For starters, fisher retainers can do waterside exploration missions which at around lvl55-60 can bring back fat cat and gestahl minions.

Each mission type brings different rewards, I'd suggest looking into the different types. Actually, I'll provide links.

http://ffxiv.gamerescape.com/wiki/Waterside_Exploration

http://ffxiv.gamerescape.com/wiki/Highland_Exploration

http://ffxiv.gamerescape.com/wiki/Woodland_Exploration

http://ffxiv.gamerescape.com/wiki/Field_Exploration

See which reward set you actually care to shoot for.