A Contribution to the Ecology of the Lamellibranch Tellina Alternata

On one muddy bottom, the lamellibranch Tellina alternata ranked second by weight and comprised 22.0 per cent of the biomass. It appears to breed twice a year, and the spring brood reaches a size of 23 mm by the first December, and 40 mm by the second. The maximum size found was about 50 mm, probably equivalent to three years of age. On comparison with other tropical molluscs, this species is found to grow at a less than average rate prior to sexual maturity, but faster than T. tenuis in Scotland. T. alternata also shows the tropical characteristic of less growth after sexual maturity than in temperate species.