Intestinal types found in Peronia species. A clockwise intestinal loop is colored in blue, a counterclockwise intestinal loop is colored in yellow, and a transitional loop between them is colored in green. The big red arrow indicates the orientation of the transitional loop (A–F) or counterclockwise loop (G–I), and the small black arrows indicates the direction of the intestinal transport A type I, with a transitional loop oriented at 3 o’clock, P. sydneyensis, Australia, New South Wales, [1517] (AM C.468915.001) B type I, with a transitional loop oriented at 6 o’clock, P. verruculata, lectotype of P. anomala, Red Sea (MNHN-IM-2000-33678) C type I, with a transitional loop oriented between 4 and 5 o’clock, P. verruculata, lectotype, Red Sea (MNHN-IM-2000-22941) D type I, with a transitional loop oriented at 3 o’clock, P. peronii, paralectotype of Onchidium peronii, Timor (MNHN-IM-2000- 22938) E type I, with a transitional loop oriented at 1 o’clock, P. peronii, lectotype of Paraperonia fidjiensis, Fiji (MNHN-IM-2000-33692) F type I, with a transitional loop oriented between 1 and 2 o’clock, P. okinawensis, holotype, Japan, Okinawa, [696-4 H] (UF 352288) G type V, with a counterclockwise loop oriented between 10 and 11 o’clock, P. madagascariensis, Madagascar, [5501] (MNHN-IM-2009-16392) H type V, with a counterclockwise loop oriented at 10 o’clock, P. platei, lectotype, French Polynesia (SMNH-Type-7537) I type V, with a counterclockwise loop oriented at 11 o’clock, P. griffithsi, holotype, Mauritius, [3157 H] (MNHN-IM-2000-35265). Scale bars: 2 mm (A, B), 5 mm (C–G), 3 mm (H, I).