Basslets are small reef fish that live in and around holes in the rock. They're colorful, they stay small, and most of them are easy to keep, which is why so many people add one early in the life of a saltwater tank. Every basslet we sell comes from the Florida Keys, the Bahamas or the Caribbean. Here's what we know about the eight species we carry, which ones get along, and how to pick the right one for the tank you actually have.
- 8species we carry
- 30 galminimum for most
- 1per tank, with two exceptions
- 7–10days in our holding system
What is a basslet?
"Basslet" is a name the hobby uses for three different groups of small fish that look alike and live the same way. The grammas (Royal Gramma and Black Cap) are the best known. Despite the name, they aren't basses; they're a family of their own. The Chalk, Harlequin, Lantern and Tobacco Bass are true miniature sea basses, and each one is both male and female at the same time, which is why a few of them can be kept in groups. The reef basslets (Swissguard and Cave) are sea basses too, just shyer and more expensive.
If you see "fairy basslet" on a stock list, that's a Royal Gramma under an older name. The Royal Dottyback is a different story. It's a Pacific fish in the same purple and yellow with a much worse temper, and people buy it by mistake. On a gramma the purple fades into the yellow; on a dottyback the two colors meet in a hard line.
The eight basslets we carry
Depths come from published reef surveys and FishBase. Tank sizes are the minimums we'd recommend.
| Species | Scientific name | Size in a tank | Minimum tank | Temperament | Reef safe | Depth on the reef | Care level |
|---|---|---|---|---|---|---|---|
| Royal Gramma | Gramma loreto | ~3 in | 30 gal | Peaceful; territorial toward its own kind | Yes | 10–200 ft | Easy |
| Black Cap Basslet | Gramma melacara | ~4 in | 40 gal | Semi-peaceful; bolder than a Royal Gramma | Yes | Usually 66–197 ft | Easy to moderate |
| Chalk Bass | Serranus tortugarum | ~3 in | 30 gal | Peaceful; can live in a group | Yes | Shallows to ~300 ft | Easy |
| Harlequin Bass | Serranus tigrinus | 2–4 in (max 11 in published) | 30 gal | Bossy; hunts small crustaceans | Coral safe; small shrimp at risk | 2–131 ft | Easy |
| Lantern Bass | Serranus baldwini | 2–3 in (max 4.7 in) | 30 gal | Peaceful | Coral safe; small shrimp at risk | 2–260 ft | Easy |
| Tobacco Bass | Serranus tabacarius | 3–6 in (max 8.7 in) | 30 gal, bigger is better | Peaceful | Coral safe; small shrimp and tiny fish at risk | 13–230 ft | Easy |
| Swissguard Basslet | Liopropoma rubre | ~3 in (max 3.9 in) | 30 gal | Peaceful and shy | Yes; tiny shrimp at risk | 10–151 ft | Easy to moderate |
| Cave Basslet | Liopropoma mowbrayi | ~3.5 in | 30 gal | Peaceful and very shy | No | 98–197 ft | Moderate |
Royal Gramma (Gramma loreto)
The standard first basslet, and for good reason. A Royal Gramma is hardy, tops out around 3 inches, eats anything meaty, and does fine in a 30-gallon tank with a few caves. It likes to hang upside down under a ledge, and it will flare its mouth wide open at anything that gets too close to its spot. That's a bluff. Royal Grammas live in the Bahamas and Caribbean rather than off Florida, so ours come from collectors we trust rather than our own boat.
Shop Royal GrammaBlack Cap Basslet (Gramma melacara)
The Royal Gramma's deeper-water cousin: purple with a black cap and a bit more nerve. Black Caps live between roughly 66 and 197 feet, which is why they cost more. A fish from that depth has to come up slowly and be given time to settle. Give it 40 gallons and some shaded rockwork. Once it's comfortable, it spends more time out in the open than a Royal Gramma does.
Shop Black Cap BassletChalk Bass (Serranus tortugarum)
The one basslet that's happier with company. Chalk Bass feed on plankton in open water, so they're out where you can see them and quick to take frozen food. Add three to five at once to a 30-gallon or larger tank and they settle into a loose group. They're scarce in the Keys; we get them in summer or from Haiti and the Dominican Republic.
