Cerastes Vipera Research Articles

Anticancer potency of Egyptian venom snakes on MCF-7 and HepG2 carcinoma cells.

Breast and hepatic cancers are the leading incidences in the globe occurring of the human sufferings from various cancers. Snake venoms have been reported to provide effective therapeutic agents. The current study investigates the anticancer potency of Egyptian venoms snakes on two cells: breast cancer cells (MCF-7) and hepato-cancer cells (HepG2) (In vitro assay). The examined venoms were more potent on MCF-7 than HepG2 cells. Their inhibition % on MCF-7 ranged from 71.47 to 99.02% with medium inhibition concentrations (IC50s): 3.48, 3.60, 3.70, 4.33, and 4.49 μg/ml for venoms: Echis pyramid (E.H), Cerastes vipera (C.V), Naja haje (N.H), Echis coloratus (E.C), and Cerastes cerastes (C.C), respectively. The values of IC50s on HepG2 were 4.32, 17.77, 59.72, 63.75, and 217.90 μg/ml for toxins: E.C, E.P, C.V, C.C, and N.H, respectively. Some biomarkers were conducted to investigate the apoptotic effects of toxins into the cells. Increasing profiles of lactate dehydrogenase (LDH) activity and levels of glutathione content (GSH) and malodialdhyde (MDA) as well as repairment of DNA indicated such these actions. So, more reliable investigations on these venoms were needed to provide intelligent therapeutic agent for cancer treatment.

Hidden in the sand: Phylogenomics unravel an unexpected evolutionary history for the desert-adapted vipers of the genus Cerastes

The desert vipers of the genus Cerastes are a small clade of medically important venomous snakes within the family Viperidae. According to published morphological and molecular studies, the group is comprised by four species: two morphologically similar and phylogenetically sister taxa, the African horned viper (Cerastes cerastes) and the Arabian horned viper (Cerastes gasperettii); a more distantly related species, the Saharan sand viper (Cerastes vipera), and the enigmatic Böhme’s sand viper (Cerastes boehmei), only known from a single specimen in captivity allegedly captured in Central Tunisia. In this study, we sequenced one mitochondrial marker (COI) as well as genome-wide data (ddRAD sequencing) from 28 and 41 samples, respectively, covering the entire distribution range of the genus to explore the population genomics, phylogenomic relationships and introgression patterns within the genus Cerastes. Additionally, and to provide insights into the mode of diversification of the group, we carried out niche overlap analyses considering climatic and habitat variables. Both nuclear phylogenomic reconstructions and population structure analyses have unveiled an unexpected evolutionary history for the genus Cerastes, which sharply contradicts the morphological similarities and previously published mitochondrial approaches. Cerastes cerastes and C. vipera are recovered as sister taxa whilst C. gasperettii is a sister taxon to the clade formed by these two species. We found a relatively high niche overlap (OI > 0.7) in both climatic and habitat variables between C. cerastes and C. vipera, contradicting a potential scenario of sympatric speciation. These results are in line with the introgression found between the northwestern African populations of C. cerastes and C. vipera. Finally, our genomic data confirms the existence of a lineage of C. cerastes in Arabia. All these results highlight the importance of genome-wide data over few genetic markers to study the evolutionary history of species.

A nocturnally-active predator is mainly a diurnal hunter

The sit-and-wait hunter, Cerastes vipera, is a presumed nocturnally-active desert snake, although it feeds mainly on the diurnally-active lizard, Acanthodactylus spp. We hypothesized that nocturnal activity of C. vipera is primarily to locate an ambush site, and that Acanthodactylus spp. is predated mainly diurnally. We used the proportion of free-ranging C. vipera that defaecated per day to estimate daily feeding rate, and prey capture per night to estimate nocturnal feeding rate. In adult snakes (n = 161), defaecation was observed in 20.5% and nocturnal feeding in 3.1% per day. The difference between the two estimates represented the diurnal feeding rate, that is, 85% of the daily feeding was diurnal. All vipers ceased movement near midnight, when approximately 50% were in ambush. They maintained their position until morning and four individuals of each sex were followed during the day. These vipers displayed caudal luring in the presence of Acanthodactylus spp., ended ambush at approximately 10:00 when air temperature reached 40 °C, and then moved into a nearby burrow. We concluded that nocturnally-active C. vipera adults are mainly diurnal hunters, but could be classified as cathemeral predators. Diurnal caudal luring and differences in ambush strategy in C. vipera are documented for the first time.

