Dr. DeVries teaches courses in Non-majors Introductory Biology and Fish Biology.
Research Interests
Dr. DeVries's research focuses on life histories, age and growth, and trophic interactions between fish species. He is particularly interested in examining how ontogenetic diet changes trophic interactions affect growth and life history aspects of endangered species and of sportfish.
Publications
Pectoral fin healing in fin spines and rays were examined in juvenile Atlantic sturgeon Acipenser oxyrinchus oxyrinchus following three different sampling techniques (n = 8-9 fish per treatment): entire leading fin spine removed, a 1-2 cm portion removed near the point of articulation, or a 1-2 cm portion removed from a secondary fin ray. Also, to determine whether antibiotic treatment influences healing, an additional group of fish (n = 8) was not given an injection of an oxytetracycline (OTC)-based antibiotic following removal of the entire leading fin spine. Following fin sampling, fish from different treatments were mixed equally between three large (4,000 I) recirculating systems and fin-ray healing and mortality were monitored over a 12 month period. To assess healing, blood samples were collected at 4 months to measure immune system responses, radiographs were taken at 4, 8 and 12 months to assess the degree of calcification in regions of damaged fins and fins were analyzed histologically at 12 months. Fish grew from a mean weight of 1.8 to 3.2 kg during the experiment and survival was near 100% in all treatments, with only one fish dying of unknown causes. Leukocyte counts, an indication of health status and survival were similar among treatments and in groups with or without antibiotic injection. Radiographs revealed mineralization took longer in fish with the entire leading fin spine removed and was the slowest near the point of articulation, presumably due to the greater structural support for the pectoral fin at this location. Histological sampling indicated spines and rays had similar healing patterns. Following injury, an orderly matrix of collagen bundles and many evenly spaced scleroblasts were present, transitioning to Sharpey fibres, with concentric layers forming lamellar bone. Healing and mineralization were characterized as periosteal osteogenesis and included embedded osteocytes surrounded by an osteoid seam. Chondroid formation was apparent in a few fractures not associated with treatments. The duration of time for external wound healing and internal mineralization of spines and rays depended on the fin treatment, with the slowest healing observed in fish with the most tissue removed, the entire leading fin spine.
P.J. Allen, R. DeVries, D.A. Fox, R.I. Gabitov, and W.G. Anderson. 2018. Trace element and strontium isotopic analysis of Gulf Sturgeon fin rays to assess habitat use. Environmental Biology of Fishes 101:469-488.
DeVries, R.J., and H.L. Schramm Jr. 2015. Similarities and differences in 13C and 15N stable isotope ratios in two non-lethal tissue types from shovelnose sturgeon. Journal of Applied Ichthyology 31:474-478.
DeVries, R.J., D. Hann, and H.L. Schramm Jr. 2015. Increasing capture efficiency of pallid sturgeon Scaphirhynchus albus (Forbes and Richardson, 1905) and the reliability of catch rate estimates. Journal of Applied Ichthyology 31:603-608.
P.J. Allen, Z.A. Mitchell, R.J. DeVries, D.L. Aboagye, M. Ciaramella, S. Ramee, H.A. Stewart, and R. Shartau. 2014. Salinity effects on Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus Mitchill, 1815) growth and osmoregulation. Journal of Applied Ichthyology 30:1229-1236.
Peterson, D.L., P. Schueller, R.J. DeVries, J. Fleming, C. Grunwald, and I. Wirgin. 2008. Annual run size and genetic characteristics of Atlantic Sturgeon in the Altamaha River, Georgia. Transactions of the American Fisheries Society 137(2):393-401.
