PDF(Pubmed)
Abstract：
The leopard coral trout generally exhibited numerous round, minute blue spots covering its head (about the size of nostril) and body (except ventral side). This is a characteristic that distinguishes them from similar species. Recently, however, we found the leopard coral trout with black spots. Here, the distribution and ultrastructure of chromatophores in the blue and black spots were investigated with light and transmission electron microscopies. The results showed that in the blue spots, two types of chromatophores are present in the dermis, with the light-reflecting iridophores located in the upper layer and the aggregated light-absorbing melanophores in the lower layer. Black spots have a similar chromatophore composition, except that the melanosomes within the melanophores disperse their dendritic processes to encircle the iridophores. Interestingly, after the treatment of forskolin, a potent adenylate cyclase activator, the blue spots on the body surface turned black. On the other hand, using the skin preparations in vitro, the electrical stimulation and norepinephrine treatment returned the spots to blue color again, indicating the sympathetic nerves were involved in regulating the coloration of blue spots. Taken together, our results revealed that the blue spots of the leopard coral trout can change color to black and vice versa, resulting from the differences in the distribution of melanosomes, which enriches our understanding of the body color and color changes of fishes.
摘要：
豹纹珊瑚鳟鱼通常表现出许多圆形，覆盖其头部（大约鼻孔的大小）和身体（腹侧除外）的微小蓝色斑点。这是区别于相似物种的特征。最近,然而,我们发现有黑点的豹纹珊瑚鳟鱼。这里,用光和透射电子显微镜研究了蓝色和黑色斑点中色团的分布和超微结构。结果表明，在蓝色斑点中，真皮中存在两种类型的色素，光反射的虹彩团位于上层，而聚集的光吸收黑色素团位于下层。黑点有相似的色团组成,除了黑色素细胞内的黑色素体分散其树突过程以包围虹膜。有趣的是,经过毛喉素的治疗,一种有效的腺苷酸环化酶激活剂，身体表面的蓝色斑点变成了黑色。另一方面,使用体外皮肤制剂，电刺激和去甲肾上腺素治疗使斑点再次恢复为蓝色，表明交感神经参与调节蓝点的着色。一起来看,我们的结果表明，豹纹珊瑚鳟鱼的蓝色斑点可以改变颜色为黑色，反之亦然，由于黑色素体分布的差异，这丰富了我们对鱼类身体颜色和颜色变化的理解。
