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Biochemistry, Biophysics, and Structural Biology Commons

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Articles 1 - 4 of 4

Full-Text Articles in Biochemistry, Biophysics, and Structural Biology

Frontiers In Otolith Chemistry: Insights, Advances And Applications, B. D. Walther, K. E. Limburg, C. M. Jones, J. J. Schaffler Jan 2017

Frontiers In Otolith Chemistry: Insights, Advances And Applications, B. D. Walther, K. E. Limburg, C. M. Jones, J. J. Schaffler

OEAS Faculty Publications

The rapid proliferation of publications employing chemical assays of fish hard parts, and otoliths in particular, has led to many novel insights into the migration patterns, life history strategies and mixed stock dynamics of fishes across the globe (Campana et al., 2000; Elsdon et al., 2008; Walther & Limburg, 2012). These insights include uncovering diverse migratory strategies within species and populations (Kerr et al., 2009; Hogan et al., 2014; Schoen et al., 2016), quantifying rates of mixing among stocks across management boundaries (Rooker et al., 2008; Walther & Thorrold, 2010) and estimating the relative importance of particular natal habitats for recruitment (Thorrold et al., 2001; Schaffler et al., 2015; Anstead et al., 2016). Much of this work has been driven by advances in instrumentation that allow more precise and higher throughput analyses with greater spatial and ...


Beyond Zar: The Use And Abuse Of Classification Statistics For Otolith Chemistry, C. M. Jones, M. Palmers, J. J. Schaffler Jan 2017

Beyond Zar: The Use And Abuse Of Classification Statistics For Otolith Chemistry, C. M. Jones, M. Palmers, J. J. Schaffler

OEAS Faculty Publications

Classification method performance was evaluated using otolith chemistry of juvenile Atlantic menhaden Brevoortia tyrannus when assumptions of data normality were met and were violated. Four methods were tested [linear discriminant function analysis (LDFA), quadratic discriminant function analysis (QDFA), random forest (RF) and artificial neural networks (ANN)] using computer simulation to determine their performance when variable-group means ranged from small to large and their performance under conditions of typical skewness to double the amount of skewness typically observed. Using the kappa index, the parametric methods performed best after applying appropriate data transformation, gaining 2% better performance with LDFA performing slightly better ...


Demographic Assessment Of The Blue Crab (Callinectes Sapidus) In Chesapeake Bay Using Extractable Lipofuscins As Age Markers, Se-Jong Ju, David H. Secor, H. Rodger Harvey Jan 2003

Demographic Assessment Of The Blue Crab (Callinectes Sapidus) In Chesapeake Bay Using Extractable Lipofuscins As Age Markers, Se-Jong Ju, David H. Secor, H. Rodger Harvey

OEAS Faculty Publications

The blue crab (Callinectes sapidus) plays an important economic and ecological role in estuaries and coastal habitats from the Gulf of Mexico to the east coast of North America, but demographic assessments are limited by length-based methods. We applied an alternative aging method using biochemical measures of metabolic byproducts (lipofuscins) sequestered in the neural tissue of eyestalks to examine population age structure. From Chesapeake Bay, subsamples of animals collected from the 1998-99 (n-769) and 1999-2000 (n=367) winter dredge surveys were collected and lipofuscin was measured. Modal analysis of the lipofuscin index provided separation into three modes, whereas carapace-width data ...


Aspects Of Larval Ecology Of Squilla Empusa (Crustacea, Stomatopoda) In Chesapeake Bay, Steven G. Morgan Jan 1980

Aspects Of Larval Ecology Of Squilla Empusa (Crustacea, Stomatopoda) In Chesapeake Bay, Steven G. Morgan

OEAS Faculty Publications

Larvae of Squilla empusa were collected from the plankton and were laboratory-reared in 16 combinations of temperature and salinity to determine their tolerances. Larvae survived longer and molted more frequently when reared at 25%, and 20° or 25° C, which corresponds to the natural conditions of Chesapeake Bay when the larvae were collected.

A 2 year planktonic survey conducted in the lower region of the bay by the Virginia Institute of Marine Sciences was compared with a survey made at the bay mouth in 1976. The seasonal occurrence of Squilla empusa larvae extended from the last week of July until ...