I have fisher as the only gathering class so far and i'm satisfied with it but i really can't find a logic behind all the big (green) fish that are available to the game. Desynthesis has a few good results in materia and items but this is meaningless in the long run since most fish require specific weather and time in order to be catched not to mention double mooches and success rate.
The introduction of the aquarium may change this but still it doesn't seem rewarding for someone who might spend even a week in order to get 1 catch. Has anyone done any research on big fish for any other usefullness?