Of the 30 or so species in this genus, two are seen much more often than any others: the Arabian Killifish and A. mento (Black Persian Minnow or Killifish, mainly from Israel and Turkey). Two subspecies of Arabian Killifish are generally recognized: A. d. dispar and A. d. richardsoni (from Jordan). Both have similar aquarium requirements. Aphanius mento, on the other hand, has lower temperature requirements (50-77°F, or 10-25°C). It can also tolerate wider pH and hardness ranges (from slightly acid and soft to alkaline and hard).