An order best known for its tiny representatives, the largest species is the jacksmelt (Atherinopsis californiensis) of the Pacific Ocean.

Grunion were originally classified as part of the Atherinidae family of silversides but are now classified in the family Atherinopsidae, along with other New World silversides including the jacksmelt and topsmelt.

Atherinopsis californiensis, the Jack silverside, is a species of neotropical silverside native to the Pacific coast of North America from Oregon, USA to southern Baja California, Mexico.

In some places, this species feeds only on a few prey types and little else (e.g. innkeeper worms and cancrid crabs in Tomales Bay, jack silverside (Atherinopsis californiensis) eggs and the crabs Romaleon antennarium and Metacarcinus magister in Humboldt Bay).

An order best known for its tiny representatives, the largest species is the jacksmelt (Atherinopsis californiensis) of the Pacific Ocean.

Grunion were originally classified as part of the Atherinidae family of silversides but are now classified in the family Atherinopsidae, along with other New World silversides including the jacksmelt and topsmelt.

An order best known for its tiny representatives, the largest species is the jacksmelt (Atherinopsis californiensis) of the Pacific Ocean.

In April 1923, oceanographer Winfred E. Allen observed a common thresher pursuing a California smelt (Atherinopsis californiensis) from a pier at the Scripps Institution of Oceanography in La Jolla, California.

In some places, this species feeds only on a few prey types and little else (e.g. innkeeper worms and cancrid crabs in Tomales Bay, jack silverside (Atherinopsis californiensis) eggs and the crabs Romaleon antennarium and Metacarcinus magister in Humboldt Bay).