How light, a predator, and experience influence bluegill use of shade and schooling

• Published in: Environmental biology of fishes Vol. 49; no. 1; pp. 79 - 87
• Main Authors: MCCARTT, A. L, LYNCH, W. E, JOHNSON, D. L
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer 01.05.1997; Springer Nature B.V
• Subjects: Agnatha and pisces; Animal ethology; Behavior; Biological and medical sciences; Fish hatcheries; Freshwater; Fundamental and applied biological sciences. Psychology; Lepomis macrochirus; Light; Light intensity; Predators; Psychology. Psychoanalysis. Psychiatry; Schools; Vertebrata; Ohio; United States; North America; America; School(aquatic animal); Lepomis macrochirus; Freshwater environment; Predator prey relation; Laboratory study; Vertebrata; Pisces; Shading; Antipredator behavior; Experimental study; Avoidance
• ISSN: 0378-1909; 1573-5133
• DOI: 10.1023/a:1007353314602

Bluegills, Lepomis macrochirus, form schools and use shade to avoid predators. How light intensity, predators, and experience might affect antipredator behavior of bluegill are not well understood. Hence, we evaluated use of shade and schooling by naive (hatchery) and experienced (wild) bluegills (50-60 mm total length) at four light levels (1.5, 85, 169, 340 lux) in the presence and absence of a model predator in experimental pools. Naive bluegills used shade extensively at all light levels, even when the predator was in the shade. They rarely schooled, preferring to shoal in the shade. Experienced bluegill used shade when the predator was in the open and avoided shade when the predator was there. Schooling was more prevalent at low light levels when shade was less intense. Use of shade became an increasingly important behavior at higher light levels, unless the predator was in the shade. A shaded predator caused experienced bluegills to shoal tightly in the opposite, open area. These data suggest naive bluegills may not have considered the model predator a threat. Their behavior suggests avian predator avoidance, a possibility given that avian predators were present at the hatchery. Experienced bluegill employed behaviors that would be useful in avoiding piscine predators.[PUBLICATION ABSTRACT]