I was reading the question Aquarium lighting systems that follow seasonal changes? and I got thinking.
If an indoor fish tank has a heater, it probably holds primarily tropical fish. As the tropics are near the equator, there is little if any seasonal change in the heat or lighting.
If you have tropical fish, what impact if any do seasonal light changes have on the fish? Are there any seasonable variables other then light that might impact the well being of tropical fish?
As with most things related to fish keeping, it will depend on the type of fish you have and what you want to do with it.
Although I don't think light will have a big impact, but the temperature definitely can. An interesting article can be found here: http://www.aquaticcommunity.com/aquarium/seasons.php
In the tropics there is not a big difference in terms of amount of daylight, but they do have a dry season and a rain season. During dry season puddles of water & rivers will have lower water levels, be warmer (also less oxygen then), not as much current in rivers,... During rain season a small puddle of water can become a big pond in a couple of hours, water temperature could drop because of the fresh rain, ...
And this can be the trigger for fish to start breeding. According to a post on this forum a slightly higher temperature in your tank will increase the chance of breeding for Cichlid fishes. For Corrydoras it's the opposite. I also read somewhere that using a watering can (to simulate rain) to add water to your tank could also trigger breeding.
