Editing Blue cod (section)

==Life cycle/phenology==

===Spawning and Hatching===
Multiple [[Spawn (biology)|spawning]] events of a female ''P. colias'' occur throughout late winter and spring<ref name="AylingCox" /><ref name="PankhurstConroy">{{cite journal | last1=Pankhurst| first1=N.W. | last2=Conroy| first2=A.M.| year=1987| title=Seasonal changes in reproductive condition and plasma levels of sex steroids in the blue cod, ''Parapercis colias'' (Bloch and Schneider) (Mugiloididae). | journal=Fish Physiology and Biochemistry |volume=4 |issue=1 |pages=11–26 |doi=10.1007/BF02073862| pmid=24226034 | bibcode=1987FPBio...4...15P | s2cid=34714507 }}</ref> in the centre to the outer [[continental shelf]].<ref name="Paul.b" />  Instead of a distinct [[Spawn (biology)|spawning]] episode, their [[Spawn (biology)|spawning]] is a continuous event that the eggs are released over time.<ref name="BrandtDunnBrouwer">{{cite journal | last1=Brandt| first1=K.K. | last2=Dunn| first2=M.R.| last3=Brouwer | first3=S.L. | year=2017| title=Assessing maturity, fecundity and hermaphroditism in blue cod ''Parapercis colias''. | journal=Aquatic Biology |volume=26 |pages=137–148 |doi=10.3354/ab00679 | doi-access=free | bibcode=2017AquaB..26..137B }}</ref> One male can be [[Spawn (biology)|spawning]] with different groups of female.<ref name="Hirt-Chabbert" /> Eggs could possibly drift 74&nbsp;km away from the [[Spawn (biology)|spawning]] site and hatch potentially after 116 hours.<ref name="Robertson1980" /> Young fish are found below 20 metres<ref name="Paulin1998" /> then move to shallow water in summer.<ref name="Paul.b" />

===Age, Growth, Sex and Maturity===
Growth of ''P. colias'' is measured by the relationship between age and their body length.<ref name="BeentjesCarbines2012">{{cite journal | last1=Beentjes | first1=M.P. | last2=Carbines | first2=G.D. | year=2012| title=Relative abundance, size and age structure, and stock status of blue cod from the 2010 survey in Marlborough Sounds, and review of historical surveys. | journal=New Zealand Fisheries Assessment Report |volume=43 |issue=137}}</ref> ''P. colias'' are [[protogynous hermaphrodites]],<ref name="Carbines1998'" >{{cite book| last1=Carbines |first1=G.D. |year=1998 |title=Blue cod age validation, tagging feasibility and sex-inversion. Final Research |publisher=Unpublished report, Ministry for Primary Industries}}</ref> when the length of ''P. colias'' reaches 410mm, 50% of the females are transitional.<ref name="Carbines.b">{{cite thesis |last1=Carbines |first1=G.D. |year=2004 |title=Age, growth, movement and reproductive biology of blue cod (''Parapercis colias'' – Pinguipedidae): Implications for fisheries management in the South Island of New Zealand |type=Unpublished Ph.D. thesis |publisher=University of Otago |pages=225 |hdl=10523/8082 |url=http://hdl.handle.net/10523/8082}}</ref> 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.<ref name="AylingCox" /> 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.<ref name="BeentjesCarbines" /> Studies have shown that the proportion of sex change decreases afterwards<ref name="Carbines.b" /> as the presence of males in the [[population]] would discourage sex change.<ref name="BeentjesCarbines" /> Hence, it is regarded as a response to the [[demography|demographic]] structure in the [[population]] instead of a response to their size.<ref name="BeentjesCarbines" /> Another study indicated that blue cod is most [[fecundity|fecund]] 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.<ref name="BrandtDunnBrouwer" /> Sex change is also not well described that the transitional [[gonads]] has different definitions.<ref name="BrandtDunnBrouwer" />

Their growth rate can differ due to food supply, water temperature and habitat as other fish do.<ref name="Paul.b" /> Sex can also influence the growth rate. Male grow faster and larger than female.<ref name="Carbines2004.a" >{{cite journal | last1=Carbines |first1=G.D. | year=2004 | title=Age determination, validation, and growth of blue cod ''Parapercis colias'', in Foveaux Strait, New Zealand | journal=New Zealand Journal of Marine and Freshwater Research | volume=38 |issue=2 |pages=201–214|doi=10.1080/00288330.2004.9517231|s2cid=84616975 |doi-access=free |bibcode=2004NZJMF..38..201C }}</ref><ref name="Paul.b" /> ''P. colias'' have the potential to grow up to 50&nbsp;cm in length and weight 4&nbsp;kg.<ref name="Ayling1987" >{{cite book| last1=Ayling |first1=T. |last2=Cox |first2=G.J. |year=1987 |title=Collins guide to the sea fishes of New Zealand (Revised edition).| publisher=William Collins Publishers Ltd.|pages=343}}</ref>  Growth ring interpretation shows that they can live about 10 to 15 years,<ref name="Paul.b" /> but a study showed that the known maximum age of blue cod is 23 years old.<ref name="RodgersWing">{{cite journal | last1=Rodgers | first1=K.L. | last2=Wing | first2=S.R. | year=2008| title=Spatial structure movement of blue cod ''Parapercis Colias'' in Doubtful Sound, New Zealand, inferred from δ<sup>13</sup>C and δ<sup>15</sup>N | journal=Marine Ecology Progress Series |volume=359 |pages=239–248 |doi=10.3354/meps07349| bibcode=2008MEPS..359..239R | doi-access=free }}</ref>

