The physiological response of juvenile steelhead (Oncorhynchus mykiss) to prolonged heat stress was examined by exposing replicated groups of fish to 25 consecutive days at 15°C, 23°C, and 25°C followed by a 55 day recovery period at 15°C. We found that at temperatures ≥25°C, steelhead consumed significantly less food per...
Blood levels of the egg yolk precursor vi-
tellogenin (VTG) can be used as a definitive marker for
the onset and progress of maturation in female teleosts.
In the present study, an enzyme-linked immunosorbent
assay (ELISA) was developed to measure VTG in blood
plasma from three species of temperate basses....
In the US Pacific Northwest, rockfishes Sebastes spp. have recently become a focus for increased management efforts; several species are currently managed under extreme conservation measures due to low population levels and intense fishing pressure. Rockfish recruitment is extremely variable, and a better understanding of the factors influencing recruitment and...
This study examined the potentially stressful
effects of tagging juvenile rainbow trout Oncorhynchus mykiss
with passive integrated transponder (PIT) tags by measuring
short-term (<120-h) changes in plasma concentrations of
cortisol and hepatic heat shock protein 70 (hsp70). In a
laboratory experiment, plasma cortisol levels were measured
in fish before they...
Concurrent measurements of predator and prey δ¹⁵N isotope values demonstrated that a cross-shelf
isotopic gradient can propagate through a marine food web from forage species to top-tier predators and
indicate foraging areas at a scale of tens of kilometers. We measured δ¹³C and δ¹⁵N in muscle tissues of
thick-billed murres...
We sought to characterize the distribution of juvenile walleye pollock Theragra chalcogramma in an area of intense predator-prey interactions and to describe habitat features that lead to their observed distributions. The distribution of juvenile walleye pollock around the Pribilof Islands in the southeastern Bering Sea in 2008 and 2009 was...
To address patterns of genetic connectivity in a mass-aggregating marine fish, we analyzed genetic variation in
mitochondrial DNA (mtDNA), microsatellites, and single nucleotide polymorphisms (SNPs) for Nassau grouper (Epinephelus
striatus). We expected Nassau grouper to exhibit genetic differentiation among its subpopulations due to its reproductive
behavior and retentive oceanographic conditions...
Full Text:
Mitcheson Y, Nemeth RS, Heppell SA, et
al. (2014) Population Structure and Phylogeography in Nassau Grouper
To address patterns of genetic connectivity in a mass-aggregating marine fish, we analyzed genetic variation in
mitochondrial DNA (mtDNA), microsatellites, and single nucleotide polymorphisms (SNPs) for Nassau grouper (Epinephelus
striatus). We expected Nassau grouper to exhibit genetic differentiation among its subpopulations due to its reproductive
behavior and retentive oceanographic conditions...
Nassau grouper Epinephelus striatus are a large bodied, top level predator that is ecologically important throughout
the Caribbean. Although typically solitary, Nassau grouper form large annual spawning aggregations at predictable times in specific
locations. In 2003, The Cayman Islands Marine Conservation Board established protection for a newly rediscovered Nassau
grouper...
Thiamine (vitamin B₁) deficiency is a global concern affecting wildlife, livestock, and humans. In Great Lakes salmonines, thiamine deficiency causes embryo mortality and is an impediment to restoration of native lake trout (Salvelinus namaycush) stocks. Thiamine deficiency in fish may result from a diet of prey with high levels of...