Xiphophorus couchianus (Girard C. 1859)

Etymology:

Xiphophorus: Greek, xiphos = sword + Greek, pherein = to carry

couchianus after Lieutenant D.N. Couch.

First description:

Girard C. 1859

Ichthyological notices, 41 – 59.

Academy of Natural Sciences Philadelphia. No.11: 113 – 122.

Synonyms:

Limia couchianus Girard 1859

Common Name

Monterrey Platy

History:

Described by Girard in 1859 as Limia couchianus & later placed in Xiphophorus.

A female was used as a holotype measuring 41 mm. This was collected in the San Rio Juan in the area of Cadarecta & Monterrey, Nuevo León State, Mexico.

Group:

Xiphophorus couchianus is one of the three northern platys that belong to the Rio Grande platy subset consisting of consisting of X. couchianus, X. gordoni and X. meyeri.

Type Locality:

Rio San Juan, Cadarecta and Monterrey, Nuevo León State, Mexico.

There is some doubt as to the validity of this type location as there is a town named Cadereyta 35Km east of Monterrey.

Distribution:

Extinct in the wild

Populations:

Huasteca Canyon (Nuevo León State, Mexico)

Habitat:

Headwater streams, spring pools & rarely in sluggish flowing streams & ditches. The base is mostly clay & mud with a few areas of rock. Aquatic plants are quite dense with marginal plants near the banks.

Size:

Males: 30 mm, females: 40 mm

Colour/Pattern Variability:

The upper part of the body is dark brown, the scales have darker edging to give a net like appearance. The lower part of the body is off white.

The dorsal and anal fins have several dark crescents on them. All other fins are clear.

Behaviour:

A shy species and secretive species that like plenty of plant cover to hide in.

Husbandry:

A well planted aquarium with a temperature of 24°C and regular small water changes, although fairly tolerant of water conditions a sudden change in pH will kill this sp.

This species is reported as short lived and only expected to reach 12 months of age.

Breeding Notes:

Older females are known to produce weak young which have a high mortality rate. Brood sizes are reported at an average of 20 but 40 has been recorded in young adult females.

General remarks:

The original populations from the Huasteca Canyon died out in 1964 when the springs dried out due to excessive water pumping lowering the water table.

 A Xiphophorus species was discovered at Apodaca 20km northeast of the centre of Monterrey which was believed to be an undescribed sp. possibly a spotted form of X. couchianus (markings reminiscent of X. meyeri) or even a new species. Unfortunately this species has also died out and as the type specimens of X. couchianus cannot be found comparisons between the two species cannot be made.

References:

The Genus Xiphophorus in Mexico and Central America – Klaus D. Kallman and Steven Kazianis

Platies and swordtails – Derek and Pat Lambert