Iron is vital for normal development – its acquisition by red blood cells (RBCs) allows hemaglobin (Hb) production and the delivery of oxygen to developing tissues. However, free iron is toxic to cells and its uptake and transport requires precise regulation. Vertebrate cells mostly obtain iron through transferrin (Tf) receptors, which bind the iron carrier, Tf. Wingert and colleagues now describe three new Tf receptors in zebrafish, Tfr1a, Tfr1b and Tfr2 (see p. 6225). They report that tfr1a mutations cause perturbed Hb production and anemia in the chianti zebrafish mutant, and that tfr1a is specifically required by developing RBCs for iron uptake. By contrast, tfr1b is not required by developing RBCs and probably acquires iron for non-erthyroid tissues instead. Importantly, the authors' findings highlight chiantias the ideal model for studying Tfr1 functions specifically in erythropoiesis,in the absence of other developmental defects.