Campeche Bank hamlet
Hypoplectrus espinosai
Campeche Bank hamlet, distinguished by its bright yellow-orange body and bold dark spots, exhibits a somewhat flattened, oval shape.
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About the Campeche Bank hamlet
This is a hamlet (a small serranid) that lives on shallow coral reefs on the Campeche Bank off the Yucatan Peninsula in Mexico. Its max recorded size is under 10 cm, and in the wild it is described as a diurnal, solitary little predator that hangs around the reef picking off meaty prey.
Quick Facts
Size
97.6 mm TL
Temperament
Semi-aggressive
Difficulty
Advanced
Min Tank Size
75 gallons
Lifespan
5-10 years
Origin
Gulf of Mexico (Campeche Bank, Mexico)
Diet
Carnivore - meaty foods like shrimp, mysis, chopped seafood; will eat small fish/crustaceans
Water Parameters
22.2-25.6°C
8.1-8.4
8-12 dGH
Need a heater for this species?
This species needs 22.2-25.6°C in a 75 gallon tank. Use our heater calculator to find the right wattage.
Calculate heater sizeCare Notes
- Give it a real reef rock layout with caves and overhangs - they pick a lair and will patrol it, so a bare scape stresses them out and makes them cranky.
- Plan on a bigger tank than you think: 55+ gallons for one, and more if you want other fish; they act like a small grouper and will claim chunks of the tank.
- Keep salinity steady around 1.025-1.026 and run nitrate low (under ~10-20 ppm); swings in salinity and dirty water are where they start looking rough fast.
- Feed like a predator: meaty frozen (mysis, chopped shrimp, clam, squid) 3-5 times a week, and train to eat from tongs so food does not vanish into the rocks.
- Do not mix with tiny fish or tiny shrimp unless you are fine with them becoming snacks - anything that fits in its mouth is on the menu once lights go down.
- Tankmates that work are tough, similar-sized reef fish that hold their ground (bigger wrasses, tangs, rabbitfish); skip other hamlets and most basslets unless the tank is huge.
- Watch for ambush-predator issues: they get fat easily and can go on hunger strikes after shipping, so start with live or very smelly frozen foods and wean to a routine.
- If you ever try breeding, hamlets do the egg-trading thing (they take turns as male/female), but you basically need a bonded pair and a larval setup - expect tiny pelagic larvae that are not beginner-friendly.
Compatibility
Good Tankmates
- Other semi-tough Caribbean reef fish that can hold their own, like fairy basslets (Gramma loreto) or chalk bass (Serranus tortugarum) - they usually coexist fine as long as everyone has caves and you do not cram the rockwork
- Moderate wrasses that stay busy and do not just hover in the hamlet's face - think Halichoeres types (melanurus, yellow wrasse) or a sixline in a big, established tank - they can take a little attitude and keep moving
- Reef-safe angels on the smaller side like a coral beauty or flame angel - not pushovers, not typically scared of a hamlet, and they use different parts of the tank
- Tangs in appropriately sized tanks (kole, tomini, yellow, etc.) - they are fast, confident, and usually ignore the hamlet's bluffing, just give everyone room and algae to graze
- Clownfish pairs (ocellaris/percula) especially if they have their corner or an anemone - they are feisty enough to not get bullied, and the hamlet usually learns to leave them alone
- Bigger, bold gobies and blennies that are not bite-sized, like a lawnmower blenny or a decent-sized watchman goby - fine if they have burrows and you do not add the goby as a tiny snack
Avoid
- Tiny shrimp gobies, small firefish, or little dartfish - hamlets are basslets by nature and will absolutely treat small, skinny fish like food once the lights go down
- Very peaceful, slow hoverers like Banggai cardinals or sleepy anthias - they tend to get stressed by the hamlet's ambushy posturing and can get chased off food
- Other hamlets (Hypoplectrus) or similar small basslets in the same footprint - unless the tank is big with tons of rock, you are asking for territory wars and one fish getting pinned in a corner
- Big bullies that will run the whole tank (large dottybacks, nasty damsels, triggerfish) - the hamlet is semi-aggressive, but it is not going to outmuscle a real thug long-term
Where they come from
The Campeche Bank hamlet (Hypoplectrus espinosai) is a little Caribbean serranid from the Campeche Bank area off the Yucatan Peninsula. Think shallow reef slopes and rubble zones where there are plenty of holes to duck into and a steady stream of small fish and crustaceans to ambush.
They are one of those fish that look cute in photos, then you meet them in person and realize: yep, that is a tiny grouper relative with grouper attitude.
Setting up their tank
If you have kept hawkfish, dottybacks, or small groupers, you will feel at home. The big theme is: give them structure, give them territories, and keep your filtration ready for a predator that eats meaty foods.
