Otoliths of Chinook Salmon (Oncorhynchus tshawytscha): Daily Growth Increments and Factors Influencing Their Production

Abstract

The effects of photoperiod, feeding frequency, and water temperature on formation of otolith daily growth increments in juvenile chinook salmon (Oncorhynchus tshawytscha) were examined. Feeding frequency influenced both increment number and width, whereas photoperiod and temperature affected only increment width. Fish fed once/24 h produced one increment every 24 h on average, while fish fed 4 times/24 h produced more than one increment every 24 h. Wider increments were produced in fish exposed to warmer water (11 °C) or 24 h of darkness. The ratio of otolith size to fish size remained constant throughout and between the photoperiod, temperature, and feeding frequency experiments, regardless of the number or width of increments produced. Although otolith growth is isometric with respect to increase in fish length under these experimental regimes, otolith microstructure will differ in fish of the same size reared under different environmental conditions. An understanding of factors affecting otolith increment production is required before increment number and width can be used to assess growth rates.Key words: otolith, daily, growth increments, chinook salmon

Otolith microstructure of Oxygymnocypris stewartii (Cypriniformes, Cyprinidae, Schizothoracinae) in the Lhasa River in Tibet, China

“…Several factors may influence the daily increment width, especially temperature of water (Marshall and Parker 1982;Neilson and Geen 1982;Campana 1984a). The change of width of daily increments in O. stewartii's otolith section within annulus was consistent with that of the water temperature.…”

“…Aging techniques based on daily increments are commonly used in ecological studies of various fish species. In addition to age and growth, fish otoliths may also record life history events, such as the movement from one habitat to another (Neilson and Geen 1982), metamorphosis (Campana 1984b) and settlement (Victor 1982). Therefore, otolith microstructure analysis has become a useful tool for studying the biological characteristics of fish (Campana and Neilson 1985).…”

Evaluation of periodic and aperiodic otolith structure and somatic-otolith scaling for use in retrospective life history analysis of a tropical marine goby, Bathygobius coalitus

“…This study found no evidence for a growth effect on somatic-otolith scaling in Bathygobius coalitus. Negligible growth effects on somatic-otolith scaling have also been reported for bloater (Rice et al 1985) and chinook salmon (Neilson & Geen 1982).…”

Effects of temperature and ration on the otolith-to-somatic size relationship in juvenile Chinook salmon (Oncorhynchus tshawytscha): a test of the direct proportionality assumption

“…However, the discrepancy in the explanatory power of the different otolith metrics in the different seasons suggests that the juvenile Chinook otoliths grew at different rates along the OL and OW axes. This is an interesting finding because daily growth increments are known to be deposited in concentric rings on the fish otoliths (Tanaka et al 1981;Neilson and Geen 1982), thus we expected that the coefficients of determination for OL and OW would have been equivalent within each season. Coefficients of determination between otolith growth and somatic growth much greater than observed here have been reported for juveniles of other fish (Waessle et al 2003), even over a range of environmental conditions (Otterlei et al 2002).…”

“…The deposition of daily growth increments on otoliths has been validated for juvenile Chinook salmon, with the ratio of otolith size to somatic size remaining constant for approximately 2 months across different photoperiods, suboptimal temperatures and feeding frequencies (Neilson and Geen 1982). However, the interactive effects of food quantity and superoptimal temperature regimens on the otolith-to-somatic size relationship have not been investigated and may have implications for Chinook salmon management, because otolith microstructure analysis has become a common technique for estimating critical life stage events, including size at marine entry and early marine growth rates (Marrin Jarrin and Miller 2013;Claiborne et al 2014;.…”