i have 5 serpais recently bought the label on the tank in petshop said community never said fin nippers as it did with barbs and the likes, i have the in a fairly large tank along with the following
1 loach,
3 black widows,
3 glass cats,
4 danios, 2 zebra & 2 leopard (1 is long finned)
i havent noticed any problems with fin nipping the danios and the widows can hold their own if the serpai annoy em