Boa Constrictor Research Articles

A Human Space.

A Human Space.

Boid Inclusion Body Disease (BIBD) is Associated with Altered Haematological Parameters and Immune Functions in Captive Boa Constrictor

Boid Inclusion Body Disease (BIBD) is Associated with Altered Haematological Parameters and Immune Functions in Captive Boa Constrictor

Short '1.2× Genome' Infectious Clone Initiates Kolmiovirid Replication in Boa constrictor Cells.

Human hepatitis D virus (HDV) depends on hepatitis B virus co-infection and its glycoproteins for infectious particle formation. HDV was the sole known deltavirus for decades and believed to be a human-only pathogen. However, since 2018, several groups reported finding HDV-like agents from various hosts but without co-infecting hepadnaviruses. In vitro systems enabling helper virus-independent replication are key for studying the newly discovered deltaviruses. Others and we have successfully used constructs containing multimers of the deltavirus genome for the replication of various deltaviruses via transfection in cell culture. Here, we report the establishment of deltavirus infectious clones with 1.2× genome inserts bearing two copies of the genomic and antigenomic ribozymes. We used Swiss snake colony virus 1 as the model to compare the ability of the previously reported “2× genome” and the “1.2× genome” infectious clones to initiate replication in cell culture. Using immunofluorescence, qRT-PCR, immuno- and northern blotting, we found the 2× and 1.2× genome clones to similarly initiate deltavirus replication in vitro and both induced a persistent infection of snake cells. The 1.2× genome constructs enable easier introduction of modifications required for studying deltavirus replication and cellular interactions.

Identification of an integrated stress and growth response signaling switch that directs vertebrate intestinal regeneration

BackgroundSnakes exhibit extreme intestinal regeneration following months-long fasts that involves unparalleled increases in metabolism, function, and tissue growth, but the specific molecular control of this process is unknown. Understanding the mechanisms that coordinate these regenerative phenotypes provides valuable opportunities to understand critical pathways that may control vertebrate regeneration and novel perspectives on vertebrate regenerative capacities.ResultsHere, we integrate a comprehensive set of phenotypic, transcriptomic, proteomic, and phosphoproteomic data from boa constrictors to identify the mechanisms that orchestrate shifts in metabolism, nutrient uptake, and cellular stress to direct phases of the regenerative response. We identify specific temporal patterns of metabolic, stress response, and growth pathway activation that direct regeneration and provide evidence for multiple key central regulatory molecules kinases that integrate these signals, including major conserved pathways like mTOR signaling and the unfolded protein response.ConclusionCollectively, our results identify a novel switch-like role of stress responses in intestinal regeneration that forms a primary regulatory hub facilitating organ regeneration and could point to potential pathways to understand regenerative capacity in vertebrates.

Analysis of Wildlife Roadkill in a Road Circuit. Case study of a Colombian road in the Department of Huila: Neiva - Rivera - Campoalegre

This research contributes information related to records of wildlife roadkill in the different roads of the department of Huila. The results come from samplings carried out during the rainy season from October to December of 2017 on the Neiva - Rivera - Campoalegre road circuit. The highest roadkill rate was recorded in section 1, Neiva - Rivera (Los Cauchos tollbooth); which had high traffic flow during the day (5045 vehicles/month), high speed limit (90 km / h), and an arboreal coverage that forms a green tunnel due to the lack of lighting on this road.
 A total of 102 dead specimens were registered in this case study; predominantly mammals (53 specimens, 51.96%) and the species Didelphis marsupialis (48, 47.06%), followed by reptiles (34, 33.33%) whose most affected species were the Boa constrictor (9, 8.82%) and the Iguana iguana (7, 6.86%). Additionally, birds were the third most affected group (12, 11.76%) classified in 8 species, such as the Megascops choliba which was the most affected (4, 3.92%). Amphibians were the least affected group (3, 2.94%), mainly the Rhinella horribilis species (2, 1.96%).

Predation of Boa constrictor (Boidae) by Cerdocyon thous (Canidae) in Caatinga in Brazil

Predation of Boa constrictor (Boidae) by Cerdocyon thous (Canidae) in Caatinga in Brazil

Functional activation of the periaqueductal gray matter during conditioned and unconditioned fear in guinea pigs confronted with the Boa constrictor constrictor snake.

