Mónica Botero

Growth, Survival, and Body Composition of Sunshine Bass after a Feeding and Fasting Experiment

Abstract There is continuous interest in experimental, semipurified diet formulations and in the formulation of practical, inexpensive diets for grow out of sunshine bass (female white bass Morone chrysops × male striped bass M. saxatilis). The effects of four diets on growth, survival, and body composition of sunshine bass after a feeding period (51 d) and a subsequent fasting period (14 d) were examined. To our knowledge, no previous sunshine bass feeding experiments have incorporated a fasting period to simulate the handling and acclimation conditions experienced by farmed fish that are stocked into new environments. Diets consisted of a high-nutrient commercial diet, a wheat-gluten-based practical diet, a semipurified diet (meeting standard nutrient requirements), and a frozen natural diet (chironomids). Fish were hand fed three times per day at 4% of body weight. At the end of the fasting period, samples were collected for histological analysis of the liver and posterior intestine. Survival was signi...

Threatened fishes of the world: Salminus affinis Steindachner, 1880 (Characidae)

Common name: Picuda, Rayada, Rubia, Rubio, Dorada (Spanish).Conservation status: Listed as vulnerable by the Red Book of Colombian Freshwater Fishes (Lehmann and Alvarez-León 2002). Identification: Presence of dark post-orbital stripe, absence of any development of the median caudal-fin rays beyond the primary margin of the fin, caudal-peduncle spot spreads onto the caudal fin, 68–79 lateral line scales; D.ii + 9; P.i + 12–14; V.i + 7; A.iii + 23–25 (Eigenmann 1922; Lehmann 1999; Lima 2006). Illustration corresponds to Collection of ichthyology University of Antioquia (CIUA)-970, by Andres Montoya. Distribution: Magdalena, Cauca, San Jorge, Cesar, Sinú and Rancheria river basins (Lehmann and Alvarez-León 2002; Lima 2006; Mojica et al 2006). Abundance: Current reports in the Magdalena River basin suggest a drastic decrease in population size (Lehmann and Alvarez-León 2002; Lehmann and Niño 2008). Habitat and ecology: Migratory species, it can be found in the main river channel, in clean-water tributaries. Its diet is composed of fish and insects (Lehmann and Alvarez-León 2002). Reproduction: Breeding individuals have been observed in the rainy season and gonadal development reaches its peak during November (Lehmann 1999). Threats: Water pollution, overfishing, gold mining and hydroelectric dams (Galvis and Mojica 2007). Conservation action: The minimum capture size of 35 cm total size is legally established. Considered as priority species for conservation (Lehmann and Niño 2008). Conservation recommendations: Conservation of undisturbed tributaries, fishing regulations, biological research, Environ Biol Fish (2009) 85:285–286 DOI 10.1007/s10641-009-9494-3