All three of these forms are found in the North Sea. These fish are migratory, moving into fresh water to spawn during the spring. When the spring thunder storms occur huge masses of sticklebacks can be seen gathering in the mouth of low land rivers to begin a massive upstream migration. This is especially prevalent in Germany. During this time the temperatures are higher and the day light hours increase causing the germ cells to accelerate in development toward maturity.
Sexual maturity is reached during the upstream migration for both male and female sticklebacks.
The females retain their coloration while the males take on a bright display of color with the throat and breast taking on a cherry red hue and the back acquiring a bright blue or deep green coloration. When the migration site is reached spawning takes place in sandy ground in shallow waters. Inc. PageWise makes no representations about the content published on this site. PageWise hereby disclaims all warranties and conditions with regard to this information, and user agrees that all such use is at its own risk. If you are under 18, please do NOT opt-in to receive email offers on this page.