The periaqueductal gray matter (PAG) is an essential structure involved in the elaboration of defensive responses, such as when facing predators and conspecific aggressors. Using a prey vs predator paradigm, we aimed to evaluate the PAG activation pattern evoked by unconditioned and conditioned fear situations. Adult male guinea pigs were confronted either by a Boa constrictor constrictor wild snake or by the aversive experimental context. After the behavioral test, the rodents were euthanized and the brain prepared for immunohistochemistry for Fos protein identification in different PAG columns. Although Fos-protein-labeled neurons were found in different PAG columns after both unconditioned and conditioned fear situations at the caudal level of the PAG, we found greater activation of the lateral column compared to the ventrolateral and dorsomedial columns after predator exposure. Moreover, the lateral column of the PAG showed higher Fos-labeled cells at the caudal level compared to the same area at the rostral level. The present results suggested that there are different activation patterns of PAG columns during unconditioned and conditioned fear in guinea pigs. It is possible to hypothesize that the recruitment of specific PAG columns depended on the nature of the threatening stimulus.

Recovering trace reptile DNA from the illegal wildlife trade

PurposeThe Illegal Wildlife Trade (IWT), aided by improved global transport, and the expansion of the internet, has facilitated the international demand for exotic reptiles. The risks associated with trafficking of live reptiles requires robust forensic techniques for detecting housed or transported animals. Detection of species of high IWT demand can be challenging due to the illicit nature of the trade, particularly when a specimen is missing. The ability to detect trace DNA in empty holdings and transport containers can be pivotal as a source of evidence. MethodsVivaria, containing either a corn snake (Pantherophis guttatus) or boa (Boa constrictor), were set up and monitored for 24 h simulating reptile holdings. Once removed, Diamond Nucleic Acid Dye™ (DD) was sprayed on experimental glass and plastic tiles recovered from within the vivaria, and trace DNA was visualized using a Polilight. Trace DNA was amplified using a novel reptile target specific qPCR assay and sequenced to identify both species. ResultsMovement patterns and scale imprints associated with reptile contact were visible on experimental tiles after DD-staining. Successful qPCR amplification and subsequent bi-directional Sanger sequencing confirmed the presence of both the species in the respective vivaria. DNA recovered from glass tiles had significantly greater amplification success than plastic tiles. ConclusionsDD revealed valuable information about the presence, and movement, of reptiles in the absence of a specimen. Successful amplification of trace reptile DNA demonstrated that this approach could offer an effective tool for biosecurity staff to rapidly identify live reptiles in the IWT.

Ileocolic Intussusception Associated with a Multicentric Round Cell Tumor in a Red-Tailed Boa (Boa constrictor constrictor)

A 5-year-old, female red-tailed boa constrictor ( Boa constrictor constrictor ) was presented with hyporexia, regurgitation and progressive focal distention of the caudal coelom since two months. During physical examination a firm, well-demarcated and movable intracoelomic mass was detected halfway down the caudal coelom but no other abnormalities were noticed. Ultrasonographic examination showed the mass to consist of an intestinal intussusception. A complete blood cell count and serum biochemistry blood test results revealed mild anemia and leukocytosis as well as hyperuricemia and hyperphosphatemia with inversion of the calcium/phospohorus ratio. Explorative coeliotomy was performed and revealed anterograde invagination of the ileum into the colon through the ileocolic junction. Although the intussusception was surgically repositioned, the snake died three weeks post-operatively despite showing a good general condition and defecation following assisted feeding. During necropsy, a thickened wall of the caudal segment of the ileum that was previously involved in the intussusception was observed as well as the presence of multifocal, white nodules throughout the parenchyma of the liver, spleen and kidneys. Histopathological examination demonstrated a malignant round cell tumor of the ileum with infiltration of neoplastic round cells in the liver, spleen and kidneys. Immunohistochemical staining (CD3, CD20, MAC387, S100 and NSE) could not confirm the cell origin of the round cell tumor. The present case highlights the need to include round cell tumors as a differential diagnosis in the development of ileocolic intussusception in red-tailed boa constrictors.

Huni kuin: Yube Baitana - An anthropological game adventure

The article presents the development process of the video game Huni Kuin: Yube Baitana (The ways of the boa constrictor) created by a group of Brazilian anthropologists with a Huni Kuin indigenous community from Acre, Brazil. Understood from a perspective in which video games must be taken seriously, a reflection is made on how the game Huni Kuin: Yube Baitana is inserted in the discussions and productions arising from multimodal anthropology.

