[4] Adults migrate vertically to near the ocean surface and large numbers occasionally wash up on beaches during warm water events.

[5] The life cycle of Grimothea planipes appeared for a long time to form a paradox: while an adult population was maintained along the south-western coast of the United States, the planktonic larvae they released were immediately swept by the California Current thousands of miles out to sea.

[7] As the most abundant species of micronekton in the California Current, Grimothea planipes fills an important ecological niche converting primary production into energy that larger organisms can use.

[1] Other fish known to feed on G. planipes include billfishes, yellowtail amberjack, sharks[9] and Epinephelus analogus.

[15] Since G. planipes may be washed ashore in large numbers, it can be a valuable addition to the diets of seabirds such as the herring gull (Larus argentuatus), whose food supply is usually diminished in El Niño years.