ABSTRACT
Most blennioids are small bottom-dwelling site-attached fishes, many of them territorial, showing strong associations with the microhabitats they inhabit and spending a lot of time keeping close to the substrate, often in cryptic microhabitats (e.g., holes, crevices, under overhangs or small boulders). They are generally highly sedentary, swimming only for short distances and spending very little time in open water (Gibson, 1969). This is especially true for the intertidal species, for which a tight association with the substratum can prevent the risk of displacement caused by water turbulence (Gibson, 1969; Gonçalves and Almada, 1998). Territoriality is quite common in many species, not only during the breeding season (e.g., Almada et al., 1987, 1992, 1996; Almada and Santos, 1995; Gonçalves and Almada, 1998), but also throughout the year, probably to ensure an
efficient use of food and shelter resources (Gibson, 1969, 1982; Lindquist, 1985; Koppel, 1988; Mayr and Berger, 1992).
