Great Little Goby, No Cap
When is a Whitecap Goby not a Whitecap Goby? Well, actually, when it's a Whitecap Goby, and then it's still probably actually a Whitecap Goby. We understand if that doesn't make a ton of sense on the face of it. Digging a little deeper, there are two species with this one common name. They look ALMOST identical, grow to the same size, act the same, eat the same stuff, and live in the same habitats but they have different ranges. Lotilia gracilosa comes from the Indian Ocean and the Red Sea, but Lotilia klausewitzi comes from the western Pacific Ocean, and their ranges do not overlap.
Visually these are both absolutely stunning fish, with a body that is mostly black, or rich deep brown, with a stark white cap running from their nose to the front of their dorsal fin. Both have a clear tail and pectoral fins, with body color matching spots in a row. The only real difference is that the Indian Ocean version (L. graciliosa) has a more defined eyespot on its dorsal fin. We didn't reference Whitecap Gobies in our recent article on Symbiosis, but we could have. This is another Goby that will cohabitate with Pistol Shrimp, there are differing reports on what species of Pistol Shrimp, based on where the Whitecap and the Shrimp were collected. Quality Marine partner stores have the option to order them together!
No matter which one you have, they're only going to get about two inches long. Which means you can have them in a small aquarium, a single specimen would be just fine in a 20-gallon setup. They don't like to get too far from their burrow or their little shrimpy pal. The Pistol Shrimp will dig them both a borrow and spend his day maintaining it. To get the most out of having this unique pair, you'll need to have a sandbed that is at least a couple of inches deep and up to about four inches deep in places. It will be best if that sand is a mixed grain size as they tend to support caves better. Avoid sugar sand and other super fine options as the caves collapse. The tank could offer some rockwork for cover but makes sure any rocks you place in the tank are placed securely on the bottom of the aquarium, so they don't get undercut by your Pistol Shrimp's mining efforts. Filtration should be good; try to overturn the tank volume ten times per hour at least.
Whitecap Gobies are pretty easy to feed. They'll take thawed foods like Gamma Mysis, Brine Plus Omega 3, Rotifers, Copepods, etc. In time they'll take both Nutramar Pellets and Shots. Really the only struggle is making sure they aren't hiding during mealtime. The cave is a safe spot, and you're a great big shadow on the aquarium, which usually means danger in the wild. In time they'll recognize you as a food source, but in the short term, they might be shy. This makes the shots a great option. You can stick a shot just outside of their burrow, and both critters can get a meal at their leisure.
These are super peaceful little fish, and as we've referenced, they can be shy too. This means you should choose them as tankmates that aren't aggressive, and preferably, move around predictably too. Cardinals (especially the matching Banggais) make an excellent choice. Other small peaceful fish like Fairy and Flasher Wrasses, smaller Halichoeres, Pseudojuloides or Macropharngydon Wrasses could work, as well as Dragonettes, Midas Blennies, peaceful Clowns like Ocellaris and Percula, and Firefish make great choices too! Super active and fast swimming fish may push your Whitecap into hiding more than you'd like. Honestly though, a Whitecap and a Pistol Shrimp are a really fun display all on their own. They're reef safe, unless you get a malfunctioning one, which we've never seen; so, feel free to add some corals to that display too. Just be wary of sandbed corals that are too close to the burrow as they could get buried.
Whitecaps are pretty hardy little fish and aren't picky about water chemistry, as long as it is reasonable and stable. Keep your temperature in the mid-70s, your pH between 8.0 and 8.4. Specific gravity should be in the invertebrate friendly zone of 1.025-1.026 to be amenable to your Pistol shrimp. Keep up with the water changes which will help stabilize the pH and will also keep nutrients in check. Try to keep nitrates under 5ppm.
There's nothing like a symbiotic relationship in an aquarium. The Whitecap Goby (and the Pistol Shrimp) offer you the opportunity to have exactly that and because they are very infrequently seen in the home aquarium, they've got that rarity panache too. They'll fit in a small display, don't have crazy requirements and are a wildly peaceful combo too! There's really a lot to love. Ask your Local Fish Store if they can nab you a Whitecap and a Pistol from Quality Marine today!