Shop Chalk BassHarlequin Bass (Serranus tigrinus)
The toughest fish on this list. A Harlequin Bass is a small predator that swallows shrimp and other small crustaceans whole, and it gets pushier as it grows. Leave the small shrimp out and give it 30 gallons with plenty of rock.
Shop Harlequin BassLantern Bass (Serranus baldwini)
Small, calm and inexpensive. A Lantern Bass picks a perch and watches the tank from it. It eats small shrimp in the wild, so think of it as coral-safe rather than safe with every invertebrate. Thirty gallons is plenty. It's seasonal for us, so if it's out of stock, sign up for a restock alert.
Shop Lantern BassTobacco Bass (Serranus tabacarius)
More bass than basslet. A Tobacco Bass is peaceful with anything it can't swallow, but it reaches 6 inches or more, so plan on 55 gallons even though it will live in 30 for a while. Not a fish for a nano tank or a tank full of small shrimp.
Shop Tobacco BassSwissguard Basslet (Liopropoma rubre)
Red and yellow stripes, lives at the back of a cave, comes out at dusk. Swissguards are common on Keys reefs but rarely seen, and they behave the same way in a tank. Give it 30 gallons, deep rockwork, softer light and a tight lid. It leaves corals alone; only the tiniest shrimp are at risk.
Shop Swissguard BassletCave Basslet (Liopropoma mowbrayi)
Our rarest basslet, from 98 to 197 feet down. A Cave Basslet is solitary, peaceful and even more secretive than a Swissguard, and ours are eating frozen brine shrimp. We list this fish as not reef safe, so make sure you have an aquarium set up for it: fish-only, plenty of rock and caves, subdued light. Ask us before you order if you're not sure.
Shop Cave BassletWhich basslet fits your tank?
Start with the tank you have, not the fish you like the look of.
| Your situation | Our pick | Why |
|---|---|---|
| 20–29 gallons | Wait, or a single Royal Gramma in a rock-heavy 29 | Every basslet we sell wants 30 gallons of real territory. A 29 built around caves is the only exception, and only for a Royal Gramma. |
| 30–39 gallons with shrimp | Royal Gramma or Swissguard | Both leave corals and all but the tiniest shrimp alone. One fish, not two. |
| 30–39 gallons, no small shrimp | Harlequin Bass or Lantern Bass | Tough, cheap, easy to feed. The Harlequin is the bolder of the two. |
| 40–54 gallons | Black Cap, or three Chalk Bass | Room for a Black Cap to be seen instead of hidden. Chalk Bass give you movement in open water. |
| 55 gallons and up | Tobacco Bass, or a Royal Gramma and a Black Cap added the same day | Room for the Tobacco to grow into, or enough caves for two grammas to each claim one. |
| I want a group | Chalk Bass, 3–5 at once | The only basslet here that does well with its own kind in a normal-sized tank. |
| I want the boldest | Black Cap Basslet | Settles in faster and stays out longer than the rest. |
| I want the one nobody else has | Cave Basslet | Deep-water, rarely offered, and not reef safe, so it needs a fish-only tank set up for it. |
| First saltwater fish ever | Royal Gramma | Hardy, forgiving, eats anything, and cheap enough that a mistake isn't a disaster. |
Setting up for a basslet
All eight want the same few things.
Rock with real holes in it. A pile of rock isn't a cave. Basslets want overhangs to hang under and tunnels with a back door. Build it before the fish arrives, not after.
A lid. All of them jump, and the shy ones jump most in the first week. Mesh is fine.
Stable water. Our guarantee lists what we expect a tank to hold before we ship, and those are the right numbers for basslets: 75 to 83°F and steady, specific gravity 1.020 to 1.025, pH 8.1 to 8.4, zero ammonia and nitrite, nitrate under 30 ppm. A tank that has been running a few months beats a new one with perfect readings.
Meaty food in small pieces. Frozen mysis, enriched brine shrimp and chopped seafood are the staples, and most basslets learn to take a good pellet. Feed once or twice a day, and make sure the shy ones are getting some. A Swissguard that comes out at dusk won't compete with a clownfish at noon, so feed near its cave or after the lights dim.
Can basslets live together?
