Rainbow Gill

The Rainbow Gill has adapted itself to be an ocean traveler, with streamlining adaptations and behaviors allowing it to seek the best feeding areas. Its branching gills have developed into flattened ribbons, greatly reducing turbulence and drag caused by them trailing behind its body. While its body is only 50 centimetres long, its gills extend another 25 centimetres behind the tip of its posterior arm. Its arms have developed into broad paddles which can provide powerful strokes, allowing them to reach speeds of 2 meters per second. Its proximal arm can be curled underneath its body to create a more hydrodynamic profile. Its bristles used in filter feeding can be folded under its body when not feeding. To protect from stabbing itself with its bristles, its belly is protected with thickened skin layers.

The Rainbow Gill has developed a wide range of coloration in connection with their mating types. The proteins which encode for their mating types have lost the null allele for the XYZ genes. The XYZ alleles each code for a different coloration, with the X allele encoding for red, Y for yellow, and Z for blue. The X allele also encodes for venom, much as it does for its ancestor. This gene being tied to color may be the first step towards warning coloration, with venomous individuals being red, orange or purple while non-venomous individuals are yellow, green or blue. The general coloration of the population tends towards a larger share of individuals with orange, green or purple coloration due to their specific genes being twice as likely to occur. This has been the only significant change in their mating types and their reproduction method is otherwise unchanged from their ancestor. They gather in large congregations in the shallow seas, breeding occurs twice yearly in the subtropical coastal waters bordering Vailnoff. Breeding occurs in that hemispheres winter, just before spring. This ensures when their young are born, they have an ample food supply to fuel their growth.

The Rainbow Gill has also developed its eyes to be enclosed, with simple lenses able to form simple images. This lens cannot be manipulated so the gills can’t focus their vision, but they can identify shapes and color. Their retinas possess three distinct cones, allowing them to distinguish between reds, yellows and blues. This assists in them identifying other mating types and in forming groups. These schools number between 5 and 20 individuals, and are composed of many different sexes so as to have a fair percentage with venomous defenses. These schools are paramount to their safety due to the presence of Roths, which are able to attack lone gills and avoid their defenses. Rainbow Gills schooling behavior reduces the risk of Roth attack to only the weak, slow or old individuals. They will travel across the ocean along currents in search of upwellings, where nutrients trigger blooms of life and concentrations of food are most rich.