Download The Monterrey Platy - Xiphophorus couchianus

The Monterrey Platy - Xiphophorus couchianus
By Gerald Griffin, OKCAA 2004
Xiphophorus couchianus. Monterrey Platy (Monterrey Platyfish)
Status in nature:- Extinct 1961 Status in hobby:- Being maintained Range:- (former) Huasteca
Caynon Comments:- All stocks of fish derived from Osborn Lab. Collected by Dr. Klaus,
D.Kallman, Apodaca Platyfish, status as species not confirmed.
That quote comes directly from the British Livebearer Association. That statement pretty much
determines the need for aquarists to conserve species and why Breeder Award Programs are
necessary. With breeding in captivity stocks can be maintained but it is doubtful if the fish can
be reintroduced into the wild. With that in mind the only way this fish will survive is captivity.
What happened? This fish was known to inhabit a particular region in Monterrey, mainly the
spring and the tributaries of that spring. With the lowering of the water table in that area for
human consumption the spring dried up and the tributaries with them, any remaining waters
sources had been polluted so no known population of the Monterrey Platy have been observed
since the 1960s. If there are specimens in the wild they have gone unnoticed. This is the story of
a number of fishes and the number one killer is habitat destruction or modification.
Red List Category & Criteria CR A1ce+2ce, B1+2abc, C2a ver 2.3 (1994) Year Assessed
1996 Assessor/s Contreras-Balderas, S. & Almada-Villela, P.
Translated means
CRITICALLY ENDANGERED (CR) - A taxon is Critically Endangered when it is facing an
extremely high risk of extinction in the wild in the immediate future, as defined by any of the
criteria (A to E) as described below.
A) Population reduction in the form of either of the following:
1) An observed, estimated, inferred or suspected reduction of at least 80% over the last 10 years
or three generations, whichever is the longer, based on (and specifying) any of the following:
a) direct observation
b) an index of abundance appropriate for the taxon
c) a decline in area of occupancy, extent of occurrence and/or quality of habitat
d) actual or potential levels of exploitation
e) the effects of introduced taxa, hybridization, pathogens, pollutants, competitors or parasites.
2) A reduction of at least 80%, projected or suspected to be met within the next 10 years or three
generations, whichever is the longer, based on (and specifying) any of (b), (c), (d) or (e) above.
B) Extent of occurrence estimated to be less than 100 km2 or area of occupancy estimated to be
less than 10 km2, and estimates indicating any two of the following:
1) Severely fragmented or known to exist at only a single location.
2) Continuing decline, observed, inferred or projected, in any of the following:
a) extent of occurrence
b) area of occupancy
c) area, extent and/or quality of habitat
d) number of locations or subpopulations
e) number of mature individuals
C) Population estimated to number less than 250 mature individuals and either:
1) An estimated continuing decline of at least 25% within three years or one generation,
whichever is longer or
2) A continuing decline, observed, projected, or inferred, in numbers of mature individuals and
population structure in the form of either:
a) severely fragmented (i.e. no subpopulation estimated to contain more than 50 mature
individuals)
b) all individuals are in a single subpopulation
The Monterrey Platy is a drab fish when compared to other platys but it is not for the colors as to
why many keep them but to preserve them from becoming extinct. The overall size is about one
and a half inch for the female and an inch for the male. The overall color is a drab olive with a
dark lateral band running down the body of the fish. When excited they will develop dark
vertical banding as well which may appear as banding or diamond shape. The dominant pair will
have the darkest coloration of the tank when in a community situation. Some fish will show a
little yellow or red pigmentation in the dorsal fins.
Keeping the Monterrey Platy in captivity is very easy, you would keep it like any other
livebearer and they do well in Ten Gallon Aquaria although a larger tank encourages growth and
gives them more fin room. For best results the tank should be heavily planted however I have
never observed parents predating on the fry unlike many other livebearers. The parents have
relatively small mouths and the fry are good size which is supposed to prevent predation. The
female when breeding darkens up and displays the “gravid” spot. When the female is delivering
fry she will darken over the entire body and the gravid spot will be quite large. Litters average
between 10 – 20 fry with very large females delivering up to 35 fry.
The fry can reach maturity in two to three months depending on food, temperature and water
quality. The fry are greedy eaters and will accept almost any food. Baby brine and grindal
worms work best but flake food is also readily accepted. The adults are barely large enough to
eat blood worm but greedily will eat the grindals and baby brine. Care should be taken with
feeding too much baby brine as it has been linked to swim bladder problems. Although all stock
is supposed to have originated from the same source inbreeding problems have not been reported
with this species which is so common in other species.
Because of hybridization they should be kept as a species tank or with tank mates that they could
not possibly interbreed with. Many aquarists have dedicated tank space to this species and I for
one will always keep at least one tank for them. It would a shame if another species becomes
extinct when people could have saved it. It will probably never be reintroduced because of
habitat loss but at least for now it has found a place in many aquarists tanks.