the effect of structural complexity, prey density, and “predator-free space” on prey survivorship at created oyster reef mesocosms结构复杂性的影响,猎物密度,和u201c空间u201d上的猎物存活创造了牡蛎礁昌盛.pdfVIP

The Effect of Structural Complexity, Prey Density, and ‘‘Predator-Free Space’’ on Prey Survivorship at Created Oyster Reef Mesocosms 1,2 3 1 Austin T. Humphries *, Megan K. La Peyre , Gary A. Decossas 1 School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, Louisiana, United States of America, 2 Department of Zoology and Entomology, Rhodes University, Grahamstown, South Africa, 3 United States Geological Survey, Louisiana Fish and Wildlife Cooperative Research Unit, School of Renewable Natural Resources, Louisiana State University AgCenter, Baton Rouge, Louisiana, United States of America Abstract Interactions between predators and their prey are influenced by the habitat they occupy. Using created oyster (Crassostrea virginica) reef mesocosms, we conducted a series of laboratory experiments that created structure and manipulated complexity as well as prey density and ‘‘predator-free space’’ to examine the relationship between structural complexity and prey survivorship. Specifically, volume and spatial arrangement of oysters as well as prey density were manipulated, and the survivorship of prey (grass shrimp, Palaemonetes pugio) in the presence of a predator (wild red drum, Sciaenops ocellatus) was quantified. We found that the presence of structure increased prey survivorship, and that increasing complexity of this structure further increased survivorship, but only to a point. This agrees with the theory that structural complexity may influence predator-prey dynamics, but that a threshold exists with diminishing returns. These results held true even when prey density was scaled to structural complexity, or the amount of ‘‘predator-free space’’ was manipulated within our cre