Nest Sites Used by Radio-Tagged Largemouth Bass in Orange Lake, Florida

The bottom substrates of many Florida lakes are predominantly unconsolidated organic matter with only limited areas of firm substrate typically used for spawning by largemouth bass Micropterus salmoides. The purpose of this study was to locate by radiotelemetry and describe the nest sites of male Florida largemouth bass Micropterus salmoides floridanus in a lake with essentially no firm inorganic substrate. We located 20 nests during the 1983 and 1984 spawning seasons: 13 in spatterdock Nuphar luteum (25% of the available habitat), 5 in emergent grasses Paspalidium geminatum and Panicum hemitomon (1% of the available habitat), and 2 in smartweed Polygonum hydropiperoides (10% of the available habitat). No nests were found in open water (64% of the available habitat). Observed nests were constructed on rhizomes in the spatterdock habitat or on firm detritus in the emergent grass and smartweed. Spatterdock, due to its abundance, was the most extensively used nesting habitat, but selectivity for nest sites was higher for the less abundant emergent grass. Although all nests were associated with vegetation, firm bottom or above-bottom substrate appeared to be important in nest-site selection.