養魚上より見たるコイとフナの二,三の比較

抄録

With regard to ecological characteristics of the carp and the crucian carp when used as objects of loosely diffused culture, the present study was carried out to compare them with each other.
(1) Survival rate of the crucian carp is always higher than that of the carp, and yearlings of the crucian carp grow faster than the other in such circumstances as without sufficient food for them.
(2) While there occurs unevenness of growth among the batch of carps, the crucian carps grow always rather evenly.
(3) The difference of the feeding habit of the two species is considered as one of the main causes of above mentioned phenomenon. The carp feeds mainly on comparatively large bottom fauna (Chironomus larva etc.), but the other depends on the so-called “Aufwuchs” (minute adherent organisms), algae and organic detritus, namely matters as available to the crucian carp are more ubiquitously present than those for the carp.