Carpolanta
The carpolanta is a simple, brainless, largely passive, translucent, watery filter-feeder, something like a jellyfish or a salp. Its body shape, bioluminescence, floating, and occasional appearance in unconnected chains of individuals give it a vague resemblance to a floating Chinese lantern, hence its name. A Carpolanta's most remarkable feature is its mouth: the sticky nasal patch of its ancestor now coats a huge internal space within its body, forming a primitive stomach.
The carpolanta's stomach/mouth membrane is ribbed with slightly stiffer cells, which reinforce it, and it is coated in a stickier goo than its ancestor's nasal patch. The carpolanta draws in tiny organisms floating in the water, such as Binucleus Stella Dodecahedron, and digests them, pitcher plant-like, within its mouth.
Many small disc-shaped pockets within the carpolanta's body are filled with air. By filling and draining these pockets, it can control its buoyancy in the water. Over a day, it can travel up to two meters in the water column (which is impressive for something only 1.5 cm tall).
Over time, it can migrate between the LadyM Twilight Zone and roughly a meter above the seafloor LadyM Twilight Slope habitats. Though it can move rapidly upwards if needed, it's slower about descending, and even slower with any non-vertical movement.
It reproduces primarily by budding, cloning itself. Microscopic (90 micrometers), globe-shaped clumps of cells with no bioluminescence are ejected from tiny (not visible in picture) pores linked to its lower water pockets, in the "finpits" of its lower fins. After releasing its buds, the carpolanta often rapidly swims upward, a habit that spreads the buds a little and reduces the likelihood it will simply filter-feed its own offspring out of the water.
However, in conditions of environmental stress, such as low food or sensing injury chemicals from its kind, it will reproduce sexually. Like many Earth organisms, its male gametes are tiny, minimally-equipped, and swim using flagella or similar structures, though its gametes are remarkable for being green and shaped like rectangular prisms. The male gametes merge with female ones, which are simply expelled into the water.
Due to their small, slow, gelatinous bodies, filter-feeding, quick maturation, and abundant offspring they are among the most common creatures in their environments, much like jellyfish or salps. Also like jellyfish, a carpolanta's watery body has little nutrition; most of its nutritional value comes from their stomach tissue and what's collected within it. The buds and microscopic young of the carpolanta are so tiny and passive they have little control over where the current takes them. Should the current bring them to the Twilight Floor or Twilight Slope environment, they are often devoured by Waving Pseudosi (presently its chief predator) or Supergoliathpseudopodia, or even digested by the enzymes of the Binucleus Crystal Shrub. However, as adults, they presently have no predators.