No, it cant be done naturally. As I said before it would have to be through the use of strong hormones. Many fish are bred through hormones these days, including bala sharks, red tailed black sharks, sucking loaches, clown knifefish, etc...(just incase you were interested). And if you are interested, you may be interested to learn that the main hormone used is from the pituitary gland of carp, which are sacrificed for that purpose in Asia. The chorionic gonadotropin hormone is also regularly used for breeding marine fish in Spain.
Thom.
Thom.
