How are Babies Made?

Atlantic cod Reproduction

 

Cod can reach sexual maturity anywhere between 2 and 7 years.  The females mature at the ladder end of that range, usually maturing around 5-6 years with the males reaching sexual maturity around 2 or 4 years.  Atlantic cod are also very fertile fish with their fecundity increasing as the fish matures and grows.  They can lay anywhere from 3 to 9 million eggs during their spawning season, which usually runs from early winter to early spring.  The most active area of spawning occurs off the coast of New England in water depths from 30 to 350 feet with temperatures varying from 36 to 39 degrees F.  The eggs are fertilized externally by the males on the ocean floor.  The eggs will hatch 2 to 4 weeks after fertilization, and larvae measuring less than a quarter of an inch will emerge.  However, mortality is extremely high in the cod hatch, and nearly all of the eggs and larvae will die within the first 3 months of life.  Fortunately, a healthy population can be sustained by having only 2 fish per hatch surviving to maturity. 

 

Did you know:  The Atlantic cod has natural enzymes in its body that act as a kind of anti-freeze, allowing them to live in freezing water temperatures.           

 

    Young Atlantic Cod                                                                      Fingerling Cod

 

 

Nicholas Bortz

UW - La Crosse