Abstract

Temporal and spatial variations in the recruitment of Bankia martensi Stempell, 1899 (Teredenidae: Bivalvia: Mollusca) were analysed in southern Chile. B. martensi is the only species of shipworm inhabiting Chilean waters and the cause of severe damage to wooden structures in the sea. Two experiments were carried out over a period of approximately 20 years, in Codihué (41°547prime;5; 72°25′W) during 1979-1980 and Metri Bay (41°36′S; 72°42′W) during 2000-2001. Pine and oak panels were suspended at three depths and the density of recruits was determined based on the perforations or calcified cones produced when animals penetrate the wood. Recruitment patterns were similar during both series of experiments. Average recruitment density did not differ statistically, neither did the incidence of attacks on pine and oak panels. Similarly, no differences were registered between the occurrence of attacks on the upper or underside of the panels. Seasonal differences did occur with regard to the period of maximum recruitment, although in both locations recruitment was significantly lower in winter. No differences were registered at depths of over 3 m, and lower recruitment was registered on superficial panels only in Codihué. Results indicate continuous recruitment and low levels of temporal and spatial variability in spite of the different locations and periods when the data were collected. These patterns may be associated with the unpredictable presence of wood in the sea that is the specific substrate necessary for metamorphosis and adult development. B. martensi possesses reproductive characteristics that permit a constant supply of competent larvae, such as: reproduction throughout the year, early sexual maturity, alternative hermaphroditism and prolonged larval development, probably with teleplanic larvae. Low larval substrate selectivity also favours substrate colonization. © CMS, Inc., 2006.