“…Many studies have focused on specific dimensions along which different members of the communities may differ, including vertical distribution (Gibson, 1972;Burgess, 1978;Yoshiyama, 1981;Costello, 1992), shelter availability and habitat complexity (Behrents, 1987;Koppell, 1988;Kotrschal, 1988;Wilkins & Myers, 1993) or differentiation of trophic niches (Gibson, 1960;MacPherson, 1981;Yoshiyama, 1980;Zander, 1982). Other studies have focused on the possible role of competition as a mechanism structuring these communities (Larson, 1980a,b,c;Mayr & Berger, 1992), while still others have centred on long-term patterns of persistence and resilience of these rock intertidal fish assemblages (Thomson & Lehner, 1976;Grossman, 1982Grossman, , 1986Yoshiyama et al, 1986;Faria & Almada, 1999).…”