White Tiger Goby,
Priolepis nocturna

Common Name: Circus goby, Gecko goby, White Tiger goby, Half Moon goby; the list goes on….
Scientific Name: Priolepis nocturna
Size: Less than 2”, though their fan-like pectoral and caudal fins may make them appear larger.
Origin: Indo-Pacific. Fishbase.com lists the following: Aldabra and Assumption Island, Cosmoledo Group, Seychelles; Marquesas, Maldives.
Natural Habitat: This cryptic little goby is found in tropical rocky/reef areas, hiding upside down in caves.
Feeding Requirements: Typical of most popular gobies in the aquarium trade, the gecko goby quickly accepts all aquarium foods, both frozen and dry.
Difficulty Rating:
(1 = easy - 5 = hard)
1 = Easy. In the proper reef environment (see below), this fish is hardy and eats with gusto.
Aggressiveness Rating:
(1 = shy - 5 = nasty)
2 = Not aggressive. In my experience, this fish adopts an “ignore them and they will leave” attitude, whether faced with small inquisitive fish or very large passers by.
Captive Requirements: As mentioned earlier, these fish thrive in a standard reef environment. Their hearty appetites lend them to be excellent choices for any marine tank, assuming certain requirements are met. Caves and overhangs are a must. Beyond that, the fewer large, boisterous tank mates, the better. Obviously, tankmates large enough to eat or otherwise thrash this little gem are a no-no. Prior to adding tangs and Genicanthus angels to my aquarium, my little gecko goby would slowly patrol the entire aquarium, with quick stop/start movements. As soon as larger fish were added to the system, the goby would remain hidden under ledges and such. Brief appearances are a treat as he darts out for food.
Optional Requirements: I enjoy keeping fish in pairs. I simply added another gecko goby to my established one. They paired without incident. I have even seen one individual with a distended belly containing orange/pink eggs on more than one occasion. There are two other reefers that I know of that have had the same relatively simple experience with pairing their gobies. However, they have not witnessed breeding. It is unclear to me as to whether or not these fish will fight if paired with the same sex.
Reef Tank Compatible: Again, because of their laid back nature, the gecko goby is an excellent choice for a reef aquarium. They do have large mouths, so be cautious with VERY small ornamental shrimp such as sexy shrimp (Thor ambeonesis), and the like.
Notes: This was one of my very first fish added to my current reef aquarium. It was rather unimpressive looking at the aquarium shop, as is often the case. Fins clamped; huddled in a corner; desperately waiting for a nice cave to hide in. However, I remembered some pictures of one from a TOTM article, and decided to buy it. It turned out to be a wonderful purchase! Watching this fish sit and move around, upside down, in the caves of my tank is a treat. It keeps its large, brilliant white, fan shaped fins outstretched, giving it a fluttery appearance as it moves and turns.
Further Reading: Fishbase.com
SpringLink.com PDF file
Sept 2004 Tank of the Month

Note: All of the above information has been compiled from various sources and should be used as a guideline, not a hardfast rule. Use caution when selecting animals for your own tank and research as much as possible before purchasing any animals. Remember that certain corals and fish are very hard to keep if their special requirements are not met. The information contained here is to help you make an informed decision. The author assumes no responsibility for any consequences that may arise from the use of this information.

Fish Profile: White Tiger Goby, Priolepis nocturna by Peter Martis - Reefkeeping.com