Fig. 6

Functional changes in the tentacle branches. a–t A series of images following the same tentacle branches (Branch① in a–d, Branch② in e–h, Branch③ in i–l, Branch④ in m–p, and Branch⑤ in q–t) demonstrating that they change their functions from landing to hunting. The branches were numbered in the same way as in Fig. 2. Whether a branch sticks to the tip of a tungsten needle was used as the criterion for possessing functional adhesive organs; whether it captures Artemia Nauplius was used to evaluate whether it has functional nematocysts. Branches without either function are indicated by purple, those with functional adhesive organs only by red, those with functional adhesive organs and functional nematocysts by orange, and those with only functional nematocysts by green. The insets are blown-up images of the branches shown in orange, in which the positions of the nematocyst clusters are indicated by arrowheads. The same individual was used for the images in Figs. 2 and 6; therefore, there are several pairs of identical pictures (2a and 6a, 2c and 6b, 2e and 6e, 2g and 6i, and 2h and 6d). Scale bars: 200 μm. (u) A table showing when Branches ① to ⑤ acquired their functions in 17 cases/tentacles. Each number represents how many numbered branches had which of the four functional states, purple, red, orange or green, on a given day