Juvenile salmon (Oncorhynchus spp.) use of reservoir food webs is understudied. We examined the feeding behavior of subyearling Chinook salmon (O. tshawytscha) and its relation to growth by estimating the functional response of juvenile salmon to changes in the density of Daphnia, an important component of reservoir food webs. We then estimated salmon growth across a broad range of water temper...

Most fish cannot hear frequencies above 3 kHz, but a few species belonging to the subfamily Alosinae (family Clupeidae) can detect intense ultrasound. The response of adult specimens of the European allis shad (Alosa alosa) to sinusoidal ultrasonic pulses at 70 and 120 kHz is tested. The fish showed an intensity-graded response to the ultrasonic pulses with a response threshold between 161 and ...

Walleye (Sander vitreus) are typically associated with shoals, drop offs, or in aquatic vegetation near shore (Foust and Haynes 2007), while in some lakes and reservoirs walleye make more use of pelagic waters (Ager 1976; Festa 1987; Palmer 2005, Byrne et al. 2009). Walleye have been stocked at a target rate of 80,000/year from 2000-2006 and 40,000/year since 2007. Here, walleye occupy rocky sh...

Phylogenetic relationships among five species of Alosa (Alosa maeotica, A. tanaica, A. caspia, A. immaculata and A. fallax nilotica) was examined with sequence analyses of mtDNA ND5/6 region. In pairwise comparision, the highest genetic differences were observed between A. caspia and A. tanaica (0.691), and lowest between A. maeotica and A. tanaica (0.491). In minimum evolution tree, two phylog...

Fish pass monitoring is essential to ensure the device's effectiveness as a mitigation measure for river impoundment, guaranteeing longitudinal continuity of rivers, which particularly important diadromous fish that depend on obligatory migrations freshwater reproduction (anadromous) or feeding areas (catadromous) complete their life cycle. The upstream migration anadromous allis (Alosa alosa L...

American shad is an anadromous fish that displays asynchronous ovarian development. In an effort to enhance our understanding of the reproductive cycle of this primitive Teleostei species, and provide better management tools for the Chesapeake fishery, we have conducted studies of its gonadal and hormonal cycles. We developed various assays to measure reproductive endocrine factors including: 1...

Understanding food-web ecology is valuable to conservation by linking interactions of multiple species together and illustrating the functionality of trophic exchange. Alosa alabamae (Alabama Shad), an anadromous species, reproduces in northern Gulf of Mexico drainages from February through May, and for this study, the Pascagoula and Apalachicola rivers were chosen to sample juvenile Alabama Sh...

—We analyzed the dynamics of eight populations of anadromous alewife Alosa pseudoharengus to determine their habitat carrying capacity, their maximum reproductive rate, and whether depensation occurs at low abundances. When spawner–recruit models are fit to data sets for individual alewife populations, the resulting parameter estimates are often poorly determined, biologically unrealistic, and ...

Studies that span entire species ranges can provide insight into the relative roles of historical contingency and contemporary factors that influence population structure and can reveal patterns of genetic variation that might otherwise go undetected. American shad is a wide ranging anadromous clupeid fish that exhibits variation in demographic histories and reproductive strategies (both semelp...