Python Sebae Research Articles

Environmental DNA (eDNA) sampling improves occurrence and detection estimates of invasive burmese pythons.

Environmental DNA (eDNA) methods are used to detect DNA that is shed into the aquatic environment by cryptic or low density species. Applied in eDNA studies, occupancy models can be used to estimate occurrence and detection probabilities and thereby account for imperfect detection. However, occupancy terminology has been applied inconsistently in eDNA studies, and many have calculated occurrence probabilities while not considering the effects of imperfect detection. Low detection of invasive giant constrictors using visual surveys and traps has hampered the estimation of occupancy and detection estimates needed for population management in southern Florida, USA. Giant constrictor snakes pose a threat to native species and the ecological restoration of the Florida Everglades. To assist with detection, we developed species-specific eDNA assays using quantitative PCR (qPCR) for the Burmese python (Python molurus bivittatus), Northern African python (P. sebae), boa constrictor (Boa constrictor), and the green (Eunectes murinus) and yellow anaconda (E. notaeus). Burmese pythons, Northern African pythons, and boa constrictors are established and reproducing, while the green and yellow anaconda have the potential to become established. We validated the python and boa constrictor assays using laboratory trials and tested all species in 21 field locations distributed in eight southern Florida regions. Burmese python eDNA was detected in 37 of 63 field sampling events; however, the other species were not detected. Although eDNA was heterogeneously distributed in the environment, occupancy models were able to provide the first estimates of detection probabilities, which were greater than 91%. Burmese python eDNA was detected along the leading northern edge of the known population boundary. The development of informative detection tools and eDNA occupancy models can improve conservation efforts in southern Florida and support more extensive studies of invasive constrictors. Generic sampling design and terminology are proposed to standardize and clarify interpretations of eDNA-based occupancy models.

Origin and identity of the von Borcke collection of amphibians and reptiles in the Museum für Naturkunde in Berlin: A cache of Seba specimens?

Approximately 150 specimens of amphibians and reptiles donated by Graf von Borcke in the first years of the museum's existence are still present in the Museum fur Naturkunde, Berlin (ZMB). Based on information published by Blasius Merrem and additional historical sources, it can be determined that a portion of von Borcke's collection was purchased from the estate of Willem Xaver Janssen (= Wilhelm Xaver Jansen) and that this was probably obtained indirectly (possibly via Adrianus van Royen) from the second collection of Albertus Seba, auctioned in 1752. Comparison of the von Borcke material with Seba's illustrations reveals five credible and 18 questionable matches. Most convincing is a specimen of Python sebae partly dissected to show a bird in its abdomen. The Seba figure of this specimen is an iconotype of Python bivittatus Kuhl, 1820. An additional ten ZMB specimens are possible matches to Seba illustrations that have served as iconotypes. The stylized appearance of many of Seba's figures, particularly those of snakes, makes the unambiguous identification of surviving Seba specimens difficult. In addition, five snake specimens are probable matches to specimens from Janssen's collection that were described and figured by Merrem. Three of these are type specimens of subsequently described species, including the widespread and invasive Boiga irregularis (Bechstein, 1802). A combination of historical information and specimen correspondences yields a strong case for the survival of a large part of Seba's herpetological collection in Berlin. (© 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Rapid Microsatellite Marker Development Using Next Generation Pyrosequencing to Inform Invasive Burmese Python—Python molurus bivittatus—Management

Invasive species represent an increasing threat to native ecosystems, harming indigenous taxa through predation, habitat modification, cross-species hybridization and alteration of ecosystem processes. Additionally, high economic costs are associated with environmental damage, restoration and control measures. The Burmese python, Python molurus bivittatus, is one of the most notable invasive species in the US, due to the threat it poses to imperiled species and the Greater Everglades ecosystem. To address population structure and relatedness, next generation sequencing was used to rapidly produce species-specific microsatellite loci. The Roche 454 GS-FLX Titanium platform provided 6616 di-, tri- and tetra-nucleotide repeats in 117,516 sequences. Using stringent criteria, 24 of 26 selected tri- and tetra-nucleotide loci were polymerase chain reaction (PCR) amplified and 18 were polymorphic. An additional six cross-species loci were amplified, and the resulting 24 loci were incorporated into eight PCR multiplexes. Multi-locus genotypes yielded an average of 61% (39%–77%) heterozygosity and 3.7 (2–6) alleles per locus. Population-level studies using the developed microsatellites will track the invasion front and monitor population-suppression dynamics. Additionally, cross-species amplification was detected in the invasive Ball, P. regius, and Northern African python, P. sebae. These markers can be used to address the hybridization potential of Burmese pythons and the larger, more aggressive P. sebae.

