Some further observation on the Blood tetras.
[Update: These may not be Serpae tetras, so I'm referring to them by the broader term, 'Blood tetras']
One of the obvious questions about these interactions between the "Serpaes" is the question of what's aggression and what's mating behaviour. Several days ago I noticed a few of them and a few Glowlights hanging around the top of my (small) clump of Cambomba. From what I have read of breeding Serpaes, it seems that fine-leaved plants (like Cabomba, presumably) are attractive sites for Serpaes to spawn (and presumably other Blood tetras). It makes me wonder whether these fish were feasting on freshly laid eggs (though, of course, if they were, it might have been Glowlight eggs as well).