Hemocyanin levels in the giant keyhole limpet, Megathura crenulata, from the coast of California

Abstract

1. 1. The concentration of hemocyanin in the hemolymph of the giant keyhole limpet Megalhura crenulata, has been determined. 2. 2. In 56 specimens of M. crenulata the hemocyanin concentration ranged from 1.53 to 10.81 g/1 with a mean of 5.45 g/1 and a standard deviation of 2.71 g/1. There is no correlation between the hemocyanin concentration and the weight of the animal. The hemolymph volume and the colour of the mantle are not related to the hemocyanin level either. 3. 3. The hemocyanin concentration shows a seasonal variation, the means and the standard deviations for February, April, July, and September being 6.48 ± 2.58, 4.44 ± 1.72, 2.62 ± 1.05, and 7.65 ± 1.54 g/1, respectively. 4. 4. The lability of the hemocyanin concentration in Megathura (7-fold variation) is less pronounced than it is in California Haliotis, but comparable to that of the Australian abalones. 5. 5. It is difficult to reconcile the wide fluctuations observed in the concentration of hemocyanin with an essential respiratory task for this protein.