Conservation Implications of Rapid Shifts in the Trade of Wild African and Asian Pythons

AbstractPythons are harvested for the international leather industry and pet trade. We analyzed the CITES export records (1999–2008) of the most intensively commercialized wild pythons (Python regius, Python sebae, Python reticulatus, Python molurus, Python curtus species complex) from African and Asian countries where reliable data on trade rates and ecology are available. Mean declared annual numbers of exported pythons were 30,000 in five African countries and 164,000 in Indonesia. Trade intensity tripled in Indonesia over the last decade, but declined in Africa. African international trade is exclusively associated with the pet market (mainly United States and Europe), whereas Asian pythons are sold mostly for luxury leather, albeit more recently also for the pet trade. A negative correlation between the annual numbers of pythons traded in Africa vs. Asia suggests a rapid and recent shift of the pressure exerted on wild populations in the two main exporting continents. We also found a strong effect of the currency exchange rate (i.e., U.S.$/€, the currencies used by the major importing countries) on African python exports: when the cost per African python increased, importers relied increasingly on Asian providers for pet trade. Overall, our data indicate that Asian pythons (especially P. reticulatus) might be threatened due to the rapidly increasing pressure, whereas the decreasing international trade in African pythons is likely more sustainable.

A novel protein from the serum of Python sebae, structurally homologous with type-γ phospholipase A2 inhibitor, displays antitumour activity

Cytotoxic and antitumour factors have been documented in the venom of snakes, although little information is available on the identification of cytotoxic products in snake serum. In the present study, we purified and characterized a new cytotoxic factor from serum of the non-venomous African rock python (Python sebae), endowed with antitumour activity. PSS (P. sebae serum) exerted a cytotoxic activity and reduced dose-dependently the viability of several different tumour cell lines. In a model of human squamous cell carcinoma xenograft (A431), subcutaneous injection of PSS in proximity of the tumour mass reduced the tumour volume by 20%. Fractionation of PSS by ion-exchange chromatography yielded an active protein fraction, F5, which significantly reduced tumour cell viability in vitro and, strikingly, tumour growth in vivo. F5 is composed of P1 (peak 1) and P2 subunits interacting in a 1:1 stoichiometric ratio to form a heterotetramer in equilibrium with a hexameric form, which retained biological activity only when assembled. The two peptides share sequence similarity with PIP {PLI-γ [type-γ PLA(2) (phospholipase A(2)) inhibitor] from Python reticulatus}, existing as a homohexamer. More importantly, although PIP inhibits the hydrolytic activity of PLA(2), the anti-PLA(2) function of F5 is negligible. Using high-resolution MS, we covered 87 and 97% of the sequences of P1 and P2 respectively. In conclusion, in the present study we have identified and thoroughly characterized a novel protein displaying high sequence similarity to PLI-γ and possessing remarkable cytotoxic and antitumour effects that can be exploited for potential pharmacological applications.

Tsetse fly blood meal modification and trypanosome identification in two sleeping sickness foci in the forest of southern Cameroon

