What Is the Rarest Guppy Type?

Guppies, a small fish native to Trinidad, are characterized by sexual dimorphism, or the color variations between males and females. Scientists, through research and experimentation, are finding exotic color variants in guppy fish has accelerated. In evolutionary vocabulary, frequency -- dependent survival means that guppies with rare gene differences have a survival advantage. Researchers from the Institute of Genomic Biology have developed a theory that revolves around predation. As a primary food source for larger fish, guppies have evolved to appear unfamiliar to potential predators. Further research confirms, female guppies prefer to mate with uncommon males, giving their fry a better chance at survival.

Ichthyology is the branch of zoölogy dedicated to the study of fish. Ichthyologists assert, there are four prominent color strains for guppies including blonde, golden, albino and wild gray. These common colored fish are responsible for innumerable off-shoot color variations. From these ordinary off-shoot variations, uncommonly rare colors have patterned. Another indicator for rarity is dictated by the lavishness of a guppy fish. Frilly finnage impedes a male guppy's ability to swiftly fertilize a female's ovum, giving less ornate males the advantage. According to Dr. Herbert R. Axelrod, acclaimed scientist and author of "Starting Your Tropical Aquarium," a rare guppy lineage includes the bronze and blue strain, such as the Moscow purple or blue.

The International Fancy Guppy Association, or IFGA, often determines the rarity of a new guppy strain along with its conformity to IFGA standards. The IFGA holds competitions and guppy expos year round. Winning fish are determined through a contemporary points system. The accumulation of points dictates each color class rarity and recognizes fish that place in the top four color classes. Senior judge for the IFGA, and a best of show winner many times over, Bill Carwile has been raising champion guppies for more than 20 years. Carwile says, when it comes to winning guppies, color is the most important quality.

A rare Japanese strain called a blue variegated cobra, known globally as a galaxy blue glass guppy, garnished fourth place in the recent World Guppy Contest. This rare blue glass has tremendous potential with exceptionally good finnage and form. Another uncommonly rare guppy type, the dwarf blue panda has recently become more readily available, but is still difficult to find. Guppies from the snakeskin class produce some of the most rare offspring. Fish who carry the snakeskin genetic trait, and show a rosette pattern on the body, are exceptional. A solid blue tail snakeskin would be an example of a rare fish, a matching dorsal and tail color, is rarer still.