Thamnophis eques cuitzeoensis (Conant, 2003); The Lake Cuitzeo Garter Snake


Thamnophis eques cuitzeoensis, neonate, unusual bright pattern, Lago de Cuitzeo.

Thamnophis eques cuitzeoensis, a subspecies of the Mexican Gartersnake, is still quite rare in most private garter snake collections.

This subspecies occurs only occurs in Lago de Cuitzeo, Michoacán, Mexico.

It is described by Conant (2003).

Length and size of Thamnophis eques cuitzeoensis

Thamnophis eques cuitzeoensis, vrouw 2 op 4 jarige leeftijd , Lago de Cuitzeo.T.eques is a very large and heavily built gartersnake and Conant (2003) had set the new record for T.eques (obscurus) at 121,6 cm total length. Especially female Thamnophis eques can grow very large and heavy. In fact adult female T.eques are the largest gartersnakes I have ever seen. The only garter snake that really grows to much larger size is Thamnophis gigas from California. The new record for T.eques is now set at 130,7 cm (Bol, 2012).

When I compare T.e.cuitzeoensis with T.e.scotti and T.e.obscurus so far I have the impression that cuitzeoensis remains somewhat smaller and the juveniles do not grow as fast as the other 2 subspecies. My females were 91 – 97 cm at an age of 3 and 5 years, the males were 80 – 86 cm at an age of 3 and 5 years.

Description of Thamnophis eques cuitzeoensis

Thamnophis eques cuitzeoensis, neonates, Lago de Cuitzeo.

Thamnophis eques cuitzeoensis, neonates, Lago de Cuitzeo.

This subspecies of T.eques is almost completely black. Especially in the newborn young traces of a striped and spotted pattern are visible. But as the snakes grow older and bigger they all turn into a solid black color with sometimes tiny lighter colored spots. The ventral scales are dark gray with black lines. The chin, throat and underside tail are white or crème-colored and are strikingly in contrast with the remainder of the underside of the snakes.

Thamnophis eques cuitzeoensis, neonates, Lago de Cuitzeo.When seen in sunlight some specimens have a beautiful fluorescent bluish shine in the black dorsal scales (especially after shedding) and also the remnants of the lateral stripe may have that bluish shine.

The yellow scales in the head region (supralabials, pre- and post oculars and the yellow ring behind the head) also become dark with old age in some specimens, whereas in others they remain yellow or whitish.


The Lake Cuitzeo Gartersnake does very well in captivity. Due to its large size its recommended to keep them in a terrarium with a minimum size (for one adult couple) of 100 x 50 x 50 cm. They do well in a dry and well ventilated cage with just a water bowl for swimming and drinking. The water bowl should be big enough for them to submerge in. Local temperatures in the terrarium should rise to 30 – 35 °C.

A very nice and attractive way for keeping this species is giving them a very large aqua terrarium with a lot of water. The dry part could consist of a floating plateau.

The cage should be very well ventilated and the dry land part should be kept at 30 – 35 °C  during day time so the snakes can bask and completely dry.

Thamnophis eques cuitzeoensis, neonate, unusual bright pattern, Lago de Cuitzeo.T.e.cuitzeoensis are good feeders and relatively easy to keep. They tend to be relatively shy although especially the captive bred specimens often lose much of their shyness when they grow older. In certain times of the year, especially in spring and fall, the snakes show themselves a lot basking on a branch under the lamp. Especially when the terrarium is not so warm and the snakes need to bask on the hottest spot to reach their optimal body temperatures. When you move too much however they will often retreat in their hiding spots.

So observing the snakes in the terrarium is almost like you do observations in the wild. A hibernation will not be absolutely necessary although it is expected that they will have a resting period in nature when they are less active.

A cool period in the terrarium of 2 – 3 months will probably be sufficient to keep the snakes in good health and to stimulate breeding. Up to now I hardly give the snakes a hibernation. But the snakes are clearly less active in the coldest winter months; they bask less and often refuse to eat for several months. So do not worry when this happens. Night temperatures in my snake room (and in the terrariums) drop at night to 8 – 12 °C. I keep my adult snakes in a completely dry terrarium with a water bowl. This species is also very suitable for a so-called “aqua-terrarium” with a lots of water and only a small (completely dry!) land part which is heated by a powerful lamp to 30 – 35 °C. In such a habitat terrarium the highly aquatic snakes will show more of their natural behavior.

When fed with life fish one should be able to observe a unique hunting technique (that I have personally never witnessed) which the snakes use in the wild (Conant, 2003). The snakes float in a single looped position, head submersed near the tail. They wiggle their tales as a lure to attract fish.

The young are usually born in my terrariums in June or July.

Sometimes females have a second clutch in October.

Distribution and habitat of T.e.cuitzeoensis

Lago de Cuitzeo, Michoacán, Mexico - by Lucy Nieto

Lago de Cuitzeo, Michoacán, Mexico – Photo by Lucy Nieto

Thamnophis eques cuitzeoensis occurs only occurs in Lago de Cuitzeo, Michoacán, Mexico. This large endorheic lake is situated in the Mexican state of Michoacán (and for a small part in Juanajato) at 1821 meters above sea level. It is the second largest lake in Mexico with a length of 30 km. On November 20th 2005 I have observed this subspecies in the wild in Lake Cuitzeo (Bol, 2007).

Underside Thamnophis eques cuitzeoensis.I found 3 juveniles of this subspecies beneath dead water plants washed ashore. Two have them probably were young of the year and had a total length of 25,6 and 29,7 cm. A third snake was probably one year old and measured 45,7 cm.

The snakes still felt cold, although it was a clear blue sky with temperatures rising up to 25 °C. The previous night had been pretty cold with temperatures close to or below the 10 °C.

Thamnophis eques cuitzeoensis, male 3 at the age of 5 years, lago de Cuitzeo.A large specimen of 80 cm (estimated) probably was sunning on the shore and disappeared very fast in a small hole in the dyke. Despite it was late in the year the snakes were still active and some were still feeding. T.e.cuitzeoensis shares its habitat with the much smaller T.melanogaster canescens.

The latter species is very abundant in Lake Cuizeo. Sometimes I found 2 – 3 snakes under 1 large rock. In total 30 melanogaster were observed that day in November. Conant (2003) also found much more T.melanogaster then T.eques in the lake.


My recent article about Thamnophis eques scotti that can be found online in english on this website can serve as a standard recommendation (caresheet) how to care of Thamnophis eques cuitzeoensis.

Breeding group

Thamnophis eques cuitzeoensis, female 2 at the age of 4 years , Lago de Cuitzeo.

My breeding group consist of offspring of 4 adult (unrelated) wild caught specimens.
This gives me the opportunity to have young that are completely unrelated.

Which is perfect for future breeding programs.

I am breeding this subspecies since 2007.

Bol, S., 2007. Thamnophis eques cuitzeoensis, the “Lake Cuitzeo Garter Snake”. The garter snake 12(4): 46-50.
Conant, R., 2003. Observations on Garter Snakes of the Thamnophis eques complex in the Lakes of Mexico’s Transvolcanic Belt, with descriptions of New Taxa. American museum novitates 3406: 1-64.

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