Light response of cultured melanophores of a freshwater teleost, Zacco temmincki.

Factors Influencing Motile Activities of Fish Chromatophores

“…Both innervated and denervated melanophores in scales isolated from Zacco attained the fully aggregated state in darkness and responded to light (about 600 Ix) by the dispersion of melanosomes. In cultured melanophores from adult Zacco, the dark-induced aggregation response was conspicuous 2 days after initiation of culture (Naora and Iga 1989). In addition, cultured melanophores of "adult" Oryzias latipes were found to respond directly to light in the same manner as Zacco melanophores .…”

“…The responses to illumination appeared after 1 day in culture, and the degree of melanosome translocation depended on the intensity of the incident light. The most effective wavelength for inducing the dispersion of melanosomes was close to 415 nm in the medaka, whereas Zacco melanophores showed the maximum sensitivity to light with a peak wavelength of 525 nm, suggesting that a porphyropsin was active in the light response (Naora et al 1988). …”

Direct Reception of Light by Chromatophores of Lower Vertebrates

“…Pigment granules in melanophores of 'adult' dark chub Zacco temmincki aggregate in darkness and disperse in light (36), the most effective wavelength being 525 nm (37). Cultured Zacco melanophores also exhibit light sensitivity in the same manner as melanophores in isolated scales (38).…”

“…The relative sensitivities of Zacco melanophores were examined at various wavelengths, and light with wavelengths from 500 to 550 nm is highly effective for inducing pigment dispersion (37). The action spectrum closely resembles a porphyropsin absorbance curve, suggesting that a porphyropsin or similar photopigment might be active in the photoresponse.…”

Direct Control of Pigment Aggregation and Dispersion in Tilapia Erythrophores by Light

“…In some fish species however, chromatophores of "adult" fish also have a light-sensitivity; such as pigment dispersion in melanophores of the dark chub, Zacco temmincki, (Iga and Takabatake, 1983) and in leucophores of the medaka, Oryzias latipes (Ohta and Sugimoto, 1980), pigment aggregation in medaka xanthophores (Kawai, 1989;Oshima et al, 1998) and longer-wavelength light-reflecting response of motile iridophores of the neon tetra, Paracheirodon innesi (Lythgoe and Shand, 1982;Nagaishi and Oshima, 1989). The most effective wavelength that induced melanosome dispersion in Zacco melanophores was 525 nm (Naora et al, 1988), while pigment aggregation within medaka xanthophores was effectively caused by light with wavelengths between 410 and 420 nm (Oshima et al, 1998). Very recently, we found that erythrophores of adult tilapias respond rapidly to light even if the luminous intensity is low, and that the direction of pigment migration changes when the peak wavelength of incident light is varied.…”