Kg. Ostrand et al., GAR ICHTHYOOTOXIN - ITS EFFECT ON NATURAL PREDATORS AND THE TOXINS EVOLUTIONARY FUNCTION, The Southwestern naturalist, 41(4), 1996, pp. 375-377
Spotted gar (Lepisosteus oculatus) and alligator gar (L. spatula) roe
were fed to green sunfish (Lepomis cyanellus) and channel catfish (Ict
alurus punctatus) at a rate of 2 eggs/g of body weight for 14 days. Th
e dosage, equivalent to the LD50 established for small mammals and cra
yfish, did not result in mortality of these fish. Further, our study s
howed that fish fed gar roe maintained or gained weight, which leads t
o the conclusion that these fish do not reject the gar roe as a food s
ource. Consumption of gar roe by potential natural predators, such as
L. cyanellus and I. punctatus, establishes the basis for the argument
that gar roe toxin has not been evolutionarily selected to serve as a
protective mechanism. Gar roe may simply be toxic to small mammals and
crayfish by chance.