Jacksmelt

The Jacksmelt (Atherinopsis californiensis) is a schooling marine fish in the family Atherinopsidae, native to the eastern Pacific coast from Oregon to Baja California, Mexico. It is the largest silverside species found regularly along this coastline, distinguishing it from smaller relatives such as the Topsmelt with which it frequently co-occurs. Jacksmelt are common in nearshore coastal waters and large bays, often forming extensive schools near the surface. The species has long been recognized as an important component of nearshore fish communities along the California coast and is a well-studied representative of the New World silverside family.

Jacksmelt are elongated, slender fish that grow notably larger than most other silversides, typically 20-35 cm.

• Body: long and slim, with an iridescent blue-green back
• Markings: a broad, bright silver stripe runs along the midline of each side
• Snout: elongated and pointed relative to the small mouth
• Fins: two separate dorsal fins
• Tail: deeply forked Jacksmelt are distinguished from the similar but smaller Topsmelt by their larger maximum size, longer and more pointed snout, and higher lateral line scale counts.

Jacksmelt occur along the eastern Pacific coast from Oregon south to Baja California, Mexico, inhabiting nearshore marine waters, large bays, and estuarine areas. They favor open coastal waters more than Topsmelt, often schooling somewhat farther offshore and in deeper nearshore zones, though they also enter bays and sheltered inlets. The species tolerates a range of temperatures across its latitudinal range and is commonly found near the surface over sandy or open bottom habitats. Jacksmelt are frequently observed in large coastal bays such as those along central and southern California.

Jacksmelt are schooling fish, forming large, often mixed aggregations with other silverside species near the surface of coastal waters and bays. They feed on small invertebrates, fish eggs, larvae, and other prey items picked from the water column, reflecting a more carnivorous diet than some smaller silverside relatives. Spawning takes place in shallow nearshore waters, where adhesive eggs are deposited on algae or other submerged structure and left without parental care. As a common, schooling nearshore species, Jacksmelt serve as an important prey source for larger predatory fish, seabirds, and marine mammals along the California coast.