Goby-one

This is one of two dragon gobies in our tropical freshwater aquarium. I don't know the sexes, but this one has reddish fins, and the other is darker in colour with yellowy fins.

I never realised there were freshwater gobies until I saw these in our local aquarium market - I had only ever seen them snorkelling or diving before.

The gobies have dug a little burrow under the rock, (just to the right in the photo), where they retreat to from time to time, just like their marine cousins.