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

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring coun ...

Tristan da Cunha Tristan da Cunha (), colloquially Tristan, is a remote group of volcanic islands in the South Atlantic Ocean. It is the most remote inhabited archipelago in the world, lying approximately from Cape Town in South Africa, from Saint Helena ...

and

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island country ...

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 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 ...

and rounded

pectoral 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 ...

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 (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or w ...

, 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 ...

when they are about 50 cm in length. They inhabit

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

and

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

waters of the southern

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by ...

and

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

, being found in

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

, southeastern Australia 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 a paraphyletic group of animals that neither possess nor develop a vertebral column (commonly known as a ''backbone'' or ''spine''), derived from the notochord. This is a grouping including all animals apart from the chorda ...

s and

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, including red cod and blue cod, hoki,

crabs Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting " tail" (abdomen) ( el, βραχύς , translit=brachys = short, / = tail), usually hidden entirely under the thorax. They live in all th ...

and

crayfish Crayfish are freshwater crustaceans belonging to the clade Astacidea, which also contains lobsters. In some locations, they are also known as crawfish, craydids, crawdaddies, crawdads, freshwater lobsters, mountain lobsters, rock lobsters, m ...

.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.

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 might be considered synonymous with adulthood, but here puberty is the name for the process of biological sexual maturation, while adulthood is based on cultural definitio ...

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.

Human consumption

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 The Quota Management System (QMS) is a type of individual fishing quota that is used in New Zealand to manage fish stocks. New Zealand fishing industry Seafood is one of New Zealand's largest export markets, with 85% of catches being exported. Over ...

(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. lot ...

. 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

Polyprion oxygeneios by Frank Edward Clarke

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 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 aqua ...

. 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 co ...

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

finfish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

species, such as

halibut Halibut is the common name for three flatfish in the genera '' Hippoglossus'' and '' Reinhardtius'' from the family of right-eye flounders and, in some regions, and less commonly, other species of large flatfish. The word is derived from '' ...

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 an im ...

, sea bass, and

sea bream The Sparidae are a family of fish in the order Perciformes, commonly called sea breams and porgies. The sheepshead, scup, and red seabream are species in this family. Most sparids are deep-bodied compressed fish with a small mouth separated by ...

. 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 (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. Th ...

. * 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.

References

* * * Tony Ayling & Geoffrey Cox, ''Collins Guide to the Sea Fishes of New Zealand'', (William Collins Publishers Ltd, Auckland, New Zealand 1982) {{Taxonbar, from=Q4929094 Polyprionidae Fauna of Temperate South America Fauna of Tristan da Cunha Marine fish of South Africa Marine fish of Southern Australia Marine fish of New Zealand Fish described in 1801