The distribution of yellow pigment cells in the veliger larvae and post-metamorphic snails of Hydrobia ulvae has been recorded. The number of cells increases with the size of the snail and the pigment is characteristic of the foot of the veliger larva, and the foot, mantle, tentacles and penis of adult snails. The cells contain numerous, double membrane-bound vesicles and have a highly granular cytoplasm. The absorption spectra of acetone and methanolic HC1 extracts show single peaks at 337 and 392 nm respectively, while chloroform extracts show peaks at 249, 274 and 283 nm with an inflexion at 293 nm. The pigment has a pale green fluorescence in ultraviolet light. The results of feeding and starvation experiments using larval and post-metamorphic snails lead to the hypothesis that the pigment is a waste product of metabolism which is stored in the vesicles of the cells. |
