Number #1 – Arowana (Scleropages)

Whatever the belief is, for those who do not even have the slightest idea about Chinese mythology will even consider getting the arowana fish for their own special reason and most people would say that the size, shape and movement are the ones that capture their attention the most. Arowana is also known to live and survive for long period of time (at least 20 years) and to get them to grow to its maximum size requires a lot of work and dedication. You need to provide the best live foods, ensure clean water quality and they require huge tank to thrive in or else all your effort will be gone to waste. These factors when combined together make total sense on why they are worth so much especially those that are already considered matured arowana fish. Some people even breed them just for sale and export businesses while small young fry can easily fetch hundreds. Below is the list and guidelines on what you would expect to pay for some of the most expensive species, all grouped under similar category.
Super Red or Golden Crossback – easily above $2000
Nami Green Arowana (with its snakeskin pattern) – at least $5000 minimum
Number #2 – Koi/Japanese Carp

Koi can be classified and grouped together according to different man-made classifications which are generally defined based on their scaling properties and color pattern. Basically some of the most common breeds you will find sold in pet shops are kohaku, sanke and showa but there are also some which are considered those special varieties which costs a little more extra like the hariwake, bekko and utsurimono. Generally there is no limit as to how much a koi collector is willing to pay and how much a single fish is worth because generally it all depends on the desirability factor that is based on how the color patterns are arranged to form special and unique marking. Thus, it is not surprising to find a well-developed specimen to sell for few hundred dollars up to thousands.
Number #3 - Discus

The patterns on each discus can be very discerning and even the color combinations can be very unique. Furthermore, it takes an experienced hobbyist to actually know how to provide the best care for the fish to develop to its true potential in terms of coloration and size, thus, all these could be the reasons on why the pet fish is sometimes described as those reserved for the elite hobbyist. Don’t get me wrong, but these are the assumption that I’ve put forward although I still can’t comprehend the real truth behind it and especially how a flat shaped and round, slow-moving fish can be worth so much. For example, when the Red and Golden Leopard Snakeskin was first introduced to the market, it was worth few thousand dollars.
For more pictures displaying the best freshwater fish, you can also visit the aquarium photo gallery