Goldfish can only be sexed at breeding time when the males develop white spots on their Gill plates and sometimes their Pectoral fins too. The females simply get chubbier as they fill with ova (eggs).
To determine the gender of a Gold Fantail is not as easy as it may seem. Basically though, a male has white dots that look like zits and tend to grow around their gills. Males are also generally big...
The sexual dimorphism of a goldfish can only be observed when the fish are in breeding condition (in Springtime) when the adult males develop white spots on their gill plates and sometimes the...
No fancy goldfish should not be housed with the more common varieties of goldfish because common goldfish are more aggressive and can swim faster which in turn would result in competition over food...
They can only be sexed during breeding season when the males develop white spots on their gill plates and pectoral fins. The females only get a bit chubbier.