Four silver arowana in 4500 gal tank, three are 30", one recent rescue is ~24".
My subjective comparative assessment is they are all males based on color on the back and the length of the pelvic fins and extensions. My only female displayed a notably darker color dorsally and longer pelvic fins+extensions. She had had three or four clutches of babies over the last few years, which were mouthbrooded by alpha male named Alf: https://www.monsterfishkeepers.com/...wana-spawn-on-mfks.670573/page-2#post-7532553
I had lost my only female Kinky not long ago but these males are still doing this circling each other thing but no significant fights anymore since Kinky had been killed in the other 4500 gal (the reason I rehomed them into this 4500 gal).
My subjective comparative assessment is they are all males based on color on the back and the length of the pelvic fins and extensions. My only female displayed a notably darker color dorsally and longer pelvic fins+extensions. She had had three or four clutches of babies over the last few years, which were mouthbrooded by alpha male named Alf: https://www.monsterfishkeepers.com/...wana-spawn-on-mfks.670573/page-2#post-7532553
I had lost my only female Kinky not long ago but these males are still doing this circling each other thing but no significant fights anymore since Kinky had been killed in the other 4500 gal (the reason I rehomed them into this 4500 gal).