Testing the morphological constraint hypothesis of tail length in the sexually dimorphic Cerastes vipera and new perspectives

The morphological constraint hypothesis (MCH) states that, in snakes, males typically have relatively longer tails than females to accommodate the hemipenes and retractor muscles. To date, most studies testing the MCH have been interspecific and results have been equivocal. We tested the MCH intraspecifically on Cerastes vipera, a species with a relatively short tail and suitable for testing the MCH. The relative tail length and length of the hemipenes pocket in Cerastes vipera were measured in preserved museum-maintained males (n = 35) and in free-ranging males and females (n = 277). Males exhibited relatively longer tails than females, which was explained fully by the length of the hemipenes pocket. The relatively short tail of C. vipera presents a constraint to the reproductive structures in males, as the length of the hemipenes pocket occupies a greater proportion in shorter- than longer-tailed individuals. This is the first report presenting these intraspecific findings in support of the MCH. Whether these relations are widespread among snake families, within Viperidae, or specifically within C. vipera warrants further studies.

Replacement of fangs in a free-ranging desert viperid, Cerastes vipera

Venomous viperid snakes possess relatively large and fragile hollow fangs that are an integral part of the envenomation apparatus for predation. We hypothesized that fangs serve like disposable needles and predicted a high loss rate and, hence, high replacement rate in free-ranging snakes. Snakes also possess smaller rear teeth that aid in gripping and swallowing the prey. We reasoned that these teeth are less delicate than fangs and predicted that their loss would be at a slower rate than fangs. To test our predictions, we analyzed fecal samples of free-ranging Saharan sand vipers, Cerastes vipera, in the Northern Negev desert, Israel. Close to 25% of fecal samples contained fangs, averaging more than one fang per sample and, consequently, our first prediction was supported. We estimated that fangs are replaced each fourth predation, and that replacement rate under natural conditions is at a high rate of approximately every twenty days. Fecal samples contained rear teeth at the same proportion as fangs, which indicated that the rapid replacement of teeth was not limited only to fangs and, therefore, our second prediction was not supported. These findings reflect the importance of both front fangs and rear teeth in the hunting of prey in free-ranging C. vipera. This is the first quantitative report of fang and rear teeth loss in a free-ranging viperid which is based on their recovery in feces; and we believe that similar high rates of loss occur in other viperid species.

Using animal tracks to decipher the foraging mode of species capable of altering between the sit-and-wait and widely foraging modes: a case study of the sand viper Cerastes vipera

Abstract The sand viper Cerastes vipera can employ one of two distinct foraging modes, the widely foraging or sit-and-wait mode, depending on the interplay between external and internal factors. Here, I illustrate how tracking methods can be used to evaluate the relative usage of each of the two foraging modes by the sand viper. Foraging theory models generally refer to the time invested in foraging as the main indicator of the energy invested in foraging. I suggest that tracking and counting print marks on trails offer a more precise method of estimating foraging costs in the field. I model the benefits and costs of the viper employing each of the two foraging modes using tracking data, and discuss how it can be used to decipher its foraging mode. I present a measurement approach by which to assess the relative usage of different foraging modes. I contend that the proposed tracking methods and their analysis should prove to be equally applicable to other animals that leave print marks on sand or snow.

In Vitro Evaluation of Antibacterial Potential of Cerastes Vipera Venom against Gram-Positive and Gram-Negative Bacterial Strains

Background: Venoms of the family Viperidae in particular are complex mixture of many substances. They include many different proteins that possess significant bactericidal inhibition. Objectives: The aim of the current work was to investigate the antibacterial profile of Sahara sand viper (Cerastes vipera) snake venom against both gram negative Pseudomonas aeruginosa and gram-positive bacteria Bacillus cereus. Materials and Methods: 1. Identification of the venom was performed using assessment of total protein, determination of the venom protein by SDS-PAGE electrophoresis and determination of the half lethal dose (LD50) of venom. 2. Antibacterial activities of Cerastes vipera venom was examined by using disc diffusion method. Microdilution method was used to determine the venom's minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). 3. The interaction between venom and bacteria was examined by Electron microscope. Results: The total protein of the venom was 1.047±0.1 mg/ml. The SDS electrophoresis showed there were four clear bands of protein nearly at 25, 35, 48, 63 Kds and another band betweee 25, and 35 Kds. The LD50 was 18.3 µg/mouse (0.915 mg/kg body weight). Concerning the antibacterial effect of tested venom, disc diffusion test showed a ring of inhibition zone of about 12 mm in the case of Pseudomonas aeruginosa and of about 0.8 mm in the case of Bacillus cereus. The Microdilution test showed that the MIC of the venom for Pseudomonas aeruginosa was 12.5 mg/ml and that for Bacillus cereus was 25 mg/ml. The electron microscopic examination supported the two previous tests, as it observed the presence of elongated, malformed, melted, no-membranous and lysed bacterial cells when treated by the venom. Conclusion: It could be concluded that Cerastes vipera venom is a potentially weak bactericidal, but can inhibit antibiotic-resistant bacteria as Pseudomonas aeruginosa.

