Shallowgob
The Shallowgob is the culmination of many years of storms picking up Vinagobs and dashing them against the beach, where they dried up, died, and rotted. While its ancestor did live in deep waters far from the beach, their abundant numbers, small, light bodies and poor swimming ability nonetheless made it fairly common for it to wash up on the beach after storms.
The Shallowgob's tail is longer and more muscular than before. With its tail, it grips the trunks of Crystal and Landfall Groves, making it harder to get carried away in storms. Given its size and the large diameter of the trunks, it has a stronger grip on younger individuals with thinner stems. In the water, it is largely sedentary, mostly unhooking itself from a branch and jetting upwards to escape predators.
Shallowgobs live in sunnier waters closer to the coast than its ancestor. If washed up (just barely) onto the beach, it uses its tail to slowly, awkwardly push against rocks or Landfall Grove trunks, using its longer, stiffer fins for traction. In this way, it can half-wriggle, half-roll itself back into the sea, or at least stay underneath the shade of its trunks until high tide takes it back. Drying up is still a possibility, so its survival chances are much higher during cloudy weather or nighttime.
"Lips" around its mouth can contract (but not completely close) its mouth opening, reducing how much moisture it loses if stranded on land. It has adapted to the more intense UV radiation of living so close to the surface of the water (especially in the tropics) with pigments on its body and even its stomach, which reduce its transparency and make its air pockets difficult to spot.
To feed, it draws water into its stomach using a system of air pockets, and then expels the water through outflow vents just underneath its lower row of fins. With Ribbon-Tailed Detriti symbionts helping to digest its food, it can afford to produce relatively weak stomach enzymes.
Tiny, chickpea-shaped yellowish clumps (its reproductive organs) under its lower fins generate 110-micrometer-sized cloned larvae, expelling them through the outflow vents. The larvae have no bioluminescence, and are simple, nigh-embryonic, globe-shaped clumps with tiny fins. While spawning, the Shallowgob contracts its mouth with its lips, making it a little harder to accidentally filter-feed its own offspring. In times of stress (including sensing injury chemicals from its own kind, low food, and cold temperatures) it instead reproduces by ejecting male and female gametes into the water. With the temperate population experiencing winter each year, the genetic drift of sexual reproduction is sure to eventually split the population into two species.
The Shallowgob's bioluminescent spots flicker like a slow heartbeat, and only sustain their glow brightly when attacked by predators. Photoreceptors just below these spots allow it to sense light, dark, and blobs of limited color, but not much else.
The glow of adult Shallowgob lights helps larval Shallowgobs (when about 2 millimeters in size) navigate to good areas, in addition to using a sense of taste from a developing mouth/stomach region. These two cues help them avoid crystalflora-associated predators, such as the Five-Fingered Crystalblight. However, with their tiny size and weak swimming, many are eaten anyway, even once they attach with their tiny tails.