My internist was just about to take the fourth squeeze to the little round ball that is part of the blood-pressure apparatus when he paused to ask, “What’s the story with matjes herring? Do they sell ...

A comparison of the fast-growing fish-eating Baltic herring (Slåttersill in Swedish) and slow-growing plankton-eating spring- and autumn-spawning Baltic herring. Credit: Leif Andersson/Uppsala ...