Osmoregulation in wolf eel (Anarrhichthys ocellatus) during acclimation to dilute seawater


Meeting Abstract

P1.117  Friday, Jan. 4  Osmoregulation in wolf eel (Anarrhichthys ocellatus) during acclimation to dilute seawater SHAUGHNESSY, C. A.*; RADLOFF, J.; BYSTRIANSKY, J. S.; BALFRY, S. K.; DePaul University; Vancouver Aquarium; DePaul University; Vancouver Aquarium ciaran.a.shaughnessy@gmail.com

Once strictly considered a marine stenohaline species, the wolf eel (Anarrhichthys ocellatus) is now shown to tolerate a wider range of salinities than previously suspected. The present study monitored the effects of sustained exposure to various reduced salinities on the physiology and growth of juvenile wolf eel. Over an eight week period, fish were maintained in triplicate groups of 25 individuals under varying (6, 9, 14, and 30 ppt) salinity regimes. To assess salinity tolerance, mortality rate, specific growth rate, plasma ion levels and muscle water content as well as gill Na+K+-ATPase activity were determined. Mortality rate was low in the 6ppt treatment group (~5%), while all individuals maintained at 9, 14 or 30 ppt survived throughout the experiment. While growth did slow in a step-wise fashion with exposure to reduced salinity, specific growth rate remained positive (2.036, 2.908, 3.259, 3.522 % body weight day-1, respectively), suggesting these animals have the capacity to acclimate to dilute seawater. The results of this study present a better understanding of the ability of the wolf eel to tolerate diluted seawater, and add to a body of literature suggesting a wider salinity tolerance in many fish species previously thought to be strictly stenohaline.

the Society for
Integrative &
Comparative
Biology