Nest characteristics of three labrid species in the Gulf of Trieste (northern Adriatic Sea)

Abstract

Temperate Labrid species are nest builders with nests usually made out of plant material or detritus. During the summer of 2004, 131 nests of three wrasses (Symphodus roissali, S. ocellatus and S.cinereus) were studied by SCUBA diving in the Slovenian coastal sea (northern Adriatic) in order to compare nest parameters and microhabitat preferences among the species. For the description of the structure of each nest, algal species, benthic invertebrates and type of substrata within the nest were determined, as well as the features of each microhabitat. A Redundancy Analysis (RDA) was performed in order to highlight the distribution of the three species in relation to environmental variables and their preferences for different biotic and abiotic variables in the construction of nests. Labrid species were found to be more abundant on rocky bottoms, where the Cystoseiretum barbatae association is dominant. It seems that the studied species show a preference for some microhabitats, although are building their nests using the most abundant algal material in the environment. Only S. ocellatus seems to select shrub-forming algae as the main nest-forming material.