The New Zealand blue cod (''Parapercis colias'') is a temperate marine fish of the

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

Pinguipedidae The sandperches are a family, Pinguipedidae, of fishes in the percomorph order Trachiniformes. Sandperches are benthic fish which normally occur over sand or rubble substrates in shallow seas. They are found off the coasts of South America, ...

. It is also known variously as Boston blue cod, New Zealand cod, sand perch, or its

Māori Māori or Maori can refer to: Relating to the Māori people * Māori people of New Zealand, or members of that group * Māori language, the language of the Māori people of New Zealand * Māori culture * Cook Islanders, the Māori people of the C ...

names rāwaru, pākirikiri and patutuki. It is exclusively found in

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 count ...

in shallow waters around the rocky coasts to a depth of 150 m, though it is far more common south of

Cook Strait Cook Strait ( mi, Te Moana-o-Raukawa) separates the North and South Islands of New Zealand. The strait connects the Tasman Sea on the northwest with the South Pacific Ocean on the southeast. It is wide at its narrowest point,McLintock, A ...

. It is bluish green to blue-black above with white toward the belly. Large examples are usually greenish blue in colour, while smaller ones are blotched in varying shades of brown. An adult may grow to 60 cm in length and weigh from 1.0 to 3.0 kg. It feeds mainly on small fish and crabs. Blue cod is territorial. Spawning takes place in southern spring. Blue cod can also change sex from female to male. It is an important recreational species in the South Island and is commercially harvested. Blue cod populations are managed under New Zealand's fisheries quota management system, although they are becoming scarce in some small areas due to fishing pressure. Annual catch range is between 2,000 and 2,500

tonne The tonne ( or ; symbol: t) is a unit of mass equal to 1000 kilograms. It is a non-SI unit accepted for use with SI. It is also referred to as a metric ton to distinguish it from the non-metric units of the short ton ( United State ...

Identification

''Parapercis colias'' are

protogynous hermaphrodites 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, ...

, which means they have both female and male reproductive organs at the beginning and some females change sex to males later in their life. ''P. colias'' is a marine bottom dwelling fish that is found in coastal

waters. Their colouring varies on age and sex. Juveniles start off being generally pale in colour and have two long dark stripes along the sides which will turn brown and barely distinguishable when they become middle-sized fish. As they mature with a body length over 25 cm, both sexes would have a blueish-grey

dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

with a white underside. Females have a tinge of orange and there is a trend for them to become green when they grow larger. Brownish

pigment A pigment is a colored material that is completely or nearly insoluble in water. In contrast, dyes are typically soluble, at least at some stage in their use. Generally dyes are often organic compounds whereas pigments are often inorganic compou ...

s can be found at the base of

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 ...

. On the other hand, adult males have distinctive blue-grey colour coat with greenish sides and a golden brown line can be found above each eye. Body length of ''P. colias'' is about 30–40 cm in general, but can up to 60 cm and their weight is 0.8–1.5 kg in general, but can up to 3 kg. Males tend to be larger than females. They can live up to 32 years old. Heads of ''P. colias'' are prominent and rounded with scales. They have a plump shaped body covered with firm scales. Above their non expanded cheeks are two large lateral eyes which can rotate independently, this allows them to see almost everywhere around them. ''P. colias'' possess a terminal mouth with bulbous lips. Their pelvic fins are generally placed forward on the throat with brown dots appear underneath it. There is a single horizontal stripe where ten to twelve scales above across their side of the body. The anterior section of their

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 c ...

is small and short, followed by fins with five short spines. In contrast their second

is long. A key used in an article of Cantwell can distinguish ''P. colias'' from other parapercids. Key features are listed below: Parapercis colias Blue Cod Closeup

*The outer row of lower jaw has eight teeth *

Dorsal Dorsal (from Latin ''dorsum'' ‘back’) may refer to: * Dorsal (anatomy), an anatomical term of location referring to the back or upper side of an organism or parts of an organism * Dorsal, positioned on top of an aircraft's fuselage * Dorsal c ...

spines longer to the posterior (rear end) *Soft

s have 20

rays Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science and mathematics * Ray (geometry), half of a line proceeding from an initial point * Ray (gra ...

and anal fins with 17 *10 to 11 scales are present from lateral line to base of first soft

ray *23 to 26 counts of

gill raker Gill rakers in fish are bony or cartilaginous processes that project from the branchial arch (gill arch) and are involved with suspension feeding tiny prey. They are not to be confused with the gill filaments that compose the fleshy part of the ...

