Pigment cells development and body color variation of postembryonic development in Amphilophus citrinellus(Günther 1864)

Abstract:

The changing process of body color and distribution of chromatophores, as well as morphological characteristics during early life history of Amphilophus citrinellus(Günther, 1864) were observed and photographed by microscope and anatomical lens at water temperature of (27±1) ℃ and pH 8.3. Melanin existed on the body surface of hatchling, and increased at 2 days post hatching (dph). By this time the eye socket of the fish larvae turned black, whereas visual sense undeveloped. The fish larva still had yolk sac, while its melanophores branched and diversified morphological characters at 3 dph. At 4 dph, larvae had optic function and swam. Mouth opened at 5 dph, while yolk sac decreased significantly. Irridophores appeared at 7 dph and xanthophores appeared at 10 dph. Young fin membrane were replaced by adult fin at 12 dph. As the number of melanophores and xanthophores continued to increase, their body color became black. Scales occurred and fin fully developed at 19 dph, hence the larvae turned into juveniles. The erythrophores were found at 30 dph. 7 black stripes were formed across the body which became totally black, and the scales spread over the whole body at 35 dph. Melanin started to fade at 65 dph, and disappeared at 85 dph, then body color turned bright yellow. These results provide a theoretical basis for cultivating Amphilophus citrinellus with stable gene and pure color.