Crotalus Research Articles

Choosing among Hypotheses of Rattlesnake Phylogeny: A Best-Fit Rate Test for DNA Sequence Data

Large head scales distinguish the three species of Sistrurus from other rattlesnakes assigned to the speciose genus Crotalus, but this trait is plesiomorphic and therefore not indicative of monophyly. Do rattlesnakes comprise two clades, one with large head scales and one with fragmented head scales, or must the traditional taxonomy of this group be revised? Evidence from comparative DNA sequence analysis of portions of the 12S and 16S mitochondrial ribosomal RNA genes supports the monophyly of Sistrurus. These data also suggest that rattlesnakes are monophyletic with a mid-Cenozoic origin. A phylogenetic hypothesis is proposed that is congruent with morphological and DNA sequence data

A new family of proteinases is defined by several snake venom metalloproteinases.

Recently, the complete amino acid sequences have been determined for several snake venom metalloproteinases from the genera Crotalus, Trimeresurus and Lachesis of the Crotalidae family. Among these are both hemorrhagic and nonhemorrhagic metalloproteinases. Despite differences in their molecular weights and activities, they all appear to be related through a single ancestral gene, as observed by the comparison of their amino acid sequences. None of these proteins bear significant similarity to any other known protein, with the exception of the zinc binding site demonstrated in thermolysin and other metalloproteinases. Thus we propose that these proteins define a new family of zinc metalloproteinases which is likely to consist of (but is not necessarily limited to) many of the zinc metalloproteinases found in snake venoms.

Evaluation of platelet function and of serum fibrinogen levels in patients bitten by snakes of the genus Crotalus: preliminary report

Evaluation of platelet function and of serum fibrinogen levels in patients bitten by snakes of the genus Crotalus: preliminary report

The Hypotensive Activity of Crotalus Atrox (Western Diamondback Rattlesnake) Venom: Identification of its Origin

Viperidae snakes belonging to the genus Crotalus, subfamily Crotalinae, include the species durissus terrificus, durissus durissus, adamanteus, atrox, cerastes, horridus, molossus, scutulatus, viridis and others. All of them, except for the first 2, are found in North America. Crotalus atrox, or diamondback rattlesnakes, live in the southwest United States and in Mexico. This paper describes the fractionation of C. atrox venom in order to isolate and identify its hypotensive agents.

A comparative study of the biological activities of rattlesnake (genera Crotalus and Sistrurus) venoms

1. The hemorrhagic, procoagulant, anticoagulant, protease, arginine ester hydrolase, phosphodiesterase, alkaline phosphomonoesterase, 5'-nucleotidase, hyaluronidase, phospholipase A and l-amino acid oxidase activities of 50 venom samples from 20 taxa of rattlesnake (genera Crotalus and Sistrurus) were examined. 2. The results show that notwithstanding individual variations in the biological activities of Crotalus venoms and the wide ranges of certain biological activities observed, there are some common characteristics at the genus and species levels. 3. The differences in biological activities of the venoms compared can be used for differentiation of the species. Particularly useful for this purpose are the thrombin-like enzyme, protease, arginine ester hydrolase, hemorrhagic and phospholipase A activities and kaolin-cephalin clotting time measurements.

Comparative enzymatic study of HPLC-fractionated Crotalus venoms

1. 1. Ten venoms of the genus Crotalus ( Crotalus adamanteus, Crotalus atrox, Crotalus durissus durissus, Crotalus horridus horridus, Crotalus lepidus, Crotalus polystictus, Crotalus molossus molossus, Crotalus pusillus, Crotalus scutulatus scutulatus, venom B, and Crotalus viridis lutosus) were fractionated using HPLC anion and cation exchange chromatography. 2. 2. HPLC venom fractions were tested for hemorrhagic, hemolytic, and proteolytic activities. 3. 3. Crude Virginia opossum ( Didelphis virginiana) serum neutralized the hemorrhagic activity of HPLC fractions.

