Rank 1-10 :
- Tiger Cod x1
- Fire Shard x1

Rank 11-20 :
- Wahoo x1
- Fire Shard x1

Rank 21-30
- Bianaq Bream x1
- Fire Shard x1

Rank 31-40
- Ash Tuna x1
- Fire Shard x1

Rank 41-50
- Saber Sardine
- Fire Shard x1

You wont make gils while you leveling but all fishes i wrote are easy to get, and cheap in case you want to buy them.