The Hawaiian grouper (''Hyporthodus quernus''), also known as the Hawaiian black grouper, Seale's grouper or Hapuʻupuʻu, is a species of marine

ray-finned fish Actinopterygii (; ), members of which are known as ray-finned fishes, is a class of bony fish. They comprise over 50% of living vertebrate species. The ray-finned fishes are so called because their fins are webs of skin supported by bony or hor ...

, a

grouper Groupers are fish of any of a number of genera in the subfamily Epinephelinae of the family Serranidae, in the order Perciformes. Not all serranids are called "groupers"; the family also includes the sea basses. The common name "grouper" is u ...

from the

subfamily In biological classification, a subfamily (Latin: ', plural ') is an auxiliary (intermediate) taxonomic rank, next below family but more inclusive than genus. Standard nomenclature rules end subfamily botanical names with "-oideae", and zoologi ...

Epinephelinae Groupers are fish of any of a number of genera in the subfamily Epinephelinae of the family Serranidae, in the order Perciformes. Not all serranids are called "groupers"; the family also includes the sea basses. The common name "grouper" is u ...

which is part of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Serranidae The Serranidae are a large family of fishes belonging to the order Perciformes. The family contains about 450 species in 65 genera, including the sea basses and the groupers (subfamily Epinephelinae). Although many species are small, in some case ...

, which also includes the

anthias Anthias are members of the family Serranidae and make up the subfamily Anthiinae. Anthias make up a sizeable portion of the population of pink, orange, and yellow reef fishes seen swarming in most coral reef photography and film. The name Anthi ...

and sea basses. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only stat ...

Taxonomy

The Hawaiian grouper was first formally described in 1901 as ''Epinephelus quernus'' by the

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, pe ...

ichthyologist Ichthyology is the branch of zoology devoted to the study of fish, including bony fish ( Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 33,400 species of fish had been described as of Octobe ...

Alvin Seale Alvin Seale (July 8, 1871 – July 28, 1958) was a naturalist known for his aquarium design and as an ichthyologist. Early life Alvin Seale was born on July 8, 1871, in Fairmount, Indiana, to a family of Quakers. In 1892, he attended Stanford Uni ...

(1871-1958) with the type locality given as

Honolulu Honolulu (; ) is the capital and largest city of the U.S. state of Hawaii, which is in the Pacific Ocean. It is an unincorporated county seat of the consolidated City and County of Honolulu, situated along the southeast coast of the island ...

. It was formerly considered to be in the genus ''

Epinephelus ''Epinephelus'' is a genus of marine ray-finned fish, groupers from the subfamily Epinephelinae, part of the family Serranidae, which also includes the anthias and sea basses. They are predatory fish, largely associated with reefs and are found i ...

'' but is now considered to belong to the genus ''Hyporthodus''. The specific name ''quernus'' means "oaken", presumably a reference to its reddish colour as an adult.

Description

The Hawaiian grouper has a body which has a

standard length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

that is 2.3 to 2.7 times its depth. It has an angular preopercle which has 3-4 enlarged serrations at its angle, with the lowest pointing downwards. The upper margin of the gill cover is convex. The

dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through conv ...

contains 11 spines and 14-15 soft rays while the

anal fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as se ...

has 3 spines and 9 soft rays. The membranes between the dorsal fin spines are deeply notched. The caudal fin is rounded. The adults are dark brown in overall colour and are marked with 8 vertical series of faint white spots which are obscured by many extra pale spots and blotches which vary in size. The fins of adults are largely plain and have a similar colour to the body apart from a small number of pale spots along the base part of the dorsal fin. Depending on habitat and where geographically found, some have a slight blue tint to their belly in the mature older adults, whereas in other areas they can have a slight reddish tint possibly for camouflage from predators. Juveniles are more variable in colour and may be pale greyish and the series of pale spots are more distinct and unobscured. This species has a maximum published

total length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish ...

of and a maximum weight of . The largest recorded specimen caught was 31.75 kilograms (70 lbs) off of Puako, Northwest Hawaii Island.

Distribution

The Hawaiian grouper is endemic to Hawaii and its range includes the

Northwestern Hawaiian Islands The Northwestern Hawaiian Islands or Leeward Hawaiian Islands are a series of islands and atolls in the Hawaiian island chain located northwest (in some cases, far to the northwest) of the islands of Kauai and Niihau. Politically, they are all p ...

and the

Johnston Atoll Johnston Atoll is an Unincorporated territories of the United States, unincorporated territory of the United States, currently administered by the United States Fish and Wildlife Service (USFWS). Johnston Atoll is a National Wildlife Refuge and ...

Habitat and biology

The Hawaiian grouper is a demersal species which is found on coral and rocky reefs at depths between . It is a

protogynous hermaphrodite Sequential hermaphroditism (called dichogamy in botany) is a type of hermaphroditism that occurs in many fish, gastropods, and plants. Sequential hermaphroditism occurs when the individual changes its sex at some point in its life. In particular, ...

and 50% of the females are sexually mature at , when they are around 6 years old, although it has been recorded in fish at . At a total length of 50% of the females change sex to become males, although this can occur at . The

spawning Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquati ...

season runs from February to June, peaking in March. This predatory species prefers to prey on other fishes with

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s, especially

shrimp Shrimp are crustaceans (a form of shellfish) with elongated bodies and a primarily swimming mode of locomotion – most commonly Caridea and Dendrobranchiata of the decapod order, although some crustaceans outside of this order are refer ...

, as a second preference.

Utilisation

The Hawaiian grouper is valued for having clear white flesh which has a delicate flavour. It is regarded as a member of the "Deep 7" group of fish species which live in deep water, near the bottom, and are a valuable resource for fisheries in Hawaii, these species accounting for 50% of the total commercial catch in the State.

References

*Pacific Islands Fisheries Science Center Administrative Report H-08-06, 19 p, http://www.pifsc.noaa.gov *Gillgren, Jerry G.; Ballam, Anthony: Malama Charters Hilo LLC, Commercial fishing vessel "Jovan Lee" field work, Northeastern coast of Hawaii Island (12/2019-3/2020) Hawaiian grouper Fish of Hawaii Natural history of the Northwestern Hawaiian Islands Midway Atoll Near threatened animals Near threatened biota of Oceania Hawaiian grouper Taxonomy articles created by Polbot {{Serranidae-stub