Fish otoliths: daily growth layers and periodical patterns.
The early-stage annual rings in otoliths from some cold-temperate fish consist of thin growth bands, the number of which corresponds to that of the days in a year. This indicates that growth takes place by daily increments. Other recurrent patterns show a fortnightly and monthly periodicity. Spawning rings are microscopically distinguishable from winter rings.
D000818:Animals; D007758:Ear, Inner / Q000166:cytology / Q000254:growth & development; D005399:Fishes / Q000254:growth & development*; D009656:North America; D010507:Periodicity; D012621:Seasons