Bristle Fin

Another descendant of Bristle Swimmer: [link]

These ones, unlike their recent cousins, do not have skin pigmentation. Instead they avoid the surface of the water, preferring to feed on the lumps of seperated algae beneath the bubble-algae raft on the ocean surface.

A brush in their mouth, which connects to the underneath of its chin, extends as a filter to catch drifting plant matter when its fairly idle. It can be squeezed between the purse-like lips to scrape off anything it senses to be toxic, such as tropical molds and fungi.

They are one of the largest animals of this time period. They are one of only a handful of species so far that can be seen (barely) without the aid of a microscope. Miniscule to us, dwarved even by a sea monkey, but on their home world they are giants.

Their sidewards bristles have thin membranes of skin joining them. As well as increasing water resistance from below, slowing the rate that it sinks, they can also flap them up and down as a form of propulsion to compliment their more primitive s-shaped ripple. This saves them energy in the long run.