Immune and hormonal regulation of the Boa constrictor (Serpentes; Boidae) in response to feeding

Feeding upregulates immune function and the systemic and local (gastrointestinal tract) concentrations of some immunoregulatory hormones, as corticosterone (CORT) and melatonin (MEL), in mammals and anurans. However, little is known about the immune and hormonal regulation in response to feeding in other ectothermic vertebrates, especially snakes, in which the postprandial metabolic changes are pronounced. Here, we investigated the effects feeding have on hormonal and innate immune responses in the snake, Boa constrictor. We divided juvenile males into two groups: fasting and fed with mice (30% of body mass). We measured the rates of oxygen consumption, plasma CORT levels, heterophil/lymphocyte ratio (HL ratio), plasma bacterial killing ability (BKA), and stomach and intestine MEL in fasting snakes and 48 h after meal intake. We observed increased rates of oxygen consumption, plasma CORT levels, and HL ratio, along with a tendency of decreased stomach and intestine MEL in fed snakes compared to fasting ones. BKA was not affected by feeding. Overall, we found that feeding modulates metabolic rates, CORT levels, and immune cell distribution in boas. Increased baseline CORT may be important to mobilize energy to support the metabolic increment during the postprandial period. Increased HL ratio might be an immunoregulatory effect of increased CORT, which has been shown in different physiological situations such as in response to immune challenge. Our results suggest that feeding activates the hypothalamic-pituitary-adrenal axis and modulates immune cell redistribution, possibly contributing to fighting potential injuries and infections derived from predation and from pathogens present in ingested food.

Feeding effects on liver mitochondrial bioenergetics of Boa constrictor (Serpentes: Boidae)

Snakes are interesting examples of taxa that can overcome energy metabolism challenges, as many species can endure long periods without feeding, and their eventual meals are of reasonably large sizes, thus exhibiting dual extreme adaptations. Consequently, metabolic rate increases considerably to attend to the energetic demand of digestion, absorption and protein synthesis. These animals should be adapted to transition from these two opposite states of energy fairly quickly, and therefore we investigated mitochondrial function plasticity in these states. Herein, we compared liver mitochondrial bioenergetics of the boid snake Boa constrictor during fasting and after meal intake. We fasted the snakes for 60 days, and then we fed a subgroup with 30% of their body size and evaluated their maximum postprandial response. We measured liver respiration rates from permeabilized tissue and isolated mitochondria. From isolated mitochondria, we also measured Ca2+ retention capacity and redox status. Mitochondrial respiration rates were maximized after feeding, reaching an approximately 60% increase from fasting levels when energized with complex I-linked substrates. Interestingly, fasting and fed snakes exhibited similar respiratory control ratios and citrate synthase activity. Furthermore, we found no differences in Ca2+ retention capacity, indicating no increase in susceptibility to mitochondrial permeability transition, and no changes in mitochondrial redox state, although fed animals exhibited increases in the release of H2O2. Thus, we conclude that liver mitochondria from B. constrictor snakes increase respiration rates during the postprandial period and quickly improve the bioenergetic capacity without compromising redox balance.

Monitoring of the Reproductive Cycle in Captive-Bred Female Boa constrictor: Preliminary Ultrasound Observations

Simple SummaryIn recent years, reptiles have become increasingly popular pets. The growing interest in snakes has led to an increase in captive-bred ophidians, and the Boa constrictor is one of the most common reptiles bred in captivity. These snakes can be found in tropical South America, as well as some islands in the Caribbean. With the exception of one subspecies, the Boa constrictor is now included in Appendix II of the Convention on International Trade of Endangered Species (C.I.T.E.S.). In order to achieve the proper management of boas in captivity, it is essential to have in-depth knowledge on the reproduction of this species and to identify minimally invasive methods for a correct monitoring of the reproductive cycle and gestation, guaranteeing the animal’s welfare. Currently, ultrasonography is the most common technique used in veterinary medicine for evaluating reproductive activity in both mammals and reptiles. In this regard, knowledge of the Boa constrictor is rather scarce. A group of captive-bred female boa constrictors were monitored by ultrasound over an entire breeding season. Results suggest that this technique allows an accurate monitoring of the captive female boas’ reproductive cycle, as well as a precise control of the embryos’ development and viability.The Boa constrictor is one of the most common reptiles bred in captivity. To achieve a successful breeding season, thorough knowledge of the females’ reproductive activity is necessary. In this regard, information on the Boa constrictor is still rather scarce. The aim of the present study was to monitor the ovarian activity and the embryonic development of boas by ultrasound. We performed brief scans on thirty non-anaesthetized snakes using a portable ultrasound system and a 7.5–10 MHz linear array transducer (Esaote MyLab™ Classic). Ultrasound features, dimensions, and echogenicity of the preovulatory and postovulatory follicles were determined. As gestation progresses, the postovulatory follicle size increases, and the embryonic silhouette becomes increasingly recognizable. During the second month after ovulation, by using color Doppler, early embryos’ heart activity could be evaluated. It is possible to highlight vascular connections between the mother and the membrane covering the embryonic structures. Ultrasound also allows one to identify follicular regression or slugs (nonfertilized eggs) early. The present study suggests that ultrasound could be an excellent noninvasive technique to evaluate the reproductive activity of Boa constrictor, allowing us to precisely identify the correct time for mating, monitor embryo development and viability, and allow the early diagnosis of follicular regression.

