Greenscale Cish
Replacing the Coral Cish and outcompeting the Algae Cish, the Greenscale Cish has adapted to predation and spread about the world. Its vibrant colors have switched to a duller green-grey that better disguise it across its range; vivid coloration was not that vital to its social life and just put it in danger. It has developed a thick hide of chitinous scales to help reduce damage caused by the bites of its predators; its innards remain soft. On each jaw, one of these scales has been modified into a beak of sorts, which increases the effectiveness of the Greenscale Cish’s nipping ability; similarly, its cartilaginous jaws are also shortened for greater bite strength. The changes to its jaw are far more effective than the related Algae Cish’s mushy cartilage teeth, hence it was able to invade its relative’s niche as well.
Any purpose the Greenscale Cish’s ancestral coloration once had is replaced by the shimmer of its lighter underbelly scales. When socializing, the Greenscale Cish will turn belly-up, letting light reflect off of these scales. Its eyes have advanced into primitive camera eyes with lenses, which help it to see the shimmering effect. Its tail is now rounded, good for escaping predators with a burst of speed.
The Greenscale Cish is otherwise much like its ancestor. It is somewhat intelligent and capable of play and socializing in shoals, it filter-feeds by gulping water and filtering it through its gills, it can nip at larger prey to break it apart, and mated pairs can produce thousands of eggs daily over a period of a few weeks.