To avoid hungry predators, anchovies swim in schools of thousands. With all those moving targets, it’s hard for a predator to focus on just one.

Visitors often ask: how do you tell the difference between anchovies and sardines on exhibit? Sardines have a row of distinctive black spots running the length of their bodies, for one thing. Sardine schools also tend to move in darting motions, while anchovy schools form a vertical funnel or “swirl.” Anchovies tend to swim with their mouths wide open, gathering food.

Baitfish like anchovies and sardines tend to flourish one year in the Monterey Bay, and disappear the next. No one knows for sure why this occurs. In the 1940s and 1950s, overfishing certainly played a role, but ocean currents, which transport nutrients and affect the production of larvae, may also be a factor.

How do we keep our exhibits topped up with baitfish like anchovies? Local fishermen are key. Aquarium collecting team members have developed relationships with local fishermen who specialize in these fish and know what we need. “We depend on these fishermen for the thousands of anchovies and sardines we display,” says Joe Welsh, associate curator of collecting. The relationship seems only fitting, since the Aquarium is built on the site of a former cannery! 

Anchovies may be small, but collectively they use a lot of oxygen. This is because there are so many tightly packed fish in a given volume of water. Consequently, our aquarists are careful to maintain high oxygen levels in the water and have plentiful backup supplies to ensure that these fish thrive.

• Anchovies frequently seem to be “yawning” — that's how you know it’s mealtime. They’re opening wide, straining tiny plant and animal plankton from the water.
• Life is short: anchovies rarely live more than four years, but some as old as seven have been recorded. A lot depends on anchovies. For instance, the reproductive success of California brown pelicans and terns correlates with anchovy abundance.