The colonial filtersquid moved into open waters and doubled in size. There are two castes of adults, the ones that resembles their ancestor, and one that is a massive float. The massive float caste uses nitritus, nitratus, and denitritus to form nitrogen gas which it fills a sectioned off portion of it's gut with to form a gas bladder. The compounds that the microbes need to produce the gas are provided by the colonial filtersquid itself or taken in from the water surrounding it.
The more conservative caste colonize the tendrils of the float caste in great masses, grasping onto the float caste with their own tendrils. In this way the species provides itself with something to attach to, removing the need to stay near shores. Several generations can exist on a single float.
Individuals that colonize the ventral side tendrils go through hormonal changes triggered by the float caste itself. The individual migrates down to the end of the floats tendril and grasps with its mouth instead of its own tendrils. The floats tendril elongates to remove the individual from the rest of the colony and the colonial filtersquid begins to transform, it stimulates the nitritus, nitratus, and denitritus populations inside it and start collecting the nitrogen gas produced, it's body elongates and becomes larger and the gas forces its gut to expand, and eggs released by the other colonial filtersquid begin collecting and hatching on its own tendrils, so as to begin its own colony. Eventually the individual is released and it becomes a part of the float caste itself.