The physiology of deepwater sharks: can biochemical methods be used to develop stress profiles?

SIMPFENDORFER, C.; AWRUCH C. A.; JONES, S.

Simposio; 26th Annual Meeting American Elasmobranch Society; 2010

American Elasmobranch Society

  Deepwater sharks are among the most vulnerable of marine species, increasing on the world’s endangered and threatened species lists. Currently, there is no information available on the fate of released or discarded deepwater sharks to help inform managers. Thus there is a need to quantify the level of stress and post-release mortality of these species. During March 2008, blood samples were obtained from four species of deepwater shark species including 60 individuals of deepwater draughtboard shark (Cephaloscyllium species A), 43 individuals of Australian sawtail catshark (Galeus boardmani), 150 individuals of the endangered greeneye spurdog  (Squalus mitsukurii) and 23 individuals of the critically endangered southern dogfish (Centrophorus uyato). Levels of the stress hormone corticosterone, was measured by radioimmunoassay (RIA), and lactate concentrations were determined by spectrophotometry. During capture and release, the condition of these sharks was recorded. We determined if measurable levels of corticosterone are present in four species of deepwater sharks including the variability in hormone levels between species and between individuals within a species. Secondly, we correlated corticosterone levels with lactate levels and with ancillary data on condition of the shark during capture and release to determine the degree of variability in this stress hormone and the relationship being found between this hormone and different levels of stress.