Table 2.

Average heartbeat measured at 15°C and 26°C in st.24 and st.34 medaka embryos of the Hd-rR and ODT strains

Developmental stage	Heart rate (mean ± SD)
	Hd-rR strain		ODT strain
	15°C	26°C	15°C	26°C
st.24	9.08 ± 1.66	24.0 ± 4.43	8.78 ± 2.67	21.1 ± 3.93
st.34	70.7 ± 3.21	116.0 ± 10.6*	67.3 ± 2.31	116.9 ± 6.44

Average heart rate (bpm) at st.24 and st.34 recorded 3 h after the onset of the 15°C treatment (15°C, n = 3 each) in the Hd-rR and ODT strains. Control embryos were incubated at 26°C (n = 3; n = 26 at st.34). The asterisk indicates the same data as presented in Table 1.