I love Killifish and what you have there is a male Aphyosemion Australe (Cap Lopez Lyretail) he will benefit from soft, slightly acid water and feed some live foods. If you cannot get hold of live foods then feed frozen. (Bloodworm, Brineshrimp etc) Nice fish though.
Regards
BigC
By the way tomsteer I used to live in Bradford (Undercliffe) Tell me is QSS tropical fish shop still open. My wifes a Bradfordian and I'll be over again in July. Is there any more Aquarists shops locally?