The water-table urhook split from sleeping urhooks that found their way from the Martyk Sandstone Caves to the Ittiz Water Table. There, the only prey they could find was the aquatic plateworm. In order to hunt them with more success, they evolved a hook facing up, allowing them the stab their prey from below, avoiding the iron coating. While they feed on the aquatic plateworm, they absorb lots of iron that is stored in the back sack that once contained only fat. This iron is used later for many purposes. One of those is a special magnetic organ in their foreheads that is used to help them navigate and find the iron-rich aquatic plateworms. Their hollow tooth is also reinforced using the iron they store. Because they are totally blind and have no hearing organ and are at total darkness, they mainly use this sense and their touch and smell sensors that could be found on their tentacles to find their way through. They often touch/smell the table walls and water, sensing organic and iron residues their prey leaves behind. They are very good swimmers and often swim in the underground lakes.
Another usage of their stored iron is for reproduction and hibernation. Instead of hibernating for 10 months like their ancestors, the water-table urhook hibernates for 6 months. When the females hibernate, the males are awake and visa-versa using a unique biological clock. When the males are awake and find a mucus-covered female they insert their sperm using their hollow teeth, fertilizing her. Once the females awaken, the young are already relatively big and the females can take care of them for a month or so with ease. The mucus-sacks that they use to hibernate in contain lots of iron that is released from the fat-iron sack and therefore could only be breached by the iron-reinforced tooth.