Unlike the least killifish, the Pachypanchax playfairii is a true killifish. These are the quartet I obtained as replacements for the pair that were poisoned in the heater die-off. They are still quite young, only about two inches long. They will double in length.
This fish is interesting in that the male features scales that stand up, similar to the dreaded fish illness dropsy. It is a normal feature of this fish, which still makes me think of dropsy even though I know better. The close-up is poor due to a bad angle. I have a worm culture just below and in front of the tank, so I can’t get the angle I want for photos.
Females are easy to identify with this species even this young. They have a black mark at the rear of the dorsal fin.