Fig. 3

Effects on metamorphosis by all-trans RA or DMSO treatments in P. pectinifera. a–e Metamorphosis induction of 14-dpf larvae by exogenous all-trans RA (0.1 or 1 µM) treatment (n = 50 from each three batch). a, b, d, e Induced juvenile of 96 h after RA 0.1, 1 µM treatment, respectively. c DMSO-treated larvae (96 h after treatment). Arrow heads indicate developed juvenile rudiment, white arrowheads point out absorbed larval body, and arrows show primary podia. The scale bars in a–c, d–e display 250, 50 µm, respectively. The number in figure show the ratio of metamorphosed larvae/treated larvae. f Temporal effects on metamorphosis induction of all-trans RA (1 µM). Numbers in figure show percentage of metamorphosed specimen (n = 20 from each three batch in each treatment) and background colors are depended on their percentage and divided into five darkness levels, meaning 0, 0–25, 25–50, 50–75 and 75–100%. Vertical axis indicates days after treatment and horizontal axis indicates days after fertilization