Brazil is a vast country with many different fauna regions, as you know well. But it must be fun to contemplate what you can find as an aquarist.
When I was in my 20s, I was a very urban animal who didn't realize how many food and decor sources were all around me. I tended to think if it was from a store, it was safe, and from nature, dangerous. Later, I met people who took boats out to local swamps, collected driftwood, hosed it down and sold it to local stores. I realized if I avoided the worst water pollution (it's hard to avoid it completely), even in the city there were places with live food and interesting wood and rocks.
I don't know about those worms. Usually, thin white aquatic worms and larvae that we find in Canada are not very nutritional, and are often shunned by fish. Maybe, some of what we are the same as what you have there, because of the aquarium trade. But maybe not. It's so hard to comment from a distance given how different our environments and fauna are.
The largest biodiversity of the world is in Brazil. However, as you can check in this book (
which is in Portuguese), thanks to our extreme regulatory burden, taxes, legal uncertainty, poor currency and infrastructure (among other issues), while foreigners are already breeding Brazilian species such as
Paracheirodon axelrodi, in Brazil, we continue with artisanal fishing as if this is not occurring outside the country (and the artisanal fishermen make so little money...). Countries such as Germany do not have the fauna as here, but they have high-quality aquarium equipment and goods, things that are rare and extremely expensive here.
While Brazil still exports interesting fish to other countries (but is currently a poor ornamental fish exporter, losing to countries such as Singapore and Spain), there are few options here. Although we have improved thanks to some associations such as ABLA (
Associação Brasileira de Lojas de Aquariofilia), there is still so much to improve. We can be a superpower on this as we are already in agriculture (but, believe me, the good coffee is exported, and when I lived in Florida, the Brazilian coffee was far better than the same sold for Brazilians). Do you know the crab mentality? So, this applies so much to Brazil, since the 16th century, when it was still Portuguese America.
Oh, I forgot to show this interesting video. This nauplius was from my undergraduate thesis in 2022: