Okay, so you've got your bucketful of fish and you want a reward for your hard-earned fish, but you're just a bit blasé over more gold. You want something new, something exciting, something nifty.
Fear not! You can receive other rewards to show your perserverance against the more piscine elements of Gaia. And it all starts right here:
This or something like it is at the top of almost every page on Gaia. What you want is to go shopping, so go to the Shops tab and click on Shops Directory.
Now where's the most logical place for a Fish Exchange here? That's right! The Ole Fishing Hole, fishing store and probable home of Old Man Logan. Look along the right side of the screen until you find:
Just under Logan's cheery countenance should be a little box with words in it, which looks something like this
Click on the obvious place and head on in.
Now, depending on what fish you've caught and how much of each you have, Logan will offer various different things.
Each item that Logan offers falls under one of three different broad classes: Basic, Genus, and Combo. The process is much the same for each, but we'll cover the differences.
What we have here is a Cool Rainbow Helm. You only need Cool Rainbow Trout in order to make one, and nothing else.
Just hit the top Exchange button if you only want one, or the bottom one if you want as many Cool Helms as possible. (If you have less than 200 Cool Trout, only one option will show up.)
With the Catfish Whiskers, all you need are 25 Bass. You can use any color you like or use the bottom tally to mix and match. When you're done, just hit the appropriate Exchange button.
With some items like the 4xBlackrocque Helm, you need more than one species of fish in order to receive your new nifty item. You can only exchange for these one at a time, but if you want one, hit the Exchange button.
No matter what item you want, you will be asked to confirm your choice and then you've got a brand new item in your inventory.
What is Direct Trading?
Direct Trading is essentially giving 10 of your smaller fish to Logan so you can get a larger fish. Logan follows an exact formula here as to which fish he hands out depending on which fish you've got.
It is unknown to the general public if you can trade for rare fish, but it is widely considered unlikely by members of the fishing community.
I don't see the item I want when I'm in the Fish Exchange! Where is it?
If you don't have the requirements in your inventory, Logan isn't going to offer it. If you do, he will. It's really that simple.
If you would like an item that Logan isn't offering you, you can either fish until you get the requirements, or you can buy fish/junk from other Gaians until you have the requirements, or you can just try to buy the item from another Gaian and skip the whole fishy business.
If you're after a fishing trophy, those cannot be acquired through the Fish Exchange.
Do the exchange items cost anything?
Not really. The only gold that you spend to get the exchange items would be  the amount you spent buying it from another Gaian,  the amount you spent buying fish or junk from another Gaian to make the item, or  the amount you spent on rods and bait to catch the fish yourself.
What does a "greyed-out" fish with ANY on it mean?
Basically, any color of that fish works. For example, with the Catfish Whiskers, you need 25 Bass. This could be 25 Green Bass, or 15 Brown Bass and 10 Blue Bass, or 1 Green Bass and 17 Blue Bass and 7 Brown Bass. Just as long as you have more than 25 Bass in your inventory, you can make the trade.
How can I just sell the fish instead?
There are three ways to sell fish:
 Go to your Inventory and click on the Game tab. [Quicklink] Click on the fish, then Sell Item and type in how many you want to sell. After that, hit Sell Item again and revel in your newfound gold!
 Go to the Gaia Marketplace, then pull down the menu to where it says Sell an Item, then go to your Game tab. [Quicklink] Scroll down the list until you find the fish you want to get rid of and type in how many you want to sell. Then fill in the rest of the form according to your desires for selling.
 Go to the Game Item Exchange forum [Quicklink] and either look for someone wanting to buy what you're selling or create a new topic selling your fish. Do your trades with the Gaia Bank for security.
Do I get to keep my fish afterwards?
Nope. This is an exchange: you give something, you get something.
Is there anywhere else I can buy this stuff?
You can buy items from other Gaians, but almost all Fish Exchange items come from the Fish Exchange. The exceptions are the rare occasions when will the admins hand out Fish Exchange items to Gaians as prizes.
