Killifish, Surprise Shipment

How exciting! Please post pics when acclimated. Would love to see them.

If you're getting single pairs of each , a hiding place , like some floating hornwort , is probably not a bad idea . Just in case the males get pushy . Keep the species separate , though . All the females will look the same . The only one of your 4 I've got experience with is guentheri ; and that was too long ago . Don't remember them beating up on each other , though . Gonna try to breed them?

Agree with above...give them cover. In a 5 or 10 gallon with lots of cover females are chased but not seriously harmed; however, mixing small numbers of males may be trouble. I have two N. guentheri pairs and the smaller male is constantly rather ragged in their stuffed to the brim planted 10 gallon (note that this tank uses no salt...the nothos have never gotten velvet even when other fish in the same tank have, leading me to the conclusion that in spite of the fact they don't have a lot of submerged vegetation in their native habitat, they highly appreciate dense aquatic plants)