In Vitro Evaluation of Antibacterial Potential of Cerastes Vipera Venom against Gram-Positive and Gram-Negative Bacterial Strains

Background: Venoms of the family Viperidae in particular are complex mixture of many substances. They include many different proteins that possess significant bactericidal inhibition. Objectives: The aim of the current work was to investigate the antibacterial profile of Sahara sand viper (Cerastes vipera) snake venom against both gram negative Pseudomonas aeruginosa and gram-positive bacteria Bacillus cereus. Materials and Methods: 1. Identification of the venom was performed using assessment of total protein, determination of the venom protein by SDS-PAGE electrophoresis and determination of the half lethal dose (LD50) of venom. 2. Antibacterial activities of Cerastes vipera venom was examined by using disc diffusion method. Microdilution method was used to determine the venom's minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). 3. The interaction between venom and bacteria was examined by Electron microscope. Results: The total protein of the venom was 1.047±0.1 mg/ml. The SDS electrophoresis showed there were four clear bands of protein nearly at 25, 35, 48, 63 Kds and another band between 25, and 35 Kds. The LD50 was 18.3 μg/mouse (0.915 mg/kg body weight). Concerning the antibacterial effect of tested venom, disc diffusion test showed a ring of inhibition zone of about 12 mm in the case of Pseudomonas aeruginosa and of about 0.8 mm in the case of Bacillus cereus. The Microdilution test showed that the MIC of the venom for Pseudomonas aeruginosa was 12.5 mg/ml and that for Bacillus cereus was 25 mg/ml. The electron microscopic examination supported the two previous tests, as it observed the presence of elongated, malformed, melted, no-membranous and lysed bacterial cells when treated by the venom. Conclusion: It could be concluded that Cerastes vipera venom is a potentially weak bactericidal, but can inhibit antibiotic-resistant bacteria as Pseudomonas aeruginosa.

Sexual dichromatisation and sexual differences in hunting behavior and dietary intake in a free-ranging small viperid snake, Cerastes vipera

The tip of the tail in female Cerastes vipera, a small viperid snake, is black and conspicuous, whereas that of the male is not. We tested the hypothesis, albeit indirectly, that this sexual dimorphic chromatisation is related to caudal luring, a feeding mimicry hunting strategy. C. vipera can hunt nocturnally-active lizards only via sit-and-wait ambush and, consequently, we predicted that females would use caudal luring more often than males and that the proportion of nocturnal prey items in the diet of females would be higher than in males. Our hypothesis was supported as: 1) only females demonstrated caudal luring towards nocturnally-active lizards and more than 85% did so, whereas none of the males demonstrated such behavior; and 2) females consumed a significantly higher proportion (15/40 vs 4/27) of nocturnally-active lizards than did males. We concluded that sexual dichromatisation in C. vipera is associated with hunting strategy that results in different hunting behavior and different dietary intake between sexes. These novel findings: 1) provide a functional explanation for the black tail of female C. vipera; and 2) suggest different evolutionary driving forces between sexes and, consequently, different ecological impacts of male and female C. vipera on lizard populations.

A hemorrhagic metalloprotease of Egyptian Cerastes vipera venom: Biochemical and immunological properties.

