Why do herring have fine bones?

Question

Most fish have largish bones which support the core muscles. Around the abdomen, they act as a sort of framework protecting the organs. With herring, the bones are really fine: almost thread like and there are lots of them: more than on any other fish I've eaten. I would like to know why herring have such fine bones.

Answer 1

Herring evolved to have fine, thread-like bones, known as intermuscular bones, to serve a couple of primary functions:

1. Predator Evasion: A dense grid of tiny, flexible bones allows herring to twist, turn, and maneuver instantly within a school to escape danger.
2. Buoyancy Management: The lighter, highly distributed network of micro-bones helps the fish maintain neutral buoyancy as they rapidly shift depths in the water.

Other forage fish species, such as anchovies, smelt, and capelin, also have very fine bones.