MEPS 488:247-254 (2013)  -  DOI: https://doi.org/10.3354/meps10431

ABSTRACT: To test theories of resource segregation and coexistence, we studied 2 goby species: the eastern sand goby Favonigobius lentiginosus (which typically occupies soft sediment tidepools) and the half-bridled goby Arenigobius frenatus (typically found in nearby subtidal seagrass beds). We used mesocosm experiments to test the hypotheses that (1) occupation of tidepools by F. lentiginosus is a function of exclusion (i.e. realized niche) from subtidal habitats by A. frenatus rather than habitat preference (i.e. fundamental niche) and (2) intraspecific competition among F. lentiginosus may also play a role in their occupation of intertidal pools. In single-species experiments, single specimens of both A. frenatus and F. lentiginosus spent significantly more time in the seagrass habitat. When together in the same mesocosm, F. lentiginosus significantly altered its habitat use to sand, while A. frenatus used more detritus habitat. At higher densities in single-species experiments with F. lentiginosus, a significantly greater number of individuals used the apparently less desirable sand habitat. Habitat preferences displayed by gobies in the laboratory setting did not directly reflect their distribution in their natural habitat, suggesting that the use of soft sediment tidepools by F. lentiginosus may be a consequence of competition with A. frenatus for space in seagrass beds, causing the former to occupy their realized niche of sandy habitat.

KEY WORDS: Soft sediment · Tidepools · Competition · Seagrass · Gobiidae