The Experts below are selected from a list of 372 Experts worldwide ranked by ideXlab platform
Elliott R Jacobson - One of the best experts on this subject based on the ideXlab platform.
-
Longitudinal and Cross-Sectional Sampling of Serpentovirus (Nidovirus) Infection in Captive Snakes Reveals High Prevalence, Persistent Infection, and Increased Mortality in Pythons and Divergent Serpentovirus Infection in Boas and Colubrids.
Frontiers in Veterinary Science, 2019Co-Authors: Laura L. Hoon-hanks, Elliott R Jacobson, Robert J. Ossiboff, Pia Bartolini, Susan B. Fogelson, Sean M. Perry, Anke C. Stöhr, Shaun T. Cross, James F. X. Wellehan, Edward J. DuboviAbstract:The aim of this study of serpentovirus infection in captive snakes was to assess the susceptibility of different types of snakes to infection and disease, to survey viral genetic diversity, and to evaluate management practices that may limit infection and disease. Antemortem oral swabs were collected from 639 snakes from 12 US collections, including 62 species, 28 genera, and 6 families: Pythonidae (N = 414 snakes; pythons were overrepresented in the sample population), Boidae (79), Colubridae (116), Lamprophiidae (4), Elapidae (12), and Viperidae (14). Infection was more common in pythons (38%; 95% CI: 33.1-42.4%), and in boas (10%; 95% CI: 5.2-18.7%) than in colubrids (0.9%, 95% CI:
-
Immunohistochemical Detection of a Unique Protein within Cells of Snakes Having Inclusion Body Disease, a World-Wide Disease Seen in Members of the Families
2016Co-Authors: Li-wen Chang, Marjorie Chow, Diane G. Duke, Karen Kelley, Linda Green, Edward Wozniak, Jorge A. Hern, Elliott R JacobsonAbstract:Inclusion body disease (IBD) is a worldwide disease in captive boa constrictors (boa constrictor) and occasionally in other snakes of the families Boidae and Pythonidae. The exact causative agent(s) and pathogenesis are not yet fully understood. Currently, diagnosis of IBD is based on the light microscopic identification of eosinophilic intracytoplasmic inclusion bodies in hematoxylin and eosin stained tissues or blood smears. An antigenically unique 68 KDa protein was identified within the IBD inclusion bodies, called IBD protein. A validated immuno-based ante-mortem diagnostic test is needed for screening snakes that are at risk of having IBD. In this study, despite difficulties in solubilizing semi-purified inclusion bodies, utilizing hybridoma technology a mouse anti-IBD protein monoclonal antibody (MAB) was produced. The antigenic specificity of the antibody was confirmed and validated by western blots, enzyme-linked immunosorbent assay, immuno-transmission electron microscopy, and immunohistochemica
-
Immunohistochemical detection of a unique protein within cells of snakes having inclusion body disease, a world-wide disease seen in members of the families boidae and Pythonidae
PLoS ONE, 2013Co-Authors: Li-wen Chang, Ann Fu, Marjorie Chow, Diane G. Duke, Karen Kelley, Linda Green, Edward Wozniak, Jorge A Hernandez, Elliott R JacobsonAbstract:Inclusion body disease (IBD) is a worldwide disease in captive boa constrictors (boa constrictor) and occasionally in other snakes of the families Boidae and Pythonidae. The exact causative agent(s) and pathogenesis are not yet fully understood. Currently, diagnosis of IBD is based on the light microscopic identification of eosinophilic intracytoplasmic inclusion bodies in hematoxylin and eosin stained tissues or blood smears. An antigenically unique 68 KDa protein was identified within the IBD inclusion bodies, called IBD protein. A validated immuno-based ante-mortem diagnostic test is needed for screening snakes that are at risk of having IBD. In this study, despite difficulties in solubilizing semi-purified inclusion bodies, utilizing hybridoma technology a mouse anti-IBD protein monoclonal antibody (MAB) was produced. The antigenic specificity of the antibody was confirmed and validated by western blots, enzyme-linked immunosorbent assay, immuno-transmission electron microscopy, and immunohistochemical staining. Paraffin embedded tissues of IBD positive and negative boa constrictors (n=94) collected from 1990 to 2011 were tested with immunohistochemical staining. In boa constrictors, the anti-IBDP MAB had a sensitivity of 83% and specificity of 100% in detecting IBD. The antibody also cross-reacted with IBD inclusion bodies in carpet pythons (Morelia spilota) and a ball python (python regius). This validated antibody can serve as a tool for the development of ante-mortem immunodiagnostic tests for IBD. [ABSTRACT FROM AUTHOR]
-
Inclusion Body Disease, A Worldwide Infectious Disease of Boid Snakes: A Review
