Moon-spotted shrimp goby

Where they come from

Moon-spotted shrimp gobies hang out on sandy patches at the edges of coral reefs in the Indo-Pacific. Think gentle slopes with scattered rubble, right where a pistol shrimp can dig a safe burrow. They spend most of their day posted at the burrow entrance, watching the world and diving back in if anything sketchy cruises by.

Setting up their tank

Give them a calm, sandy spot and a tight lid. I like a 20-30 gallon+ footprint tank for a goby-shrimp pair. They are small, but floor space matters more than height.

• Sand bed: 2-3 inches of fine aragonite. Sugar-size or oolite on top, a little coarser mix below helps the shrimp build.
• Rubble: A handful of small shells and broken coral pieces near the front glass makes great burrow entrances you can actually see.
• Rockwork: Set rocks on the bare bottom or egg crate, then add sand. Do not perch rocks on sand or the shrimp will undermine them.
• Flow and light: Moderate flow, not blasting the sand. Any reef lighting is fine; they do not need strong light themselves.
• Lid: They jump. Use tight mesh or a fitted lid with no gaps.
• Water: 1.024-1.026 SG, 75-80 F (24-27 C), pH 8.0-8.4, alkalinity 8-10 dKH, low nitrate (<20 ppm). Keep it steady.

What to feed them

They are micro-predators. Mine took frozen foods after a few days, but I had to feed right at the burrow. Small portions, twice a day, works well while they settle.

• Frozen mysis (chopped if large)
• Enriched brine shrimp (as a training food, not a sole diet)
• Calanus, copepods, and small marine zooplankton blends
• Finely chopped krill or clam meat on occasion
• High-quality nano carnivore pellets (1 mm or smaller) once they recognize them as food

How they behave and who they get along with

They are cautious little sentries. With a pistol shrimp partner they gain a ton of confidence. Without one, they hide more and can be outcompeted at feeding time.

• Good tankmates: small peaceful fish like firefish, small wrasses (fairy/flasher), clownfish, cardinalfish, other non-burrowing gobies, and most inverts.
• Use caution: other shrimp gobies in small tanks (territory disputes), boisterous sand-sifters that might bulldoze their spot.
• Avoid: aggressive dottybacks, large hawkfish, big wrasses that hunt, predatory crabs, and anything that can swallow a goby whole.

Breeding tips

They will pair up and spawn in the burrow, but raising the larvae is a project. If you want to try, start by getting a known male-female pair and protect their burrow area from nosy neighbors.

• Watch for courtship: the pair stays close, the male fusses at the burrow, and you will see quick dashes and body quivers.
• Eggs are laid in the burrow; the male guards. Larvae are released at night and drift into the water column.
• If you are serious, set up a larval snagger at lights-out and have greenwater and rotifers ready. You will need small live foods for days before moving to Artemia nauplii and then copepods/fine prepared feeds.
• Keep flow gentle at night so larvae are not pureed by pumps; use foam covers on intakes.

Common problems to watch for

• Jumping: they spook easily. Lids stop heartbreaks.
• Going hungry: new imports may refuse pellets. Start with frozen mysis and live pods, then wean to prepared foods.
• Getting bullied: even mild harassment sends them underground. If they vanish, reassess tankmates and feeding spots.
• Burrow collapses: fine powdery sand alone can cave in. Mix grain sizes and add rubble for structure.
• Parasites: stringy white feces or sudden weight loss can point to internal worms or protozoa. I prophylactically feed a medicated food (e.g., praziquantel/metro) during quarantine.
• Cryptocaryon (marine ich): they are not immune. Quarantine and keep stable parameters to reduce stress.