Figure 5. Stunted growth is reversible in surface fish.

Individual fish were raised in confining volumes of water (10 ml) for 32 days, and then divided into two groups. One group was transferred to a larger volume of water (40 ml), the other was transferred to the same volume of water (10 ml), and both groups were raised in these conditions for an additional 40 days. A, B. Surface fish compensate for stunted growth in terms of mass (A) or length (B). C, D. Pachón cavefish show no appreciable change in growth rate in terms of mass (C) or length (D) when transferred from 10 ml to 40 ml volumes of water. Gray squares: growth rate in small volumes (10 ml). Black spheres: growth rate after fish raised in 10 ml volumes were transferred to 40 ml volumes. Open squares: growth rate after fish grown in 10 ml volumes were transferred into 10 ml volumes. Error bars represent standard errors of the mean.