Noteworthy Longevity in Crotalus viridus viridus (Rafinesque)

Recently, Tabor College learned that its captive prairie rattlesnake (Crotalus viridus viridus) has probably established the species' record for longevity captivity (J. Collins, pers. comm.). At 27 years and 9 months (as of May 1988) in residence the Tabor Biology department, the known age substantially exceeds that reported for any other captive prairie rattlesnake. The previous longevity record for C. viridus, published by Bowler 1977, was given as 19 years, 3 months, and 10 days. In the same paper, Bowler also reported a record of 13 years, 4 months for C. horridus. Shaw (1962, 1969) described a C. atrox specimen that attained the age of 24 years, 4 months. The Tabor C. viridus is a new longevity captivity record for all reported specimens the genus Crotalus. The Tabor specimen was captured July 1960 by Monroe Bartel (presently employed at Moorehead State University, Minnesota) near Lakin, Kearny County, Kansas. Age at capture was estimated at ca. 2 years, according to S. L. Loewen, who headed the Biology department at that time. At capture, the snake measured 60 cm length. Average length for an adult prairie rattlesnake is 91 cm (Boles, 1971), while maximum length may range from 145 cm (Collins, 1982) to 152 cm (Boles, 1971). Present statistics of the Tabor snake are length, 102.9 cm, and weight, 1.11 kg. No record of capture weight could be found. From the outset the Tabor rattler has been housed glass-fronted wooden cages approximately 60 cm square. The snake cages are near laboratories and classrooms and are viewed by the public. Temperature has always been fairly constant (21-27?C) and lighting averages 10-20 foot candles, with a 14/10 photoperiod. Food consists mainly of live rodents and birds with ad libitum water. Feeding is stopped about 1 November and resumed toward the end of March, a regimen approximating the natural activity cycle of the species (see Collins, 1982). Stress is the chief obstacle which a reptile must overcome if it is to adapt successfully to confinement. Lhatka (1980) noted that C. atrox may literally

Neutralization of toxic and enzyme activities of 4 venoms from snakes of Guatemala and Honduras by the polyvalent antivenin produced in Costa Rica

We studied the ability of the polyvalent antivenom produced in Costa Rica to neutralize lethal, hemorrhagic, edema-forming, proteolytic, hemolytic, hyaluronidase and fibrinolytic activities of the venoms of Bothrops asper and B. nummifer from Honduras, and of Agkistrodon bilineatus and Crotalus durissus durissus from Guatemala. Neutralizing ability of antivenom was expressed as ED50 (effective dose 50%), defined as the antivenom/venom ratio at which the activity of the venom is reduced 50%. Antivenom is highly effective in the neutralization of lethal, hemorrhagic, hemolytic, hyaluronidase, and caseinolytic activities of B. asper, B. nummifer, and C. d. durissus venoms. In the case of B. nummifer venom, neutralization of fibrinolytic effect was only partial, whereas this activity was adequately neutralized when studying the venoms of B. asper and C. d. durissus. The venom of A. bilineatus was adequately neutralized by the antivenom, with the only exception of hemolytic effect that was reduced only partially. However, in quantitative terms, a relatively large volume of antivenom was required to neutralize some effects induced by A. bilineatus venom. Regarding edema-forming activity, antivenom neutralized efficiently the venoms of B. asper and A. bilineatus, whereas that of B. nummifer was neutralized only partially; on the other hand, edema induced by the venom of C. d. durissus was not neutralized at all. Immunochemical results indicate a close immunological relationship between venoms of B. asper, B. nummifer and C. d. durissus collected in Honduras and Guatemala with those of the same species collected in Costa Rica. Interspecies comparison, however, showed variation between venoms obtained from different species.(ABSTRACT TRUNCATED AT 250 WORDS)

Venom properties of the rattlesnakes ( Crotalus) inhabiting the Baja California region of Mexico

Seven species of rattlesnakes (genus Crotalus) from Baja, Mexico, were investigated for venom yield, protein content, lethal toxicity, ‘Mojave toxin’ content and hemorrhagic, esterase (BAEE), phosphodiesterase and protease activities. Venom yield was lowest in C. catalinensis and C. enyo enyo and highest in C. ruber ruber. All venoms exhibited esterase and phosphodiesterase activities, except that three (of 14) specimens of C. e. enyo lacked esterase activity. Protease activity was extremely low or absent in adult C. e. enyo, adult C. mitchellii mitchellii, adult C. viridis caliginis and juvenile C. r. ruber venoms. The venom of C. m. mitchellii was the only venom lacking hemorrhagic activity. This venom also had the highest lethal toxicity (i.p. ld 50 0.13 – 0.24 mg/kg) in mice, and was the only venom that exhibited a toxin antigenically related to ‘Mojave toxin’.

