Wouter's pygmygoby

Where they come from

Wouter's pygmygoby (Trimma woutsi) is one of those tiny reef gobies that lives tucked into the nooks and crannies of Indo-Pacific reefs. Think steep rock faces, rubble zones, and little caves where there is constant micro-life drifting by. In the tank, that translates to one thing: they want structure and lots of small food floating past their face.

Setting up their tank

These guys are small enough that people underestimate what they need. You do not need a huge tank, but you do need a mature tank with pods, stable parameters, and plenty of hiding spots. My best results were in established nano reefs where the rock was alive and the fish could disappear whenever it felt like it.

• Tank size: 10+ gallons is workable, 20+ is just easier to keep stable
• Rockwork: lots of holes, overhangs, and tight crevices (they pick a home and hover nearby)
• Flow: moderate, with a couple calmer pockets so food can hang in the water a bit
• Lighting: whatever your reef runs - they do not care, but they appreciate shaded perches
• Cover: use a lid or mesh top - small gobies can and do jump, especially right after introduction

Acclimation matters with this species. They are hardy once settled, but they are not fans of big swings. Slow acclimation, lights dim the first day, and do not let bigger tankmates crowd them during those first hours.

What to feed them

This is where most people struggle. Trimma woutsi has a tiny mouth and likes small, frequent meals. In my tanks, they did best when I fed "clouds" of micro-food instead of one big dump of chunky frozen.

• Great staples: live or frozen baby brine (enriched), cyclops, calanus (smaller pieces), copepods, rotifers
• Prepared foods: fine pellets (0.3-0.6 mm) and small granules can work once they recognize them
• Feeding rhythm: 2-4 small feedings a day beats one big feeding
• Target feeding: a pipette or turkey baster helps put food right into their hover zone

I like to turn the return pump down for 5-10 minutes during feeding, just enough that the food stays suspended instead of rocketing into the overflow. If you have aggressive eaters (wrasses, anthias, clowns that act like piranhas), you may need to distract-feed them first.

How they behave and who they get along with

Trimma are classic hover-gobies. They pick a spot, hover, dart for food, and dive back into cover. They are not bullies, but they are also not going to compete with pushy fish. You will see the most natural behavior in a calm, reefy community where nobody is constantly charging around.

• Good tankmates: small peaceful gobies, firefish (in a calm tank), small blennies, tiny cardinals, gentle clownfish pairs, cleaner shrimp
• Use caution: wrasses, dottybacks, hawkfish, larger basslets, or anything that loves hunting tiny fish
• Corals/inverts: reef-safe, and they generally do not bother anything

With other tiny gobies, you can get some squabbles if the tank is small and the rockwork is simple. More hiding spots solves most of that. If you want more than one, add them together and give them lots of little "apartments" to choose from.

Breeding tips

They can spawn in captivity, but raising the babies is the real challenge. Adults will usually lay eggs in a tucked-away crevice or small cave, and the male tends to guard. You might notice a pair staying tight to one little hole and chasing others away.

• Give them spawning spots: tiny caves, small shells, or narrow rock gaps they can defend
• Feed heavy with small meaty foods to condition them
• If you try to raise larvae: you will need live plankton (rotifers first, then copepods/bbs) and a dedicated larval setup

Common problems to watch for

• Starvation from competition: they are tiny and can get outcompeted easily
• Jumping: especially in the first week or after a scare
• Shipping stress: they can arrive thin or dehydrated, and may need gentler flow and frequent small meals
• Ich/velvet sensitivity: like most small reef fish, they do not handle parasites well if stressed
• Getting lost in "too clean" tanks: brand-new tanks without pods make feeding harder

My personal checklist if one is acting off: first I watch them eat (or not), then I check for bullying, then I look at breathing rate and any flashing. Nine times out of ten, fixing the feeding situation and reducing stress turns things around before it becomes a medical issue.