How do you tell the gender of a common goldfish?

Answer:
The males can only be identified in breeding season (spring) when they develop white spots on their gill plates and pectoral fins. The females simply get a bit chubbier around the middle area where their eggs are situated internally
First answer by EddyJ. Last edit by EddyJ. Contributor trust: 132 [recommend contributor recommended]. Question popularity: 2 [recommend question].