Distribution, diel movement, and growth of the grass shrimp Palaemonetes paludosus in the Kissimmee River-floodplain ecosystem, Florida

Historically, the Kissimmee River meandered over an extensive floodplain wetland. In response to catastrophic flooding and settlement pressures in Central Florida, the Kissimmee was channelized, converting the complex, braided channel into a straightened canal. The result has been a sharp decrease in fringing wetland habitat and associated biota, Soon after channelization was completed, environmental concerns prompted the State of Florida to start examining options for restoration to reestablish the river's natural hydrology and restore lost wetland habitat. The grass shrimp, Palaemonetes paludosus has been identified as a keystone invertebrate species in this system. This study was designed to examine its distribution, diel movement, and growth within the two dominant macrophyte communities of the Kissimmee River riparian marsh: Nuphar and Polygonum. Results indicated that grass shrimp were more abundant in Polygonum beds. This species also showed no well-defined diel migration, although we found a significant vertical pattern in some instances. Palaemonetes paludosus growth was highest on periphyton and Polygonum leaves, Grass shrimp distribution may be explained by their decreased susceptibility to predation because of the higher habitat complexity inherent in Polygonum beds.