Heme is essential and synthesised via highly-regulated processes. For this reason, most organisms strive to recycle it or acquire it from their environment. When heme is bound to proteins non-covalently, degradation of the polypeptide is sufficient to release it. However, in some hemoproteins, such as c-type cytochromes, heme is covalently bound to the protein backbone. We use the heme auxotroph Caenorhabditis elegans to investigate if cytochromes c can be a heme source, and we show that this organism must encode a novel system, which specifically cleaves the thioether bonds of c-type cytochromes. We also find that at limiting heme concentrations, while somatic tissues develop normally the germline fails to proliferate, suggesting the presence of a heme-sensing checkpoint in C. elegans.