- Tank size: I would not do one in anything under 30 gallons, and 40+ is way more comfortable if you want tankmates.
- Rockwork: build a few separate "caves" or overhangs with sight breaks. They pick a home base fast.
- Flow and oxygen: moderate reef-style flow is fine. These fish like clean, oxygen-rich water.
- Lid: they can jump when spooked, especially new additions or after lights-out surprises.
- Lighting: whatever your reef/fish-only setup uses. They do not care, but dimmer corners help them settle in.
I have had the best luck adding the hamlet after the rockwork is already established and algae/copepods are showing up. A sterile, brand-new scape makes them more skittish and picky at first.
Advanced difficulty is not because they are delicate. It is because of compatibility and feeding discipline. A hamlet that is hungry will re-decorate your stocking plan.
What to feed them
They are carnivores with a strong "eat it whole" style. Mine took to frozen pretty quickly, but I still had to be consistent and not let it go on a hunger strike waiting for live food.
- Staples: frozen mysis, chopped shrimp, chopped clam, krill (as a treat, not the main food), quality marine carnivore pellets once they recognize them.
- Variety: rotate foods. They do better long-term when you are not feeding one thing forever.
- Feeding schedule: small portions 1-2x daily. They will act starving no matter what.
- Target feeding: a feeding stick or turkey baster helps if tankmates are faster.
If yours is shy, feed with pumps briefly turned down and drop food right near its cave. Once it learns you are the food source, it will start meeting you at the glass.
Do not make live ghost shrimp your regular solution. It can train them to ignore frozen and it is an easy way to bring in pests or gut issues. Use live only as a short "get them eating" bridge if you have to.
How they behave and who they get along with
Hamlets are small but bold. They perch, watch, then dart out for food. Expect territorial behavior, especially toward fish with a similar shape or those that hover near their chosen cave.
The rule that saves you headaches: if it can fit in their mouth, it is food. If it cannot, it might still be bullied if it annoys them.
- Good tankmates: tougher reef fish that hold their ground (bigger clowns, some damsels, larger wrasses), and larger gobies/blennies that will not get swallowed.
- Risky: small gobies, small wrasses, small cardinals, tiny basslets - anything bite-sized.
- Avoid: ornamental shrimp and tiny crabs. Cleaner shrimp are a gamble depending on size and the hamlet's attitude.
- With other Hypoplectrus: I would not mix hamlets in most home tanks unless you are experienced and have a larger setup with multiple territories. Even then, watch closely.
Do not trust them with sexy shrimp, anemone shrimp, small peppermint shrimp, or little decorative crabs. It might work for weeks, then one day you just have fewer inverts.
They are generally reef-safe with corals. The trouble is not coral nipping, it is predation on small mobile inverts and occasional aggression toward small fish.
Breeding tips
Hamlets are famous for interesting spawning behavior in the wild (paired rises into the water column and releasing eggs). In home tanks it is possible to see courtship, especially in calm, stable systems, but raising the larvae is the hard part.
If you want to try, you are basically signing up for a marine larval project: live plankton cultures, dedicated larval tank, and patience.
- Watch for: two fish hanging out at dusk, gentle circling, short upward "rises" together in the water column.
- Spawning window: often around lights-out or late evening in peaceful tanks.
- If eggs show up: collect with a surface skimmer cup or gentle scoop and move to a separate, aerated larval setup.
- First foods: you will need appropriate live foods (rotifers at minimum, then copepods/Artemia as they grow), and you will be doing water management daily.
Even if you are not breeding, a gradual ramp down in lighting (or a short dusk period) makes them less jumpy and you may see more natural evening behavior.
Common problems to watch for
Most issues I have seen are husbandry and social problems, not mystery diseases. Get the basics right and they are pretty hardy.
- Not eating after introduction: common if the tank is too bright/open or if aggressive tankmates crowd them. Give them a cave, target feed, and do not panic on day one.
- Bullying or being bullied: they can both dish it out and take it. Rearrange rockwork if they claim the whole tank.
- Missing small fish/inverts: the "it vanished" problem. Assume predation first.
- Marine ich/velvet risk: like most wild marine fish, they can carry parasites. Quarantine is your friend.
- Fin nips and torn mouths: happens if they wedge into sharp rock or fight. Smooth out sharp points and give multiple hideouts.
If you are running a reef where you hate losing shrimp, skip this species. You might get lucky for a while, but eventually that hunting instinct shows up.
Quarantine with a few pieces of PVC and low stress lighting helps a lot. Once they are eating confidently in QT, they usually transition to the display without the drama.
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