The otoliths of larval fish may be useful data-storage systems if the mechanisms of formation and carbonate deposition are discerned. Striped mullet Mugil cephalus were reared from hatching under controlled laboratory conditions. The start and periodicity of otolith growth increments were examined by light and scanning electron microscopy, and ratios of stable isotopes in otolith carbonate were determined. Otoliths formed their first increment 1 day after the larvae hatched and increment formation continued on a daily schedule regardless of growth rate. Electron microscopy revealed a transition area in otoliths that corresponded to the time of yolk-sac absorption. Isotopic analyses showed that otolith carbonate is deposited in disequilibrium with the ambient water chemistry, in contrast to prevailing theory.
展开▼