The blood meal origins of 222 tsetse flies (213 Glossina palpalis palpalis, 7 Glossina pallicera pallicera, one Glossina nigrofusca and one Glossina caliginea) caught in 2008 in two Human African trypanosomiasis foci (Bipindi and Campo) of south Cameroon were investigated. 88.7% of tsetse flies blood meals were identified using the heteroduplex method and the origin of the remaining blood meals (11.3%) was identified by sequencing the cytochrome B gene. Most of the meals were from humans (45.9%) and pigs (37.4%), 16.7% from wild animals. Interestingly, new tsetse fly hosts including turtle ( Trionyx and Kinixys) and snake ( Python sebae) were identified. Significant differences were recorded between Bipindi where the blood meals from pigs were predominant (66.7% vs 23.5% from humans) and Campo where blood meals from humans were predominant (62.9% vs 22.7% from pigs). Comparison with the data recorded in 2004 in the same foci (and with the same molecular approach) demonstrated significant modifications of the feeding patterns: increase in blood meals from pigs in Bipindi (66.7% in 2008 vs 44.8% in 2004) and in Campo (20.5% in 2008 vs 6.8% in 2004), decrease in that from human (significant in Bipindi only). 12.6%, 8.1% and 2.7% of the flies were, respectively, Trypanosoma congolense forest type, Trypanosoma congolense savannah type and Trypanosoma brucei gambiense infected. These results demonstrate that tsetse fly feeding patterns can be specific of a given area and can evolve rapidly with time. They show an active circulation of a variety of trypanosomes in sleeping sickness foci of southern Cameroon.

Is the Northern African Python (Python sebae) Established in Southern Florida?

Is the Northern African Python (Python sebae) Established in Southern Florida?

R.N. Reed and G.H. Rodda (eds): Giant constrictors: biological and management profiles and an establishment risk assessment for nine large species of pythons, anacondas, and the boa constrictor

Giant Constrictors estimates ecological risks associated with colonization of the United States by the world’s four largest snakes (green anaconda, Indian or Burmese python, northern African python, and reticulated python) plus four very similar species (the southern African python, yellow anaconda, DeSchaunsee’s anaconda, and Beni anaconda) and the boa constrictor. Possible economic costs are also detailed but not quantified. This book follows massive publicity about the establishment in the Florida Everglades of a large population of the Burmese python. Deer and alligators are known to be taken by this behemoth, and further north in Florida a 4-m ‘‘pet’’ of this species recently strangled a 2-year old girl. Also, in their native ranges there are credible accounts that several others of these species have (rarely) killed people, and these facts alone should generate interest in Giant Constrictors. There is yet another angle; a paper by Rodda et al. (2009) using similar methods as this volume to forecast the climatically suitable U.S. range of the Burmese python galvanized opposition from ReptileChannel.com (‘‘the website for reptile lovers’’) and the ‘‘Reptile Nation,’’ a reptile-loving segment of the American population estimated at five million by USARK (United States Association of Reptile Keepers), and USARK has already responded with similar alarm to Giant Constrictors. The threat they see is not from the constrictors but from the possibility that this book will support federal legislation to ban the import of all large constrictors. Snake importation and the reptile pet trade are multimillion dollar industries, and these industries have successfully mobilized supporters to stymie invasive species legislation in the U.S. Congress.

Initiation and patterning of the snake dentition are dependent on Sonic Hedgehog signaling

Here we take the first look at cellular dynamics and molecular signaling in the developing snake dentition. We found that tooth formation differs from rodents in several respects. The majority of snake teeth bud off of a deep, ribbon-like dental lamina rather than as separate tooth germs. Prior to and after dental lamina ingrowth, we observe asymmetries in cell proliferation and extracellular matrix distribution suggesting that localized signaling by a secreted protein is involved. We cloned Sonic hedgehog from the African rock python Python sebae and traced its expression in the species as well as in two other snakes, the closely-related Python regius and the more derived corn snake Elaphe guttata (Colubridae). We found that expression of Shh is first confined to the odontogenic band and defines the position of the future dental lamina. Shh transcripts in pythons are progressively restricted to the oral epithelium on one side of the dental lamina and remain in this position throughout the prehatching period. Shh is expressed in the inner enamel epithelium and the stellate reticulum of the tooth anlagen, but is absent from the outer enamel epithelium and its derivative, the successional lamina. This suggests that signals other than Shh are responsible for replacement tooth formation. Functional studies using cyclopamine to block Hh signaling during odontogenesis prevented initiation and extension of the dental lamina into the mesenchyme, and also affected the directionality of this process. Further, blocking Hh signaling led to disruptions of the inner enamel epithelium. To explore the role of Shh in lamina extension, we looked at its expression in the premaxillary teeth, which form closer to the oral surface than elsewhere in the mouth. Oral ectodermal Shh expression in premaxillary teeth is lost soon after the teeth form reinforcing the idea that Shh is controlling the depth of the dental lamina. In summary, we have found diverse roles for Shh in patterning the snake dentition but, have excluded the participation of this signal in replacement tooth formation.

