The Family Gobiesocidae (Clingfish) is a group of small fish which usually are found clinging to rocks, sponges or sea urchins and even larger fish.
This particular species of clingfish, the Pink Clingfish, has about ten darker bands down its body, giving it its species name "Aspasmogaster costata" because costata means ribbed. I have not seen this species many times as it is good at hiding and very shy. This species is endemic to only a few parts of Australia.