s * Caudal (tail) fins have 15 branched

that looks rounded but bi-lobed. Other characters of detailed skeleton structures (osteology) of '' Parapercis'' species can be found in an article written by Gosline. Swimming bladder is usually present in osteichthyids, it helps the fish to stay at a certain water pressure level (depth) without spending more energy. Swimming bladder in ''P. colias'' are absent. They will automatically sink to the sea floor if they stop swimming; therefore, they are called bottom-dwelling or sedentary bottom-hugging species. Their body shape of having a flattened abdomen indicates this as well. Normally, ''P. colias'' use their

to swim, their body muscles and tails fin are only involved in swimming when a sudden burst or speed is needed, this type of swimming character is called labriform. As a result, their pelvic fins, used as props when they are resting on the seabed, are reduced and thicken. Due to their nature of being bottom-dwelling species, sand can clog their gills when they are resting. To remedy this, ''P. colias'' often hold their breath and open their mouths for a long interval like having a yawn to take good gulps of air every now and then. Speaking of having a yawn, if you look closely you will notice that ''P. colias'' do not have palatine teeth and only have small teeth; however, you would not want to feel their sharp and well developed

pharyngeal teeth Pharyngeal teeth are teeth in the pharyngeal arch of the throat of cyprinids, suckers, and a number of other fish species otherwise lacking teeth. There are some other detailed morphological characteristics inside the body of ''P. colias'' that determine their taxonomy, such as the presence of a lentiform body (an

ocular Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and con ...

vascular The blood vessels are the components of the circulatory system that transport blood throughout the human body. These vessels transport blood cells, nutrients, and oxygen to the tissues of the body. They also take waste and carbon dioxide away f ...

structure) and others, are mentioned by Eastman.

Distribution

Natural global range

Pinguipedid fishes (

Sandperch The sandperches are a family, Pinguipedidae, of fishes in the percomorph order Trachiniformes. Sandperches are benthic fish which normally occur over sand or rubble substrates in shallow seas. They are found off the coasts of South America, So ...

es) are widely found in the southern Atlantic and Indo-Pacific regions. However, ''P. colias'' 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 else ...

New Zealand range

''P.colias'' is found from the shore to the shelf edge around New Zealand's entire coastline, but there are no records in either the

Kermadec Islands The Kermadec Islands ( mi, Rangitāhua) are a subtropical island arc in the South Pacific Ocean northeast of New Zealand's North Island, and a similar distance southwest of Tonga. The islands are part of New Zealand. They are in total ar ...

or the Snares Islands / Tini Heke. They are more abundant from south of

and they are an iconic species for the South Island. They are most common around

Southland Southland may refer to: Places Canada * Dunbar–Southlands, Vancouver, British Columbia New Zealand * Southland Region, a region of New Zealand * Southland County, a former New Zealand county * Southland District, part of the wider Southland Re ...

and the

Chatham Islands The Chatham Islands ( ) (Moriori: ''Rēkohu'', 'Misty Sun'; mi, Wharekauri) are an archipelago in the Pacific Ocean about east of New Zealand's South Island. They are administered as part of New Zealand. The archipelago consists of about te ...

Habitat preferences

''P. colias'' can be found at 150 m in depth occupying bedrock outcrops on gravel or sandy seabed. These habitats with macro algae or Sponges are even more preferred. Furthermore, their abundance in each habitat varies between age. Juvenile are found more frequently in sponge gardens (more than 16m deep) dominated by orange finger sponges ('' Raspalia topsenti'' & '' Raspalia flaccida''), large black massive sponge (''

Ancorina ''Ancorina'' is a genus of sea sponges belonging to the family Ancorinidae. It is the type genus of its family. This genus is characterized by a high density of siliceous spicules. Members of this genus are known to be eaten by hawksbill turtle ...

alata'') and the small bright yellow clumps of '' Polymastia granulosa'' that provide more shelters and safer refuges, whereas adults are mainly found on reef margins and deeper areas. Since ''P. colias'' are generalists, which means that they prey on various species instead of depending on only one species, habitats that are rich in

diversity Diversity, diversify, or diverse may refer to: Business *Diversity (business), the inclusion of people of different identities (ethnicity, gender, age) in the workforce *Diversity marketing, marketing communication targeting diverse customers * ...

of species are also favoured by them. An example of this is the

kelp forest Kelp forests are underwater areas with a high density of kelp, which covers a large part of the world's coastlines. Smaller areas of anchored kelp are called kelp beds. They are recognized as one of the most productive and dynamic ecosystems on Ea ...

