Abstract
Attraction activities of the 12 representatives of algae for abalone Haliotis discus were estimated by applying a logistic curve (y=g/{1+exp[-r(x-a)]}) to the cumulated number polygons of the individuals entered into or retained into the baited sector, for the purpose of evaluating their attraction activities, paying attention to all the specificity, which were indicated by the respective parameters of the curves. Considering the parameters and correlation between them, wakame seaweeds Undaria pinnatifida was found to be one of the favorable baits, because many individuals retained in the sector with it along a sharp increasing curve, although it took longer time to attain the half of the asymptote of retained individuals. The bait should be chosen primarily according to the intended specificity, which varies depending on its aimed role. This is, however, insufficient, and attention should be paid to other specificity, because the estimated index sometimes varies keeping correlation to one another. The correlation between the level of asymptote of retained individuals and other parameter was helpful in choosing the suitable baits.
