We tried capturing adults and juveniles in Ecuador in the 1990’s for Japanese scientists. Full oxygen gear, fish stretchers, acclimitized water. All Mahi Mahi we brought back did not make it.
However, fish still alive and flapping on bottom of boat at end of day were some amberjacks (Seriola) we had caught at same time at our marked FAD point. Very surprised scientists – but a hardy species makes for a good candidate for aquaculture so we suggested to try.
Sure enough they ate pelleted feed immediately when put into tanks at local shrimp hatchery.