Enhancing　substrate　transfer　is　crucial　for　promoting　the　nitrogen　removal　rate　of　Anammox　granular　sludge,　as　the　shape　of　the　granules　significantly　influences　substrate　diffusion.　In　this　study,　inspired　by　biomimicry　principles,　we　propose　a　novel　red　blood　cell-like　granular　sludge　to　increase　the　contact　area　and　improve　substrate　transfer.　The　startup　and　operation　of　Anammox　granular　sludge　in　low-strength　ammonia　nitrogen　wastewater　were　successfully　achieved　through　an　increase　in　substrate　volume　flux　(SVF).　As　the　SVF　increased　from　2.38　to　7.43　L²/(g　VSS·h),　specific　Anammox　activity　(SAA)　rose　from　0.138　to　0.483　g　N/(g　VSS·d).　The　Anammox　granular　sludge　system　achieved　a　total　nitrogen　removal　efficiency　of　85.70　%　and　a　nitrogen　removal　rate　(NRR)　of　0.792　kg　N/(m³·d)　after　126　days.　Notably,　red　blood　cell-like　granular　sludge　was　observed　by　day　116.　The　rise　in　SVF　induced　a　granule　structure　more　conducive　to　substrate　transport,　improving　the　granules＇　efficiency　in　substrate　uptake　and　thereby　enhancing　their　SAA.　High-throughput　pyrosequencing　revealed　that　the　dominant　bacteria　using　the　SVF-enhancing　strategy　remained　anaerobic　ammonium　oxidizing　bacteria　(AnAOB)　(29.53　%-29.89　%),　with　an　increased　diversity　of　species,　including　Candidatus　Kuenenia,　Candidatus　Anammoxoglobus,　and　Candidatus　Brocadia.　©　2024　Elsevier　Ltd