Analysis of Circulating Fatty Acid Profiles in Free-Ranging and Managed Care Marine Toads (Rhinella marina) with a Comparison of Whole-Blood Vial and Whole-Blood Dried Blood Spot Card Analyses

Abstract

This study provides novel data on circulating concentrations of whole-blood fatty acids (FAs) in marine toads (Rhinella marina) via dried blood spot (DBS) card technology as a potential amphibian model species. Free-ranging (n = 10) animals were compared to managed populations fed two diet strategies for 60 days (n = 6 per diet). Thirty-six individual FAs were analyzed, with 28 found in significant reportable quantities. Eight FA groupings were represented. Traditional whole-blood vial (WBV) FA percentages were also collected and compared to DBS after managed care for 60 days. Results showed eleven individual FAs and four FA groups were higher in free-ranging toads (n = 10; p ≤ 0.05), while three FAs and three groups were higher in managed care (n = 12; p ≤ 0.05). FA concentrations compared between DBS cards and WBV at day 60 generally agreed, although two individual FAs and one grouping were higher in DBS (p ≤ 0.05). When free-ranging FAs were analyzed by sex, four individual FAs and two groupings were higher in females, while four individual FAs and one grouping were higher in males. Understanding normal FA circulating levels and how husbandry changes them may impact amphibian health. Additionally, DBS cards may provide a convenient sampling tool for fieldwork.

Fatty Acid Profiles in Managed Care Green and Kemp’s Ridley Turtles over Time

“…Lipid depot samples have long been the method of determining fatty acid status of sea turtles, however the invasive nature of this approach limits its application [5]. A strategy of blood analysis that has been more recently implemented in research efforts is the use of one drop of whole blood on a dried blood spot card (DBS) to provide a fatty acid profile [5,[8][9][10][11][12][13][14][15].…”

“…Blood spot card fatty acid profiles are a relatively novel method of analysis, and thus previous research into wild and managed animal nutrition using this method is limited. However, the nutritional data provided has significant practical importance for animal health [10][11][12][13][14][15].…”

“…Total whole-blood individual and fatty acid grouping profiles (%, mean ± SEM) for juvenile green (GST; Chelonia mydas) and Kemp's ridley (KR; Lepidochelys kempii) turtles in rehabilitation (rehab) housing compared to published wild juvenile turtle data[15] 1 .…”