The Arrow Darter one of the first deuterostomes on Miqum. Bilaterally symmetrical and cephalized, it can swim one direction at high speeds to outswim predators. Its nervous system meets at two ganglions in its head. With no light in the caves it uses large sensitive antennae to map its surroundings. Using its circular toothed mouth, it can eat small bits off of feather like chemotrophic "plants" that grow over the mouths of hydrothermal vents. By expelling waste from a pore separate from its mouth, it can digest food much more effectively than its monosomal counterparts.