Bryozoan interactions: Observations on stolonal outgrowths

Abstract

Tropical bryozoan and colonial ascidian species were transplanted in pairs onto small slabs of coral skeleton. Microscopic examination of the slabs was carried out every 6 weeks. Five out of eight species of bryozoan studied produced terminal and/or frontal stolonal outgrowths at interfaces with adjacent bryozoans and colonial ascidians. Secondary growing edges, which had the potential to grow back over intruding colonies, sometimes formed subsequently at the position of frontal stolonal outgrowths. The sequence of events following contact between the two species Celleporaria sp. A and Stylopoma duboisii (Audouin) is described. A possible function of stolonal outgrowths is colony defence, and the importance of long-term studies in revealing the dynamic nature of colony interfaces is noted.