Basslets are peaceful toward fish that don't look like them and don't want their cave. The trouble is with their own kind. A Royal Gramma that ignores a clownfish will chase a second Royal Gramma until one of them is dead, and it treats a Black Cap or a dottyback the same way. Harlequin Bass won't tolerate other dwarf basses. Swissguards and Cave Basslets fight their own species hard.
So the rule is one per tank, with two exceptions. Chalk Bass go in as a group of three to five, all on the same day. And two different grammas can share a tank of 55 gallons or more if both go in the same day and there are caves at both ends, so neither has a home to defend yet. People who add the second fish a month later usually report a war.
Good tank mates
clownfish, gobies, blennies, cardinalfish, firefish (with a lid) and most peaceful community fish.
Bad ones
dottybacks, big wrasses, triggers, puffers, large angels, and anything with a mouth wide enough to eat a 3-inch fish.
Where you can, add the basslet before the bolder fish. A basslet that arrives after an established bully will spend months in its cave.
Are basslets reef safe?
None of them bother corals, clams or anemones. Grammas and Chalk Bass ignore shrimp too. The four Serranus basses are crustacean hunters, and the bigger they get the wider their idea of food: a full-grown Harlequin or Tobacco will eat sexy shrimp, small hermits and young cleaner shrimp, while an adult cleaner or fire shrimp is usually too big to bother with. Swissguards only threaten the tiniest shrimp. The Cave Basslet is the exception; we list it as not reef safe. Snails and medium-to-large hermit crabs are safe with all eight.
How we get them to you
Between 85 and 90 percent of the Caribbean livestock on our site is collected by our own team. Basslets split by depth. Harlequin, Lantern, Tobacco and Swissguard live in the 10 to 25 feet of water we dive every day, and we catch them one at a time with a drop net. Chalk Bass mostly come from Haiti and the Dominican Republic. Royal Grammas, Black Caps and Cave Basslets come from partner collectors, because they either don't live off Florida or live deeper than we work. The full routine is on our Our Process page.
From there every fish gets the same treatment: a 30-minute medicated bath the day it arrives, then 7 to 10 days in our holding system while we watch it eat. Anything that won't feed doesn't ship. Fish get their last meal Sunday morning, go into bigger bags with more water than strictly necessary, and leave UPS Priority Overnight on Monday through Wednesday only, so nothing sits in a warehouse over a weekend. Orders over $249.99 ship free.
When the box arrives, sign on the first attempt, drip acclimate for at least an hour, and then leave the fish alone. It will disappear into the rock for three to seven days. That's normal. It ate in our system and it will eat in yours once it figures out where the food comes from. If it's still invisible after two weeks, look for a bully. Our live arrival guarantee covers the rest.
Questions we get a lot
Royal Gramma or Black Cap?
Royal Gramma for a 30-to-40-gallon tank, a first saltwater fish, or a fish you want to see all day. Black Cap for 40 gallons and up, when you want something bolder and don't mind paying for it. They eat the same food and both leave corals alone.
How long do basslets live?
Several years in a stable tank. Royal Grammas are commonly reported at five years or more. Steady water and no bully in the tank matter more than anything else.
Wild or captive-bred?
Captive-bred Royal Grammas and Chalk Bass exist and are a fine choice. Ours are wild. Hobbyists who've kept both often report deeper color in wild grammas, and wild fish come in a wider range of sizes, so you can pick one that's past the fragile stage. Either way, quarantine it.
What's the best basslet for a 20-gallon tank?
We'd rather you wait for 30. If you're set on it, a single Royal Gramma in a 29 built around caves is the only setup we'd put our name on.
Ready to pick one?
It comes down to three questions: how big is the tank, are there small shrimp in it, and do you want a fish you'll see every day or one you'll catch at dusk. Our basslet collection shows what's available this week, and the in-stock page updates as fish come out of holding. If you're not sure, email or call before you order. We'd rather lose the sale than send you the wrong fish.
Sources for the biology in this article: FishBase: Serranus tabacarius, FishBase: Liopropoma mowbrayi, Reefguide: Fairy Basslet, Reefguide: Harlequin Bass, Reefguide: Lantern Bass, Reefguide: Tobaccofish, Wikipedia: Royal gramma, Wikipedia: Blackcap basslet, Wikipedia: Chalk bass, Wikipedia: Harlequin bass, Wikipedia: Lantern bass, Wikipedia: Liopropoma rubre.