I've no clue why the Barbsium are still considered Benthic predetors. Well, time to abandon ship.
Team X2: Extinction Trigger
Pixie Barbesium speciation:
\One linage switches to gathering air directly rather than from water, creating a lighter than air creature. It promptly migrates to Lauv Island, using it's fin-tipped tentacles to navigate the skies with it's jet used to drop on and drug prey, which it swiftly eats before re-ascending. It's spends much of it's awake time in the air, dropping in from above in swarms. It occasionally drops in nearby water to refill it's jet reserves. When it rains they gather together to "talk" on solid surfaces and spread their spores. [SS Roll] (The Executioner Turps it carries are cultivated within itself as part of the creature, given to newborn young if they survive. Skyborne Pixies are fairly small and live in groups, high as a kite.)
\The other goes gigantic, behemoths forming hunting grounds which occasionally speak of current events and dangers. They cultivate a number of Executioner turnips to insure their many sharp fin-tentacles drugs are kept concentrated and deadly, and pass new ones to young giants. They may occasionally gather together against threats to their kind. The venting of the drug into water is capable of killing lesser creatures not adapted to it, and drugging others. [SS Roll]
Dartfrog Barbesium speciation:
\One compacts and improves upon their poison, using it in place of the drugs of their ancestor. Extremely poisonous to life, they are ambush hunters, hiding within seaweed. [SS Roll]
\The other has lost their shells, choosing to bury into lifeforms and poison them from within, stealing food until it dies. They are more like the sludgiboo of old, squeezing into cracks. While very small, they make use of this to be eaten by their prey before absorbing the acid in their stomachs. [SS Roll]
Forestformer Falselily speciation:
One becomes a choking mass of plantlife, spreading itself and consuming anything caught in it's vines. Extremely invasive, it's vines drift down from the surface like giant hooks, and many a mat breaks off and covers the ocean floor. [SS Roll]
Another ends up sinking below the surface, their hardened leaves serving as an enticement to prey, encircling it's body. When one seeks to nibble upon them, they snap out around the foe and drag it into the center body to be digested. If it is instead too large the leaves stick to the outside of the prey like a snowflake, as the center slowly digests a hole in the side. They float among the currents as innocent tempters. [SS Roll]
Also, Magmacube. The Executioner Turnips no longer have a life outside the Skyborne Pixies, they are now it's herd animal. They have no means of survival outside it.
[Yes Knightwing, they are divorcing, and taking the child with them.]