Testing assumptions underlying cabezon (Scorpaenichthys marmoratus) otolith microstructure analysis using wild‐caught juveniles and opportunistic rearing of eggs and larvae

Abstract

Otolith microstructure analysis provides critical biological and ecological information about the early life history of fishes. This information is particularly important to interpret and predict population dynamics for socio‐economically important fisheries species; nonetheless, several key assumptions underpin the use of otolith techniques. The authors validated the use of this analysis for cabezon (Scorpaenichthys marmoratus; Ayres, 1854), a long‐lived, large‐bodied cottid constituent of nearshore fisheries from Baja California, Mexico, to Alaska, USA. To test three critical assumptions, the authors coupled otolith and morphometric analyses from an opportunistic rearing study of cabezon eggs and larvae with a long‐term time series of juvenile cabezon field collections. The authors confirmed the daily otolith increment deposition in laboratory‐reared larvae, identified the timing of first otolith increment deposition and examined the relationship between otolith growth and somatic growth in field‐collected juveniles, validating the use of otolith microstructure analysis in biological and ecological interpretations of early life‐history traits for this species. The findings of this study also indicated that the absorption of yolk‐sac reserves, and likely the transition to exogenous feeding, plays an important role in regulating otolith increment deposition. Finally, the authors found within‐brood size‐at‐age variation, which may be an advantage for young fish in prey‐limited environments.

Differences in Otolith Microstructure between Reared and Wild Hedinichthys yarkandensis

“…Tis practical and straightforward method can be used to identify wild and reared fsh and provide a database for the study of otolith microstructure in fsh. It enriches the basic biological data of H. yarkandensis and promotes the conservation of germplasm resources of H. yarkandensis [19].…”

“…Te researchers assessed the growth of the larval stage in detail by daily incremental analysis of otoliths [14][15][16][17]. Some studies show that otolith microstructure data can be used to reveal the impact of the environment on the growth of young fsh, the transfer process between life stages, and the performance of young survival in specifc habitats [18][19][20]. No relevant studies have been reported to discern the early life history of H. yarkandensis by otolith daily increments.…”

“…Otolith microstructure analysis provides important biological and ecological information on the early life history of fsh. Tis information is particularly important for interpreting and predicting the population dynamics of socioeconomically important fshery species [19]. In this study, the diferences between wild and reared H. yarkandensis were investigated by observing the width of daily otolith increments in H. yarkandensis caught in the Tarim River and reared at the Tarim University Experimental Station.…”