I have 800-1000 gallon, well planted pond in NJ with an assortment of 9 goldfish(fantails, comets, shubunkins). Would banded killifish be a suitable companion for the goldfish or would it be a problem?
Not familiar with the species ,do you have a latin name?? Most of the killifish that I'm familiar with are not very aggressive . but most are very tropical
I see no problem for your goldfish and with a well planted pond it should fit in OK if it can find the kind of crustaceans and plant matter that it eats.
Here is a link that might be useful: Virtual Aquarium