The hāpuku, hapuka or whapuku (''Polyprion oxygeneios''), also known as groper, is a wreckfish of the family Polyprionidae, found around southern

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

, southern

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Tristan da Cunha Tristan da Cunha (), colloquially Tristan, is a remote group of volcano, volcanic islands in the South Atlantic Ocean. It is one of three constituent parts of the British Overseas Territories, British Overseas Territory of Saint Helena, Ascensi ...

and

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

at depths between 30 and 800 m. Its length is between 60 and 180 cm, and it can weigh up to 100 kg. It is sometimes described locally as cod, although that properly refers to other fish.

Description

Hāpuku are grey in colour with silvery white underbellies, with juveniles generally being blue in colour. They have 10 dorsal spines running along their back, a rounded

anal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported o ...

and rounded

pectoral fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish aquatic locomotion, swim. Apart from the tail or caudal fin, fish fins have no direct connection with the vertebral column ...

s, and a large, powerful, square-shaped tail. Its lower jaw protrudes from the top, and their very large eyes are adapted for hunting and inhabiting low-light conditions.Ocean Hunter Ltd
"Hapuku"
, ''OceanHunter'', n.d. Retrieved September 12, 2010.

Habitat and feeding

Juveniles are thought to be

pelagic The pelagic zone consists of the water column of the open ocean and can be further divided into regions by depth. The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or water column between the sur ...

, switching to

demersal The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer o ...

when they are about 50 cm in length. They inhabit

temperate In geography, the temperate climates of Earth occur in the middle latitudes (approximately 23.5° to 66.5° N/S of the Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ran ...

and

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...

waters of the southern

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or approximately 20% of the water area of Earth#Surface, Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia (continent), ...

and

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five Borders of the oceans, oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is ...

, being found in

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

, southeastern

and

. They can be found in waters between 10 m and 800 m deep, but generally prefer waters deeper than 50 m. They are usually found living in cracks, caverns, or caves when found in shallow waters. They are voracious predators, feeding on a large range of other fish species,

invertebrate Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordata, chordate s ...

s and

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

s, including red cod and

blue cod The New Zealand blue cod (''Parapercis colias'') is a temperate Marine (ocean), marine ray-finned fish of the family (biology), family Pinguipedidae. It is also known by its Māori language, Māori names, rāwaru, pākirikiri and patutuki, and ...

, hoki,

crabs Crabs are decapod crustaceans of the infraorder Brachyura (meaning "short tailed" in Greek), which typically have a very short projecting tail-like abdomen, usually hidden entirely under the thorax. Their exoskeleton is often thickened and ha ...

and

crayfish Crayfish are freshwater crustaceans belonging to the infraorder Astacidea, which also contains lobsters. Taxonomically, they are members of the superfamilies Astacoidea and Parastacoidea. They breathe through feather-like gills. Some spe ...

.Beentjes, M. P., and Francis, M. P., "Movement of hapuku (''Polyprion oxygeneios'') determined from tagging studies", ''New Zealand Journal of Marine and Freshwater Research'', 1999 33: 1-12. The fish has an overlapping range with the Atlantic wreckfish, its closest known relative. In the 19th century, the fish was found around the shores of New Zealand, but by the 20th century it was found almost exclusively in deeper waters.

Age and growth

Hāpuku are a large, slow growing, long-lived species. They reach

sexual maturity Sexual maturity is the capability of an organism to reproduce. In humans, it is related to both puberty and adulthood. ''Puberty'' is the biological process of sexual maturation, while ''adulthood'', the condition of being socially recognized ...

between 10 and 13 years and have lifespans up to 60 years. They can grow as large as 100 kg, but are usually found around the 25 kg mark. They have an average size of 80–100 cm but can grow up to 180 cm in length.

In a human context

The hāpuku is a traditional food for Māori, considered one of the most prestigious fish. The name hāpuku originated in

Polynesian languages The Polynesian languages form a genealogical group of languages, itself part of the Oceanic branch of the Austronesian family. There are 38 Polynesian languages, representing 7 percent of the 522 Oceanic languages, and 3 percent of the Austr ...

