Seba's goby

Where they come from

Seba's goby (Feia seba) is one of those little Indo-Pacific reef gobies that shows up around rubble zones, sandy patches, and the bases of reefs. They spend a lot of time tight to cover, picking at tiny foods in the sand and rockwork. They are not a "open water" fish at all, which is why they can look invisible in a bare tank and totally confident in a well-built one.

Setting up their tank

If you want this fish to settle in, build the tank for a small, nervous bottom-dweller: lots of broken line-of-sight, a sandy area, and a bunch of tight little caves. I have had the best luck when there are several spots that look like "goby apartments" so it can choose and move if it feels pressured.

• Tank size: bigger is easier long-term, but footprint matters more than height. Aim for a tank with decent bottom space and stable parameters.
• Substrate: fine sand is your friend. They will hover low and pick at the sand. Coarse crushed coral can irritate them and makes natural feeding harder.
• Rockwork: small caves and crevices near the sand line. Think rubble piles and overhangs, not one big boulder.
• Flow: moderate is fine, but give them calmer pockets near the bottom so they can feed without getting blasted.
• Lighting: they do not need intense light, but your reef lighting is fine as long as there is shade and cover.

Because this is an advanced pick, I would not add one to a brand-new tank. They do better once the tank has some life in it: pods, microfauna, and that general "seasoned" feel. Even if you plan to feed heavy, having natural snacks around takes a lot of pressure off.

What to feed them

Feia seba is small-mouthed and can be picky in a sterile tank. Mine did best when I treated it like a finicky micro-predator: frequent small meals and the right particle size. If you try to feed like you would a clownfish, you will wonder where all the food went and why the goby is still thin.

• Great starters: live baby brine, live copepods, live or refrigerated cyclops, and small live mysis (if you can find the tiny stuff).
• Frozen staples (once eating well): finely chopped mysis, brine with enrichment, calanus, fish eggs, and small plankton mixes.
• Dry food: sometimes they learn pellets, but do not count on it. If you try, go tiny (nano pellets) and mix with frozen so it gets taken by accident at first.
• Feeding frequency: 2-3 small feedings a day beats one big dump of food.

Watch the belly. A healthy goby should look filled out, not pinched behind the head. If it is hiding all day and you never see it eat, assume it is not getting enough and adjust fast.

How they behave and who they get along with

They are shy, bottom-oriented, and basically allergic to chaos. In a calm tank they will perch, hover, and pick at the substrate. In a high-energy community they can get pushed into permanent hiding and slowly waste away.

• Good tankmates: other peaceful nano fish, small cardinals, firefish (in roomy setups), and calm wrasses that do not hunt the sand all day.
• Risky: fast, aggressive feeders that rush every meal (damsels, some dottybacks), and anything that likes to "inspect" and harass gobies.
• Do not mix with predators: hawkfish, big wrasses, big dottybacks, lionfish, etc. If it can fit it, it can become food.
• With other gobies: depends on space and personality. Provide multiple bolt-holes if you try it.

Breeding tips

Breeding them in a typical home reef is possible in the same way a lot of small marine gobies are possible: you might see pairing behavior and eggs, but raising the larvae is the hard part. Most pairs choose a tight cave or crevice and guard a clutch.

• If you want a shot: keep them in a species-focused tank with calm tankmates and lots of caves.
• Conditioning: heavy feeding with small meaty foods, stable temperature and salinity, and a predictable light cycle.
• Spawning site: a small cave with a narrow entrance near the sand line often gets chosen.
• Larvae: expect tiny pelagic larvae that need live foods (rotifers, then copepods) and clean, stable rearing water.

Common problems to watch for

Most of the trouble with Seba's goby comes from the same theme: stress plus not eating enough. They can look "fine" right up until they are suddenly not, so you want to be proactive.

• Refusing food after arrival: common. Start with live or very small frozen foods and feed in the evening when the tank is calmer.
• Getting outcompeted: if other fish are vacuuming food, the goby loses. Target feed and/or distract the group with a broadcast feeding first.
• Jumping: especially early on or after a bully encounter. Use a tight lid or mesh cover.
• Skin/parasite issues (marine ich/velvet): gobies are not immune. Quarantine is worth it, and avoid big temperature or salinity swings.
• Thin belly over time: often a sign of too-large food, too-infrequent feeding, or not enough natural microfauna.

The win with this species is pretty simple: give it cover, give it tiny foods often, and keep the tank peaceful. Do that, and you will actually see the personality come out instead of just owning a fish you never spot.