Image Credit : Gila Sierra

Crotalus polystictus is a medium sized venomous pit viper species. The dark blotched pattern of the snake is very distinctive compared to other rattlesnakes. The blotches are often oval or elongated at the front part of the body and become more circular toward mid-body.

The snake’s coloration ranges from tan or brown to gray and sometimes white. An orange-brown stripe also runs along this species back, most noticeably between spots.

  • Scientific name : Crotalus polystictus
  • Distribution : Central Mexico
  • Average Size : 0.65 m (2.15 ft)
  • Life Span : 20 years or more
  • Difficulty : Advanced


Crotalus polystictus is found in high elevations, as well as lowland areas where there’s a marked cycle in season. This species needs a big cage with lots of room, the bigger the better. The minimum size that we house our breeding pairs is 1.2 meters (4 feet) long by 0.6 meters (2 feet) wide and 0.6 meters (2 feet) tall but again the bigger the better. The ventilation issue is of mayor importance. The cages we use are customized so the top is screen mesh and the back has small windows, the sides have several small holes drilled in so we make sure the air flows all the way in. it also helps to keep a thermal gradient which is one of the most important aspects of husbandry.

Hide box

It is very important to provide several hiding spots in all the different temperature ranges inside the cage. Hiding spots should be big enough to hold a pair of animals since they sometimes like to share the same hiding spots.


There are 2 options that we normally use in a cage with no filtration system we prefer to use a mix of fake grass covered with a layer of previously disinfected dead litter, about one inch deep. That is accompanied with disinfected moss placed in the most humid and cold corner of the cage. The other option is having a mix of natural substrates like soil, peat moss and other organic substrates that will help keep a balanced ecosystem with live plants. This of course will only work with the correct design of a filtration system to create the right conditions for a vivarium.

Lighting – Heating

This issue will depend on several factors. Due to the distribution area of this species the winters aren’t very extreme, so by the end of the season we start to take the breeding pair out of brumation by gradually increasing the number of hours we turn on the light bulbs, like shown in the table. By the time winters arrive again, if we desire to breed this species, we should make sure there are healthy animals with the right size, age and weight so they can go through the process of brumation.
For the young animals that will not go through brumation the temperatures should stay constant along the year, only dropping the temperatures a little bit in winter time. Shown in the table below. We use heat pads to help maintain the temperatures in winter time or in very cold locations during the night.


Season Temp Range/Hotspot Lighting Heat Pad
Spring 12-25 °C (54-77 °F) / 30 °C (86 °F) 10 hours/day OFF
Summer 18-30 °C (65-86 °F) / 32 °C (90 °F) 12 hours/day OFF
Autumn 15-28 °C (60-82 °F) / 30 °C (86 °F) 10 hours/day OFF
Winter 10-15 °C (50-60 °F) / 20 °C (68 °F) 8 hours/day ON


Season Temp Range/Hotspot Lighting Heat Pad
Spring 16-25 °C (60-77 °F) / 30 °C (86 °F) 10 hours/day ON
Summer 18-30 °C (65-86°F) / 32 °C (90 °F) 12 hours/day OFF
Autumn 16-28 °C (60-82 °F) / 30 °C (86 °F) 10 hours/day ON
Winter 16-25 °C (60-77°F) / 30 °C (86 °F) 10 hours/day ON


It is very important to provide a big water bowl with enough size so the snakes can soak sometimes. It always should be keep clean with fresh water.


The humidity level ranges according to the season as you can see on the table below. We normally simulate the rain season by spraying the cages once or twice a day always allowing for the substrate to dry before the next spraying time. It depends on the kind of substrate and cage you are using. If it’s a naturalistic vivarium with all the ecosystem working perfectly then it’s ok to simulate a heavy rain more often. But if you are housing this species in artificial substrate then you should give it a lighter rinse and let the substrate dry before the next one.

Season Humidity Rain Stimulation
Spring 15% NO
Summer 80% YES
Autumn 70% YES
Winter 15% NO


Adult Crotalus polystictus should be fed once every 10 to 15 days, except for females that are getting into breeding conditions. Weaned rats or full size mice are accepted without hesitation. Adding variety to the diet is always beneficial for the health of the animals. We use quail parts to complete their diet. Juveniles and babies should be fed every 8 to 10 days with proper size rodents and quail parts. New born babies accept pinkie mice right away without hesitation.


No venomous snakes should only be handled when necessary for cleaning or any other management issue. Crotalus polystictus are very easy to handle since their behavior is quite calm. They should only be handled with proper sizes snake hooks.


Depending on the substrate it can be very easy by only removing the residues that are on top of dead litter as soon as they are found, and every 2 months change all the
substrate. If you keep the snakes in a vivarium then you just have to worry about keeping all the ecosystem healthy inside the cage.


Crotalus polystictus rarely has issues with shedding as long as humidity and temperatures are kept according to the parameters mentioned previously.

Potential Health Problems

Crotalus polystictus isn’t a very sensitive species to deal with if kept under the conditions described above. As always, rules don’t apply to all cases. Most of the time it depends on the origin of the animals. The common issues are parasites. Intracellular and extracellular parasites are the main concern. If treated properly and on time there’s normally no major issues with them, but it has to be revised and treated by the veterinarian to get the right medication and dosage. Other health issues are respiratory infections if kept too cold and humid with poor ventilation.

Bite Protocol

It’s highly recommended for every venomous species that you keep or interested to keep to have the bite protocol. Each species has a dedicated bite protocol that includes general information regarding the species, information about their venom and signs and symptoms of envenomation if bitten. It also includes a detailed information about first aid (what to do and what not to do), specific treatment recommendations for medical personnel to provide appropriate care including information about the antivenom or antivenoms required for treatment. Finally it includes a list of people who specialize in snakebites and their contact information so they can be consulted to assist with the care if needed and a list of all the references used for the create the protocol.


Najil Kaan

The information contained in this care sheet reflect the opinions and methods of the mentioned breeder, based on their expertise and long-established experience.