It's during courtship that most fish species will look their best. It's an exciting time for a hobbyist, as the displays that take place in the days or weeks leading up to a spawn, can make for some wonderful photo opportunities.
So how can you tell when your pair is ready to spawn? To make things easy for those who might never owned a pair of bubblenesting wilds before, I have written up a brief summary outlining some of the key behaviours I have witnessed in my own fish.
The very first thing you may notice, is that the behaviour of your pair changes. Quite often pairs will become more aggressive towards each other and engage in display related behaviour. The male may flare at the female, chase her away or even physically attack her.
Nonetheless, the female is by no means an unwilling participant in all this. In fact, she will usually give as good as she gets, and males can end up looking the worse for wear by the time the actual act occurs.
Both fish may suffer from torn fins, nipped ventrals and missing scales. However, unless the damage is severe enough that secondary infection is a concern, there is no need for intervention. Damage sustained during courtship/spawning tends to heal up surprisingly fast without any special attention required.
During the courtship process, females will often start to look plumper around the stomach area. Her ovipositor or 'egg spot' (the white tube that is located behind the ventral fins) may become more prominent, and the female will usually display vertical barring when in the presence of the male. These bars are referred to by many hobbyists as 'breeding bars', and as their name suggests, can indicate that a spawn is forthcoming.
While bubblenests can also be a good indication that your pair may be close to spawning, their presence is by no means a certainty.
Some males will build multiple bubblenests in the lead-up to a spawn, while some males may not even build a single one. When my Betta brownorum pair first spawned, the eggs remained on the bottom of the film canister because the male hadn't built a nest at all.
With that said, if you find a bubblenest in your tank, a spawn is most likely on the cards. The chance of a spawn happening becomes even more probable, if you notice the male actively trying to encourage the female to join him under the nest.
He may spread his fins, flare, flick his body and chase the female around in quite an elaborate display. It is usually at this point in time that your pair will put on their best show. This is the time to get out your camera and get as many photos as you can, because rarely are the colours on your fish going to be as intense as they are right before a spawn.
Of course, the above is based purely on my experiences with breeding coccina complex species over the past two years.
Some readers may experience something completely different with their fish, and that is one of the great things about this hobby. Each fish is an individual, and I have learned there rarely any hard or fast rules when it comes to successful fishkeeping. A lot of what I do is based on conjecture and trial and error. Therefore, it doesn't mean you are doomed to failure if your fish exhibit only one or two of the behaviours listed above.
Hailing from Melbourne, Australia, I currently keep and breed a number of species from the coccina complex.