which is often established on rock beds where it is also desirable for ''P. colias''. However, they can be also found in less species diverse habitats such as barren rock flats (4-12m deep) that are dominated by sea urchins grazing on algae. As mentioned before, ''P. colias'' can be found at 150 m in depth and was reported to be caught at 350m below the surface, other important aspects such as temperature, salinity and oxygen content in the ocean are often influenced by water depth. 766 samples were taken to determine the water temperature and chemistry ranges of ''P. colias'' as listed below: :

Life cycle/phenology

Spawning and Hatching

Multiple

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 aquat ...

events of a female ''P. colias'' occur throughout late winter and spring in the centre to the outer continental shelf. Instead of a distinct

episode, their

is a continuous event that the eggs are released over time. One male can be

with different groups of female. Eggs could possibly drift 74 km away from the

site and hatch potentially after 116 hours. Young fish are found below 20 metres then move to shallow water in summer.

Age, Growth, Sex and Maturity

Growth of ''P. colias'' is measured by the relationship between age and their body length. ''P. colias'' are

, when the length of ''P. colias'' reaches 410mm, 50% of the females are transitional. Sex inversion occurs with the colour change from whitish with a brown band at both sides or an orange tinge to bluish colour with a blue green band. Though sex inversion found to occur across a wide range of age and size, the cause of activating the sex inversion has not been well understood. Studies have shown that the proportion of sex change decreases afterwards as the presence of males in the

population Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a ...

would discourage sex change. Hence, it is regarded as a response to the demographic structure in the

instead of a response to their size. Another study indicated that blue cod is most

fecund Fecundity is defined in two ways; in human demography, it is the potential for reproduction of a recorded population as opposed to a sole organism, while in population biology, it is considered similar to fertility, the natural capability to pr ...

at the size which closes to the average size of the first maturity of males. It has been regarded as a sign of potential sex change by reducing egg production for saving the resource. Sex change is also not well described that the transitional

gonads A gonad, sex gland, or reproductive gland is a mixed gland that produces the gametes and sex hormones of an organism. Female reproductive cells are egg cells, and male reproductive cells are sperm. The male gonad, the testicle, produces sper ...

has different definitions. Their growth rate can differ due to food supply, water temperature and habitat as other fish do. Sex can also influence the growth rate. Male grow faster and larger than female. ''P. colias'' have the potential to grow up to 50 cm in length and weight 4 kg. Growth ring interpretation shows that they can live about 10 to 15 years, but a study showed that the known maximum age of blue cod is 23 years old. Maturity values are derived from the length of the fish. Their growth rate varies between locations. For example, male can reach maturity when their length reached 10–19 cm (which is about 2–3 years old) in Northland, but in Southland the male needs to reach 26–28 cm (which is about 4–6 years old). Besides, males generally have a faster growth rate compared to females. Both female and male ''P. colias'' are assumed to reach sexual maturity with the measuring of 28 cm. The maximum lifespan of ''P. colias'' is 32 years.

Behaviours

Similar to other '' Parapercis'' species, male ''P. colias'' hold

territories A territory is an area of land, sea, or space, particularly belonging or connected to a country, person, or animal. In international politics, a territory is usually either the total area from which a state may extract power resources or a ...

and their

home range A home range is the area in which an animal lives and moves on a periodic basis. It is related to the concept of an animal's territory which is the area that is actively defended. The concept of a home range was introduced by W. H. Burt in 1943. He ...

increases as the individual grows. Mutch found that they tend to hold large territories rather than but loose territories with small social groups that contain three to five females. Though they hold stable

, ''P. colias'' moves from time to time. In a study, ''P. colias'' can move with on average of 2.09±2.12 km, this could potentially be

shifts. It is reported that ''P. colias'' emigrate from coastal to offshore waters in May of each year, this is thought to be a preparation for mating and

in early winter.

Migration

''P. colias'' seem to be migratory at certain times in a year, but little is known about their

migration Migration, migratory, or migrate may refer to: Human migration * Human migration, physical movement by humans from one region to another ** International migration, when peoples cross state boundaries and stay in the host state for some minimum le ...

. Other studies indicated that they are relatively sedentary, however, long-term dispersal has been suggested due to a record that one individual travelled 156 km over 20 months.

Diet and foraging

Many fish species are generalists; thus, they are not limited by the predator-prey cycle. ''P. colias'' is one of them. They have been recorded to have 52

taxa In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

in their diet, where adults are found to be more selective than juveniles. It makes sense that when ''P. colias'' grows bigger, the variety of species in their diet also increases, this includes

polychaetes Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made ...

crustaceans 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 gro ...

molluscs Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estim ...

