The Astounding Northern Anchovy
Famously, or perhaps infamously, known for their place in the culinary world, Northern Anchovies or California Anchovies (Engraulis mordax) is a species of pelagic forage fish native to the Pacific ocean. Like all anchovies, they are silver with bluish-green coloring on the back and sides. They generally weigh up to 10 g, and can be as long as 9 cm. The best way to distinguish E. mordax from other anchovy species is their anal fin; unlike other anchovies, the Northern Anchovy’s bottom fin begins parallel to the end of the top fin.
The California Anchovy’s range spans from British Columbia in Canada to Cabo San Lucas, Mexico. Their ideal habitat is in open oceans near coastal upwellings, with a maximum depth of 200 m and a temperature range of 8 to 25 C. Generally they’re found between 30-400 km offshore, but they are known to enter bays and inlets in search of food. Two main sub-populations exist; one off the coast of the Pacific Northwestern United States and another near Baja California, Mexico. The northern population is more migratory, travelling to deeper waters in the winter.
Northern Anchovies have a relatively short lifespan; only about 4 or 5 years without predation. In that time, however, they can produce hundreds of offspring. They become sexually mature at around 2 years old, at which time females begin spawning eggs. About once a week they release batches of over 500 eggs, which are then fertilized with sperm released by the males. Fertilized eggs can hatch only 4 days later, and larvae develop quickly. E. mordax breeds throughout the year, but reproduction peaks in spring. This is an especially bountiful time for the California Anchovy’s predators, as planktivores, fish, seabirds, and marine mammals will gather to feed on the transparent larvae and their swarming parents.
When predated upon, Northern Anchovies perform a unique defense mechanism called schooling. Their bluish-green and silver coloring provides a sort of camouflage against the open ocean and makes it difficult for predators to distinguish individuals for targeting. The school moves together as one tightly balled unit, and stragglers who cannot keep up with the group are quickly singled out and eaten.
Despite their reputation as prey, northern anchovies are themselves predators of tiny invertebrates like copepods and decapod larvae. They can filter-feed and actively pursue prey. When hunting, an individual forms an S-shaped posture, using its coloring as camouflage, and undulates its dorsal fins to propel itself. Generally, anchovy larvae are more active hunters than adults.
Conservation status: Rated as Least Concern by the IUCN. The Northern Anchovy has been fished extensively as a source of food and fishing bait for human use. While the current population is thought to be stable, catch rates have been steadily decreasing since 1983.
