Lungs or Gills would be better suited to improve a species efficiency in movement and increase size since O2 or CO2 wouldn't need to be absorbed directly through the skin anymore
I thought tough Skin/Exoskeleton needed to be evolved?
Anyway, great job. Didn't the Clanessia Kill Zone happening. However... Swarmer attack!
Cutter : Terrance888
Evolved from: Stabber
Genes (4) : Eating Dead Things x1, Eating Live Things x1, Crawling x1, Claws x1, Vision Recognition X1
Description: (Short)- The Cutter took advantage of their longer reach by developing vision. This allows them to life the veil both on prey hiding by staying still and on other predator's clumsy attacks. They are named cutters because the way they start using their claws for much more sophisticated combat maneuvers.
Swarmer : Terrance888
Evolved from: Cutter
Genes (5) : Eating Live Things x1, Crawling x1, Claws x1, Vision Recognition X1,
Pack Hunting x1
New Gene: Pack Hunting
Deleted Gene: Eating Dead Things
Description: Cutters begun signalling to each other using plume-like fringes and their claws to coordinate attacks. Often, the stronger a cutter is the larger the plume, leading to an Alpha-Cutter. As they developed the necessary skills to understand each other's messages, Swarmers developed. They use pack attacks mostly for efficient hunting or dividing of resources, although increasingly, they are used aggressively to clear an area of a pack's enemies with pickets stationed on the "borders" to warn the eaters of enemies.
Long Description: Cutters sometimes followed another cutter in hopes of scavenging a kill, but at first these hanger-ons were driven away by the stronger hunter who did the actual killing (unless it was wounded.) They had no real way to communicate other than with their claws, which is aggression, or their... you know... which will cause reproduction (and leech more resources than a starving cutter can afford compared to a single meal.)
At the same time, some cutters are developing fleshy fringes to aid in reproduction both as a more peaceful demonstration between males and to spread reproductive products from the producers. Those with larger fringes show off their successful hunting history and often led a harem of the opposite sex with them.
Slowly, these harems developed into proto-packs. The Alpha-protoSwarmer would be strong enough to defeat a harem's worst foes while the other proto Swarmers hunt normally, except they start to recognize other members in the harem and they bring their food down communally. Still, this "Of the Harem of the Alpha Cutter under between large Slimey and Poison Claws" and such signals were still of limited use.
It was when multiple members of both sexes begun congregating that the first true pack hunting came into being. Each tribe has their own messages given via fringe to help coordinate a hunt. Against blind foes, these lead to much success. The Alpha Swarmer grew large and were able to defend the pack against any larger threats while all swarmers worked together to avoid casualties in hunting. They still lack recognition of themselves, and these messages are more instinctive "Don't Fight-Intimate 'Ally'" and "See This Now Attack" instead of "Sneak around the Clanessias and kill their babies" (although the latter can appear in a series of messages, confusing scientists).
The most advanced pack tactic is for a Swarmer Pack to kill all the threatening hunters, clanessias, and such in a relatively sheltered area, say a rock outcrop. Then, a few of the lower classed Swarmers will keep literal watch while the rest eat, often able to procreate another generation before needing to hunt further.
Some swarmers start to move out of the water with the aid of the Condenser. A pack leader who learned how to utilize the Condenser would share it with his entire pack, then lead them out of the water. The weaker swarmers would die, but they would simply drink the moisture of their lead with their condenser and move on. Since they can see the water, they can move back when they sense that they are a bit too dry for comfort without just wandering around and get back in the water by luck.
Finally, they lost their ability to eat "Dead Things" simply because as a pack, they would quickly eat any thing brought down before it has a chance to degrade significantly. This ability is completely superceded by their meal of fresh meat.
Physical details: The Claw is placed even, or slighty higher than the mouth to ease their use in communication. Peacock-like fringes develop both as a crest over the top of the Swarmer, as well as a wide "tail" on the end. These were initially aids to reproduction, and now used to convey information in the pack.