Pisces Pisces may refer to: * Pisces, an obsolete (because of land vertebrates) taxonomic superclass including all fish * Pisces (astrology), an astrological sign * Pisces (constellation), a constellation **Pisces Overdensity, an overdensity of stars in ...

, algae and even its own spawn! This means that ''P. colias'' are

omnivores An omnivore () is an animal that has the ability to eat and survive on both plant and animal matter. Obtaining energy and nutrients from plant and animal matter, omnivores digest carbohydrates, protein, fat, and fiber, and metabolize the nut ...

which "feeds on more one

trophic level The trophic level of an organism is the position it occupies in a food web. A food chain is a succession of organisms that eat other organisms and may, in turn, be eaten themselves. The trophic level of an organism is the number of steps it ...

". In short, you can say that they consume anything that is abundant and available locally. Other than the development of the fish itself, what they consume differs from region to region and whether the area is fished or not plays an important role as well. One study showed that oyster dredged habitat can reduce their prey diversity and have a negative effect on fish size. They usually stalk, seize and swallow their prey. After being caught, they tend to regurgitate the stomach contents. ‘Our Big Blue Backyard’ is a documentary of

marine and shoreline species. In the

episode, blue cod (''P. colias'') waits to feed on pāua, an

sea-snail that attaches itself on hard surfaces such as rocks, at its most vulnerable phases – when they move or are grasped up by a starfish using hundreds of

tube feet Tube feet (technically podia) are small active tubular projections on the oral face of an echinoderm, whether the arms of a starfish, or the undersides of sea urchins, sand dollars and sea cucumbers; they are more discreet though present on br ...

. They are also said to be voracious.

Predators, parasites, and diseases

Predators

Homo sapiens Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

'' (humans) fish 2000 to 2500 tons of ''P. colias'' annually. Natural predators include: *

Great white shark The great white shark (''Carcharodon carcharias''), also known as the white shark, white pointer, or simply great white, is a species of large Lamniformes, mackerel shark which can be found in the coastal surface waters of all the major ocean ...

* Benthic feeders, such as: **

Yellow-eyed penguin The yellow-eyed penguin (''Megadyptes antipodes''), known also as hoiho or tarakaka, is a species of penguin endemic to New Zealand. Previously thought closely related to the little penguin (''Eudyptula minor''), molecular research has shown it ...

s **

Dolphins A dolphin is an aquatic mammal within the infraorder Cetacea. Dolphin species belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (t ...

* Sea birds, such as

mollymawk The mollymawks are a group of medium-sized albatrosses that form the genus ''Thalassarche''. The name has sometimes been used for the genus ''Phoebetria'' as well, but these are usually called sooty albatrosses. They are restricted to the Sout ...

s As many marine predators are generalists there are many other potential predators not listed. ''P. colias'' are known to predate upon juveniles of their own species.

Parasites

Hewitt and Hine summarised the parasites found on blue cod including species in five main groups: Blood sucking

sea lice Sea lice (singular: sea louse) are copepods (small crustaceans) of the family Caligidae within the order Siphonostomatoida. They are marine ectoparasites (external parasites) that feed on the mucus, epidermal tissue, and blood of host fish. The ...

are also known to parasitise ''P. colias''.

Disease and Injuries

No specific

disease A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that a ...

is found on ''P. colias'', but some

injuries An injury is any physiological damage to living tissue caused by immediate physical stress. An injury can occur intentionally or unintentionally and may be caused by blunt trauma, penetrating trauma, burning, toxic exposure, asphyxiation, or o ...

have been recorded. Hooking injuries could cause tissue damage and possibly lead to mortality. Despite having greater risk for

parasitic Parasitism is a close relationship between species, where one organism, the parasite, lives on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The entomologist E. O. Wilson ha ...

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...

l, or

fungal A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from th ...

infections, mortality after having a hook injury is often caused by blood loss rather than disease. An article suggests that small hooks cause more blood loss problems than big hooks to ''P. colias''. Compared to other bony fish, swimming bladder in ''P. colias'' is absent, this means that they do not suffer from

barotrauma Barotrauma is physical damage to body tissues caused by a difference in pressure between a gas space inside, or contact with, the body and the surrounding gas or liquid. The initial damage is usually due to over-stretching the tissues in tens ...

– an injury due expansion or eruption of the swimming bladder in fish, it is often caused by rapid water pressure change when rising from deep water to water surface.

Cultural uses

Heads of rāwaru (''P. colias'', blue cod) were often given back to the sea as offerings to the god Maru before

return from fishing.

