Experimental acrylic plastic panelswere submerged in the intertidal zone at Mikhmoret, the Mediterranean coast of Israel, at three vertical levels and facing four compass directions. Balanus amphitrite (Darwin), a common warm-water fouling barnacle, dominated the panels. Chthamalus stellatus (Poli), the commonest rocky intertidal barnacle in the Mediterranean and on nearby rocks, was rare on the panels. Recruitment, growth, and survival of both species were monitored over 3.3 years, through periodic photography of the panels. Survivorship was lower and growth was faster in B. amphitrite than in C. stellatus. For B. amphitrite, recruitment did not vary between vertical levels, but growth was fastest at the upper level, greatly exposed to physical stress. Density was positively correlated with survival, but it depressed growth rate. Mortality was highest at the lower level, where competition with other sessile species is intense. Only 2.7% of B. amphitrite recruits could have reproduced in two successive breeding seasons, 68% did not survive to breed, and the rest could have bred only once in their lifetime. The life-history traits of B. amphitrite, though observed in a relatively stable environment, seem to be adaptive for a fouling lifestyle in unstable habitats.
ASJC Scopus subject areas
- Animal Science and Zoology