Craig G. Lilyestrom

Effects of Reservoir Drawdown on Available Habitat: Implications for a Tropical Largemouth Bass Population

In temperate reservoirs, habitat quality and availability can be vital to year-class formation of young largemouth bass. We assessed littoral habitat availability for largemouth bass in a tropical reservoir. Habitat characteristics (slope, substratum, and cover) were measured at 5 water levels (169, 170, 171, 172, and 173 m above mean sea level) at 15 30-m sites in Lucchetti Reservoir. Total structural habitat availability declined sharply at lower water levels, and both inundated terrestrial vegetation and woody debris were absent at the lowest water level examined. Coarse substrates (...


Temporal Variability in the Littoral Fish Community of a Puerto Rico Reservoir

Electrofishing the littoral zone of Lucchetti Reservoir, Puerto Rico, from 1992 through 1997 indicated dynamic changes in fish community structure, despite consistent annual water level regimes. Nine species of fish, including 2 cichlids, 2 centrarchids, and 2 ictalurids, were collected. Relative abundance varied significantly over seasons and years for most species. One species, the bigmouth sleeper (Gobiomorus dormitor), may have become extirpated during the period and 1 new species, armored catfish (Liposarcus multiradiatus), became established. Adult largemouth bass (Micropterus...


Diet and Movement of Largemouth Bass and Butterfly Peacocks in La Plata Reservoir, Puerto Rico

Diet and telemetry studies were conducted in La Plata Reservoir, Puerto Rico, to investigate potential interactions between largemouth bass (Micropterus salmoides) and butterfly peacocks {Cichla ocellaris). Partitioning of food resources between the 2 species was evident and consistent over several size classes. Interspecific differences were observed in home range size, diel movement, and habitat preference during telemetry studies conducted on adults for up to 250 days. Maximum activity for both species corresponded with periods of elevated food consumption. Although the current studies...