Journal of Exotic Pet Medicine, 2010Co-Authors: Li-wen Chang, Elliott R JacobsonAbstract:Abstract A disease called inclusion body disease (IBD) is seen worldwide in snakes that are members of the families Boidae and Pythonidae. Snakes affected by this disease often have neurological signs. A diagnosis is based on light microscopic examination of tissues for the presence of intracytoplasmic inclusions that consist of a unique protein that has been termed inclusion body disease protein (IBDP). In some cases, inclusions are found exclusively in the central nervous system, whereas in others they may be diffusely disseminated in multiple tissues. In a few cases, the IBD inclusions have overlapped in appearance with other types of nonviral intracytoplasmic inclusions. The specific etiologic agent of IBD remains unknown. Because the underlying cause of IBD is unknown, recent research has focused on understanding the formation and nature of IBDP. A monoclonal antibody has been developed against IBDP and is currently being used in immunodiagnostic assays to develop a reliable diagnostic test for IBD. This monoclonal antibody is going through rigorous validation testing and will provide more specificity and sensitivity than currently available routine histological diagnostics. Because large numbers of boas and pythons are being bred and sold for the pet trade, better diagnostic tests are needed to help develop IBD-free breeding colonies of these snakes. Further, because IBD is one of the few worldwide diseases of captive snakes, there is concern in many countries (e.g., Australia, where it has been identified in captive pythons) that it will become established in native wild populations. Thus, there is conservation value in developing better diagnostic tools for screening snakes intended for release as part of reintroduction programs.
M. Fitzgerald - One of the best experts on this subject based on the ideXlab platform.
-
Variation in mating systems and sexual size dimorphism between populations of the Australian python Morelia spilota (Serpentes: Pythonidae)
Oecologia, 1995Co-Authors: R. Shine, M. FitzgeraldAbstract:Although adaptationist hypotheses predict a functional relationship between mating systems and sexual size dimorphism, such predictions are difficult to test because of the high degree of phylogenetic conservatism in both of these traits. Taxa that show intraspecific variation in mating systems hence offer valuable opportunities for more direct tests of evolutionary-ecological hypotheses. Based on a collation of published and unpublished records, we document intraspecific geographic variation in mating systems (presence versus absence of male-male combat) within the widely-distributed Australian python Morelia spilota . Radiotelemetric monitoring of 19 free-ranging pythons in a population in north-eastern New South Wales showed that these animals display a mating system of female defence polygyny. Previous studies on a southern population of the same species found that males engaged in long mate-searching movements, showed no overt agonistic behavior, and formed long-term (>2 months) aggregations around reproductive females. In strong contrast, our adult male carpet pythons (i) moved about relatively little (mean displacement
-
variation in mating systems and sexual size dimorphism between populations of the australian python morelia spilota serpentes Pythonidae
Oecologia, 1995Co-Authors: R. Shine, M. FitzgeraldAbstract:Although adaptationist hypotheses predict a functional relationship between mating systems and sexual size dimorphism, such predictions are difficult to test because of the high degree of phylogenetic conservatism in both of these traits. Taxa that show intraspecific variation in mating systems hence offer valuable opportunities for more direct tests of evolutionary-ecological hypotheses. Based on a collation of published and unpublished records, we document intraspecific geographic variation in mating systems (presence versus absence of male-male combat) within the widely-distributed Australian python Morelia spilota. Radiotelemetric monitoring of 19 free-ranging pythons in a population in north-eastern New South Wales showed that these animals display a mating system of female defence polygyny. Previous studies on a southern population of the same species found that males engaged in long mate-searching movements, showed no overt agonistic behavior, and formed long-term (>2 months) aggregations around reproductive females. In strong contrast, our adult male carpet pythons (i) moved about relatively little (mean displacement <11 m/day) during the mating season, (ii) remained with females only briefly (<5 days), and (iii) engaged in male-male combat in the vicinity of females. This male-male combat included vigorous biting as well as ritualised "wrestling" matches, resulting in a high incidence of bite scars in adult males. In keeping with predictions from sexual selection theory, males attain larger body sizes than females in this population, whereas females grow larger than males in the previously-studied southern population where males do not engage in physical combat for mating opportunities.
