A monster in the wild and in the aquarium, the Grouper is a giant of a fish. Known for growing over three feet in length and weighing more than 200 pounds, this fish is hardly built for sprints along the ocean floor. Thankfully, such monsters are not common in the aquarium, though Groupers will grow quickly and even the smaller varieties require space. Groupers are predominantly floor-dwelling and prefer to dig themselves into the substrate or to hide themselves in a reef and wait for prey to pass by. They have exceptionally strong gill muscles that they can use to brace themselves into a hiding place when they feel threatened. Once they have used their gills to brace themselves, it is nearly impossible to get them loose of their hiding spot.

Sub-Species for Aquariums:

Panther/ Polka-Dot – The beautiful Panther Grouper is a lovely, if not large, addition to the aquarium. Its white body is covered with obvious brown spots outlined in black, but when it shifts the owner is treated to additional, larger brown spots that are hidden in certain lighting.

Alexandria – Fairly plain, the Alexandria Grouper is brown or violet colored with horizontal white stripes. It looks quite similar to the “common” Grouper. The Alexandria Grouper is highly territorial and not recommended for community tanks as it is known for picking fights with significantly larger fish and winning.

Clown/ Bearded – The Clown or Bearded Grouper is found in two patterns. The first is silver-bodied and covered in small white spots with broad black stripes along its back. The second is a black bodied fish with yellow spots covered in white dots. Both have a small “beard” that juts out from their chin.

Blue-Spotted – Though the name may bring up the image of a blue fish with spots, the Blue-Spotted Grouper is quite the opposite. With bodies ranging in color from brown to orange, the Blue-Spotted Grouper is covered in small, turquoise spots, like freckles. In addition, the pectoral, dorsal, anal fins and tail are a deep blue.

Six- Line – Though the Six-line Grouper is certainly covered in more than six lines, it isn’t hard to see where the name came from. This fish is a solid black or brown and striped with both solid and broken lines that cross the fish horizontally.


Groupers are quite hardy. They need a pH of 8 and water temperatures between 75-82˚F. They are highly predatory, so keeping them in aquariums with smaller fish would not be a wise idea. Groupers grow quickly and many varieties grow larger than two feet, so keeping them in aquariums larger than 150 gallons saves having to move them later. While they are territorial, they are also very solitary and most varieties of Groupers will leave other fish alone once they have established their territory. The exception to this is that the Alexandria who will pick a fight with pretty much anyone.


Groupers are carnivores and prefer live food to frozen. Live brine shrimp are ideal, however chopped squid is appreciated. They also have a crushing tooth on their palate that allows them to crush things like clams. Because of their large size, Groupers have a somewhat ravenous appetite and require feeding often in order to keep them from going after other fish in the tank.

Size: 24 Inches
Freshwater/ Saltwater: Saltwater
Diet: Carnivore
Reef Compatibility: 5
Tank Mate Compatibility: 3
Lifespan: Up to 10 Years

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