[[Sexual maturity|Maturity]] values are derived from the length of the fish.<ref name="BeentjesCarbines2012" />  Their growth rate varies between locations.<ref name="Mutch" /><ref name="Smith" /> For example, male can reach maturity when their length reached 10–19&nbsp;cm (which is about 2–3 years old) in Northland, but in Southland the male needs to reach 26–28&nbsp;cm (which is about 4–6 years old).<ref name="Smith">{{cite book | last1=Smith | first1=H.M. | year=2012 | title=Characterisation of the mitochondrial genome and the phylogeographic structure of blue cod (Parapercis colias).| url=http://researcharchive.vuw.ac.nz/xmlui/bitstream/handle/10063/2139/thesis.pdf?sequence=2}}</ref> Besides, males generally have a faster growth rate compared to females.<ref name="Carbines2004.a" /><ref name="Mutch" /><ref name="Paul.b" />  Both female and male ''P. colias'' are assumed to reach sexual maturity with the measuring of 28&nbsp;cm.<ref name="Carbines.b" />  The maximum [[life expectancy|lifespan]] of ''P. colias'' is 32 years.<ref name="MPI2014" />

===Behaviours===
Similar to other ''[[Parapercis]]'' species, male ''P. colias'' hold [[territory (animal)|territories]] and their [[home range]] increases as the individual grows.<ref name="Mutch" />  Mutch found that they tend to hold large territories rather than but loose territories with small social groups that contain three to five females.<ref name="Govier" />  Though they hold stable [[territory (animal)|territories]], ''P. colias'' moves from time to time.  In a study,<ref name="Carbine1998" /> ''P. colias'' can move with on average of 2.09±2.12&nbsp;km, this could potentially be [[home range]] shifts.<ref name="RodgersWing" />  It is reported<ref name="Stroud" /> that ''P. colias'' emigrate from coastal to offshore waters in May of each year, this is thought to be a preparation for mating and [[spawn (biology)|spawning]] in early winter.

[[Thunder]] is known to agitate the fish. Reports since the 1950s have documented thunder activating blue cod's flight mechanisms, causing the fish to leap out of aquariums.<ref name="Secrets"/>

===Migration===
''P. colias'' seem to be migratory at certain times in a year,<ref name="Paul.b" /> but little is known about their [[Migration (ecology)|migration]]. Other studies indicated that they are relatively sedentary,<ref name="ColeVilloutaDavidson">{{cite journal | last1=Cole |first1=R.G. | last2=Villouta | first2=E. | last3=Davidson | first3=R.J. | year=2000 | title=Direct evidence of limited dispersal of the reef fish ''Parapercis colias'' (Pinguipedidae) within a marine reserve and adjacent fished areas. | journal=Aquatic Conservation: Marine and Freshwater Ecosystems | volume=10 |issue=6 |pages=421–436 | doi=10.1002/1099-0755(200011/12)10:6<421::AID-AQC423>3.0.CO;2-E}}</ref><ref name="MaceJohnston">{{cite journal | last1=Mace |first1=J.T. | last2=Johnston | first2=A.D. | year=1983 | title=Tagging experiments on blue cod (Parapercis colias) in the Marlborough Sounds, New Zealand. | journal=New Zealand Journal of Marine and Freshwater Research | volume=17 |issue=3 |pages=207–211 | doi=10.1080/00288330.1983.9515998| doi-access=free |bibcode=1983NZJMF..17..207M }}</ref><ref name="RodgersWing" /> however, long-term [[biological dispersal|dispersal]] has been suggested due to a record that one individual travelled 156&nbsp;km over 20 months.<ref name="CarbinesMcKenzie">{{cite book | last1=Carbines | first1=G.D. | last2=McKenzie | first2=J. | year=2004 | title=Movement patterns and stock mixing of blue cod in Dusky Sound in 2002.| publisher=New Zealand Fisheries Assessment Report 2004/36}}</ref>