Distribution of erythrophores, melanophores and fluorescent chromatophores in the interradial membrane of a dorsal fin of <i>E. pellucida</i>.

<p><b>a</b>) Erythrophores (red) and melanophores (black) are visible in bright field microscopy. <b>b</b>) Fluorescent chromatophores appear in fluorescence microscopy. <b>c</b>) Overlay of a) and b). Note that erythrophores, melanophores and fluorescent chromatophores are spatially distributed and can be distinguished. Scale bar  = 400 µm.</p

Morphology of a fluorescent chromatophore.

<p>Confocal Laser scanning microscopy, excitation 510 nm. Fluorosomes are the only visible structures within the fluorescent cell, but in the dispersed state they show the cell outline as they fill the cytoplasm entirely. Scale bar  = 30 µm.</p

Spectra of excitation and emission of the fluorescent pigment in fluorescent chromatophores.

<p>Fluorescence has a maximum at around 595 nm (dashed line) with an optimal excitation wavelength around 500 nm (solid line).</p

Results of cell manipulation.

<p>Bars show results of neuronal and hormonal manipulation in terms of normalized fluorescent area in interradial membranes of <i>E. pellucida</i> before (white bars) and after treatment (shaded bars, respectively). Neuronal K⁺ stimulation significantly decreased fluorescent area (paired t-test, t = 10.5, df = 5, p<0.005). The Lidocain-treatment effectively inhibited this effect (paired t-test, t = 1.86, df = 4, p>0.13). Neurotransmitter-induced aggregation of fluorosomes (NA) was highly significant (paired t-test, t = 4.67, df = 9, p<0.001). Aggregation induced by MCH was significant (paired t-test, t = 5.19, df = 3, p<0.013) as well as α–MSH significantly induced dispersal in pre-aggregated cells (paired Wilcoxon, Z = 10.5, df = 5, p = 0.03). Bars include standard errors.</p

Aggregation of fluorescence.

<p>Classified according to melanophore index 5 (a) through melanophore index 1 (e, respectively). In a completely dispersed state (a) the nucleus becomes visible as there is only little cytoplasm one the apical and basal side of the nucleus in these flat cells. In the aggregated state (e), the nucleus is tightly packed with fluorosomes. Scale bar  = 100 µm.</p