a buccal mass of Goniobranchus sinensis, MISE-047-19 b reproductive system of Goniobranchus sinensis, MISE-047-19 c buccal mass of Goniobranchus verrieri, CASIZ 203059 d reproductive system of Goniobranchus verrieri, CASIZ 203059 e bBuccal mass of Goniobranchus fabulus sp. nov., CASIZ 191271 f reproductive system of Goniobranchus fabulus sp. nov., CASIZ 191271. Abbreviations: am, ampulla; bb, buccal bulb; bc, bursa copulatrix; ej, ejaculatory duct; es, esophagus; fgm, female gland mass; ot, oral tube; p, penis; pr, prostate; ra, radular sac; rs, receptaculum seminis; va, vagina. Scale bars: 0.1 mm (c, d, e, f); 1 mm (a, b).