Vector Control has given out thousands of free mosquitofish to the public at a dozen locations over the years. Placed in neglected “green” swimming pools and spas, ornamental ponds, fountains, bird baths and even horse troughs, mosquitofish can gobble up mosquito larvae as fast as mosquitoes can lay their eggs in water. That means fewer mosquitoes that can transmit diseases like West Nile virus from birds to people.
However, Vector Control’s mosquitofish breeding wasn’t very prolific at the County Operations Center when DEH and Vector Control hired Reyes about a year and a half ago — producing about 50 baby mosquitofish a month. Reyes eventually helped multiply that 100-fold, to 5,000 mosquitofish a month.
Reyes grew up in El Cajon. He joined the Navy where he worked as a hospital corpsman, including six months tending wounded in Afghanistan, then went back to college to study biology. So, he didn’t know anything about mosquitofish when DEH hired him to work as a shop technician, maintaining Vector Control’s traps, equipment, pesticides, and — the fish room.
The fish room is one of two places Vector Control keeps its mosquitofish. The first is in a pond near Lake Hodges. The second is in several black, 500-gallon, temperature-controlled tubs in DEH’s fish room at the County Operation Center.
When Reyes started with Vector, most of the mosquitofish breeding was done at the pond. A couple of times a week he or other technicians would drive up to the pond, “fish” for mosquitofish and bring them back to the holding tanks at the COC. After a few months, Reyes’ supervisor, County Veterinarian Dr. Nikos Gurfield, encouraged Reyes to think about whether they could boost breeding in the holding tanks.
With Gurfield’s support, Reyes reached out to other agencies and experts, including Mike Saba, then a biologist with the Orange County Vector Control District. Saba brought Reyes into the Mosquitofish and Biocontrol subcommittee of the Mosquito and Vector Control Association of California — a collection of roughly 70 vector control agencies and districts. Suddenly Reyes was swimming in mosquitofish information.
“I had no idea there were so many people dedicated to this,” Reyes said.
He learned the County wasn’t feeding its mosquitofish enough and increased feeding from four times a day to every hour of the workday.
That boosted reproduction, but it still left a problem. See, mosquitofish eat their young.
Mosquitofish are used as a mosquito-fighting tool because of their voracious appetites. They bear their young live, and the adults will eat the newborns if the little ones can’t find places to hide.
Reyes said through his work on the subcommittee, he had heard about a biofilter called Matala. It’s thick and mat-like, often used for water filtration, but also in mosquitofish breeding. Baby mosquitofish are much smaller than adults, and the twisting coils of the Matala were just big enough for baby mosquitofish to swim through and small enough to keep the hungry adults out.
