Marine Ecology Progress Series 573:215
This authors' personal copy may not be publicly or systematically copied or distributed, or posted on the Open Web, except with written permission of the copyright holder(s). It may be distributed to interested individuals on request. Vol. 573: 215–228, 2017 MARINE ECOLOGY PROGRESS SERIES Published June 21 https://doi.org/10.3354/meps12164 Mar Ecol Prog Ser Diet shifts in a native mesopredator across a range of invasive lionfish biomass Joseph S. Curtis1,*, Kara R. Wall1, Mark A. Albins2, Christopher D. Stallings1 1College of Marine Science, University of South Florida, St. Petersburg, FL 33705, USA 2University of South Alabama, Mobile, AL 36608, USA ABSTRACT: In marine ecosystems, little is known about how competition with invasive fishes may affect the resource use of native predators. Throughout the western Atlantic, invasive Indo-Pacific lionfishes (Pterois spp.) are likely to compete with native mesopredators such as the graysby Cephalopholis cruentata, an ecologically similar serranid. In conjunction with a before-after- control- impact lionfish removal experiment, this study measured whether graysby population size, diet, and condition varied in relation to cohabitant lionfish biomass. Lionfish, graysby, and prey popu- lations were surveyed and sampled along a contiguous reef ledge in Biscayne National Park, south Florida. Mesopredator diet was measured with stable isotope (δ13C and δ15N) and gut con- tent analyses, and isotopic niches were used to compare patterns of inter- and intraspecific resource use diversity. The isotopic niches of graysby and lionfishes overlapped by 67%, suggest- ing similar population-level resource use. On sites with higher lionfish biomass, graysby isotopic niche was 34% smaller and overlapped 47% less with that of lionfishes, possibly indicating both a narrower breadth of resource use and associated interspecific niche segregation.
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