Otolith microstructure characteristics in White Sea spring-spawning herring (Clupea pallasi marisalbi Berg) larvae

Otolith microstructure characteristics were studied in White Sea spring-spawning herring (Clupea pallasi marisalbi Berg) in the laboratory and in nature. Slow daily growth rate (∼0.15 mm d−1), small increment width (∼0.8 μm), and irregular increment deposition were observed in the experimental group of larvae raised at lower temperatures (2.8 and 9.1°C before and after hatching, respectively), low plankton density and unnatural photoperiod. By contrast, a fast daily growth rate (∼0.31 mm d−1), wider increments (∼4.1 μm) and daily increment deposition were found in the group of larvae cultivated at higher temperatures (11.0 and 12.3°C before and after hatching, respectively), high plankton density and with continuous light. Back-calculation showed that in the field, larvae hatched mainly between 1 June and 7 June, and the average daily growth rate was 0.51 mm d−1.