Schindleriidae
This family has only three species within it, the fewest number of species of all the other families. These fish are called the infant fishes this is due to their size.These fish reach maturity and are able to reproduce once they reach a length of 2 cm. Another reason for the name of infant fishes is because these fish are neotenic. Neoteny is when adults retain traits or their juvenile form. This is true for these species because they spend their entire life in a larval state. Some characteristics which they retain are the lack of pigmentation or color, a larval kidney, and also they have an unossified skeleton. Ossification is the process in which new bone material is made to make bones bigger and stronger
Read more about this topic: Gobioidei