The blind goby or Typhlogobius californiensis is a small costal specie that is native to California and Mexico. It is a very interesting goby that has a mutual relationship with a ghost shrimp Callinassa biffari. While juvenile, it enters shrimp's burrow and stays there all of its life. When still young, they have normal eyes. But after maturing, the eyes degenerate completely, making the goby totally blind. Unlike other blind fish, Typhlogobius californiensis does not have a very well developed lateral line. This is due to the fact that it never leaves the shrimp's burrow. Most of it's sensory organs are located on top of its head and it relies mostly on its sense of smell.
I am a big fan of sorts of cavefish, and while this goby is not a cave dweller, it exhibits all the traits of troglodyte fish. It is completely pigment free and has no eyes. A good example of convergent evolution, I suppose))) However, I still do not understand why it never leaves the burrow. I am sure it's safe and everything, but he can't be getting that much food there. Most of the food is brought into the burrow by current created by shrimp's swimmerettes. The shrimp would eat smaller particles of sea weed, decaying matter, and parts of dead animals, while Typhlogobius californiensis would clean up larger pieces. Sometimes, the shrimp was even observed physically bringing larger food particles to the goby.