A hemorrhagic metalloprotease (CVHT1) was isolated from Cerastes vipera (CV) viper venom and characterized in a set of biochemical and immunological assays. A simple two-step purification procedure included gel filtration and ion-exchange increase the purity of enzyme 39-fold with specific activity of 20,200 Umg-1 compared to 520 Umg-1 for crude venom. CVHT1 is a dimer enzyme with two subunits of ~60 kDa. The LC-MS/MS analysis of CVHT1 revealed that the identified peptides show high homology to other P-III snake venom zinc-metalloproteases. The activity of CVHT1 showed stability at pH (6.5-8.5) and temperature (30-60 °C) with optima at pH 8.5 and 60 °C. Activators for CVHT1 included Mg+2, Zn+2, Ca+2, K+, Ba+2 and Na+, while the full inhibition was given by other tested ions, SH-group reagents and metalloproteinase inhibitors. The CVHT1 potentially digested gelatin, fibrinogen, fibronectin and inhibited the platelet aggregation. The hemorrhagic and proteolytic activities of medically important Egyptian viper venoms were highly cross-neutralized by anti-CVHT1. The anti-CVHT1 increased the survival time of mice injected with lethal dose of CV venom to 23 ± 2.5 h compared to the mice injected with venom alone 0.52 ± 0. 05 h. This study could be useful for production of safer and more efficient therapeutic anti-venom.

Isolation and Characterization of a Myotoxic Fraction from Cerastes Vipera Snake Venom

Isolation and Characterization of a Myotoxic Fraction from Cerastes Vipera Snake Venom

Seasonal biotic and abiotic factors affecting hunting strategy in free-living Saharan sand vipers, Cerastes vipera

Sit-and-wait ambushing and active hunting are two strategies used by predators to capture prey. In snakes, hunting strategy is conserved phylogenetically; most species employ only one strategy. Active hunters encounter and capture more prey but invest more energy in hunting and have higher risks of being predated. This trade-off is important to small predators. The small Cerastes vipera employs both modes of hunting, which is unlike most viperids which use only sit-and wait ambushing. This species hibernates in October and emerges in April. Energy intake should be high prior to hibernation to overcome the non-feeding hibernation period and for reproduction on their emergence. We predicted that more individuals would hunt actively towards hibernation and an abiotic factor would trigger this response. Furthermore, since more energy is required for active hunting, we predicted that snakes in good body condition would use active hunting to a greater extent than snakes in poor body condition. To test our predictions, we tracked free-living snakes year round and determined their hunting strategy, estimated their body condition index (BCI), and calculated circannual parameters of day length as environmental cues known to affect animal behaviour. Two novel findings emerged in this study, namely, hunting strategy was affected significantly by 1) the circannual change in day length and 2) by BCI. The proportion of active hunters increased from 5% in April to over 30% in October and BCI of active foragers was higher than that of sit-and-wait foragers and, therefore, our predictions were supported. The entrainment between the proportion of active hunting and the abiotic factor is indicative of an adaptive function for choosing a hunting strategy. A trend was evident among life stages. When all life stages were present (September–October), the proportion of active foragers increased with age: 0.0% among neonates, 18.2% among juveniles and 31.4% among adults. We concluded that vulnerable small neonates used sit-and-wait ambush not only as a hunting strategy but also as a hiding technique.

Body size and seasonal body condition in two small coexisting desert snake species, the Saharan sand viper (Cerastes vipera) and the crowned leafnose (Lytorhynchus diadema)

The Saharan sand viper, Cerastes vipera, and the crowned leafnose, Lytorhynchus diadema, are small coexisting psammophilic desert snake species, consume primarily lizards and do not engage in male to male combat. They differ in that C. vipera is ovoviparous and L. diadema is oviparous, C. vipera moves by sidewinding while L. diadema uses serpentine movement and C. vipera is a sit-and-wait ambusher while L. diadema is an active hunter. Results showed that C. vipera was heavier than L. diadema per unit snout-vent length (SVL). We concluded that this was related to foraging, as L. diadema had to move quicker than L. diadema, and to reproduction, as C. vipera needed more abdominal space for developing embryos. Sexual size dimorphism was found in adults in both species and it appeared that ecological advantages took precedence over phylogenetic affinity in determining size differences. The relatively small size, ovoviparity, sandy habitat with sidewinding, and lack of male to male combat for C. vipera whereas oviparity and sandy habitat for L. diadema may explain partly sexual size dimorphism in these species. Females showed seasonal fluctuations in BCI in both species but males did not and C. vipera females showed greater fluctuations than L. diadema females. We concluded that the former resulted from higher energy costs of females than males and the latter because ovoviparity is costlier than oviparity.

