Most marine fish larvae undergo distinct transitions during their development, often associated with functional shifts in their ecology. The purpose of the present study was to document the ontogenetic record contained within otoliths of the early life history stages of the bluefish Pomatomus saltatrix (Linnaeus), so that future work could use this otolith record to examine the ecological and population level consequences of bluefish life history transitions. Seven distinct ontogenetic stages were defined using multivariate analyses of 16 morphological, meristic and coded variables measured from larval and pelagic juvenile bluefish (standard length, SL=25 mm) collected on the Middle Atlantic Bight shelf during the summer of 1988. Otoliths were examined from the individuals utilized in the multivariate analysis, and from bluefish eggs and yolk-sac larvae, which were also collected on the Middle Atlantic Bight shelf during the summer of 1988 and staged using previously published descriptions. Important ontogenetic stage transitions were found to be recorded in otolith microstructure: hatching was marked by the formation of the first otolith increment, flexion was marked by an apparent change in increment formation rate of the lapillus, and the transition from larva to juvenile was marked by the initial formation of secondary growth centers. Thus, otolith microstructure provides a detailed record of ontogeny, and this record will prove useful in future studies of the ecology and dynamics of bluefish early life history stages.
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics
- Aquatic Science