Sky distribution of star-forming galaxies with colours of the symbols coded in Fig. 2. Filled symbols indicate galaxies with a normal HI content (HI − def ≤ 0.4), empty symbols HI-deficient galaxies (HI − def> 0.4). The size of the symbols is proportional to the stellar mass of galaxies: big symbols are for galaxies with M_star> 10^9.5M_⊙; medium size symbols for objects with 10^8.5<M_star ≤ 10^9.5M_⊙; small size symbols for M_star ≤ 10^8.5M_⊙.