The cave phibi split from its ancestor and moved into Darwin Water Table. There it evolved neoteny by only growing up to its juvenile state. Thus it only grows fins and is only half the size. They have also lost their lungs and go back to passively absorbing oxygen from the water through their skin. Eventually they lost all their pigment and eyesight as well. To compensate for having no sight their fins evolved feelers and little hairs on the end to feel the cave walls around them. They will snap at anything that touches them. They appear pinkish from their red blood below the pigmentless tissue.
They use their strong beaks to crack open the exoskeletons of the various cave invertebrates such as the obscurpede, white obscurpede, cave prickworm and even clingerpedes that fall into the water. However they are not above scavenging for food either. They can mate at any time of the year and will lay many eggs directly into the water. They must do this since only a few survive to adulthood.