Influence of light intensity and wavelength on phototactic behaviour of larval silver perch Bidyanus bidyanus and golden perch Macquana ambigua and the effectiveness of light traps

摘要: Larval golden perch, Macquaria ambigua, and silver Bidyanus bidyanus, were exposed to light gradients in wavebands centred on 400, 496, 601 695 nm at nominal quantum irradiance values of 0–1, 1–0 10 μmol m−2 s−l. Silver perch larvae displayed stronger phototactic behaviour than both species most responsive the waveband. The intensity responses was greater higher levels. Enhanced responsiveness longer wavelengths reflects possible adaptations life turbid habitats where underwater field is dominated by yellow/orange wavebands. At night, traps fitted with 12 h yellow lightsticks attracted more blue, green, orange, red or no lightstick. efficacy may be due not being attenuated under water as rapidly blue wavebands. Yellow also emit a over time other colours tested, which have increased effectiveness traps. Light ineffective during day.