History of the name

Blue cod (''P. colias'') is not a cod. The use of blue cod can date back to the time of

Captain Cook James Cook (7 November 1728 Old Style date: 27 October – 14 February 1779) was a British explorer, navigator, cartographer, and captain in the British Royal Navy, famous for his three voyages between 1768 and 1779 in the Pacific Ocean and ...

. Some early writers listed them as coal-fish which derived from unrelated European fish. However, this name is so widely used in

that it is unlikely to be changed.

Economic and population management issue

Blue cod is well known by the public due to its commercial and recreational importance. As mentioned before, we fish 2000 to 2500 tones of ''P. colias'' per year. The value of ''P. colias'' as being the third popular recreational fishing species cannot be ignored, this includes using their flesh as rock lobster bait. It is estimated that the marginal willingness to pay for an additional ''P. colias'' is $1.61 per fish and the average willingness to pay is $24.46 per fish. It is estimated that in 1999, 1.2 million ''P. colias'' was harvested, of which 70% were from the South Island. Thus,

Ministry for Primary Industries (New Zealand) , logo = MPINZ-logo.svg , logo_width = , logo_caption = , picture = , picture_width = , picture_caption = , formed = , preceding1 = Ministry of Agriculture and Forestry , preced ...

has set minimum capture length and maximum capture limit of ''P. colias'', which varies between areas mainly depending on abundance, to avoid depletion. For example, in the South-East area (of South Island from Clarence Point to

and extended to the

), no fish shorter than 30 cm can be taken and each fisher has a limit up to 30 fish per day. To achieve

sustainable fishing A conventional idea of a sustainable fishery is that it is one that is harvested at a sustainable rate, where the fish population does not decline over time because of fishing practices. Sustainability in fisheries combines theoretical discipli ...

, it is crucial to persist healthy

structure with continuous monitoring and quotas set to date. However, as the largest fish in the

would be the male, males are often being caught and is thought to affect the females changing their sex earlier. This is an emerging issue to all hermaphrodites. Surprisingly, the sex ratio male to females of ''P. colias'' is about 5:1 which is biologically implausible. This suggests that sex changes might not purely depend on fish length, but we cannot ignore the fact that fishery has changed the natural population composition of "P. colias". To understand the direct impact on P. colias despite population decline further research is required. In addition, the fundamental unit of concern of its management of

is the genetic structure that can lead to the reduction of the evolutionary potential for responding to

environmental change Environmental change is a change or disturbance of the environment most often caused by human influences and natural ecological processes. Environmental changes include various factors, such as natural disasters, human interferences, or animal in ...

, the increase of

inbreeding Inbreeding is the production of offspring from the mating or breeding of individuals or organisms that are closely related genetically. By analogy, the term is used in human reproduction, but more commonly refers to the genetic disorders and o ...

risk and the force of selective genetic change. Since a number of evidence indicated that blue cod are relatively sedentary, the

fishing pressure Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in t ...

may lead to potential local depletion. Recent studies showed that the genetic differences were significant between mainland

List of islands of New Zealand New Zealand consists of more than six hundred islands, mainly remnants of a larger land mass now beneath the sea. New Zealand is the seventh-largest island nation on earth, and the third-largest located entirely in the Southern Hemisphere. Th ...

and

Chatham Island Chatham Island ( ) (Moriori: ''Rēkohu'', 'Misty Sun'; mi, Wharekauri) is by far the largest island of the Chatham Islands group, in the south Pacific Ocean off the eastern coast of New Zealand's South Island. It is said to be "halfway bet ...

. On the other hand, the differences within mainland

s were limited while the pattern of the isolation by distance was detected. Further research using microsatellite DNA markers suggested that some significant genetic differences between

mainland Mainland is defined as "relating to or forming the main part of a country or continent, not including the islands around it egardless of status under territorial jurisdiction by an entity" The term is often politically, economically and/or dem ...

exist which indicate the potential long-distance dispersal, but the dispersal rate is too low to have demographic effect in the

References

* *

External links

Blue Cod Fishing and a link to the Blue Cod Fishing Regulations
Ministry of Fisheries. {{DEFAULTSORT:cod, blue

blue cod The New Zealand blue cod (''Parapercis colias'') is a temperate marine fish of the family Pinguipedidae. It is also known variously as Boston blue cod, New Zealand cod, sand perch, or its Māori names rāwaru, pākirikiri and patutuki. It is ...

Endemic marine fish of New Zealand Commercial fish

Taxa named by Johann Reinhold Forster