Temporal activity and dietary selection in two coexisting desert snakes, the Saharan sand viper (Cerastes vipera) and the crowned leafnose (Lytorhynchus diadema)

The Saharan sand viper (Cerastes vipera) and the crowned leafnose (Lytorhynchus diadema) are two snake species well adapted to desert sand dunes and, in Israel, coexist in the western Negev Desert. C. vipera is a sit-and-wait ambusher while L. diadema is an active hunter. We studied the seasonal and diel activity patterns and dietary selection of these two species while free-living in the field. Both species were active from early spring until late fall but displayed (i) different seasonal activity patterns –C. vipera was bimodal with peaks in spring and autumn whereas L. diadema was basically unimodal with a peak in summer; (ii) different nocturnal above-ground activity patterns –C. vipera was active mainly during the first three hours of darkness while L. diadema was constantly active during the first seven hours of darkness; and (iii) different patterns of nocturnal behavior –C. vipera moved up to 50m while L. diadema moved several hundred meters each night. Dietary selection differed between these snake species although lizards, mainly Nidua fringe-fingered lizards (Acanthodactylus scutellatus), were the main dietary item for both. We concluded that temporal partitioning in above-ground activity, different foraging strategies and differences in dietary selection may contribute towards the coexistence of the two snake species.

Reproductive cycle of free-living male Saharan sand vipers, Cerastes vipera (Viperidae) in the Negev desert, Israel

The Saharan sand viper, Cerastes vipera (Linnaeus, 1758), is distributed in all Saharan countries, being confined to sand and dune systems. This relatively small snake, up to 35cm, is nocturnal, is active from spring to autumn (April to October) and hibernates during the winter (November to March). We predicted that C. vipera would have peak plasma testosterone concentration at mating and that the vas deferens would contain abundant spermatozoa at that time. To test our predictions, we collected information on the time of mating and measured monthly testosterone concentration, testes size and testicular activity in free-living male C. vipera during its active period from April to October. Mating occurred only during spring. The pattern of plasma testosterone concentration, testes volume, seminiferous tubule diameter and spermatogenesis all followed the general pattern of high values in autumn and spring and low values in early summer. Our predictions were partially supported. There was a high plasma testosterone concentration at mating in spring and the vas deferens contained abundant spermatozoa, as predicted, but there was also a high plasma testosterone concentration in autumn without mating. We concluded that: (1) males are both aestival in that they produce spermatozoa in autumn, which they store over the winter hibernation period, and vernal in that they produce spermatozoa in spring prior to mating; (2) matings are associated with spermatogenesis; and (3) the high plasma testosterone concentration is concomitant with both matings and spermatogenesis in spring and with spermatogenesis in autumn. We propose that C. vipera has a single peak of testicular activity and plasma testosterone concentration which start in autumn and end in spring. We also propose that spermatogenesis is prior to spring mating and, consequently, is prenuptial.

Armées en marche et découvertes herpétologiques dans l'Antiquité*

Expeditionary forces and herpetological discoveries in AntiquityA number of impressive cases of armies confronted by venomous serpents in remote parts of the world are mentioned in ancient texts: from the eastern campaigns of Alexander and of Pompey to the expeditions led in Northern Africa, the Levant and Arabia, several recurring themes raise questions about the epistemological function of these military episodes. As well as traditional fears about the potential dangers of unknown territory, various aspects of these accounts are related to the discovery of knowledge about ophidians: an exploratory mission, the behaviour of the group, unfavourable circumstances, the presence or absence of medical specialists, information supplied by native people. This paper offers an overview of these different expeditions and of the ophidians discovered and explores the boundaries between legend, history and science. The study reveals that two types of situation generally occur: the armies are either confronted with truly dangerous species (Bungarus, Eristicophis macmahonii, Cerastes cerastes, Cerastes vipera), or they consider serpents which are in fact harmless to be harmful (Eryx jaculus, Coluber elegantissimus). Both situations serve to exaggerate the portrayal of this kind of encounter as catastrophic.

