The remarkable lungfish otolith

Otoliths and macula from the Australian lungfish Neoceratodus forsteri were examined by light and scanning electron microscopy. The otoliths, corresponding to the sagitta and lapillus in teleosts, were found to consist of crystalline oto-conia consisting of calcite, aragonite, and a previously undescribed form of calcium carbonate bound in what appears to be a protein matrix. The inner-vation and hair-cell anatomy of the lungfish macula exactly parallels those of teleosts. Thus in function the otolith appears similar to teleosts, whereas its crystal complement has parallels in mammals, reptiles, and chondrichthyans.