Reliable estimates of short- and longer-term in situ growth and condition of organisms are critical if one hopes to understand how the environment regulates survival. This laboratory study reports the first comparison of somatic- (K), biochemical- (RNA–DNA ratio, RD) and otolith- (increment widths, OIW) based indices of condition of a young juvenile fish. It found that RNA:DNA ratios react 2x faster to growth changes due to changes in feeding level than otolith increment widths, while condition factor was the most variable proxy.
Peck, M. A., H. Baumann, C. Clemmesen, J. P. Herrmann, M. Moyano, and A. Temming 2015. Calibrating and comparing somatic-, nucleic acid-, and otolith-based indicators of growth and condition in young juvenile European sprat (Sprattus sprattus). Journal of Experimental Marine Biology and Ecology 471:217-228.