Myonecrosis, myoglobinuria and acute renal failure induced by south american rattlesnake ( Crotalus durissus terrificus) envenomation in brazil

The venom of the Brazilian rattlesnake Crotalus durissus terrificus is know to have hemolytic and neurotoxic physiopathological activities which may cause acute renal failure with hemoglobinuria and/or methemoglobinuria. As far as we know, no report has been published on the ability of the venom of this rattlesnake species to cause rhabdomyolysis. In the present paper we demonstrate that the venom of Brazilian snakes of the genus Crotalus can induce systemic myonecrosis. Clinical, laboratory and anatomo-pathological data for two patients referred to the University Hospital of the Faculty of Medicine of Ribeirão Preto, University of São Paulo, 24 hr after a rattlesnake bite, are presented. In both cases, exaggerated elevation of serum levels of the enzymes creatine phosphokinase, lactate dehydrogenase and glutamic-oxaloacetic transaminase were detected, as well as data suggesting acute hypercatabolic renal failure. Immunoelectrophoresis of the serum and urine of these patients, carried out against specific anti-myoglobin serum (Behringwerke), demonstrated myoglobinemia and myoglobinuria, confirming injury to muscle tissue. Electron microscopy of a calf muscle biopsy taken from the leg contralateral to the bite from one patient revealed foci of myonecrosis.

Rattlesnakes (Genus Crotalus) of the Pedro Armendariz Lava Field, New Mexico

Rattlesnakes (Genus Crotalus) of the Pedro Armendariz Lava Field, New Mexico

Rattlesnake Venom Enzymes that Interact with Components of the Hemostatic System

AbstractVenom from snakes of the genus Crotalus (rattlesnakes) contain several enzymes that interact with platelets or proteins of the blood coagulation system. Although recognized experimentally by their effect on components of the hemostatic system, it should be noted that these venom enzymes are proteinases and their specificities may not be uniquely directed to the clotting proteins or platelets. There are primarily three different activities in rattlesnake venoms that account for interactions of the venoms with blood-borne components of the hemostatic system; thrombin-like, platelet aggregating, and fibrin(ogen)olytic. Although these activities are present in many rattlesnake venoms, they are not always present simultaneously in venom from every species. Thrombin-like enzymes are serine esterases that have been described in a variety of rattlesnake venoms and have been purified from several of them. These enzymes produce a benign state of defibrinogenation following intravenous infusion. They have li...

Immunological comparison of phospholipases A 2 present in rattlesnake (genus Crotalus) venoms

The immunological properties of phospholipase A 2 present in venoms from seven species of rattlesnakes (genus Crotalus) from different geographical distributions have been compared. Rabbit antiserum to purified PLA 2 of Crotalus scutulatus salvini venom was used, employing inhibition of enzymic activity and immunodiffusion techniques. The amount of antiserum required for 50% inhibition of the PLA 2 activity in the venoms varied from slightly more than that required for inhibition of the activity in the homologous venom to a large amount (effectively zero inhibition). A particularly close relationship in the antigenic makeup was observed between the phospholipases of C. s. salvini and C. atrox venoms as evidenced by inhibition of enzymic activity and immunodiffusion studies. No immunological cross reactivity was observed between the enzymes of the subspecies C. s. salvini and C. s. scutulatus. The results suggest extensive variations in the antigenic structure of the phospholipase molecules. The findings may also have some taxonomic significance.

