Louti (Cherry) Grouper

The Red Louti Grouper (Variola louti), also sold as the Moon Grouper, Coronation Grouper, Lyretail Grouper, or Yellow Edge Lyretail, is a large serranid distributed across the tropical Indo-Pacific and the Red Sea. It favors clear water around islands and offshore reefs, generally below about 15 meters. Juveniles are orange to yellow-tan across the back with a paler lower half, dark spotting, and occasionally a mottled black stripe dividing the two tones. Mature fish transform into deep red, maroon, purple, or brown animals marked with white to blue and pink-purple spots, a lighter head, and a lyre-shaped tail rimmed in brilliant yellow that suggests a crescent moon.

Adult housing begins at 300 gallons, and larger volumes are better given how quickly this predator grows and how much waste it produces. Build the layout around abundant live rock that is anchored firmly to the substrate, since this grouper digs and can topple loose structures, and leave broad open lanes for cruising and ambush runs. Rockwork should include caves or overhangs deep enough for a heavy-bodied fish to shelter in comfortably. A mature system with robust biological and mechanical filtration, a high-quality protein skimmer, and decent water movement will keep pace with the nutrient load from frequent meaty feedings.

On the reef, Variola louti hunts primarily fishes, supplemented with crabs, shrimps, and stomatopods. In the aquarium it remains a strict carnivore with an appetite for large, substantial pieces of seafood. Offer a rotation of krill, raw table shrimp, squid, clam, mussel, silversides, crab meat, and fresh marine fish. Live, frozen, and freeze-dried items are all taken readily, and many individuals will learn to accept carnivore or omnivore pellet formulas once they are settled. An occasional herbivore-oriented offering rounds out the diet.

Feed three to five times per week rather than daily, sizing portions to the fish and removing anything uneaten. Variety matters more than volume here, since a single-item diet of one frozen food tends to produce a fish in poor condition over time. Because this grouper is a heavy feeder, coordinate feeding schedules with water change and skimmer maintenance to keep nitrate and phosphate in check.

Krill Raw Table Shrimp Squid Clam Mussel Silversides Crab Meat Carnivore Pellets
This is an aggressive, territorial ambush predator that spends much of the day tucked into rockwork watching for movement. Aggression escalates as the fish matures and is directed at both conspecifics and unrelated species. Introduce it last, after every other inhabitant has claimed a territory, and expect it to renegotiate boundaries anyway. Appropriate tankmates are similarly large, assertive fish with the bulk and confidence to stand their ground. Community stocking is not an option.

Regarding invertebrates, this species will not pick at or damage corals and sessile invertebrates, so it can be maintained alongside established coral colonies. The risk lies elsewhere: anything small enough to enter that cavernous mouth will be eaten, including shrimp, crabs, small snails, and any fish under its swallowing threshold. Most keepers house it in a large fish-only-with-live-rock system for that reason, and those who keep it with corals should stock only large, fast tankmates and forgo ornamental crustaceans entirely.

FAQ

Frequently Asked Questions

About the Red Louti Grouper

  • How large an aquarium does an adult Red Louti Grouper need?
    Plan on a minimum of 180 gallons for an adult, with more volume preferred given its 16-inch adult size and heavy feeding. Secure all rockwork to the substrate, since this grouper digs and can topple loose structures.
  • Can a Red Louti Grouper be kept in a reef tank?
    It does not harm corals or other sessile invertebrates, so it can live among established coral colonies. However, it will eat shrimp, crabs, and any fish small enough to swallow, so most aquarists choose a large fish-only-with-live-rock system.
  • What are suitable tankmates for a Red Louti Grouper?
    Only similarly large, aggressive fish that can hold their own belong in the same system. Add the grouper last so existing residents have already established territories.