A totally ambicolorate flounder, Platichthys stellatus, from Alaskan waters
A totally ambicolorate flounder, Platichthys stellatus, from Alaskan waters
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来自阿拉斯加水域的完全双色比目鱼 Platichthys stellatus
作者：
E. Gudger
白化和变色是比目鱼颜色中常见的异常现象，在从白色海到直布罗陀海峡以及整个地中海及其分区的欧洲海岸发现的Platichthys物种中并不罕见。但是，据我所知，在从南加州到日本的北太平洋地区，从来没有描述过星状假单胞菌的双色现象。最近，一个有趣的全双色的标本是由卡尔·L。哈布斯在阿拉斯加收集了它，它是在离彼得堡15或20英里的地方被捕获的。当它躺在我面前，这比目鱼措施约12.5英寸。在解剖和保存收缩之前，它可能总共测量了大约13.5英寸。正常的重量当然无法确定，但是，由于鱼达到15到20磅的重量，这个标本显然是一个年轻的。这是一个真正的ambicolorate比目鱼，是黑暗的左侧或下侧，因为它是在右侧或上侧。此外，右侧的暗条和斑点在左侧几乎完全相同。这是我见过的最完美的双色比目鱼。最不幸的是，在清洗冷冻鱼的过程中，头部和腹部被严重切开。这当然使它不可能有一个照片或绘图。然而，幸运的是，左眼或旋转的眼睛逃过了刀。这个风眼刚好在中脊上方它的左边或右边的边缘几乎不清晰。这种不完全旋转的眼睛产生了另一种总是相关的畸形--背鳍前点的钩。要么是钩状的尖端在眼睛穿过中背线迁移时得到了最终的生长，要么是不完全旋转的眼睛在穿过这条线的永久位置上抑制了这条中鳍内部的任何进一步向前和向下的生长。必须强调的是，比目鱼的总ambicoloration总是伴随着背鳍钩在前部和不完全旋转的眼睛。然而，这些头部异常可能只出现部分的ambicoloration，但据我所知，他们从来没有出现，除非有部分着色以下。幸运的是，我已经能够研究一系列的比目鱼显示完美的渐变，从很少的颜色在较低的一面，以完美的条件下，ambicoloration称为“黑腹。“这些鱼中的每一条，从颜色最浅的到下侧完全黑暗的，都有一个钩状的背部和一个不完全旋转的眼睛。因此，Gudger和Firth在1936年描述了一种长方体牙鲆，其下半部的后半部有五分之二的颜色与上半部相似，但没有头部异常。同一物种的另一条鱼的头部异常，但只有大约五分之一（最后一部分）的下表面着色。另一个头部异常的人，其下半部的后半部五分之二的颜色与上半部相同。1935年，他们描述了一种大比目鱼，河马-
ALBINISM and ambicoloration, common abnormalities in the coloration of flatfishes, are not unusual in those species of Platichthys found on the European coast from the White Sea to the Straits of Gibraltar, and throughout the Mediterranean Sea and its subdivisions. But, so far as I know, ambicoloration has never before been described in P. stellatus, which ranges the North Pacific from southern California to Japan. Recently an interesting totally ambicolorate specimen was sent to me by Dr. Carl L. Hubbs, who collected it in Alaska, where it had been caught 15 or 20 miles off Petersburg. As it lies before me, this flounder measures about 12.5 inches. Before dissection and shrinkage from preservation, it probably measured about 13.5 inches over all. The normal weight of course cannot be ascertained, but, since the fish attains a weight of 15 to 20 pounds, this specimen is plainly a young one. It is a true ambicolorate flounder, being as dark on the left or lower side as it is on the right or upper side. Furthermore, the dark bars and splotches of the right side are almost identically reproduced on the left. This is the most perfectly ambicolorate flatfish I have ever examined. It is most unfortunate that, in the process of cleaning the fish for freezing, the head and abdomen had been cut up badly. This of course makes it impossible to have a photograph or a drawing made. Fortunately, however, the left or rotating eye escaped the knife. This eye is barely over the median ridge. Indeed its outer or left edge is barely clear on the right of the median line. This incompletely rotated eye has produced the other always associated deformity-the hook at the anterior point of the dorsal fin. Either the hooked point got its final growth settled while the eye was migrating across the mid-dorsal line, or else the incompletely rotated eye in its permanent position just across this line inhibited any further forward and downward growth of the interior part of this median fin. It must be emphasized that total ambicoloration in flatfishes is always accompanied by a dorsal fin hooked at the anterior part and by an incompletely rotated eye. However, these head anomalies may occur with only partial ambicoloration, but so far as I know they are never present unless there is partial coloration below. Fortunately I have been able to study a series of flounders showing perfect gradation from very little color on the lower side to the perfect condition of ambicoloration called "black belly." Every one of these fish, from the least colored to those completely dark on the under side, had a hooked dorsal and an incompletely rotated eye. Thus Gudger and Firth in 1936 described a Paralichthys oblongus having the hinder two-fifths of the lower side colored like the upper side but lacking head anomalies. Another fish of the same species had the head anomalies but only about one-fifth (the extreme hinder part) of the lower surface colored. Another with the head anomalies had the hinder two-fifths of the lower side colored like the upper. In 1935 they described a halibut, Hippo-