Left: the atomic gas fractions f_gas = 1.33 M_{H I} /M_dyn versus M_dyn calculated within the optical radius R_opt. Large, black dots and small, grey dots indicate BCDs (this work) and Irrs (Swaters et al. 2009), respectively. Middle: f_gas versus the SFR surface density where SFR_p is the peak SFR over the last 1 Gyr (see Table 1). Right: f_gas versus the look-back time t_p at SFR_p.