immediately_preceded_by developmental stage Medaka stage 37 Medaka stage 38 Differentiation of caudal fin begins OlatDv:0000410 Zoological Science 11: 825-839 (1994) - 8 days Stage 38 (8 days) Spleen development stage (Differentiation of caudal fin begins): The tip of the tail extends beyond the otic vesicle (total length ca. 3.6 mm), and the rudiments of the caudal fin rays can be seen within the round membranous fin. The spleen is recognized as a small reddish globule dorsal to the gut tube beneath the left region of the 3rd-4th somites. The gut tube curves to the left between the 1st and the 4th somites, appearing to detour around the swim bladder (3rd-4th somites). A large well- developed gallbladder can be identified by its yellow or yellowish green tint. Both eyes move actively at the same time accompanying movement of the mouth and the pectoral fins. - 8 days medaka_ontology spleen development stage