Larger Image Figure 1. The starfish Patiria pectinifera. The aboral side (a) and oral side (b) of an intact animal are illustrated. The position of the apical muscles on the inner surface of the aboral body wall of a dissected animal is shown in (c) marked by arrows. An extract of P. pectinifera containing peptidic materials relaxed apical muscle that was pre‐contracted with 1 μM acetylcholine (ACh); up and down arrows represent application of ACh and the extract, respectively (d). Image published in: Kim CH et al. (2016) Image downloaded from an Open Access article in PubMed Central. © 2016 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. Permanent Image Page Printer Friendly View ECB-IMG-182912