Our results suggest that circulatory system dysfunction triggered by cbsa downregulation is important for inhibiting eye growth in Astyanax. We substantiated this conclusion by showing that eye growth is arrested by CRISPR-Cas9 editing of the rap1b gene in SF, which is required for vascular integrity and in mutant form can induce eye hemorrhages during larval development. The gene discussed is RAP1B; the disease is eye hemorrhage.