I need to catch dekoi fish other than the mainstream dekoi, for recipes for fish tanks. But for some reason I have only caught mainstream ones after completing Lucky's quest. How/where can I catch the fire and death dekois?
I find this Fish Locator table from Wizard101 Central super duper handy: Fish Locator Table
The Charred (Fire) Dekoi can be found primarily in Mooshu and Dragonspyre. However, I recommend fishing in Mooshu so you can avoid those pesky DS sentinel fish. Jade Palace is a good place to start.
The Corroded (Death) Dekoi is a bit harder to find. According to the table, it can only be caught in Castle Darkmoor, Zamunda and Zamunda Outskirts (Zafaria), Ancient Burial Grounds (Mooshu), or the Private Fishing Retreat. If you're already fishing for the fire one in Mooshu, perhaps starting in the Ancient Burial Grounds would be easiest for this one.
As Vanessa already mentioned the Wizard 101 Fishing Locator Table is the place to use as a guide. I have found it to be not 100%, but it is in what you are seeking.
The next item I always recommend is the use of the Reveal Fish Spell it is the best tool. Once you know where to look and what to cast you should find it easier assuming you are using the School Fishing Spell (Level 1).
Remember for each location you will need to have earned the right to enter them. So it might be best to do the House Tour and look for someone with Private Fishing Retreat for the Corroded. As for the Charred it appears in the Wiki as of now no houses have it, but that is not to say it is not out in the Spiral somewhere
I know what you are going through for I have at time had the same issue with my toon. But, I have become a fishing doer as an individual for am I build various tanks for my future Aquarium Display I want to make. Plus on some occasions with the Catch of the Day I will look for some quick coin to get me the other Regents I need for the fishing tanks
Hope all this helps and as Vanessa said Good Luck !!!