Otoliths, also known as "earstones," are small, calcified structures found in the inner ear of fish
Otoliths have concentric rings, similar to tree rings, which indicate the age of the fish. Each ring typically represents one year of growth
The rings form through the deposition of calcium carbonate and protein, growing incrementally as the fish ages
The thickness of each ring varies with seasonal changes. Wider rings usually indicate faster growth during favorable conditions, often in warmer months
Otoliths not only reveal age but also record environmental conditions like water temperature and chemistry, offering clues about the fish's habitat and migration patterns
Age data from otoliths is crucial for managing fish populations and setting sustainable fishing quotas
Otolith examination provides a non-lethal way to determine the age of fish, unlike other methods that may require sacrificing the specimen