Islandball Gillfin

The islandball gillfin split from its ancestor, the blue gillfin, with the evolution of the island colonialball. With the hospitable habitat provided by the false 'islands,' the gillfins soon adapted to coexist with them. They live their lives among the colonialballs, using them for shelter from weather or as defence. They burrow their way into the colonialballs or dart in and out of their dense root systems. Their eggs are even laid on colonialballs. They have adopted the colonialballs' coloration and gotten smaller to better hide amongst the 'islands.' They have developed an interesting behaviour: when young gillfins mature into adults, the males and females mate, then tear off several colonialballs from the main mass and take them out to an area with few islands and enough nutrients to sustain the growth of one. They then lay their eggs on the colonialballs and go back to their original colony, leaving the torn-off colonialballs to bud into a new island for their young. After this, they mate once a year, and raise their young with them to sustain the original colony. This behaviour has prompted the spread of both islandball gillfins and island colonialballs, but their numbers are still held in check by the amount of nutrients available in the water.