The island of Barbados, in the West Indies, is remarkably free
from malaria, and this immunity from a disease which is so
common in the tropics has been attributed to a species of fish
that inhabits the waters of that island, and whose chief food is
the larvæ of the mosquito. These fish are tiny minnows, never
exceeding an inch and a half in length, and are generally known
as “millions,” altho they bear a most impressive scientific
name. They belong to the family of “top minnows,” feeding on the
surface of the water, and their diminutive size enables them to
swim over lily-pads and similar vegetation, which is covered
only by a thin film of water, and there feast upon mosquito
larvæ and other insects.
These fish thrive in stagnant or running water, and whether it
is fresh or brackish appears to have no effect upon them. The
minnows will swim up stream against a strong current and then
enter the smaller rivulets, thus distributing themselves over
an entire water system. The young of these fish are not hatched
from eggs, but are born alive.
The Panama Canal Commission has decided to employ these minnows
in the fight to rid the Isthmus of the malarial mosquito, and
has imported a great quantity of the little fish. There are
mosquito-eating fish in the Panama waters, but they are not
sufficiently numerous to be of much value. However, a systematic
stocking of the lakes and streams in the Canal Zone with the
“millions” from Barbados should act as a severe check on the
mosquito population of Panama, and indirectly aid in stamping
out malaria.--_Harper’s Weekly._
(1544)
See DISEASE, EXEMPTION FROM.
=Immutability=--See INDIVIDUALITY OF GERMS.