Serpula israelitica, longitudinal section of the tube, calcitic lamello-fibrillar structureDitrupa arietina (Serpulidae), outer tube layer, calcitic regularly ridged prismatic structure, showing interlocked prismsGlomerula piloseta (Sabellidae), longitudinal section of the tube, aragonitic spherulitic prismatic structure
Biomineralizing polychaetes arepolychaetes that produce minerals to harden or stiffen their own tissues (biomineralize).
The most important biomineralizing polychaetes areserpulids,sabellids andcirratulids. They secrete tubes ofcalcium carbonate. Serpulids have most advanced biomineralization system among theannelids. Serpulids possess very diverse tube ultrastructures. Serpulid tubes are composed ofaragonite,calcite or mixture of both polymorphs. In addition to the tubes, some serpulid species secrete calcareous opercula. Some sabellids and cirratulids can secrete aragonitic tubes. Sabellid and cirratulid tubes have a spherulitic prismatic ultrastructure. There are thin organic sheets in serpulid tube mineral structures. These sheets have evolved as an adaptation to strengthen the mechanical properties of the tubes.[1][2][3][4][5] Fossil and present-day cirratulid bioconstructors have been confirmed to be the only known occurrence ofdouble-phased biomineralization processes in the animal kingdom.[6]
^Guido A, D'Amico F, DeVries TJ, Kočí T, Collareta A, Bosio G, Sanfilippo R (2024). "Double-phased controlled and influenced biomineralization in marine invertebrates: The example of Miocene to recent reef-building polychaete cirratulids from southern Peru".Palaeogeography, Palaeoclimatology, Palaeoecology.639 112060.Bibcode:2024PPP...63912060G.doi:10.1016/j.palaeo.2024.112060.S2CID267306998.
