It is Fundulopanchax gardneri nigerianum. Found in Nigeria and Cameroon. There are many collection sites and each is given a location or code. ie: Fundulopanchax gardneri nigerianum Misaje Whilst you can eliminate a few by colouration, finnage etc. it is sometimes hard to be precise in naming the fish correctly with the correct location. This would only come into play for die hard Killifish purists who do not want to cross breed their stock. (cross breeding is frowned upon in Killifish circles). Females are impossible to differentiate from strain to strain. If you need to know more on breeding and maintenance of these then just ask.
Regards
BigC