ISSN:
1432-1793
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Samples of Balanus balanoides (L.) in the Menai Straits were taken from their upper limit of distribution on the shore, from mean low water (MLW) and at three different times of the year, January, May and August. Individual prosomae were homogenised, electrophoresed on polyacrylamide gels and esterase isozymes determined. Group BbEI esterase isozymes fitted the Hardy-Weinberg predicted values for 4 co-dominant alleles in all samples. A comparison of BbEI phenotype frequency distribution of the upper shore and MLW samples showed no significant difference at the 5% level. The phenotype frequency of samples taken at different times of the year were significantly different at the 5% level, due to an excess of allele A in winter and an excess of allele C in summer. It is argued that the seasonal variation of phenotype frequency is probably not due to selection operating on a balanced polymorphism, but that the expression of the alleles through the synthesis of esterase isozymes is dependent on some environmental agent, postibly temperature or day length.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00386642
