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 we tland. In response to catastrophic flooding and settlement pressures in Cen tral Florida, the Kissimmee was channelized, converting the complex, braide d channel into a straightened canal. The result has been a sharp decrease i n fringing wetland habitat and associated biota, Soon after channelization was completed, environmental concerns prompted the State of Florida to star t examining options for restoration to reestablish the river's natural hydr ology and restore lost wetland habitat. The grass shrimp, Palaemonetes palu dosus has been identified as a keystone invertebrate species in this system . This study was designed to examine its distribution, diel movement, and g rowth 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-defi ned diel migration, although we found a significant vertical pattern in som e instances. Palaemonetes paludosus growth was highest on periphyton and Po lygonum leaves, Grass shrimp distribution may be explained by their decreas ed susceptibility to predation because of the higher habitat complexity inh erent in Polygonum beds.