GROWTH CURVE AND FEED EFFICIENCY OF BOA CONSTRICTOR SUBSPECIES KEPT IN CAPTIVITY

The growth curve is an important parameter for estimating the development of an animal and assisting breeding programs and assessing welfare. However, little data is available on the growth curves of snakes, including native species such as Boa constrictors. Therefore, the objective of the present study was to determine the growth curve of three subspecies of Boa constrictor juveniles (B. constrictor constrictor - Bcc, B. constrictor amarali - Bca and B. constrictor occidentalis - Bco) using data from a commercial breeder located in Brazil. Thirty-seven newborn snakes were placed in individual plastic boxes and kept in a temperature-controlled room (30±2°C and 70-80% humidity) until they reached commercial size (58 days). The snakes' weight and food intake were recorded weekly. These data were used to calculate total food intake, relative weight gain, feed efficiency and growth curves for snakes, comparing animals within subspecies and sexes. There was no difference in growth between genders for Bcc (p = 0.9844) and Bco (p = 0.9845), while for Bca females presented a greater growth (p = 0.0052). There were no statistical differences in relative weight gain and feed efficiency among subspecies. The parameters and growth curves determined in this study can be used as an initial reference guide to monitor the growth of Boa constrictor newborns and contribute to the establishment of an adequate food management for snakes kept in captivity, being a possible parameter for quantifying to determine welfare during the development of newborn snakes.

Patterns of energetic substrate modifications in response to feeding in boas, Boa constrictor (Serpentes, Boidae)

Ambush-foraging snakes that ingest large meals might undergo several months without eating when they use the internal reserves to support the energetic costs of living. Then, morphological and physiological processes might be orchestrated during the transition from fasting to the postprandial period to rapidly use the energetic stores while the metabolic rate is elevated in response to food intake. To understand the patterns of substrates deposition after feeding, we accessed the morphological and biochemical response in Boa constrictor snakes after two months of fasting and six days after feeding. We followed the plasma levels of glucose, total proteins, and total lipids, and we performed the stereological ultrastructural analysis of the liver and the proximal region of the intestine to quantify glycogen granules and lipid droplets. In the same tissues and stomach, we measured the activity of the enzyme fructose-1,6-biphosphatase (FBPase1) involved in the gluconeogenic pathway, and we measured pyruvate kinase (PK) and lactate dehydrogenase (LDH) enzymatic activities involved in the anaerobic pathway in the liver. Briefly, our results indicated an increase in boas' plasma glucose one day after meal intake compared to unfed snakes. The hepatic glycogen reserves were continuously restored within days after feeding. Also, the enzymes involved in the energetic pathways increased activity six days after feeding in the liver. These findings suggest a quick restoring pattern of energetic stores during the postprandial period.

Maintained barostatic regulation of heart rate in digesting snakes (Boa constrictor).

When snakes digest large meals, heart rate is accelerated by withdrawal of vagal tone and an increased non-adrenergic-non-cholinergic tone that seems to stem from circulating blood-borne factors exerting positive chronotropic effects. To investigate whether this tonic elevation of heart rate impairs the ability for autonomic regulation of heart during digestion, we characterised heart rate responses to pharmacological manipulation of blood pressure in the snake Boa constrictor through serial injections of sodium nitroprusside and phenylephrine. Both fasting and digesting snakes responded with a robust tachycardia to hypotension induced by sodium nitroprusside, with digesting snakes attaining higher maximal heart rates than fasting snakes. Both fasting and digesting snakes exhibited small reductions of the cardiac chronotropic response to hypertension, induced by injection of phenylephrine. All heart rate changes were abolished by autonomic blockade with the combination of atropine and propranolol. The digesting snakes retained the capacity for compensatory heart rate responses to hypotension, despite their higher resting values, and the upward shift of the barostatic response curve enables snakes to maintain the cardiac limb of barostatic regulation for blood pressure regulation.

Reproductive cycles of neotropical boid snakes evaluated by ultrasound.

