The exusfiltra kept most of its ancestor's appearance and hunting strategy, but next to its false worm-technique, it has grown its front tentacles longer, allowing it to grab prey when they touch it, and inject them with toxins. Using this tactic, it can eat everything foolish enough to wander close enough to its grabbing tentacle. Because of this, it can also eat non-carnivorous prey, like Dark Swarmers.
If it eats something larger then it can handle, a seadragolden for example (thus creatures larger then 15 cm), it'll pull it, until the exusfiltra notices it can't eat it. Then it'll rapidly pull inside in his shell, and use all his front tentacles to make a sand cloud, avoiding its discovery.
It has replaced its ancestor due to these improvements.