Xiphophorus andersi

Xiphophorus andersi  Meyer & Schartl, 1980

Affiliation: southern platyfish

IUCN status: endangered

Distribution: Endemic to the Río Atoyac drainage system, Veracruz, Mexico. Its known distribution is highly restricted, confined to a small section of this river above cataracts and waterfalls, with no records of occurrences outside this limited geographic area.

Known locations (existing/former): 2/2 (?) – Río Atoyac at Finca St. Anita (Finca La Ceiba) & Nacimiento del Río Atoyac

Type locality: Río Atoyac at Finca St. Anita, near Chico, Veracruz, Mexico

(24. 2. 1979, E. Hnilicka)

Habitat description: Occupies clear, slowly to fast flowing streams or springs, with substrates comprising of rocks, gravel or sand. Aquatic vegetation is often present.

Biotope reports:

• none yet

Description: Males typically reach up to 4,5 cm in total length, while females are slightly larger. The species is notably distinguished by a distinctive elongated, spike-like extension of the caudal fin rays in males, absent in females. Body colouration ranges from graphite grey to pale brown, usually exhibiting minimal pigmentation patterns, contributing to an overall uniform and subdued appearance. Adult females have large gravidity spot, and large males also develop a pseudo-gravidity spot. Some males remain small and lack the spot.

Variability: Limited variability observed; generally uniform in coloration.

XWG status: not yet actively managed

Represented in aquaria: Rare overall, but relatively well-established among specialized aquarists and breeders compared to northern Xiphophorus species.

Known issues:

• Susceptibility to diseases, particularly bacterial infections (e.g., Mycobacterium spp.).

Known collections or populations: basically all fish come from the same locality, but collection details are unknown:

• Río Atoyac, Veracruz, Mexico

(header photo: Juan Carlos Merino)