Ontogenetic Changes in Body Shape and the Scaling of Metabolic Rate in the American Eel ().

AbstractThe body mass () scaling of resting metabolic rate (RMR) may vary significantly throughout ontogeny for multiple reasons that are not perfectly understood. To compare two major geometric theories of metabolic scaling, surface area (SA) theory and resource transport network (RTN) theory, we tested whether ontogenetic shifts in metabolic scaling relate to changes in body shape in the American eel (). To do so, we compared the log-linear scaling exponents of RMR to () and to body length () in juvenile and subadult eels (glass and yellow eel life stages, respectively).

American eels produce and release bile acid profiles that vary across life stage.

The American eel (Anguilla rostrata) is an imperilled fish hypothesized to use conspecific cues, in part, to coordinate long-distance migration during their multistage life history. Here, holding water and tissue from multiple American eel life stages was collected and analysed for the presence, profile and concentration of bile acids. Distinct bile acid profiles were identified in glass, elver, yellow eel and silver eel holding waters using ultraperformance liquid chromatography high-resolution mass spectrometry and principal component analysis.

Exposure to synthetic hydraulic fracturing waste influences the mucosal bacterial community structure of the brook trout () epidermis.

Production of natural gas using unconventional technologies has risen as demand for alternative fuels has increased. Impacts on the environment from waste generated from these processes are largely unexplored. In particular, the outcomes of organismal exposure to hydraulic fracturing waste have not been rigorously evaluated.

The complete maternal mitochondrial genome sequences of two imperiled North American freshwater mussels: and (Bivalvia: Unionoida: Unionidae).

The freshwater mussels and historically inhabited rivers along the North American Atlantic coast from the Carolinas, U.S.A.

Reestablishing a host-affiliate relationship: migratory fish reintroduction increases native mussel recruitment.

Co-extirpation among host-affiliate species is thought to be a leading cause of biodiversity loss worldwide. Freshwater mussels (Unionida) are at risk globally and face many threats to survival, including limited access to viable host fish required to complete their life history. We examine the relationship between the common eastern elliptio mussel (Elliptio complanata) and its migratory host fish the American eel (Anguilla rostrata), whose distribution in the Chesapeake Bay watershed is limited, in part, by dams.

Linking otolith microchemistry and surface water contamination from natural gas mining.

Unconventional natural gas drilling and the use of hydraulic fracturing technology have expanded rapidly in North America. This expansion has raised concerns of surface water contamination by way of spills and leaks, which may be sporadic, small, and therefore difficult to detect. Here we explore the use of otolith microchemistry as a tool for monitoring surface water contamination from generated waters (GW) of unconventional natural gas drilling.

Draft Genome Sequence of a Picorna-Like Virus Associated with Gill Tissue in Clinically Normal Brook Trout, .

Here, we report a draft genome sequence of a picorna-like virus associated with brook trout, , gill tissue. The draft genome comprises 8,681 nucleotides, excluding the poly(A) tract, and contains two open reading frames. It is most similar to picorna-like viruses that infect invertebrates.

RNA sequencing analysis of transcriptional change in the freshwater mussel Elliptio complanata after environmentally relevant sodium chloride exposure.

To identify potential biomarkers of salt stress in a freshwater sentinel species, we examined transcriptional responses of the common mussel Elliptio complanata to controlled sodium chloride (NaCl) exposures. Ribonucleic acid sequencing (RNA-Seq) of mantle tissue identified 481 transcripts differentially expressed in adult mussels exposed to 2 ppt NaCl (1.2 ppt chloride) for 7 d, of which 290 had nonoverlapping intervals.

Regional assessment of persistent organic pollutants in resident mussels from New Jersey and New York estuaries following Hurricane Sandy.

Resident mussels are effective indicators of ecosystem health and have been utilized in national assessment and monitoring studies for over two decades. Mussels were chosen because contaminant concentrations in their tissues respond to changes in ambient environmental levels, accumulation occurs with little metabolic transformation and a substantial amount of historic data were available. Mussels were collected from 10 previously studied locations approximately a year after Hurricane Sandy.

Transcriptomic analysis of the mussel Elliptio complanata identifies candidate stress-response genes and an abundance of novel or noncoding transcripts.

Mussels are useful indicator species of environmental stress and degradation, and the global decline in freshwater mussel diversity and abundance is of conservation concern. Elliptio complanata is a common freshwater mussel of eastern North America that can serve both as an indicator and as an experimental model for understanding mussel physiology and genetics. To support genetic components of these research goals, we assembled transcriptome contigs from Illumina paired-end reads.

The effects of salinity exposure on multiple life stages of a common freshwater mussel, Elliptio complanata.

There is growing concern over the effects of increased salinization on freshwater organisms, which are largely unknown for unionid mussels. Adult and larval Elliptio complanata were exposed to low-level salt concentrations to determine the effects on mussel survival, physiology, and reproduction. Adults were exposed to salt concentrations of 0 parts per thousand (ppt), 2 ppt, 4 ppt, and 6 ppt NaCl and monitored over 7 d for mortality.

A tale of two rivers: implications of water management practices for mussel biodiversity outcomes during droughts.

Droughts often pose situations where stream water levels are lowest while human demand for water is highest. Here we present results of an observational study documenting changes in freshwater mussel communities in two southern US rivers during a multi-year drought. During a 13-year period water releases into the Kiamichi River from an impoundment were halted during droughts, while minimum releases from an impoundment were maintained in the Little River.

Species traits and environmental conditions govern the relationship between biodiversity effects across trophic levels.

Changing environments can have divergent effects on biodiversity-ecosystem function relationships at alternating trophic levels. Freshwater mussels fertilize stream foodwebs through nutrient excretion, and mussel species-specific excretion rates depend on environmental conditions. We asked how differences in mussel diversity in varying environments influence the dynamics between primary producers and consumers.

Three-dimensional kinematics of the breast during a two-step star jump.

Anecdotal reports suggest two-step star jumps cause excessive breast movement and discomfort, leading to recommendations for this activity as a diagnostic tool to determine effective breast support in a retail environment. The aim was to investigate multiplanar bare-breast kinematics during the two-step star jump and to establish the relationship between breast kinematics, discomfort and cup size. Thirty-nine females completed five two-step star jumps with no breast support after which breast discomfort was rated.

Context-dependent species identity effects within a functional group of filter-feeding bivalves.

We asked whether species richness or species identity contributed more to ecosystem function in a trait-based functional group, burrowing, filter-feeding bivalves (freshwater mussels: Unionidae), and whether their importance changed with environmental context and species composition. We conducted a manipulative experiment in a small river examining the effects of mussel assemblages varying from one to eight species on benthic algal standing crop across two sets of environmental conditions: extremely low discharge and high water temperature (summer); and moderate discharge and water temperature (fall). We found strong species identity effects within this guild, with one species (Actinonaias ligamentina) influencing accrual of benthic algae more than other species, but only under summer conditions.