Abstract
To secure the role of food organisms in alluring dolphin and other fishes toward ‘Tsukegi’, the author examined the epifauna on ‘Tsukegi’ and stomach contents of fishes accompanying it. The results obtained are follows:
1) Thirty five species of animals covering seven phyla were found on ‘Tsukegi’ and its anchor rope (Table 1).
2) Fishes under ‘Tsukegi’ were devided into following four groups according to their feeding habits: Group I, feed on fishes and squid; group II, mainly feed on Cirripedia and Amphipoda; group III, mainly feed on Cirripedia and jelly fish; group IV, feed on small zooplankton (Table 2). It is only the fishes in groups II and III which feed on epifauna on ‘Tsukegi’, and dolphin belongs to group I.
3) It was found that dolphins and other fishes in group I never take those fishes belonging to groups II-IV. They take only freely swimming small sized fishes such as sardine, flying fish and squid or juvenile fishes accompanying floating seaweeds.
So far as feeding habits are concerned, dolphins and other fishes in group I seem to have no direct connection with ‘Tsukegi’. These fishes are considered to be allured toward ‘Tsukegi‚ by factors other than food.