Snakes have increasingly been bred as pets around the world. Few studies have addressed the reproduction of boid snakes, and no study has addressed their reproductive cycles in captivity. Thus, this paper describes the reproductive aspects of Brazilian boids in captivity. We used ultrasonography to characterize the reproductive cycle of four boid species in captivity in the Southern Hemisphere: the anaconda (Eunectes murinus), the red-tailed boa (Boa constrictor constrictor), the Amazon tree boa (Corallus hortulanus), and the rainbow boa (Epicrates cenchria). Nonvitellogenic follicles occurred from January to December in anaconda and red-tailed boa and for a shorter period from September to February in Amazon tree boa and from January to May in rainbow boa. Vitellogenesis occurred from late June to late March in E. murinus in year-round (12 months), from March to March in Amazon tree boa, from late September to late March in red-tailed boa, and from late March to late September in rainbow boa. Mating occurred from late March to late September in red-tailed boa and rainbow boa and from late September to late March in Amazon tree boa. No mating was observed in anacondas, but a female probably underwent parthenogenesis. Births occurred in July in anaconda and in March to July in Amazon tree boa and from December to March in red-tailed boa and rainbow boa. In males, increases in testicular size were associated with the mating season. Ultrasonography proved to be a safe and noninvasive technique to study the reproductive cycle of giant snakes in captivity.

Smoke, Dust, and Blood

Smoke, Dust, and Blood

Molecular detection of Wolbachia endosymbiont in reptiles and their ectoparasites

Wolbachia, a maternally transmitted Gram-negative endosymbiont of onchocercid nematodes and arthropods, has a role in the biology of their host; thus it has been exploited for the filariasis treatment in humans. To assess the presence and prevalence of this endosymbiont in reptiles and their ectoparasites, blood and tail tissue as well as ticks and mites collected from them were molecularly screened for Wolbachia DNA using two sets of primers targeting partial 16S rRNA and Wolbachia surface protein (wsp) genes. Positive samples were screened for the partial 12S rRNA and cytochrome c oxidase subunit 1 (cox1) genes for filarioids. Of the different species of lizards (Podarcis siculus, Podarcis muralis and Lacerta bilineata) and snakes (Elaphe quatuorlineata and Boa constrictor constrictor) screened from three collection sites, only P. siculus scored positive for Wolbachia 16S rRNA. Among ectoparasites collected from reptiles (Ixodes ricinus ticks and Neotrombicula autumnalis, Ophionyssus sauracum and Ophionyssus natricis mites), I. ricinus (n = 4; 2.8%; 95% CI, 0.9–7) from P. siculus, N. autumnalis (n = 2 each; 2.8%; 95% CI, 0.9–6.5) from P. siculus and P. muralis and O. natricis (n = 1; 14.3%; 95% CI, 0.7–55.4) from Boa constrictor constrictor scored positive for Wolbachia DNA. None of the positive Wolbachia samples scored positive for filarioids. This represents the first report of Wolbachia in reptilian hosts and their ectoparasites, which follows a single identification in the intestinal cells of a filarioid associated with a gecko. This data could contribute to better understand the reptile filarioid-Wolbachia association and to unveil the evolutionary pattern of Wolbachia in its filarial host.

Effects of different levels of hypoxia and hypercarbia on ventilation and gas exchange in Boa constrictor amaralis and Crotalus durissus (Squamata: Serpentes)

Ventilation and gas exchange have been studied in relatively few species of snakes, especially regarding their response to environmental hypoxia or hypercarbia. We exposed Crotalus durissus (N = 6) and Boa constrictor (N = 6) to decreasing levels of oxygen (12, 9, 6, 3 % O2) and increasing levels of carbon dioxide (1.5, 3.0, 4.5, 6.0 % CO2) and analyzed the effect of the different gas mixtures on ventilation and gas exchange using open-flow respirometry. Neither hypoxia nor hypercarbia significantly altered the duration of expiration or inspiration, nor their proportions. Both hypoxia and hypercarbia increased minute ventilation, but the decrease in oxygen had a less pronounced effect on ventilation. Gas exchange under normoxic conditions was low and was not significantly affected by hypoxia, but hypercarbia decreased gas exchange significantly in both species. While B. constrictor maintained its respiratory exchange ratio (RER) under hypercarbia between 0.5 and 1.0, C. durissus showed a RER above 1.0 during hypercarbia, due to a significantly greater CO2 excretion. The overall responses of both species to hypercarbia and especially to hypoxia were very similar, which could be associated to similar lifestyles as ambush hunting sit-and-wait predators that are able to ingest large prey items. The observed differences in gas exchange could be related to respiratory systems with macroscopically different structures, possessing only a tracheal lung in C. durissus, but two functional lungs in B. constrictor.