Baseline Health Parameters and Species Comparisons Among Free-Ranging Atlantic Sharpnose (Rhizoprionodon Terraenovae), Bonnethead (Sphyrna Tiburo), and Spiny Dogfish (Squalus Acanthias) Sharks in Georgia, Florida, and Washington, Usa

Abstract

ABSTRACT:Sharks are of commercial, research, conservation, and exhibition importance but we know little regarding health parameters and population status for many species. Here we present health indicators and species comparisons for adults of three common wild-caught species: 30 Atlantic sharpnose sharks (Rhizoprionodon terraenovae) and 31 bonnethead sharks (Sphyrna tiburo) from the western Atlantic, and 30 spiny dogfish sharks (Squalus acanthias) from the eastern Pacific. All animals were captured during June-July 2009 and 2010. Median values and preliminary reference intervals were calculated for hematology, plasma biochemistry, trace nutrients, and vitamin A, E, and D concentrations. Significant differences, attributable to physiologic differences among the species, were found in the basic hematologic and plasma biochemistry variables. Significant species differences in arsenic and selenium plasma concentrations were found and appear to coincide with diet and habitat variability among these three species. Vitamin E was significantly higher in the bonnethead shark, again related to the foraging ecology and ingestion of plant material by this species. The Atlantic sharpnose had significantly higher vitamin A concentrations, supported by the higher proportion of teleosts in the diet. Vitamin D was below the limit of quantification in all three species. These preliminary reference intervals for health variables can be used to assess and monitor the population health and serve as indicators of nutritional status in these populations of wild elasmobranchs.

Diets of Atlantic Sharpnose Shark (Rhizoprionodon terraenovae) and Bonnethead (Sphyrna tiburo) in the northern Gulf of Mexico

“…In contrast, Bonnetheads demonstrate more benthic, specialized feeding strategies with consistent diets among various regions (Cortés et al 1996, Lessa and Almeida 1998, Bethea et al 2007, Bethea et al 2011, Haman et al 2012. This study evaluated the diets of these two species at spatial scales not previously compared and found similar results to studies conducted in singular locations.…”

“…crabs (Lessa andAlmeida 1998, Bethea et al 2007). Plant material has been observed in Bonnethead diets throughout all life stages (Cortés et al 1996, Lessa and Almeida 1998, Bethea et al 2007, Haman et al 2012 where its presence may be due to incidental ingestion during pursuit of prey (Cortés et al 1996).…”

Protein and cholesterol electrophoresis of plasma samples from captive cownose ray (Rhinoptera bonasus)

“…16,23 Overall, the fraction proportions observed in the cownose electrophoretogram correlate with the values of those reported as albumin, and alpha-, beta-, and gamma-globulins for Atlantic sharpnose, bonnethead, and spiny dogfish sharks. 13 Future studies of plasma protein electrophoresis may benefit from quantifying the 2 fractions within fraction 4 separately, and the composition of fraction 5 should be further defined. Moving forward, reference intervals for elasmobranchs should be established that are method oriented.…”

“…12,13 Differences in cholesterol levels in marine fish, including elasmobranchs, have been ascribed to age, nutrition, salinity, temperature, stress, and activity levels. 2,18 While most factors were suggested to decrease cholesterol, salinity changes and stress were reported to increase cholesterol levels.…”

“…6,12,13,29,30 While these intervals provide value for basic health assessment of these species, the applications of more advanced clinical pathology assays have not been investigated. In veterinary medicine, protein electrophoresis has been used widely to evaluate protein fractions in mammals and avian species.…”