Highland Guppies are an ingredient in the Seafood Magnifique Feast, a recipe reward from the guild achievement That's a Lot of Bait! This feast is great for raids (much like the Cauldron for flasks) and Belinia and I spend a lot of time gathering the fish for it. You need Lavascale Catfish, Fathom Eel and Highland Guppies.
However, Highland Guppies are the hardest of the 3 to get in my opinion. Lavascales can be done just mindlessly fishing in Deepholm, Fathom Eel pools are found in Tol Barad Peninsula and Uldum coastline. I prefer fishing pools (in the hope I can get my Turtle), and try to trade with Belinia for Lavascales since he prefers mindless open water fishing so he can do exercise at the same time.
Highland Guppies, as their name suggests, can only be fished from Twilight Highlands. The spawn points for Highland Guppies are shown below.
|Highland Guppy spawn points in Twilight Highlands - from Wowhead|
That one at the bottom in the open sea below Obsidian Forest is a glitch I'm sure.
There is only one other fishing pool that spawns in Twilight Highlands and that is the Algaefin Rockfish, which is found all along the coastline.
When you fish up a pool of anything, there is a chance that the new pool will be either Algaefin Rockfish or Highland Guppy. So, if you constantly fish up ONLY Guppy, then there is a chance that all the new pools that spawn will be all Algaefins, leaving you with no Guppy pools to fish.
I confirmed this with Belinia today. I had been searching for ages to find some pools and there were very few to be had, in all my favourite spawn spots. When he got online I asked if he could join in my experiment. We partied up, and I asked him to go look for Guppy pools while I fished the Algaefin pools. Sure enough, once I started fishing up the Algaefin pools, Guppy pools began to spawn. This was best done as a pair since I didn't want all our hard work to get Guppies be given to other lazy bums who just fly in and fish up my precious Guppies!
We took turns, and with him constantly or me constantly fishing Algaefins, the Guppy pools spawned continuously.
So next time if you can't find any Guppy pools, go fish up some Algaefin pools to make them spawn again. Best done with a friend or two though :)