A study in the Hauraki Gulf found sand flounder lay between 100,000 and 500,000 eggs when spawning. The variation in the number of eggs laid was attributed to the difference in size of the female laying the eggs.
A study in the Hauraki Gulf revealed that sand flounder spawn with a range of 100,000 to 500,000 eggs, which is influenced by the size difference among the females producing them.