Geographic range:
Neotropical: C. minckleyi is
an endemic cychlid species from Cuatro Ciénegas in the Coahuila
state in Mexico.
Physical characteristics: Size -
around 20 cm. There are 3 distinct forms of this species differing
in shape, pharyngeal dentition and length of intestine. Historically,
these forms used to be viewed as separate species.
The most abundant form, also considered the most primitive one and
ancestral to the other two, has a high body and thin papiliphormic
pharyngeal teeth shaped to disintegrate soft food items. Jaw muscles
are weak. The main food source is detritus. This form is also the
most widely distributed one.
The second form, less abundant than the previous one and with area
of distribution restricted to thermal pools in the vicinity of the
point of Sierra San Marcos, has high body and strong molariphormic
pharyngeal teeth used for grinding hard shells of endemic Mexipyrgus
mollusks. Jaw muscles are strong. Also the length of the intestine
is about 25 - 50% of the one of papiliphormic form.
The third form, restricted to very few thermal pools, has elongated
body shape, which allows faster swimming, crucial for catching prey,
which is represented by small fish species, mainly Axtyanax mexicanus.
This form has both molariphormic and papiliphormic teeth. Its intestine
is shorter than that of the papiliphormic form.
Food habits: Although the feeding
habits strongly correlate with the morphology of the 3 different
forms (above) and wild specimens invariably had only one kind of
food items in their digestive tracts, studies showed that under
experimental conditions of food abundance all kinds of food items
are consumed.
Reproduction & Behavior: All
three forms defend territories during the reproduction. The site
for egg deposition is selected both by male and female; the vertical
edge of the pool is usually preferred. The color of the dominant
male is dark. On the other hand, almost entire female's body turns
white contrasting with a few (3-4) black spots along its flanks
and base of the tail.
Several hundreds of yellowish, 2 mm long eggs are deposited. Clutch
is guarded by the female who also ensures a good water circulation
in the area by movements of her pectoral fins. Female guards her
offspring till they reach about 2 cm of size.
Habitat: Crystal clear thermal springs and pools with very
constant temperature, generally no bigger than 20m in diameter surrounded
by very arid environment.
Conservation: endemic species with
extremely restricted distribution |
