Did this mysterious creature turn up gasping for water after being dragged up from its ocean trench home?
No, it's living happily in my fishtank along with about a dozen of its siblings. It's a days-old Crimson-spotted Rainbowfish (Melanotaenia duboulayi).
These guys are small! Only a matter of millimetres long and less than a millimetre wide. So photography is quite a challenge as you could imagine.