A CRYSTALLOGRAPHIC STUDY OF THE LOVE DART (GYPSOBELUM) OF THE LAND SNAIL HELIX POMATIA (L.)

Love darts are formed in land snails and injected into the partner's body during the mating process. Darts of Helix pomatia (L.) were studied with synchrotron X-ray powder diffraction, X-ray absorption spectroscopy (Ca K-edge EXAFS), and scanning electron microscopy. The polycrystalline dart consists almost exclusively of non-orientated aragonite crystals (calcium carbonate) with isotropic domain sizes of c. 40-80 nm with a variation in size along the dart. The hollow central channel inside the dart is covered with elongated, [mu]m-sized crystals, possibly single crystals. Very small amounts of an unknown crystalline phase were found.