Hardest Fish To Breed?

[ncguppy830]

Clown Loaches are on the list 

Aye, but i dont get the whole hormone injecting part, how could i obtain the hormones?

 

[Livewire88]

 

Clown Loaches are on the list 

Aye, but i dont get the whole hormone injecting part, how could i obtain the hormones?
 

 
I wouldn't have a clue TBH 

 

[Blobfish]

But what really matters is why you want to spawn things. If it is to see it happen, then I can suggest one list. If its for profit, that is another list entirely. 

 
If you have the time, I would be interested to see both lists.

 

[DerpPH]

Well other than the breeding. Hatching is quite hard for gobies of the stiphodon complex

 

[TwoTankAmin]

The lists are not so hard to compile. or the curious you need to find the fish that use the following spawning methods:
 
Egg scattering
Egg placing by adhesion
Bubble nesting
Mouth brooding
Cave spawning
Substrate spawning
Group spawners
Pair spawners
Live bearing
Parent raising
 
The above may be combined. for example corys spawn in groups and then the females sticks the eggs to things. Pairs like angels and discus also adhere their eggs and raise the fry, etc.
 
But then there are also the unique spawners like splash tetras which leap from the water and deposit and fertilize the eggs on an overhanging leaf. Or the Synodontis multipunctatus which darts into a cichlid spawning in progress and deposits its eggs with the mouth brooding cichlid eggs. Sometimes they even eat all the cichlid eggs before they are picked up. But if there are mixed eggs held by the cichlid, the synos hatch and grow faster and will eat the cichlid eggs/wigglers/fry.
 
If you want to make a list of the fish to spawn for profit, simply find fish that sell for a lot and are considered hard to spawn and hard to collect in the wild. Bear in mind that large fish need large spaces to spawn, so for the hobbyist smaller species are much easier to handle.
 
Spawn rare plecos, rare corys, rarer wild type bettas, etc. Do the research. Most expensive fish are high priced for a reason. It is not so simple as what can or can not be spawned in a tank. Clown loaches are a perfect example. Can't be spawned in tanks yet it is not an expensive fish at all.