Editing Blue cod (section)

== Habitat preferences ==
[[File:Blue Cod in Milford Sound.jpg|thumb|Blue cod in [[Milford Sound]] on a bedrock outcrop]]

''P. colias'' can be found at 150 m in depth<ref name="Carbine1998" /><ref name="Hirt-Chabbert">{{cite book| last1=Hirt-Chabbert| first1=J. | year=2006| title=Fish species of New Zealand: a photographic guide. |publisher=Reed books.}}</ref><ref name="Paul.b" /> occupying bedrock outcrops on gravel<ref name="AylingCox">{{cite book| last1=Ayling| first1=T. | last2=Cox |first2=G.J. | year=1982| title=Collins guide to the sea fishes of New Zealand. |publisher=Collins.}}</ref><ref name="Graham" /><ref name="Paul.a">{{cite book| last1=Paul| first1=L.J. | year=1997| title=Marine Fishes of New Zealand 1: Shoreline and Shallow Seas. |volume=1 |publisher=Reed.}}</ref><ref name="Paulin1998">{{cite book| last1=Paulin| first1=C.D. | year=1998| title=Common New Zealand marine fishes. |publisher=Reed.}}</ref> or sandy seabed.<ref name="BeentjesCarbines">{{cite journal | last1=Beentjes | first1=M. | last2=Carbines | first2=G. | year=2005| title=Population structure and relative abundance of blue cod (''Parapercis colias'') off Banks Peninsula and in Dusky Sound, New Zealand. | journal=New Zealand Journal of Marine and Freshwater Research |volume=39 | issue=1 |pages=77–79 |doi=10.1080/00288330.2005.9517293| bibcode=2005NZJMF..39...77B | s2cid=86285680 }}</ref>  These habitats with [[Macroalgae|macro algae]] or [[Sponges]] are even more preferred.<ref name="BeentjesCarbines" />  Furthermore, their abundance in each habitat varies between age.<ref name="Mutch">{{cite book| last1=Mutch | first1=P.G. | year=1983 | title=Factors influencing the density and distribution of the P. colias, ''Parapercis colias''. Pisces: Mugiloidae. }}</ref><ref name="Paul.b" /> 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]] alata'') and the small bright yellow clumps of ''[[Polymastia (sponge)|Polymastia]] granulosa'' that provide more shelters and safer refuges, whereas adults are mainly found on reef margins<ref name="Thompson">{{cite book| last1=Thompson| first1=S.M. | year=1981 | title=Fish of the marine reserve. A guide to the identification and biology of common coastal fish of northeastern New Zealand |publisher=University of Auckland| url=http://www.thebookshelf.auckland.ac.nz/docs/Fish%20of%20the%20marine%20reserve/1%20frontmatterandintroduction.pdf}}</ref> and deeper areas.<ref name="Paul.b" />

Since ''P. colias'' are [[Generalist and specialist species|generalists]],<ref name="JiangCarbine">{{cite journal | last1=Jiang| first1=W. | last2=Carbines | first2=G. | year=2002| title=Diet of blue cod, ''Parapercis colias'', living on undisturbed biogenic reefs and on seabed modified by oyster dredging in Foveaux Strait, New Zealand. | journal=Aquatic Conservation: Marine and Freshwater Ecosystems |volume=12 |issue=3 |pages=257–272 |doi=10.1002/aqc.495| bibcode=2002ACMFE..12..257J }}</ref> which means that they prey on various species instead of depending on only one species, habitats that are rich in [[Biodiversity|diversity]] of species are also favoured by them.  An example of this is the [[kelp forest]] which is often established on rock beds where it is also desirable for ''P. colias''.<ref name="coleaylingcreese">{{cite journal | last1=Cole| first1=R.G. | last2=Ayling| first2=T.M. |last3=Creese |first3=R.G. | year=1990| title=Effects of marine reserve protection at Goat Island, northern New Zealand. | journal=New Zealand Journal of Marine and Freshwater Research |volume=24 |issue=2 |pages=197–210 |doi=10.1080/00288330.1990.9516415| doi-access=free | bibcode=1990NZJMF..24..197C | hdl=2292/4936 | hdl-access=free }}</ref><ref name="FosterS">{{cite book| last1=Foster| first1=M.S. |last2=Schiel |first2=D.R. | year=1985 | title=Ecology of giant kelp forests in California: a community profile |publisher=Moss Landing Marine Labs.}}</ref><ref name="Graham">{{cite book| last1=Graham| first1=D.H. | year=1956 | title=A treasury of New Zealand fishes. |publisher=Reed.}}</ref>  However, they can be also found in less species diverse habitats such as barren rock flats (4-12m deep) that are dominated by [[sea urchin]]s grazing on [[algae]].<ref name="Thompson" />

As mentioned before, ''P. colias'' can be found at 150 m in depth and was reported to be caught at 350m below the surface,<ref name="Carbine1998" /> other important aspects such as temperature, [[salinity]] and oxygen content in the ocean are often influenced by water depth.<ref name="McDowall">{{cite journal | last1=McDowall | first1=R.M. | year=1973| title=Relationships and taxonomy of the New Zealand torrent fish, ''Cheimarrichthys fosteri'' Haast (Pisces: Mugiloididae). | journal=Journal of the Royal Society of New Zealand |volume=3 |issue=2 |pages=199–217 |doi=10.1080/03036758.1973.10430602| doi-access=free | bibcode=1973JRSNZ...3..199M }}</ref> 766 samples were taken to determine the water temperature and chemistry ranges of ''P. colias''<ref name="EoL" >{{cite web |url= http://eol.org/ |title= ''Parapercis colias'' Blue Cod. |author=Encyclopedia of Life. |date= 2018 |access-date=2018-04-15 }}</ref> as listed below:
:{||-
! scope="col" width="width: 1000em;" |
! scope="col" width="width: 20em;" |
! scope="col" width="width: 20em;" |
|-
|Temperature:
|  7.786 - 18.158
|  (°C)
|-
|Nitrate:
|  0.205 - 18.689
|  (μmol/L)
|-
|Salinity:
|  34.283 - 35.544
|  (PPS){{clarify|date=November 2024}}
|-
|Oxygen:
|  5.121 - 6.587
|  (mL/L)
|-
|Phosphate:
|  0.258 - 1.333
|  (μmol/L)
|-
|Silicate:
|  1.911 - 7.690
|  (μmol/L)
|-
|}