Ocean Acidification and Otolith Development in Clown Fish
Munday, P.L., Hernaman, V., Dixson, D.L. and Thorrold, S.R. 2011b. Effect of ocean acidification on otolith development in larvae of a tropical marine fish. Biogeosciences 8: 1631-1641.
In further exploring this intriguing subject, Munday et al. reared larvae of the marine clown fish Amphiprion percula throughout their entire larval phase at three different ocean acidification levels -- ambient or control conditions (CO2 ~ 390 ppm, pH ~ 8.15) and higher CO2/lower pH conditions (CO2 ~ 1050 ppm, pH ~ 7.8; CO2 ~ 1721 ppm, pH ~ 7.6) representative of conditions predicted to prevail in AD 2100 and AD 2200-2300, respectively -- in order to determine if the elevated CO2/reduced pH conditions would alter otolith size, shape, symmetry (between left and right otoliths) or chemistry compared to current conditions.
The four researchers report that "there was no effect of the intermediate treatment on otolith size, shape, symmetry between left and right otoliths, or otolith elemental chemistry, compared with controls." In the more extreme treatment the story was much the same, except that otolith area and maximum length were slightly larger than controls, while "no other traits were significantly affected."
Munday et al. state that their data suggest that the larval clown fish is "capable of regulating endolymphic fluid chemistry even in waters with pH values significantly lower than open ocean values," and they thus conclude that "the larval clown fish is robust to levels of ocean chemistry change that may occur over the next 50-100 years," which conclusion is about the same as that reached by Munday et al. (2011a), who they say "detected no effects of ~850 ppm CO2 on size, shape or symmetry of otoliths on juvenile spiny damselfish, a species without a larval phase."
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