364 ANNUAL REPORE SMITHSONIAN INSTITUTION, 1926 
A California student will tackle any problem, and so I sent out 
Alvin Seale (then a senior at Stanford, now superintendent of the 
Steinhart Aquarium in San Francisco). He was instructed to go 
to Louisiana and secure from the bayous three species which might 
meet the demand. Each of them would eat mosquitoes, but in no case 
had their efficiency been tested. New Orleans was then once more 
in the throes of yellow fever, so Seale moved across to Galveston 
and filled his milk cans with the chosen fishes. Such fishes known 
as “ 'Top-Minnows,” Killifishes, and Cyprinodonts, are all very hardy 
if properly handled, especially if not handled at all, and very few 
died on the voyage to Hawaii. 
Arrived at Honolulu, each species was tested out in aquarium 
tanks in drug-store windows, these filled with stagnant water, 
stocked with mosquito eggs. The largest fishes, Yundulus grandis, 
showed little interest in the matter. They were poured into a pool 
and have not been noticed since. The next species (Mollienesia 
latipinna) did better. This is a very handsome little fish, with 
high fins and varied colors, bright blue shades and spots predomi- 
nating. But it is mainly a vegetable feeder, preferring “ frog 
spittle” (Confervaw) to insects, and seemed not likely to be of any 
value in the task assigned to it. It has become very abundant in the 
estuaries of Hawai. It is valued for aquaria and is largely used as 
bait for the Aku, or Victor-fish (’atswwomus), and other predatory 
species. 
The third set of fishes (Gambusia patruelis), rose at once to the 
occasion, and almost instantly cleared the aquarium of mosquito 
eggs and wigglers. This, with its twin of further east, Gambusia 
holbrooki, is no doubt the greatest mosquito killer in existence. 
It has lived and multiplied in all available waters in Hawai. It 
swarms in irrigation ditches and in pools in the rice fields. It is so 
abundant that it is now gathered up in nets, baked and crushed as 
food for the fishes in the Waikiki Aquarium. It does not migrate 
to the sea and it does not attack other fishes. 
In a recent visit of two months in Honolulu I saw but six 
mosquitoes, all of them small, no doubt hatched in rain pools, tin 
pans, or other small bodies of water, which the most assiduous fish 
can not reach. 
From Honolulu the fish has been taken to Formosa by another 
Stanford student, Dr. Masamitu Oshima, former director of Fish- 
eries in that island, whence specimens have been sent back to me. 
The fish was then brought over to Manila by another Stanford man, 
Dr. Albert W. Herre, director of Philippine fisheries, and it has be- 
come firmly established in Luzon. Large breeding pools have been 
established about Manila by Doctor Herre. From the Philippine 
