INFORMATIONAL ITEM

Argentine pearlfish Cynolebias bellottii (Steindachner 1881)

A Potential Ally as a Biological Control Agent

Against Immature Mosquitoes

· The Argentine pearl fish are deep bodied with a bass-like conformation. They can range from 1.5 to 4 inches in total length. The males are turquoise blue with a bold black vertical eye line and iridescent silvery blue spots or “pearls” on the flanks of the fins

· These fish are “annual killifishes” and are members of the egg laying toothed carps (shared with Desert pupfish), whose eggs are desiccation resistant. Often there is an obligatory dry incubation period.

· In their native South America, they inhabit temporary waters, such as vernal pools or slow moving intermittent streams. They are able to survive dry periods as desiccation resistant eggs. During the rainy season, when the habitat is flooded, the eggs hatch and develop rapidly in 6-8 weeks into sexually mature fish and can, therefore, complete their lifecycle before the next dry season begins.

· Their effectiveness in mosquito larvae control is being studied with the objective of establishing a cycle in California rice fields so that the fish would be present to feed on mosquito larvae without yearly introductions. Preliminary work shows that, eventually, annual killifish may find a niche in California mosquito control.