EVOLUTION ATTEMPTS: Parasitise jawshell- 6+.5=6, Speed- 2, Poison- 5+1=6, Electric shocks- 1, Senses- 3
(This is what I was talking about when I said it'd be twisted. You found some babies and the most fearsome carnivore of this period...)
(AND YOU TURNED THEM INTO A MOTORHOME.)
The symbiot swimemone has added yet another beast to its symbiotic web. The jawshell's shell now serves as a sheltered location for the hive, and the jawshell itself has evolved into the symbiot jawshell. This three-way relationship means that the swimemone has a mobile base of operations and a hunting system, the nestblob can scavenge the remains of both organism's kills and can migrate to a better habitat, and the jawshell can use the grazing of the guidelets to attack and eat sessile or hard-to-find blobs. The jets on the side of the body have become a dispenser for DEADLY NEUROTOXIN (as well as a way to turn while hovering in place), the normal poisons in the fangs have been upgraded with DEADLY NEUROTOXIN, and it even has a couple of very simple eyespots to tell how much light there is. The swimemone is also far more expansive with its new home, as it can invade new territory and bring the hive with it. However, its electrical sense has lost the ability to form pulses.
The symbiot nestblob has shrunk to fit inside its new home of the symbiot jawshell. Its various young are specializing to become different castes, with a soldier to defend the nest from anything the jawshell doesn't catch and swarmers to go with the swimemone. Swarmer castes have powerful digestive acids, which they can use to attack prey or burrow into the shell of a new home with.
The reign of the ghoulish swimemone and similar creatures is at an end. The symbiosis trio and normal jawshells have torn their hives to shreds and devoured their children. For now, at least, there are few threats to us.
GENERATION 7:
Symbiot swimemone
A dark-grey-and-white tentacled fish-like animal that swims over the surface of the reef, hunting for food. They swim with their finned foot, and use their fanged tentacles to attack and kill their prey. They grow up to 70 centimetres long, and their offspring are called tentaclets.
SENSES: It has a sense of touch that lets it figure out if it's touching food, and a fair sense of smell/taste. Symbiotic guidelets help it find live prey. An electrical sense lets it find creatures that are close to it.
REPRODUCTION: It lets out male cells when they form swarms, and growths grow on the area of the body derived from the bases of the tentacles. Younger animals are mostly male, and older animals are female, due to the pressures of swimming while pregnant. Tentaclets follow their mother until they can be dropped off at their jawshell. They eat mucus that the nestblob creates (although the nestblob sometimes takes either type of larva to supplement its diet) and, when they are large enough, find a suitable guidelet to make a nest with. The children of the jawshell (which follow the mother, and are tolerated) are attracted to the hive-forming pheremones, and a suitable animal is chosen and burrowed into. They then leave to find a new area to live.
MOVEMENT: They move by rippling their foot, swimming like a fish. Sacs of carbon dioxide keep them buoyant. They also have simple jets on their side-gills, which they use to make fine movement.
EATING: It impales nearby blobs and digests them by drawing them into the tentacles. After many generations, they are finally able to reliably prey on fast swimmers, and their poison has changed to a venom. They still have the rather inefficient absorbing-via-tentacle feeding method.
PREDATION: Some species of jawworm are able to feed on the tentaclets. Most smaller creatures are on the menu.
COMPETITION: They have little competition for their niche.
ENVIRONMENT: A shallow sub-tropical sea. Layers upon layers of various types of blobs have built massive networks of reefs. Tentablobs grow above the rest, filtering food from the open water, while crawlers of various species create ditches and clear space. Aciblobs fill the majority of space for animal life, burrowing and swimming and crawling on the seafloor. Flapworms have migrated from the open ocean, and are efficient filter-feeders and danger-avoiders. Jawworms have also arrived recently, and hunt free-swimming animals. Hive nestblobs are animals a metre or so wide, and live inside the symbiot jawshell.
NEARBY ENVIRONMENTS: Open ocean, temperate reef, tropical reef, murky estuary