, typically used to refer to fish in the

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 fo ...

genus, and in Māori the word hāpuku became a verb, meaning to cram food into your mouth. The name hapuka appears to be a corruption of the fish's

Māori language Māori (; endonym: 'the Māori language', commonly shortened to ) is an Eastern Polynesian languages, Eastern Polynesian language and the language of the Māori people, the indigenous population of mainland New Zealand. The southernmost membe ...

name by early European settlers. Hāpuku fisheries were passed down through generations, and the best locations were thought to be far off-shore. Traditionally, the hāpuku was thought to be able to tell when its name was being used, so the name was used in its place during fishing expeditions.

Modern consumption

In the 1940s, a fishing industry developed around hāpuku in New Zealand. The meat was canned, and oil was extracted from the liver of the fish. In the 21st century, hāpuku are a highly rated eating fish, reaching top value on both the local and international markets. Chefs who have tasted farmed hāpuku have stated that it outperforms wild-caught hāpuku. In New Zealand for the year of 2008, hāpuku had a commercial value of NZ$37 million with an export value of $4.29 million at a price of $10.29 per kg. Hāpuku is fished both commercially and recreationally in New Zealand. It is highly sought after, but catches are relatively low; this species is managed in the New Zealand Quota Management System (QMS). Currently, no size restriction in New Zealand is in place, but a bag limit of five fish per day exists.Ministry of Fisheries
"Fish Identification – Hapuku (Groper)"
''Ministry of Fisheries'', 2009. Retrieved September 12, 2010.

Aquaculture

Significant interest has been expressed globally for development of this species for

aquaculture Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. Nelu ...

. In Europe, a very similar species of wreckfish is highly prized and considered a local delicacy. Because of this, the ''Polyprion'' spp. have been overfished in most areas. In New Zealand, the National Institute of Water and Atmospheric Research (NIWA) have embraced hāpuku as an opportunity for New Zealand to expand, and have identified markets for this species locally in New Zealand and Australia, and internationally in Europe and Asia.National Institute of Water and Atmospheric Research
"Hapuku"
''National Institute of Water and Atmospheric Research'', n.d. Retrieved September 12, 2010.

Research and development

Since 2003, NIWA has accumulated the world's largest broodstock resource for hāpuku, and these broodstocks are held in large spawning tanks at Bream Bay Aquaculture Park. Each tank has its own controlled environment which is designed to maintain the optimum temperature and light for natural

spawning Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...

. NIWA have now progressed through every aspect of

hatchery A hatchery is a facility where eggs are hatched under artificial conditions, especially those of fish, poultry or even turtles. It may be used for ''ex situ'' conservation purposes, i.e. to breed rare or endangered species under controlled ...

technology development for hapuku. The complications encountered in this process were similar to those of other commercialised

finfish Fishery can mean either the Big business, enterprise of Animal husbandry#Aquaculture, raising or Fishing, harvesting fish and other aquatic life or, more commonly, the site where such enterprise takes place (wikt:AKA, a.k.a., fishing grounds). ...

species, such as

halibut Halibut is the common name for three species of flatfish in the family of right-eye flounders. In some regions, and less commonly, other species of large flatfish are also referred to as halibut. The word is derived from ''haly'' (holy) and ...

turbot The turbot ( ) ''Scophthalmus maximus'' is a relatively large species of flatfish in the family Scophthalmidae. It is a demersal fish native to marine or brackish waters of the Northeast Atlantic, Baltic Sea and the Mediterranean Sea. It is a ...

, sea bass, and

sea bream Sparidae is a family of ray-finned fishes belonging to the order Spariformes, the seabreams and porgies, although they were traditionally classified in the order Perciformes. The over 150 species are found in shallow and deep marine waters in te ...

. These complications were overcome with specific solutions developed for the early rearing of hapuku. The main technical complications that have been overcome are: * The system design for the successful incubation of egg and yolk-sac

larvae A larva (; : larvae ) is a distinct juvenile form many animals undergo before metamorphosis into their next life stage. Animals with indirect developmental biology, development such as insects, some arachnids, amphibians, or cnidarians typical ...

. * Initiation of first feeding. * The transition from live feed to formulated feeds to produce weaned juveniles ready for on-growing and transfer to sea cages. Currently, the sea cage trials and tank trials are base-lining the performance for hāpuku. These early on-growing trials and results are revealing considerable growth potential in aquaculture for this species. NIWA has been running a broodstock selection programme since 2007, and the results are showing which broodstock are producing the surviving first generation. With this information, it will soon be possible to start selecting desirable performance traits for the breeding programme. NIWA's aim is to maintain the competitive edge for hāpuku farming as it increases, and become an important species for New Zealand's aquaculture sector.