Document Type : Research Paper
Sturgeons and their hybrids have the highest value in terms of meat and caviar production. These fishes have gonochorist gonads, but rarely and unusual intersex gonads are reported. The present study reports the first intersex gonad in a hybrid of Sterlet (Acipenser ruthenus ♀) × Beluga (Huso huso ♂) in Iran aquaculture condition. In one fish with 10 year-old and 7.5 Kg weight, gonads (700g) were seen as testes as dominance with some oocytes upon the testes with 100g in weight. The reason of this phenomenon is unknown and needs some anatomical, hormonal, and histological examination with a higher sample size of this fish, but this is foreseen that holding condition in captivity, presence of pheromones and hormonal factors, and some pollutants and endocrine disruptors could cause this phenomenon.