Temperature-dependent otolith growth in Norwegian spring-spawning herring (Clupea harengus L.) larvae

Abstract

Norwegian spring-spawning herring larvae ( Clupea harengus L.) were reared at different temperature combinations in the laboratory, and marked twice with a fluorescent dye, alizarin complexone, to estimate otolith growth and increment deposition rate. A daily increment deposition rate was confirmed in the sagittae of larvae reared at 12 °C from day 16 (first marking age), while the apparent rate of increment formation of larvae reared at 4 °C was clearly less than one per day. A reduction in rearing temperature from 12 to 8 °C between days 16 and 30 (second marking age), significantly affected sagitta growth during the inter-mark period compared with those reared at 12 °C throughout. Similar somatic growth rates were observed in both groups temporarily reared at 8 °C between markings (about 6% day −1 ), but the otolith growth rate was more than four times higher in the group originating from 12 °C compared with the one originating from 4 °C. The body size versus otolith size relationship was temperature d...