I always thought that too calculator but saw the following in a Practical Fishkeeping article about what not to say in an aquatic store and one of them was "I must be doing something right if they’re all spawning"
Their reply was...
Good old anthropomorphic behaviour has a lot to answer for. We humans like to breed when conditions are good, when things are just right. We like to be in a position that we can provide for our kids – even if Jeremy Kyle would disagree with this. And what’s more, we assume that this mentality carries across the species into the world of fish. The problem is that it doesn’t always.
There are many species out there that tend to spawn when things are going well and truly up the creek. Certain catfish, for example, tend to be triggered by deteriorating water quality, indicative of rainfall to follow. Some creatures will only reproduce when subject to appalling conditions as their breeding indicator.
Certain inverts, too, tend to go into spawning mode when things are much less than desirable in the tank, and this isn’t an entirely freshwater phenomenon.