Gambusia affinis, called "mosquitofish" are one of the best treatments for mosquitoes. The mosquitofish feed on the mosquito larvae actively. The District uses the fish for more permanent standing water sources such as ornamental ponds, unmaintained swimming pools, and animal water troughs.

Mosquito fish do not lay eggs, but give birth to live young. They breed throughout the summer and new broods are produced at about six week intervals. The young, are about 1/4 inch in length when born and are ready to begin feeding immediately on mosquito larvae. Mosquito fish grow rapidly, and reach a maximum length of about three inches.

Mosquitofish are generally available at our office from May to October. You may pick up fish Monday through Friday from 8am to 3pm or submit a request to have an operator place the fish. Please bring a container if you plan to pick up fish at our office. To submit a request contact our office at (209) 634-1234 or complete the following form: