Figure 4

Blood regurgitation at 15°C in medaka species and heart morphology at st.34. A: Regurgitation ratio at st.34 after 15°C treatment from st.18 to st.34 in medaka strains from three medaka groups. The classification of the regurgitation phenotype was performed by visual inspection. KAM; n = 15, ODT; n = 38, KAG; n = 33, MIY; n = 23, KES; n = 37, IID; n = 46, KAS; n = 38, SYA; n = 53. B–D: Frontal view of medaka embryos at st.34. B: control Hd-rR. C: Hd-rR with regurgitation. D: ODT strain. KAM, Kamikita; ODT, Odate; KAG, Kaga; MIY, Mitatsu; KES, Kesennuma; IID, Iida; KAS, Kasumi; SYA, Shanghai.