Xiphophorus variatus (Meek, 1904)

Common Name and Maximum Length

Xiphophorus variatus, commonly called the variable platyfish, reaches a maximum total length of 7.0 cm, or 2.8 inches.

Wild Body Coloration

Wild individuals are olive-colored, with black marbling or spots on the side of the caudal peduncle.

Male Dorsal Fin Markings

Large males have blackish blotches on the dorsal fin.

Anal Fin Ray Morphology

Unlike some other species in the genus Xiphophorus, X. variatus does not have a claw at the tip of the fifth anal fin ray.

Pectoral Fin Ray Structure

The fourth pectoral fin ray has well-developed serrae, which are saw-like notches.

Scale and Fin Ray Counts

This species typically has 20 to 24 lateral scales, 10 to 12 dorsal fin rays, and two rows of jaw teeth.

Sexual Dimorphism in Anal Fin

Males have a more pointed, needle-like anal fin, while females have a more triangular anal fin.

Native Distribution Range

The variable platyfish is endemic to the Atlantic slope of Mexico, ranging from southern Tamaulipas south to northern Veracruz.

Native Population Status

It is considered uncommon throughout its native range.

Introduction Pathway Outside Native Range

The species has been introduced and established in many locations outside its native range, mostly from releases connected to the aquarium trade.

Introduced Populations in Florida, U.S.

In the United States, it has established populations in canals along the eastern shore of Tampa Bay, Florida, and in Gainesville, Florida.

Introduced Populations in Montana, U.S.

It is also naturalized in springs in Beaverhead, Granite, and Madison counties in Montana.

Non-U.S. Introduced Populations

The species has also spread to several other countries outside its original range, including Colombia, Singapore, and Hong Kong.

Ecological Impact in Hong Kong

Hong Kong has recorded a negative impact on local native species from this introduced platyfish, caused by its extremely prolific breeding.

Habitat Preferences

Variable platyfish inhabit slow-moving, vegetated waters including canals, ditches, and warm springs.

Diet Composition

They are omnivorous, and their diet includes plant matter as well as small crustaceans, insects, and annelid worms.