by Ed Kluender, guest blogger
Ask a fish its age or where it's been and what it ate for lunch, and chances are it couldn't tell you. It could probably hear your question, though, with the help of its inner ear bones, called otoliths. Otoliths are one of the most useful tools in a fish biologist’s toolbox. When removed and studied, otoliths can reveal a fish’s age, growth rate, and some history of where it’s been.
Ask a fish its age or where it's been and what it ate for lunch, and chances are it couldn't tell you. It could probably hear your question, though, with the help of its inner ear bones, called otoliths. Otoliths are one of the most useful tools in a fish biologist’s toolbox. When removed and studied, otoliths can reveal a fish’s age, growth rate, and some history of where it’s been.
Otoliths are similar to the bones in human inner ears. They are three pairs of small stone-like structures, called the lapilli, sagittae, and asterisci (singular: lapillus, sagitta, asteriscus). Otoliths are suspended in fluid-filled sacs, and as in humans, help with balance and orientation.
Inner ear structure and otolith location in typical teleost fish. The sagittae and lapilli are the two typically used for aging fish. Source: David Secor, University of Maryland. |