Portal de Periódicos da CAPES

Recruitment, growth and mortality of a coral-inhabiting barnacle Megabalanus stultus (Darwin) upon the hydrocoral Millepora complanata Lamarck

1992; Elsevier BV; Volume: 162; Issue: 1 Linguagem: Inglês

10.1016/0022-0981(92)90124-s

1879-1697

John B. Lewis,

Crustacean biology and ecology

The distribution and abundance of the coral-inhabiting barnacle Megabalanus stultus (Darwin) in Barbados were determined on the hydrocoral Millepora complanata Lamarck. Nine percent of the millepores examined were colonized, there was a mean of 2.58 barnacles per colony and adult barnacles were contagiously distributed. A positive correlation between the abundance of millepore colonies on reefs and the frequency of colonies bearing barnacles indicated that barnacle larvae were attracted to settlement sites in proportion to the density of the host millepore colonies. From size-frequency distributions and regressions it was determined that barnacles grew at the rate of 1.1 mm per month and attained a length of about 19 mm in 18 months. Recruitment was low compared to densities of recruits of shore barnacles reported elsewhere. Seventy-four percent of annual recruits occured upon the millepore colony length increment formed during the current year. It was concluded that settlement mortality was least near the growing edge of the host colony where the density of millepore predatory zooids was lowest. Mortality was higher during the second year than during the first year of growth and dead barnacles became overgrown by millepore skeleton and soft tissue. The low abundance of predators and the lack of inter- and intraspecific competition suggests that most adult mortality was due to age. In comparison to shore barnacles, the supply-side ecology of M. stultus was distinguished by lower recruitment, more rapid growth and settlement interaction with the host substratum, as well as a shorter adult life, lack of competition and escape from predators as adults.