Fig. 4

Rearing-density effects on the growth and maturation of the giant danio DM. Images of representative DM early larvae (A-i) and late larvae (A-ii) showing dramatic growth and changes in phenotype. In addition to the abundant melanophores seen in the early larvae, iridophores are prominent in the late larvae as well as the early juvenile (A-iii) giving the fish a distinctly silvery hue. Progressive phenotypic changes, increase in size and the appearance of longitudinal bands of xanthophores characterizes the late juvenile DM (A-iv) and early adult (A-v) and late adult (A-vi). Standard length (SL) measured in low and high density reared fish from 5 to 40 weeks post-fertilization (wpf), and showing differential but linear growth in length (B). Body weight (BW) measured in low and high density reared fish from 5–40 wpf showing differential but logarithmic increase in BW (C). Scale bars are 1 or 10 mm, and ruler units are 1 mm intervals. SL and BW of high and low density raised fish are analyzed using Welch two sample t-test where p < 0.05 is considered significant.