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An important physiological constraint influencing distributions of coastal freshwater organisms is their tolerance for saline conditions. We experimentally evaluated salinity tolerance for three freshwater mussel species (Utterbackia imbecillis, Elliptio jayensis, and Glebula rotundata). Mussels were transferred abruptly from well water to one of five treatments (0 [control], 6, 12, 18 or 24 parts per thousand [ppt]) with no acclimation. Utterbackia imbecillis survived on average about 2 days at treatments ≥ 6 ppt, while Elliptio jayensis survived slightly longer (about 4 days). Glebula rotundata was most tolerant to salinity, surviving as well at 6 and 12 ppt as it did in the control. Additionally, G. rotundata...
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Temperature is an important factor in understanding biogeography and species composition. In south Florida, non-native fishes’ tolerance to low temperatures is a critical factor in delineating their geographic spread. We provide a literature review summarizing the current state of knowledge of low-temperature tolerances for all seventeen non-native fishes that have been found in Everglades National Park.
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Bullseye snakehead, Channa marulius, was first detected in 2000 in the southern Florida town of Tamarac and has been expanding its geographic range. Environmental DNA (eDNA) analysis is a newly-developed technique used to non-invasively detect cryptic or low-density species, or those that are logistically difficult to study. Genetic material shed into the environment through tissue and body fluids is concentrated from water samples and analyzed for the presence of target species eDNA. To help delineate bullseye snakehead’s geographic range, we developed and validated a species-specific eDNA assay for both quantitative and droplet digital PCR (ddPCR). We then used ddPCR to assess 16 locations in southeast Florida...
Categories: Data;
Tags: Aquatic Biology,
Ecology,
Everglades,
Genetics,
Southern Florida, All tags...
USGS Science Data Catalog (SDC),
Wildlife Biology,
environment,
environmental DNA,
invasive species,
non-invasive monitoring,
occupancy estimate,
range delimitation, Fewer tags
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In this report, we evaluate this hypothesis for croaking gourami Trichopsis vittata, a non-native species that has established a reproducing population, but has not successfully spread beyond its very small (5 km2) range. We suspected the inability of T. vittata to colonize new habitats may be due to biotic resistance by the native eastern mosquitofish Gambusia holbrooki.
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Loricariid catfish of the genus Pterygoplichthys have been introduced in many localities around the world. They are freshwater fishes, but may also use low-salinity habitats such as estuaries for feeding or dispersal. Here we report results of a field survey and salinity-tolerance trials for a population of Pterygoplichthys sp. collected in Kerala, India. In both chronic and acute salinity-tolerance trials, fish were able to withstand salinities up to 12 ppt with no mortality; however, fish transferred to salinities > 12 ppt did not survive. The experimental results provide evidence that non-native Pterygoplichthys sp. are able to tolerate mesohaline conditions for extended periods, and can easily invade the brackish...
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