Editing Cod (section)

==Life cycle==
Spawning of northeastern Atlantic cod occurs between January and April (March and April are the peak months), at a depth of {{convert|200|m|ft}} in specific spawning grounds at water temperatures between {{convert|4|and|6|C|F}}. Around the UK, the major spawning grounds are in the middle to southern North Sea, the start of the [[Bristol Channel]] (north of [[Newquay]]), the [[North Channel (Great Britain and Ireland)|Irish Channel]] (both east and west of the [[Isle of Man]]), around [[Stornoway]], and east of [[Helmsdale]].

Prespawning courtship involves fin displays and male grunting, which leads to pairing.<ref>{{cite journal | last1 = Brawn | first1 = V.M. | year = 1961 | title = Reproductive behaviour of the cod ''(Gadus callarias L.)'' | jstor = 4532991 | journal = Behaviour | volume = 18 | issue = 3| pages = 177–197 | doi=10.1163/156853961x00114}}</ref> The male inverts himself beneath the female, and the pair swim in circles while spawning. The eggs are planktonic and hatch between eight and 23 days, with larva reaching {{convert|4|mm|in|frac=32|abbr=off}} in length. This planktonic phase lasts some ten weeks, enabling the young cod to increase its body weight by 40-fold, and growing to about {{convert|2|cm|in|frac=4|abbr=on}}. The young cod then move to the seabed and change their diet to small [[benthic]] [[crustaceans]], such as [[isopods]] and small crabs. They increase in size to {{convert|8|cm|in|0|abbr=on}} in the first six months, {{convert|14|-|18|cm|in|frac=2|abbr=on}} by the end of their first year, and to {{convert|25|-|35|cm|in|frac=2|abbr=on}} by the end of the second. Growth tends to be less at higher latitudes. Cod reach maturity at about {{convert|50|cm|in|0|abbr=on}} at about 3 to 4 years of age. Changes in growth rate over decades of particular stocks have been reported, current eastern Baltic cod shows the lowest growth observed since 1955.<ref>{{Cite journal|last1=Mion|first1=Monica|last2=Haase|first2=Stefanie|last3=Hemmer-Hansen|first3=Jakob|last4=Hilvarsson|first4=Annelie|last5=Hüssy|first5=Karin|last6=Krüger-Johnsen|first6=Maria|last7=Krumme|first7=Uwe|last8=McQueen|first8=Kate|last9=Plikshs|first9=Maris|last10=Radtke|first10=Krzysztof|last11=Schade|first11=Franziska Maria|date=March 2021|title=Multidecadal changes in fish growth rates estimated from tagging data: A case study from the Eastern Baltic cod ( Gadus morhua, Gadidae )|url=https://onlinelibrary.wiley.com/doi/10.1111/faf.12527|journal=Fish and Fisheries|language=en|volume=22|issue=2|pages=413–427|doi=10.1111/faf.12527|bibcode= |hdl=11585/809386 |s2cid=233795252|issn=1467-2960|access-date=21 November 2021|archive-date=21 November 2021|archive-url=https://web.archive.org/web/20211121131356/https://onlinelibrary.wiley.com/doi/10.1111/faf.12527|url-status=live|hdl-access=free}}</ref>