USE OF SPACE BY GOBIUS-CRUENTATUS AND THOROGOBIUS-EPHIPPIATUS (TELEOSTEI, GOBIIDAE) IN SOUTHWEST IRELAND

The mechanisms of spatial organisation exhibited by two co-existing sp ecies of Gobiidae, Gobius cruentatus Gmelin, 1789 and Thorogobius ephi ppiatus (Lowe, 1839) were examined to determine the nature of, and the factors contributing to, these mechanisms. This study was carried out in Lough Hyne, south-west Ireland, during 1990. Both species were fou nd to occupy territories exclusive to conspecifics, whilst G. cruentat us was also found to maintain a territory exclusive to T. ephippiatus. This and other interspecific differences in the spatial patterns exhi bited by these species are suggested to be related to size-based domin ance abilities and their differential requirements of space-related re sources.