Common name: Hawaiian grouper

Scientific name: Hyporthodus quernus (Seale, 1901)

General information

The Hawaiian Grouper, scientifically known as Hyporthodus quernus, is a species of marine fish belonging to the family Serranidae. It is also commonly referred to as the Hawaiian Seabass. This species is known for its striking appearance, with a robust body, large mouth, and a coloration that can range from a reddish-brown to a more subdued gray, often with lighter spots or blotches.

Hawaiian Groupers are solitary predators, primarily nocturnal, and are known for their slow growth and long lifespan. They are protogynous hermaphrodites, meaning they start life as females and can change to males as they mature.

Details

Recommended minimum tank volume
300 liter (79 gallons)
Salinity
S.G. 1.020 to 1.025
Temperature
22 to 26 °C (72 to 79 °F)
Acidity
pH 8.1 to 8.4
Average size
50 cm (1′8″)
Care level
Moderate to difficult Sensitive to water quality.
Diet
Carnivore Prefers meaty foods, live feed.
Social
Solo Territorial, best kept alone.
Reefsafe
No May eat smaller fish, inverts.
Aggression
Semi aggresive Can be territorial.
Captive bred
No

Taxonomy

  1. Kingdom
    Animals
    Animalia
  2. Phylum
    Chordates
    Chordata
  3. Class
    Ray-finned Fishes
    Actinopterygii
  4. Order
    Perch-like Fishes
    Perciformes
  5. Family
    Groupers
    Serranidae
  6. Genus
    Grouper
    Hyporthodus
  7. Species
    Hawaiian grouper
    Hyporthodus quernus (Seale, 1901)
  8. Synonyms
    Epinephelus quernus Seale, 1901

Care

Hawaiian Groupers require large aquariums due to their potential size, which can reach up to 80 centimeters (31 inches) in length. They need ample space to swim and plenty of hiding places to feel secure. These fish are carnivorous and require a diet of meaty foods such as fish, squid, and crustaceans. It is important to feed them a varied diet to ensure proper nutrition.

Due to their predatory nature, they should not be kept with small fish or invertebrates that they may view as prey. They are best suited for a fish-only or a large predator tank setup.

Reproduction

In the wild, Hawaiian Groupers have a complex reproductive behavior that includes forming spawning aggregations. In the aquarium, breeding these fish is quite challenging and rarely achieved. Their sex change from female to male is triggered by social and environmental factors that are difficult to replicate in captivity.

Habitat

Hawaiian Groupers are endemic to the Hawaiian Islands and Johnston Atoll. They are typically found in deep reef environments, ranging from 90 to 300 meters (295 to 984 feet) below the surface. They prefer rocky substrates and areas with plenty of crevices and overhangs for shelter.