Can I preview an item from the fish exchange before I buy it?
Yes you can! If you search for an item from the Fish Exchange on the Gaia Marketplace, you can see what your avatar will look like while wearing your brand new item. If you want to see what it looks like on a mostly naked avatar (you pervert) or you want to see what it looks like from behind, that's where this topic comes in handy. You can also try and see what the items look like on a different avatar by using an avatar creation site such as the Dream Avatar Creator. [Quicklink] (The pictures in this thread were taken from actual Gaian saved avatars, not an avatar creation site.)
What do I do with my new nifty item once I've got it?
Well, if you just got another fish from Direct Trading, then it will stay in your inventory. If you got something else, you can wear your new item or put it in your house or do pretty much anything else you want with it (within the limits of the Gaia Terms of Service).
If I decide I don't like my new item, can I trade back for the fish?
Even though Logan doesn't have a NO REFUNDS sign up, the truth is that he won't give your fish back. If you would rather not have your exchange item, try selling it on either the Gaia Marketplace as described above, or the Gaia Exchange forum. [Quicklink]
Is there a special time of day/spot to stand at to collect certain kinds of fish?
The only fish that are time-sensitive to the point where it actually matters are the rare fish. The chart at right illustrates what fish only show up at certain times of the Gaian day, to the best of current knowledge. (Dawn and Dusk have the same sets of fish.)
There is no conclusive evidence that anywhere on the minimap in game yields better fish consistently more than anywhere else. (There is a lot of circumstantial evidence to the contrary.)
Other than that, what you catch is up to the quality of bait you use, how far you cast, and just random luck.
There are some fish I've seen that I can't catch. Where are they?
All the fish catchable in the Gaia Fishing game are on the graphic at the top of this topic organized under where they can be found. They have been organized into small, medium, large, and rare fish.
The Aquarium Fish cannot be caught in Gaia Fishing. All of those either originate in Daily Chance, Phin Phang, or La Victoire.
There are also various fish-aquatic themed items that Gaia has released over the years. If it isn't listed in this sticky, you can't get it from the Fish Exchange.
The astute observer will notice that there are three fish that keep cropping up in this thread that aren't available in Fishing or in the Fish Exchange. For those, there is a story. [Quicklink]
In the advent of more Fish Exchange items being discovered, addendums will be made as necessary.
Thanks for help in this topic goes to Suroth Meldarath for supplying the female avatar pictures, Gaidin for compiling graphics and determining exchange rates, novarren for generating the shiny graphics for the sticky and most of the text, Teh Mog for supplying most of the male avatar pictures, various members of the Top Fishers Guild for their willingness to assist.
We also appreciate Cronos99, Celes, BlackPidgeot, and DarkTomoko, for their help with supplying the masks for this thread.
And many thanks to SevenTen and Gaidin for putting up with editing the sticky. Mwah! heart
And lastly, thanks to the developers who put Gaia Fishing! and the Fish Exchange in place so we could have this nifty stuff, as well as the mods who allowed this topic as a guide to the Exchange. We know the devs are overworked, but we all want Fishy Love! [Quicklink]
Okay, you've looked at the charts and the topic and you've seen some fish out there you might not have seen before. They aren't available in the Fishing Exchange and are so rare that you can't catch them in Gaia Fishing.
These are the Ole Lunkhead of Bass'ken Lake, the Writhin' Rino of the Port of Gambino, and the Sapphireback Lion of the Durem Reclamation Facility. They are the "legendary" fish, dreams that Gaian fishers have but no-one has ever dragged up on their fishing line.
Where did they come from if they can't be caught? They were inspired through Make-Your-Own-Fish contests hosted by people in the Fishing forum, and indeed were made up there. You cannot get them in your inventory, yet they are a part of fishing lore.
The images for these fish used throughout this guide were originals made by novarren for her personal amusement and she has given permission for the edited images of them used in this guide.