Methods to collect preserve and prepare elasmobr

Authors: Sora L Kim Paul L Koch

Publish Date: 2011/06/22

Volume: 95, Issue: 1, Pages: 53-63

PDF Link

Abstract

Stable isotope analysis has the potential to expand our understanding of elasmobranch ecology However elasmobranchs share unique traits ie retention of urea lack of adipose tissue cartilaginous skeletons that require modified preparation techniques Alternative tissue collection and preservation methods would allow sampling from ichthyology collections and at remote locations We compared different collection preservation and preparation techniques to identify treatments that yielded robust isotopic data Blood components collected in tubes coated with lithium heparin an anticoagulant were not isotopically distinct from blood collected in noadditive tubes Compared to frozen muscle ethanoltreated muscle had altered δ13C values but similar δ15N values Finally we removed lipids and urea with petroleum ether and deionized water respectively Although untreated and treated muscle had similar amino acid compositions treated muscle preferentially lost 14N and had greater CN ratios These results indicate that urea affects isotope ratios and that water treatment removes urea without altering muscle protein composition Although not exhaustive our study begins to address the need for elasmobranchspecific methodsWe thank L Kroll S Perry S Rumbolt A Sjostrom A Thell and C Spencer for aquarium and sampling assistance F Batista for amino acid analysis We also thank L Roland D Shizuka and two anonymous reviews for their comments and critical reviews D Casper DVM at Long Marine Lab UCSC facilitated the successful rearing of leopard sharks in captivity All sampling methods for leopard sharks followed the Guide to the Care and Use of Laboratory Animals and were approved by the Institutional Animal Care and Use Committee at UCSC The skates were caught by the Pacific Shark Research Center at MLML during regular survey trawls Financial support provided by the Institute of Geophysics and Planetary Physics at UCSC and the Myers Ocean Conservation Grant

Keywords: