Studies on the feeding repellents for fishes and shells. I. Statistical evaluation of chemotaxes, with special reference to repellence activity of food for oriental weatherfish.

Abstract

In searching for a chemotaxis index, with special reference to repellence index of food, a logistic curve yi=g/{1+exp[-r(j-a)]} was applied to the time-courses, the individual number observed yi with passing time from j=1 to 10min for three behavior patterns of oriental weather-fish Misgurnus anguillicaudatus which entered into, left from and remained in the test compartment containing repellence or attraction specimen. Of 32 time-courses estimated by two calculative methods for each behavior in the case by using 20 individuals: 31 entered, 24 left and 4 remained-time-courses fitted the logistic curve with 0.10 level by chi-square test. Among the relationships between the difference or the ratio of the same coefficients in both the specimen and a dummy, and the storage days of the specimen prepared, the general evaluation of the repellence and the attraction through observable behavior accorded well with the difference of dummy-a minus specimen-a and the ratio of dummy-a divided by specimen-a in the entered. The difference or the ratio was over 0 or 1 in the repellence index and below 0 or 1 in the attraction index. The validity of these indexes was ascertained to the specimen prepared from three kinds of food organisms.