Fig. 7. Model for cardiac homeostasis in zebrafish. Regeneration, maintenance and growth share cardiogenic signaling pathways (black arrows above ventricles) to generate new CMs and EPDCs in adult zebrafish. Regeneration involves developmental activation of the epicardium (black dots) and local recruitment of EPDCs to a focus of new CM production (pink explosions) at the wound (red dotted line). For simplicity, a cartoon of the ventricle at 7 dpa is shown, after the epicardial response has localized to the injury site. In the uninjured MS ventricle (maintenance), CM generation, epicardial activation and EPDC recruitment are diffuse and rare to counter occasional cell loss events. During rapid animal growth (growth), robust chamber-wide increases in CM generation, epicardial activation and EPDC mobilization are stimulated. Thus, similar or identical cardiogenic pathways are regulated with different intensities and localization to facilitate cardiac regeneration, maintenance or growth in adult zebrafish.