MEPS 383:273-283 (2009)  -  DOI: https://doi.org/10.3354/meps07986

ABSTRACT: Resident and transitory intertidal fish species are expected to differ in their utilization of space in the intertidal zone. Here we assessed fish zonation patterns on 2 rocky shores of the northwestern Adriatic Sea (where tides can range up to 1.5 m) using blennies as study species and distribution of both individuals and nests as methodological tools. Of the 12 species observed, 5 were found exclusively in the intertidal zone: Aidablennius sphynx, Coryphoblennius galerita, Lipophrys adriaticus, L. canevae and L. dalmatinus. Two species, Parablennius rouxi and P. tentacularis, were found only in the subtidal zone, whilst P. gattorugine, P. incognitus, P. sanguinolentus, P. zvonimiri and Salaria pavo were observed in both environments. Nest distribution mirrored individual distribution, strongly indicating that some blenny species can be considered true intertidal residents, spending the main part of their lives in this area. Intertidal and subtidal species showed different patterns of space utilization. Indeed, the former nested higher in the vertical distribution than the average depth at which individuals were recorded, and the latter, despite visiting the intertidal area at high tide, always nested below the minimum water line. These results show that, contrary to theoretical predictions, intertidal-resident fish may fully exploit intertidal habitats, for foraging and for reproduction, occupying even the sectors most distal from the subtidal zone, i.e. the most variable in terms of physical conditions. Moreover, nest distribution was found to be an effective measure of residence and thus a useful referent to evaluate space use in intertidal fish.

KEY WORDS: Blenniidae · Nest · Eggs · Intertidal fish · Vertical zonation · Adriatic Sea