The distribution is part of a week-long giveaway of Gambusia affinis — or mosquitofish — to residents in San Joaquin County.
Tracy’s community center was the first stop, with the crews later in the day visiting Lodi, and Ripon, Escalon, Manteca, Lathrop and Stockton during the week to distribute the 2 inch-long fish.
Residents were given a maximum of 15 fish to be placed in standing water containers such as ornamental ponds, animal water troughs and neglected swimming pools. They feast on mosquitoes, known to carry West Nile virus and other pathogens.
The first sign of West Nile virus this year in San Joaquin County was in late May. Since then, nine birds and five mosquito samples in the county have come back positive for West Nile. None of the samples were found inside Tracy city limits.
Statewide, 169 birds, 222 mosquito samples and two sentinel chickens have tested positive for the virus.
One human case of West Nile virus was reported in Kern County.
Officials with local vector control reminded residents to check their property and drain any water in tires, buckets, clogged rain gutters and any other items that can hold water for a few days.
Neglected or abandoned pools can be reported to vector control at 982-4675 or www.sjmosquito.org.