Embryonic development of Python sebae – II: Craniofacial microscopic anatomy, cell proliferation and apoptosis

This study explores the microscopic craniofacial morphogenesis of the oviparous African rock python ( Python sebae) spanning the first two-thirds of the post-oviposition period. At the time of laying, the python embryo consists of largely undifferentiated mesenchyme and epithelium with the exception of the cranial base and trabeculae cranii, which are undergoing chondrogenesis. The facial prominences are well defined and are at a late stage, close to the time when lip fusion begins. Later (11–12 d), specializations in the epithelia begin to differentiate (vomeronasal and olfactory epithelia, teeth). Dental development in snakes is different from that of mammals in several aspects including an extended dental lamina with the capacity to form 4 sets of generational teeth. In addition, the ophidian olfactory system is very different from the mammalian. There is a large vomeronasal organ, a nasal cavity proper and an extraconchal space. All of these areas are lined with a greatly expanded olfactory epithelium. Intramembranous bone differentiation is taking place at stage 3 with some bones already ossifying whereas most are only represented as mesenchymal condensations. In addition to routine histological staining, PCNA immunohistochemistry reveals relatively higher levels of proliferation in the extending dental laminae, in osseous mesenchymal condensations and in the olfactory epithelia. Areas undergoing apoptosis were noted in the enamel organs of the teeth and osseous mesenchymal condensations. We propose that localized apoptosis helps to divide a single condensation into multiple ossification centres and this is a mechanism whereby novel morphology can be selected in response to evolutionary pressures. Several additional differences in head morphology between snakes and other amniotes were noted including a palatal groove separating the inner and outer row of teeth in the upper jaw, a tracheal opening within the tongue and a pharyngeal adhesion that closes off the pharynx from the oral cavity between stages 1 and 4. Our studies on these and other differences in the python will provide valuable insights into in developmental, molecular and evolutionary mechanisms of patterning.

Embryonic development of Python sebae – I: Staging criteria and macroscopic skeletal morphogenesis of the head and limbs

This study explores the post-ovipositional craniofacial development of the African Rock Python ( Python sebae). We first describe a staging system based on external characteristics and next use whole-mount skeletal staining supplemented with Computed tomography (CT) scanning to examine skeletal development. Our results show that python embryos are in early stages of organogenesis at the time of laying, with separate facial prominences and pharyngeal clefts still visible. Limb buds are also visible. By 11 days (stage 3), the chondrocranium is nearly fully formed; however, few intramembranous bones can be detected. One week later (stage 4), many of the intramembranous upper and lower jaw bones are visible but the calvaria are not present. Skeletal elements in the limbs also begin to form. Between stages 4 (day 18) and 7 (day 44), the complete set of intramembranous bones in the jaws and calvaria develops. Hindlimb development does not progress beyond stage 6 (33 days) and remains rudimentary throughout adult life. In contrast to other reptiles, there are two rows of teeth in the upper jaw. The outer tooth row is attached to the maxillary and premaxillary bones, whereas the inner row is attached to the pterygoid and palatine bones. Erupted teeth can be seen in whole-mount stage 10 specimens and are present in an unerupted, mineralized state at stage 7. Micro-CT analysis reveals that all the young membranous bones can be recognized even out of the context of the skull. These data demonstrate intrinsic patterning of the intramembranous bones, even though they form without a cartilaginous template. In addition, intramembranous bone morphology is established prior to muscle function, which can influence bone shape through differential force application. After careful staging, we conclude that python skeletal development occurs slowly enough to observe in good detail the early stages of craniofacial skeletogenesis. Thus, reptilian animal models will offer unique opportunities for understanding the early influences that contribute to perinatal bone shape.

