Roundtail Guppy
Poecilia reticulata
About this strain
The Roundtail is similar to the Fantail but generally smaller and more symmetrically circular, with the fin forming a near-perfect oval or round shape. It's one of the original domestic tail forms and is associated with older, classic-style guppy breeding. Roundtails hold their shape well and are less prone to fin damage than larger fancy forms, making them a practical choice for community tanks. They don't carry the show prestige of Delta tails, but within certain association categories they are judged on their own standard — the circle should be clean and symmetrical with no points or lobes.
Origin
The Roundtail is among the earliest ornamental tail modifications documented in domestic guppy breeding, present in European hobbyist records from the early-to-mid 20th century.