LIGHT SPECTRUM PREFERENCE IN THE EUROPEAN EEL ANGUILLA ANGUILLA (L.)
Wojciech Kuliński*, Ewa Styczyńska-Jurewicz**
*Marine Biology Center, Polish Academy of Sciences, Gdynia, Poland
**Institute of Biology and Environmental Protection, Pomeranian Pedagogical Academy, Słupsk, Poland
ABSTRACT. This paper reports the results of a supplementary study to research conducted previously on the stimulating effect of defined spectral ranges of light on the growth rate of the European eel Anguilla anguilla L. The aim was to study the eel’s potential selectivity and behavioral preference for defined light band wavelengths which are recognized as optimal colors. Eel specimens from a wild population were acclimatized in a laboratory for six months under natural daylight conditions. Five randomly selected specimens were then held in an aquarium divided into four compartments. Each compartment was irradiated for 7 h daily with tungsten bulb light that was transmitted through a glass filter of a specific transmission band (white, red, violet and green). The fish could enter any of the compartments and stay in them at will. The intensity of irradiance measured at the central point of each compartment was maintained at a standard level. During the 105-day experiment, 61 records of fish distribution in the particular compartments were obtained. Individual preferences for definite colors were estimated statistically. The eels gathered twice as frequently in the compartments irradiated with violet and green light than in those irradiated with white or red. The tendency for them to congregate in groups was also significantly higher in violet and green light than in white or red (P < 0.001). The lighting preferences are considered to be optimal for the biology of this species.
Key words: EUROPEAN EEL (ANGUILLA ANGUILLA), LIGHT SPECTRUM, BEHAVIORAL PREFERENCE
Ewa Styczyńska-Jurewicz, Instytut Biologii i Ochrony Środowiska, Pomorska Akademia Pedagogiczna, ul. Arciszewskiego 22B, 76-200 Słupsk