Parasites of domestic and wild animals in South Africa. XLVII. Ticks of tortoises and other reptiles

A total of 586 reptiles, belonging to 35 species and five subspecies, were examined in surveys aimed at determining the species spectrum and geographic distribution of ticks that infest them. Of these reptiles 509 were tortoises, 28 monitor or other lizards, and 49 snakes. Nine ixodid tick species, of which seven belonged to the genus Amblyomma, and one argasid tick, Ornithodoros compactus were recovered. Seven of the ten tick species are parasites of reptiles. Amongst these seven species Amblyomma marmoreum was most prevalent and numerous on leopard tortoises, Geochelone pardalis; Amblyomma nuttalliwas present only on Bell's hinged tortoises, Kinixys belliana; and most Amblyomma sylvaticum were collected from angulate tortoises, Chersina angulata. Amblyomma exornatum (formerly Aponomma exornatum) was only recovered from monitor lizards, Varanus spp.; most Amblyomma latum (formerly Aponomma latum) were from snakes; and a single nymph of Amblyomma transversale (formerly Aponomma transversale) was collected from a southern African python, Python natalensis. All 30 Namaqualand speckled padloper tortoises, Homopus signatus signatus, examined were infested with O. compactus. The seasonal occurrence of A. sylvaticum and the geographic distribution of this tick and of A. marmoreum, A. nuttalli, A. exornatum, A. latum and O. compactus are illustrated.

FOSSIL REPTILES FROM THE PLEISTOCENE HOMO-BEARING LOCALITY OF BUIA (ERITREA, NORTHERN DANAKIL DEPRESSION)

The early to early-Middle Pleistocene fossil assemblage form the Buia area (Northern Danakil Depression, Eritrea) hosts, along with Homo and several other large mammal taxa, the following reptiles: Nile Crocodile, Crocodylus niloticus , Serrated Hinged Terrapin, Pelusios cf. P. sinuatus, Nile Monitor, Varanus niloticus and African Rock Python , Python gr. sebae . All the identified taxa belong to living species. At present, these taxa do not occur in the Northern Danakil depression since it is an arid area. P. sinuatus is not a member of the Eritrean herpetofauna. Although the marked preponderance of the crocodile remains is probably connected to the taphonomy of the sites and the collecting methods used, the ecological value of the reptile fauna corroborates that of the mammals, in indicating a lacustrine or fluvio-deltaic palaeoenvironment and a tropical/subtropical or even sub-Sahelic climate. The Buia remains represent the first reported Eritrean palaeoherpetofauna.

Cutaneous Mycobiota of Captive Squamate Reptiles with Notes on the Scarcity of Chrysosporium Anamorph of Nannizziopsis vriesii

ABSTRACT The Chrysosporium anamorph of Nannizziopsis vriesii (CANV) is a fungus that has been implicated in several recent cases of reptile dermatomycoses. A survey was conducted to investigate whether this fungus was present on the skins of healthy squamate reptiles. Skin was collected as aseptically as possible from actively shedding lizards (n = 36) or from freshly shed snake exuvia (n = 91) and placed on fungal culture media for selective recovery of cycloheximide-tolerant fungi. The CANV was cultured from only one animal, an African rock python, Python sebae. Fungi belonging to 50 genera were identified from 127 reptiles: Aspergillus spp., Penicillium spp., and Paecilomyces lilacinus were most frequently isolated. Keratinophilic fungi isolated from reptiles did not belong to zoophilic or anthropophilic species, inferring that the potential for acquisition of dermatophytosis from handling squamate reptiles is low.