Richard Shine - One of the best experts on this subject based on the ideXlab platform.
-
Natural history of the rough-scaled python, Morelia carinata (Serpentes: Pythonidae)
Australian Zoologist, 2012Co-Authors: Robert Porter, John Weigel, Richard ShineAbstract:Although the rough-scaled python Morelia carinata of north western Australia is one of the most morphologically distinctive python species worldwide, it remains virtually unstudied. Our fieldtrips have increased the number of animals seen in the wild from 2 to 12, and the 5 animals brought into captivity produced 7 clutches totalling 71 viable offspring over a period of 6 years. In this paper we provide quantitative information on reproduction and growth of these captive animals, as well as qualitative information about behaviour and dietary habits. Reflecting their close phylogenetic relationship with green tree pythons Morelia viridis from northeastern Australia, captive rough-scaled pythons are sedentary animals that spend most of their time tightly coiled in arboreal or saxicolous ambush sites. Females produce relatively small clutches of 10 to 14 eggs, which hatch as large, slenderbodied offspring averaging 406 mm snout-vent length (SVL) and 16.9 g in weight. Growth is rapid, with captive males attai...
-
Responses of three sympatric snake species to tropical seasonality in northern Australia
Journal of Tropical Ecology, 2002Co-Authors: Gregory P. Brown, Richard Shine, Thomas MadsenAbstract:In the Australian wet-dry tropics, temperatures are high year-round but rainfall is concentrated in a 4-mo wet season. Regular nightly surveys in the Fogg Dam Nature Reserve provided data on temporal (monthly, seasonal) vari- ation in biological attributes of three snake species: water pythons (Liasis fuscus, Pythonidae), keelbacks (Tropidonophis mairii, Colubridae) and slatey-grey snakes (Stegonotus cucullatus, Colubridae). Adults of all three taxa were encountered more frequently during the dry season than the wet season, whereas juveniles were more commonly encountered in the wet season. The sex ratio among adult snakes also shifted seasonally, but in different ways in different species. These sex-ratio shifts probably reflect reproductive activity (mate-searching by males, oviposition migra- tions by females) and were accompanied by increased encounter rates. Feeding rates and body condition of keelbacks (a frog specialist) were highest during the wet season when frogs were most abundant. Rats migrated away from Fogg Dam during the wet season, and most pythons (rat specialists) left this area to follow their prey. The pythons that remained at Fogg Dam exhibited low feeding rates and poor body condition. Slatey-grey snakes (a generalist predator) showed less seasonal variation in feeding rates or body condition. Our data show that tropical seasonality induces strong fluctuations in many attributes of snake populations, and that patterns of response differ both among and within species.
