filter-feeding fish .

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Three years (2007-2009) of early season lakewide endothall treatments to control curlyleaf pondweed (Potamogeton crispus) were followed by 4 years (2010-2013) of early season spot endothall treatments in 65 ha Gleason Lake, Plymouth, Minnesota. Endothall treatments controlled heavy growth of curlyleaf on an annual basis in all 7 years, but long-term control, where no future treatments would be necessary, was not achieved. During the curlyleaf control program, coontail (Ceratophyllum demersum) distribution and abundance increased dramatically as curlyleaf distribution and abundance decreased. None of the other 3 native submersed plant species found in Gleason Lake increased in frequency over the 7 years of treatment. It is not clear what triggered the rapid coontail expansion or if its heavy growth will be sustained. During the same time period, Gleason Lake transparency increased while phosphorus and chlorophyll concentrations decreased. Water quality improvements in Gleason Lake were likely related to nutrient uptake by coontail growth.