Radula synthesis by three species of iron mineralizing molluscs: production rate and elemental demand

A cold-shock technique was used to determine radula production rates for the chitonsAcanthopleura hirtosaandPlaxiphora albida, and for the limpetPatelloida alticostata, which replaced their radular teeth at rates of 0.40, 0.36 and 0.51 rows d−1, respectively. These rates are far slower than those determined previously for non-iron-mineralizing molluscs, suggesting that the improved working life of the teeth afforded by iron-mineralization acts to significantly reduce replacement rates. In addition, inductively coupled plasma-atomic emission spectroscopy has been used to determine the quantity of iron and other elements comprising the radula of each species. These data, used in conjunction with the radula production rates, reveal thatA. hirtosa,Plaxiphora albidaandPatelloida alticostatahave daily radula mineralization requirements for iron of 3.06, 4.12 and 0.55 μg, respectively. Such information is vital for continuing studies related to the cellular delivery of ions and subsequent biomineralization of the tooth cusps in chitons and limpets.