Fig. 4

Effects on settlement or metamorphosis by RO or DEAB treatments in P. pectinifera. a–i RO 3 µM treatment inhibited metamorphosis of 14-dpf larvae induction by RA 1 µM treatments (n = 20 from each three batch). a–d Left side of specimen at 24 h after treatment and e–h does ventral or dorsal side of these. Each specimen is taken from following treatment, a, e RA 0.1 µM, b, f RA 0.1 µM with RO 3 µM, c, g RA 1 µM and d, h RA 1 µM with RO 3 µM. The scale bars in a–h display 125 µm. i indicates metamorphosis ratio of 24 h after treatments. j, k Effects of RO in settlement and metamorphosis (n = 24 from each three batch). j Schematic machinery of inhibition of RA signaling by RO. k Settlement and metamorphosis ratio of 14-dpf larvae in 24 h after RO 1 µM treatment with substrate (n = 72 from three batches). l, m Effects of DEAB in settlement and metamorphosis (n = 36 from each three batch). l Schematic machinery of inhibition of RA signaling by DEAB. m Settlement and metamorphosis ratio of 14-dpf larvae in 24 h after DEAB 100, 300 µM treatment with substrate