Intensive Care Unit Treatment of Acute Renal Failure Following Snake Bite *

Twenty-nine patients with acute renal failure following bites by snakes of the genera Crotalus and Bothrops were treated in an Intensive Care Unit (ICU). Eight were given conservative treatment. Peritoneal dialysis was necessary in 21 patients, and hemodialysis in one of these. The main complications occurring while the patients were in the ICU were pulmonary edema (5 cases), respiratory failure (4), cardiac arrest (4), and hypovolemic shock (1 case). Three patients died with respiratory and hemodynamic disturbances while in the ICU, one of them during the polyuric phase. Twenty-four patients were discharged from the hospital with no clinical or laboratory evidence of renal failure. Two patients developed bilateral cortical necrosis of the kidney. One of them died in the general ward after interruption of dialysis and the other was discharged from the hospital with chronic renal failure. It was not possible to perform a kidney transplantation. The importance of the ICU in the recovery of such patients is stressed.

The Allometrics of Rattlesnake Skeletons

MODELS which have sought to describe the differential increase in the length and width dimensions of the support elements of the tetrapod skeleton have been proposed by Rashevsky (1960) and, more recently, by McMahon (1973). On the basis of engineering principles, these models have predicted that the dimensions (d, diameter or thickness and 1, length) of a support element such as a long bone (Fig. 1) should vary so that d oc 13/2 as the overall linear dimension of the body increases. The capability of such an element to support a load is a function of its cross-sectional area and is therefore proportional to d2. If the length of the bone is directly proportional to the overall linear dimension of the body (it may be assumed that such is the case in a group of geometrically similarly shaped animals) then the body volume (= weight) will be proportional to 13. Since the load on the support element is the body weight, d2 must be proportional to 13 and, hence, d oc 13/2. In an investigation of the systematic status of the Pleistocene rattlesnake Crotalus giganteus, Christman (1975) reported measurements which showed that the length of a midbody vertebra was directly proportional to the overall length of the snake within the several species of the genus Crotalus (Fig. 2a gives the regression line and his data on C. adamanteus). Christman further pointed out that the vertebral width increased at a greater rate than did vertebral length as the body length increased (Fig. 2b). These findings suggest that the dimensional relationships which have heretofore been applied only to skeletons of tetrapods might apply to snake skeletons as well. This paper reports on our further investigation of the allometrics of the skeletal dimensions of the eastern diamondback rattlesnake.

Distribution of 5S RNA in the liver of the South American rattlesnake, Crotalus durissus terrificus.

Nous avons etudie la distribution du RNA 5S dans le foie du serpent sud-americainCrotalus durissus terrificus. Nos resultats ont montre que le RNA 5S de ce reptile est associe a la sous-unite ribosomique 60 S. D'autre part, la mobilite electrophoretique de ce RNA de faible poids moleculaire est la meme que celle d'Escherichia coli et de pupe d'Apis mellifera L.

A purified procoagulant enzyme from the venom of the eastern diamondback rattlesnake (Crotalus adamanteus): in vivo and in vitro studies.

Abstract A procoagulant enzyme in the venom of the eastern diamondback rattlesnake, Crotalus adamanteus , has been isolated and purified. The enzyme acts directly on purified fibrinogen or fibrinogen in plasma, forming a friable fibrin clot. The enzyme does not activate factors of the extrinsic system, nor does it activate factor XIII. It also does not aggregate platelets and is not inhibited by heparin. Incubation with plasma produces insignificant changes in all coagulation factors except fibrinogen. The enzyme does not activate components of the fibrinolytic system, but is itself fibrinolytic at extremely high concentration. Infusion into dogs produces well tolerated hypofibrinogenemia lasting up to 8 hours. Post infusion, intense fibrinolysis is observed with high titers of nonclottable fibrinogen derivatives in the serum, some with an electrophoretic mobility similar to native fibrinogen. Following infusion declines in factors II, V, and VIII were noted by one stage assays, but may be artifactual due to high levels of fibrinogen derivatives in the test plasmas.

Mid-brain responses of the auditory and somatic vibration systems in snakes.

