Littoral Stratification in Growth form and Fecundity of the Rock Barnacle, Semibalanus Balanoides

• Published in: Journal of the Marine Biological Association of the United Kingdom
• Main Authors: Rangeley, R. W., Thomas, M. L. H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 1988
• Subjects: Aquatic Science; Dogwhelk; Nucella lapillus
• Online Access: http://dx.doi.org/10.1017/s0025315400028733; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0025315400028733

The population dynamics of rock barnacles, Semibalanus balanoides (L.), residing in low and high intertidal zones are affected by conspicuously different factors. The barnacle population in the high intertidal zone tends to show longterm stability due to a low incidence of both predation and interspecific competition. Wave exposure, desiccation and intraspecific competition are more important factors affecting abundance and size distribution in this zone (Menge, 1976). In the low intertidal zone, barnacle predation by the dogwhelk, Nucella lapillus (L.) is intense (Menge, 1976) and both the adults and larvae are smaller than in the high intertidal zone (Barnes, 1953). The growth form of S. balanoides is density dependent with taller, more columnar individuals predominating at high densities and short conical barnacles at low densities. Lower fecundity of conical individuals may be due to lower internal shell volume compared with columnar forms (Wethey, 1984). Fecundity increases both with increasing age and base length (Arnold, 1977) and is positively density dependent (Wethey, 1984).