Invasive species can have large effects on freshwater communities and ecosystems. Potamopyrgus antipodarum, a snail indigenous to New Zealand, has recently colonized North America. We documented the distribution density of P. antipodarum in major tributaries Madison River Greater Yellowstone Ecosystem, examined associations between native macroinvertebrates, experimentally how affected colonization substrates by other macroinvertebrates. In 1997 1998, we sampled benthic macroinvertebrates...

Summary 1. Studies of North American streams have shown that hydraulic parameters and stream geomorphology can explain unionid mussel abundance at both the reach catchment scale. However, few studies examined applicability hydrogeomorphic variables across broader spatial scales, such as whole catchments, or elucidated conditions under which spates affect populations in streams. 2. We quantified freshwater species richness their physical habitat 24 sites eight southern Appalachian catchments...

We quantified fish assemblages in 20 streams containing mill dams various physical conditions (dams intact, partially breached, or relict with normal flows) Alabama, USA, during the period from 2006 to 2008. used a backpack electroshocker sample three 150-m reaches per stream: 500 1000 m downstream of dam, 0 100 and upstream impoundment. Species- trait-based analyses revealed slightly different, but often complementary, information about assemblages. Fish species richness benthic differed...

Small dams are ubiquitous yet poorly understood features in many streams. Dam removal is being used increasingly stream restoration projects as a means to enhance habitat connectivity and ecosystem function. However, habitat- assemblage-level effects of small on mollusk assemblages documented. We examined associations between physicochemical variables at 22 (<10 m) 3rd–5th order Alabama sampled 66 reaches (3 reaches/dam) associated with intact, breached, relict dams. For each dam, we...

Ecological speciation is well-known from adaptive radiations in cichlid fishes inhabiting lentic ecosystems throughout the African rift valley and Central America. Here, we investigate ecological morphological diversification of a recently discovered lotic predatory Neotropical species flock subtropical South We document functional using geometric morphometrics, stable C N isotopes, stomach contents character evolution. This displays species-specific diets skull pharyngeal jaw morphology....

1. Dams, ubiquitous features in many lotic ecosystems, are believed to have broad-ranging and predominantly negative effects on stream biota. Whereas the impacts of larger dams well studied, few studies quantified small streams. 2. Recent surveys found numerous locations where mussels were abundant reaches immediately downstream from dams. We examined mussel shell growth resource conditions Sandy Creek, a (third-order) tributary Tallapoosa River east-central Alabama (U.S.A.), determine...

Abstract Earth's aquatic habitats are some of its most important ecosystems and support populations many imperilled species. The future demands growing human will increasingly stress resources on multiple spatial temporal scales, as highlighted by numerous authors when predicting trends in biodiversity key hotspots. Identifying stressors understanding potential linkages between these first steps to mitigating impacts at‐risk resources. Here, an overview is provided the established emerging...

Ontogenetic diet shifts were compared among five sympatric pike cichlids Crenicichla in a subtropical South American stream using stable C and N isotopes tissue stoichiometry (C:N). Within species, positively related to body size while C:N showed negative relationships. Stable isotopes, however, not any species. By modelling the switch piscivory gut content‐isotope‐body relationships, shown be species‐specific with regard both rate degree of piscivory. Compared other piscivorous lineages,...

Abstract Low‐head dams are ubiquitous in eastern North America, and small dam removal projects seek to improve habitat conditions for resident migratory fishes. Effects of varying status on local fish communities poorly documented, recent work suggests benefits maintaining fragmentation. We sampled at 25 (9 breached, 7 relict, 9 intact) three river basins Carolina, USA . Fishes were reaches/dam from 2010 2011. Study reaches located upstream (free‐flowing reaches), downstream (tailrace)...

Abstract Characterization of food web structure may provide key insights into ecological function, community or population dynamics and evolutionary forces in aquatic ecosystems. We measured stable isotope ratios 23 fish species from the Rio Cuareim, a fifth‐order tributary Uruguay basin, major drainage subtropical South America. Our goals were to (i) describe structure, (ii) compare trophic segregation at guild taxonomic scales (iii) estimate relative importance basal resources supporting...

Abstract The Tennessee–Tombigbee Waterway is among the largest and most expensive environmental engineering projects of 20 th century. waterway accommodates barge navigation between Tennessee River Drainage Mobile Basin through a series locks, dams, canals, dredged diverted streams. These structures have altered riverine habitat fragmented lotic habitats resulting in isolated freshwater mussel populations patches streams such as East Fork Tombigbee River, where 42 species were known...

ABSTRACT We investigated the spatial distribution and habitat associations of western pearlshell mussels (Margaritifera falcata) in a southwest Washington stream. Variation mussel occurrence differed with scale observations, being lower among study reaches higher within reaches. Additionally, exhibited highly aggregated, non-random pattern. The at large scales (across reaches) was associated dissolved oxygen shear stress. Mussel small (with 50 m wetted width, canopy, abundance gravel...

Ecological light pollution is increasing worldwide, but its threats to freshwater taxa and ecosystems are not well understood. Further, light-emitting diodes (LEDs) currently replacing incandescent, fluorescent, high-intensity discharge lights across much of the developed world. Cool-spectrum LED characterized by shorter wavelength, cool-hued light, whereas warm-spectrum longer warm-hued light. It unclear how spectral emissions produced will affect animals, especially species with strong...

Abstract Invasive species introduction is one of the major ongoing ecological global crises. Identifying factors responsible for success invasive key implementation effective management actions. The filter-feeding bivalve, Corbicula , particular interest because it has become ubiquitous in many river basins across North America and elsewhere. Here we sampled bivalve assemblages, environmental indicators, land cover parameters Ouachita highlands southeastern Oklahoma southwestern Arkansas,...

The Mobile Basin historically supported one of the most diverse freshwater mussel (Bivalvia: Unionidae) assemblages in North America. More than 65 species mussels are known from Basin, but it is difficult to determine how many were present historically. drainage's unique physical habitat was largely destroyed between late 1800s and mid-1900s by impoundment channel modifications larger rivers. Many that once common now restricted small headwater rivers mid-sized tributaries. Recent Coosa...