An investigation into the composition, complexity and functioning of snake communities in the mangroves of south‐eastern Nigeria

AbstractThe structure of the snake community was studied between 1996 and 2000 on a transect in the mangrove ecological zone of southern Nigeria, West Africa. In three major habitats, both taxonomical diversity and frequency of observations in relation to sampling effort were investigated. In general terms, the complexity of the snake community appeared less than in other habitats of the same geographic region (i.e. swamp forest and forest–plantation mosaics). In fact, only eighteen species were recorded, whereas 43 species are known to inhabit neighbouring habitats. A Principal Component Analysis allowed arrangement of the various species into two main groups in relation to the habitats of capture: (1) a group of species of rainforest biota (i.e. Toxicodryas blandingii, Thelotornis kirtlandii, Thrasops flavigularis, Rhamnophis aethiopissa, Gastropyxis smaragdina, Grayia smythii, Pseudohaje goldii, Python sebae), and (2) a group of species that, at least in Niger Delta, are typically linked to altered habitats, including derived savannas, plantations and suburbia (i.e. Psammophis cf. phillipsi, Philothamnus cf. nitidus, Hapsidophrys lineatus, Crotaphopeltis hotamboeia, Boaedon lineatus, Naja nigricollis, Python regius). The community structure in terms of food habits and body sizes appeared similar to those of other snake assemblages from different habitats of southern Nigeria. The conservation implications of our results are also discussed.

Ikpan wetland rainforest : an area of high biodiversity importance in south-eastern Nigeria

A careful survey for mammals, reptiles, and amphibians, was conducted at the wetlands and rainforests of Ikpan Forest block, Cross River State (south-eastern Nigeria), during the period 1998-2001. The surveys proved that Ikpan Forest, although formally not protected at either regional or national levels, houses an extraordinarily rich biodiversity, including many vertebrates of ecological, biogeographic, and conservation importance. Among mammals, the most important taxa are primates (11 different species, including Mandrillus leucophaeus, Pan troglodytes, Procolobus badius preussi ), forest elephants, forest buffalos, and many ungulates. Manatees and leopards may also be present. Among reptiles, Osteolaemus tetraspis, Kinixys spp., Varanus niloticus omatus, Python sebae, and chameleons are especially important in conservation terms. Moreover, the study forest houses a conspicuous diversity of species of snakes (27) and amphibians (27), including many species which are good ecological indicators of forest quality, and some species which were rarely recorded in Nigeria before (e.g., the anurans Bufo superciliaris and Conraua crassipes). The study area has potentials for conservation and sustainable development (eco-tourism), but should certainly be monitored carefully in the next years to avoid the negative effects of timber extraction, local hunting, farming, and fishing with dynamites.

Food habits of Python sebae in suburban and natural habitats

Food habits of Python sebae in suburban and natural habitats

Hemipenial Morphology of African Snakes: A Taxonomic Review. Part 1. Scolecophidia and Boidae

Techniques and terminology used in a survey of African snake hemipenial mor- phology are introduced. Descriptions are given of the hemipenes of a number of scolecophidians, including Leptotyphlops scutifrons, L. conjunctus, L. nigricans, Typhlops bibroni, T. fornasini, T. schlegeli dinga and T. lalandei. The typhlopid hemipenes are robust, simple structures, with nude bases, varied flounced ornamentation, and a terminal cup into which the undivided sulcus drains. No hemipenial features support the recognition of Rhinotyphlops. Unlike the relatively compli- cated hemipenes of Neotropical leptotyphlopids, the hemipenes of the African species are simple, unornamented, elongate structures, with undivided sulci and swollen basal regions. The hemipenes of African Phython and Eryx are described. The smaller African pythons (P. regius and P. anchietae) have undivided organs, similar to those of the Asian blood python (P. curtus). P. regius and P. curtus have an unusual oblique terminal capitulum. Terminal awns are found only in P. regius and P. sebae. The hemipenis of P. anchietae is intermediate between that of the smaller and larger species of the P. molurus group (sensu McDowell). The python hemipenis, like most boid hemipenes, has a prominent fleshy papilla on the asulcal surface of the proximal flounce. This is not found in Eryx hemipenes, or in those of Lichanura rosefusca. Erycine hemipenes are simple, or at most shallowly-forked, clavate in shape, with a divided sulcus, the forks of which drain into lateral cups. They are similar to the hemipenes of Xenopeltis (which is illustrated) and Loxocemus.

Environmental Nature Note: African Rock Python and Thomson's Gazelle

Environmental Nature Note: African Rock Python and Thomson's Gazelle

A Fatal Attack on a Young Boy by an African Rock Python Python sebae

A Fatal Attack on a Young Boy by an African Rock Python Python sebae