ABSTRACT Evoked slow potentials were recorded extracellularly from the mid-brains of snakes of the genus Crotalus. For the auditory and somatic systems, amplitude, latency, and duration of responses were studied as the parameters of intensity, frequency, and rise time of sinusoidal vibratory or click stimuli were varied. Recovery curves were constructed for paired stimuli and for trains. Effects of body temperature on frequency-response threshold curves were determined. Results were verified for species of the families Boidae and Colubridae. Intensity-amplitude curves increase logarithmically for c. 20 dB above threshold and then reach a plateau for the auditory system. These curves are generally increasing over a 40 dB range in the somatic system. Latency decreases monotonically with increasing intensity; it is independent of frequency for the auditory system but depends on frequency for the somatic system. Differences in shape of intensity-amplitude curves for different frequencies lead to the hypothesis that there are auditory units with different frequency-response curves. This finding is relevant to the study of the evolution of audition. Differences in intensity-amplitude curves for the somatic system and differences in latencies for different frequencies suggest that several types of somatic vibration receptors contribute to the central response. Increase in body temperature causes increase in the frequency of greatest sensitivity for the auditory system, and increases sensitivity by 1−3 dB per°C. Higher frequencies are affected more than lower frequencies. The somatic system sensitivity is increased by c. 1·5 dB per°C, except at the extremes of the frequency curve. These findings emphasize the importance of studying effects of temperature on the central nervous systems of cold-blooded vertebrates. Of relevance to the biology of snakes is the observation that snakes are not well suited, at the mid-brain level, for rapid analysis of sequential vibratory events. A principle of general biological significance supported by comparison of temporal characteristics of mid-brain responses of snakes and other animals is that latency and recovery are related to auditory specialization rather than to phylogeny.

A Comparative Study of the Arterial Systems of Some New World Crotalinae (Reptilia: Ophidia)

The arterial systems of seven or eight latex-injected specimens, plus two uninjected specimens, of the following species were studied: Agkistrodon contortrix, A. piscivorus, Sistrurus catenatus, S. miliarius, Crotalus horridus, C. viridis and C. atrox. Six uninjected specimens of Lachesis muta, three of S. ravus, and one or two of each of 13 additional species of Crotalus were also used for studying pulmonary artery patterns. In general, the pulmonary artery patterns show a change from the dominant right pulmonary artery pattern in primitive Agkistrodon, to a modified version of this pattern in intermediate Sistrurus, to the right- left pulmonary artery pattern in advanced Crotalus, where the left pul- monary artery is dominant. However, S. ravus differs from S. catenatus and S. miliarius in its lung patterns, resembling the triseriatus group of the genus Crotalus. Laichesis has a large right and a small left pul- monary artery. This probably represents the earliest appearance of the right-left pulmonary artery pattern in the phylogeny of the North American Crotalinae. Primitive Agkistrodon usually feeds both the pterygoid and tem- poralis muscle complexes via the venom gland artery; Sistrurus does so partly via the venom gland vessel and partly by the facial carotid artery; Crotalus usually has both complexes fed by the facial carotid. The right side of the head of Agkistrodon differs from the left in its arterial ar- rangement. The number of branches from the left carotid artery to the esopha-

A New Subspecies of the Ridged-Nosed Rattlesnake, Crotalus willardi, from Chihuahua, Mexico

BREDER, C. M., JR. 1932. On the habits and development of certain Atlantic Synentognathi. Carnegie Inst. Wash. Pub. No. 435 (Pap. Tortugas Lab. Vol. 28), pp. 1-35, pls. 1-12, figs. 110. AND PRISCILLA RASQUIN. 1952. The sloughing of the melanic area of the dorsal fin, an ontogenetic process in Tylosurus raphidoma. Bull. Am. Mus. Nat. Hist. 99(Art. 1):1-23, pls. 1-4, figs 1-3. LONGLEY, WILLIAM H. AND SAMUEL F. HILDEBRAND. 1941. Systematic catalogue of the fishes of Tortugas, Florida. ... Carnegie Inst. Wash. Pub. No. 535 (Pap. Tortugas Lab. Vol. 34), pp. 1331, pls. 1-34.