Latest update August 25th, 2026 10:20 AM
Apr 12, 2020 Interesting Creatures in Guyana, News
Crotalus durissus is a venomous pit viper species found in South America. The most widely distributed member of its genus, this species poses a serious medical problem in many parts of its range. Currently, nine subspecies are recognized, including the nominate subspecies described here.
This large Neotropical rattlesnake grows to a length of 1.5 m (4.9 ft), and rarely to a maximum length of 1.9 m (6.2 ft). It has two distinct stripes starting at the base of the head. Within the lines, the colour is lighter than the stripes.
Common names for this species include: South American rattlesnake, tropical rattlesnake, neotropical rattlesnake, Guiana rattlesnake (previously used for C. d. dryinus) and in Spanish: víbora de cascabel, cascabel, cascabela, and cascavel. In Suriname it’s known as Sakasneki.
C. durissus is found in South America except the Andes Mountains. However, its range is discontinuous, with many isolated populations in northern South America, including Colombia, Venezuela, Guyana, Suriname, French Guiana and northern Brazil. It occurs in Colombia and eastern Brazil to southeastern Peru, Bolivia, Paraguay, Uruguay, and northern Argentina (Catamarca, Córdoba, Corrientes, Chaco, Entre Rios, Formosa, La Pampa, La Rioja, Mendoza, Misiones, San Juan, San Luis, Santa Fe, Santiago del Estero and Tucumán).
Also, it occurs on some islands in the Caribbean, including Morro de la Iguana, Tamarindo and Aruba. The type locality given is “America.”
It prefers savannah and semi-arid zones. It has been reported to occur in littoral xerophilous scrub, psammophilous and halophilous littoralgrassland, thorny xerophilous scrub, tropophilous deciduous and semideciduous scrub, as well as tropophilous semideciduous seasonal forest in the northwest of Venezuela.
In the Chaco region of Paraguay, it is found in the drier, sandier areas.
Bite symptoms are very different from those of Nearctic species due to the presence of neurotoxins (crotoxin and crotamine) that cause progressive paralysis. Bites from C. d. terrificus in particular can result in impaired vision or complete blindness, auditory disorders, ptosis, paralysis of the peripheral muscles, especially of the neck, which becomes so limp as to appear broken, and eventually life-threatening respiratory paralysis. The ocular disturbances, are sometimes followed by permanent blindness. Phospholipase A2 neurotoxins also cause damage to skeletal muscles and possibly the heart, causing general aches, pain, and tenderness throughout the body. Myoglobin released into the blood results in dark urine. Other serious complications may result from systemic disorders (incoagulable blood and general spontaneous bleeding), hypotension, and shock. Hemorrhagins may be present in the venom, but any corresponding effects are completely overshadowed by the startling and serious neurotoxic symptoms.
The Guiana rattlesnake, previously recognized as C. d. dryinus, is now considered a synonym for C. d. durissus. In fact, after the previous nominate subspecies for the C. d. durissus complex became the current nominate for C. simus, which now represents its Mexican and Central American members, C. d. dryinus became the new nominate for the South American rattlesnakes as represented by C. durissus. The subspecies previously known as C. d. collilineatus and C. d. cascavella were moved to the synonymy of C. d. terrificus following the publication of a paper by Wüster et al. in 2005. (Source: Wikipedia)
Subscribe to get the latest posts sent to your email.

Aug 25, 2026
MOE/Beharry Secondary School’s Under-19 T20 tournament finals…BEI vs. Annandale Secondary Kaieteur Sports – After more than a decade-long absence from the school system, competitive youth...Aug 25, 2026
(Kaieteur News) – The results of the 2025 general and regional elections were a shocker. And anyone who now claims that they predicted the performance of We Invest in Nationhood (WIN) coming should seriously consider going into the fortune-telling business. WIN did not merely emerge from the...Aug 23, 2026
By Sir Ronald Sanders (Kaieteur News) – I have been an advocate of the Caribbean Court of Justice from its conception. In 2015, on the Court’s tenth anniversary, I described its creation as arguably the most significant institutional achievement of the English-speaking Caribbean since the...Aug 25, 2026
(Kaieteur News) – I think that the Hon Leader of the Opposition (LOO), Mr. Azruddin Mohamed, blundered. Three Local Govt seats in hand. One went to the Hon Ms. Amanza Walton-Desir’s Forward Guyana Movement. Good! The second should have gone to the APNU. Would have been reflective of...Freedom of speech is our core value at Kaieteur News. If the letter/e-mail you sent was not published, and you believe that its contents were not libellous, let us know, please contact us by phone or email.
Feel free to send us your comments and/or criticisms.
Contact: 624-6456; 225-8452; 225-8458; 225-8463; 225-8465; 225-8473 or 225-8491.
Or by Email: glennlall2000@gmail.com / kaieteurnews@yahoo.com