Sailfin molly

The sailfin molly reaches about 12.5 cm standard length (males grow larger than females) and comes from coastal fresh and brackish waters from the Carolinas down to Mexico. It must be kept in hard, alkaline water — a pH of 7.0–8.5 and moderate to hard general hardness, without which the fish quickly weakens. A temperature range of 21–26 °C and a tank of at least 30 by 15 inches (about 88 L) suits a small group of one male with two or three females. The diet should be predominantly vegetable matter: blanched spinach, spirulina flake, and algae; insufficient greens stunt dorsal-fin development in males. Males spar with each other and can harry smaller tankmates, so keep only one male per group and choose robust companions. The species is a prodigious livebearer — a single female can drop up to 50 relatively large fry after a two-month gestation.