mollies

Mollies are freshwater aquarium fish in the family Poeciliidae. The term molly refers to several species in the genus Poecilia, most commonly Poecilia sphenops (short-fin molly) and Poecilia latipinna (sailfin molly), as well as many domestic color morphs. They are popular in home aquariums for their hardiness and active behavior.

Natural range and habitat: Mollies originate in Central America and northern South America. They inhabit rivers, streams, marshes, and coastal lagoons and can tolerate a range of water conditions, including mildly brackish environments. In the wild they prefer warm, slow-moving water with moderate vegetation.

Biology and appearance: Mollies are livebearers; males possess a gonopodium, a modified anal fin used to inseminate females. They typically reach 2-4 inches (5-10 cm), though some varieties may be larger. Color morphs include black, dalmatian, gold, and sailfin varieties; fins may be enlarged in sailfin types.

Care and behavior: In aquariums they prefer stable temperatures around 24-28°C (75-82°F) and pH roughly 7.5-8.5, with moderately hard water. They are omnivores, eating flakes, pellets, algae, vegetables, and occasional live foods. They are generally peaceful but males can be persistent; keep them with other peaceful tank mates. Because they readily breed, a planted tank or a separate fry tank makes breeding easier.

Reproduction: Mollies are livebearers; after internal fertilization, females give birth to free-swimming fry after about 28 days, with litters ranging from a few dozen to over a hundred depending on conditions. Fry are small and can be raised in a nursery or separate rearing tank; providing hiding places helps survival.