Comparative Morphology of the Skin ofNatrix tessellata(Family: Colubridae) andCerastes vipera(Family: Viperidae)

We studied beneficial difference of the skin of two snakes. Two snakes were chosen from two different habitats and two families: Colubridae (Natrix tessellata) and Viperidae (Cerastes vipera). The investigations were performed by light and electron microscopy. Histologically, the skin of the studied species show pronounced modifications that correlated with functional demands. The scales in Natrix tessellata overlapped slightly, while in Cerastes vipera they were highly overlapped. SEM shows that scales of Natrix tessellata had bidentate tips while the scales of Cerastes vipera were keeled. Histochemically, in both studied species, melanocytes and collagenous fibres were distributed throughout the dermis. Polysaccharides were highly concentrated in the epidermis and dermis of both species while proteins were highly concentrated only in the epidermis. Transmission electron microscopy (TEM) showed that the skin of both snakes consisted of keratins located in the epidermis. Some lipids and mucus were incorporated into the outer scale surfaces such that lipids were part of the fully keratinised hard layer of the snakes' skins. Lipids are probably responsible for limiting water loss and ion movements across the skin. Melanosomes from epidermal melanocytes were present only in Cerastes vipera. In aggregate, these results indicate that snakeskin may provide an ecological indicator whereby epidermal and integumentary specializations may be ecologically correlated.

Foraging behavior and predation success of the sand viper (Cerastes vipera)

Activity levels and foraging success of ectotherms are dependent both on extrinsic factors (e.g., ambient temperature) and intrinsic factors (e.g., hunger level). We focus here on activity and foraging of sand vipers ( Cerastes vipera (L., 1758)) (Squamata: Viperidae) in the northwestern Negev desert of Israel. Viper activity is bounded by a specific thermal range, but within this range, temperature does not affect the distance moved. Movement distances are, however, positively correlated with relative humidity. The capture success of lizards, the main prey of this viper, is strongly related both to movement distances of the snake and to the number of the lizard burrows scanned. Body size and shape have a direct effect on the number of burrows scanned and on the number of lizards captured. The increase in capture success with size is probably due to the consequent increase in the range of prey items the sand viper can subdue or handle. Vipers are larger and have a higher mass to length ratio in one of the three study sites, characterized by higher mean annual rainfall and vegetation cover. Finally, females tend to have a higher mass to length ratio than males, which may provide some space within the female body for reproductive materials such as eggs.

The karyology of Vipera aspis, V. atra, V. hugyi, and Cerastes vipera

AbstractIn the current paper we show the results obtained using standard and banding staining methods (Ag-NOR-, CMA3-, C-banding and sequential colorations (or Alu I digestions) + CMA3 + DAPI) in specimens of Cerastes vipera, Vipera aspis, V. atra, and V. hugyi. Cerastes vipera presented chromosomal characters, primitive in snakes, as a karyotype of 2n = 36 chromosomes, with 16 biarmed macrochromosomes and 20 microchromosomes, NORs on one microchromosome pair and absence of cytologically evident sex chromosomes, at least with the methods used. The three taxa of Vipera studied showed chromosomal characters either derived, or primitive or at an initial stage of differentiation. All three species showed a karyotype (derived) of 2n = 42 chromosomes with 22 macro- and 20 micro-chromosomes; they all showed NORs on one micro-chromosome pair and presented Z and W chromosomes at an initial stage of differentiation. Sexchromosomes Z and W, were in fact homomorphic, but the former was near all euchromatic, while the W chromosome was almost completely heterochromatic. All the three taxa of Vipera resulted, however, karyologically diversified, mainly due to the number of macro-chromosomes pairs with a centromeric, CMA3 positive heterochromatin: almost all the pairs in V. aspis, two pairs in V. atra and absent in V. hugyi.

Snake venomics: Comparative analysis of the venom proteomes of the Tunisian snakesCerastes cerastes, Cerastes vipera andMacrovipera lebetina

The protein composition of the crude venoms of the three most important vipers of Tunisia was analyzed by RP-HPLC, N-terminal sequence analysis, MALDI-TOF mass determination, and in-gel tryptic digestion followed by PMF and CID-MS/MS of selected peptide ions in a quadrupole-linear IT instrument. Our results show that the venom proteomes of Cerastes cerastes, Cerastes vipera, and Macrovipera lebetina are composed of proteins belonging to a few protein families. However, each venom showed distinct degree of protein composition complexity. The three venoms shared a number of protein classes though the relative occurrence of these toxins was different in each snake species. On the other hand, the venoms of the Cerastes species and Macrovipera lebetina each contained unique components. The comparative proteomic analysis of Tunisian snake venoms provides a comprehensible catalogue of secreted proteins, which may contribute to a deeper understanding of the biological effects of the venoms, and may also serve as a starting point for studying structure-function correlations of individual toxins.