Redbone Gilltail

The redbone gilltail's ancestor, the elongated gilltail, was hunted by numerous predators. The predation pressures forced it to adapt. In the redbone gilltail's case, this forced the elongated gilltail to move to deeper waters near the North Sagan 4 Ice Sheet. Specifically, it lives 170 to 270 m below sea level. During daytime, it lives in the deeper end of its vertical range. At night, it swims into the upper part of its range to feed on tiny, floating flora or flora that have sunk from the upper depths. At daytime, it is sedate, swimming only slowly through the water. Essentially, it is nocturnal and sleeps at daytime. As it lacks shelter in the open ocean, its transparent body and red color make it very difficult and perhaps impossible to see. During autumn and winter, they migrate south to avoid excessively cold temperatures.

Redbone Gilltails lay their eggs in thick patches on basilliphyta on the underside of ice sheets. The transparent eggs are covered in sticky, fatty globs, like congealed chicken fat. While redbone gilltails are ectotherms, and thus can survive at a variety of temperatures, excessively cold temperatures can kill them. The small eggs, due to their high surface area to volume ratio, cool down much faster than the adults, necessitating insulation. The eggs contain very little yolk, so when the eggs hatch, the young eat the fatty globs surrounding the eggs.

Redbone Gilltails lay an average of sixteen eggs per year. They grow slowly compared to their ancestors, reaching adult size at four years. Redbone gilltails can live for fourteen years, and can reproduce for all their adult lives.