Like many other marine species, this week’s Fish of the Week is a small, bright yellow fish, and it is the turn of the yellow watchman goby (also known as the yellow prawn-goby) to be in our spotlight. This species (Cryptocentrus cinctus) comes from coastal bays and lagoons in the Western Pacific, and can be found at depths ranging from 1 meter to 25 meters. Reaching around 8 cm (3 inches), this small fish will easily merge into your reef tank, and won’t munch its way through your beautiful corals. To make them feel more at home in your aquarium, why not add some pistol shrimp alongside? In the wild, these form a symbiotic relationship: the shrimp has poor eyesight but can burrow like there’s no tomorrow, whilst the goby is less adept at making burrows but has far superior vision. These two species have evolved to work together, with the shrimp providing a home for the goby, whilst the goby watches for predators. If you don’t fancy adding shrimp, these fish will still burrow into the substrate, and are fascinating to watch. For its great choice of cohabitants, bright colours and durability, the yellow watchman goby is a great addition to a reef tank, and so is our Fish of the Week.