-
Geographic variation in sexual size dimorphism within a single snake species (Morelia spilota, Pythonidae)
Oecologia, 2002Co-Authors: David Pearson, Richard Shine, Andrew WilliamsAbstract:Unusually among reptiles, Australian carpet pythons ( Morelia spilota ) display substantial geographic variation in mating systems and sexual size dimorphism. We studied a population of the south-western subspecies ( M . s . imbricata ) of this widely distributed taxon, on Garden Island near Perth, Western Australia. Our data greatly expand the range of variation previously documented for populations of this species. Unlike eastern Australian populations where sex differences in mean adult body size are relatively minor [
-
geographic variation in sexual size dimorphism within a single snake species morelia spilota Pythonidae
Oecologia, 2002Co-Authors: David Pearson, Richard Shine, Andrew WilliamsAbstract:Unusually among reptiles, Australian carpet pythons (Morelia spilota) display substantial geographic variation in mating systems and sexual size dimorphism. We studied a population of the south-western subspecies (M. s. imbricata) of this widely distributed taxon, on Garden Island near Perth, Western Australia. Our data greatly expand the range of variation previously documented for populations of this species. Unlike eastern Australian populations where sex differences in mean adult body size are relatively minor [<10% in snout-vent length (SVL), <30% in mass], female M. s. imbricata grow to over twice the length and more than 10 times the mass of adult males. Mean adult size averages 104 cm SVL (305 g) for males versus 214 cm SVL (3.9 kg) for females. This sex difference is a consequence of cessation in growth by males, in turn due to a reduced rate of feeding. Males display low feeding rates even in captivity, suggesting that their "dwarf" sizes reflect genetic control rather than local prey availability. Observations of free-ranging snakes suggest that males do not engage in overt agonistic interactions during the mating season, and that larger body size does not enhance male mating success. These results fit well with previous interpretations of the relationship between mating systems and sexual size dimorphism in snakes, including other populations of carpet pythons. M.s. spilota displays the greatest geographic variation in sexual size dimorphism yet recorded for any vertebrate species.
-
large snakes in a mosaic rural landscape the ecology of carpet pythons morelia spilota serpentes Pythonidae in coastal eastern australia
Biological Conservation, 1996Co-Authors: Richard Shine, Mark FitzgeraldAbstract:Abstract How can large pythons coexist with human beings in highly modified habitats throughout the eastern coastal region of Australia, when the same species has undergone rapid declines in other parts of the country? To investigate this question, we surgically implanted miniature temperature-sensitive radiotransmitters into 19 adult carpet pythons Morelia spilota (body lengths 1·3–2·8 m; 1·4–7·0 kg) from two study sites near Bangalow and Mullumbimby, NSW. We located the snakes every few days for the next 32–567 days (mean = 308 days), to obtain data on their movements, habitat use, postures, thermal biology, and food habits. Radio-tracked snakes were primarily arboreal (45% of locations), and generally selected trees with a dense covering of vines. Arboreality was more common in males than females, and more common in winter than in other seasons. The snakes generally avoided open areas, but frequently used artificial shelter (e.g. roof spaces in buildings; thickets of non-native tree species). Distances moved were generally small (mean 6 snakes/ha; >20 kg/ha). The success of carpet pythons in these areas reflects their inconspicuousness (due to their selection of densely vegetated arboreal habitats, their sedentary nature, and their cryptic coloration), and their preparedness to utilise ‘artificial’ habitats (such as roof spaces) and non-native prey species (mainly, commensal mammals). Prolonged immobility is possible because of the snakes' reliance on ambush predation, and their large body size facilitates thermoregulation without overt shuttling behavior. Pythons are vulnerable to predators (especially canids) when they move across large open areas, but generally avoid such habitats. Morelia spilota have declined in regions of Australia where agricultural practices have left no thickly vegetated habitats. Patches of such habitat (even if small, and composed of introduced plant species) appear to be vital for the continued presence of large pythons in the agricultural landscape.
Li-wen Chang - One of the best experts on this subject based on the ideXlab platform.
-
Immunohistochemical Detection of a Unique Protein within Cells of Snakes Having Inclusion Body Disease, a World-Wide Disease Seen in Members of the Families
2016Co-Authors: Li-wen Chang, Marjorie Chow, Diane G. Duke, Karen Kelley, Linda Green, Edward Wozniak, Jorge A. Hern, Elliott R JacobsonAbstract:Inclusion body disease (IBD) is a worldwide disease in captive boa constrictors (boa constrictor) and occasionally in other snakes of the families Boidae and Pythonidae. The exact causative agent(s) and pathogenesis are not yet fully understood. Currently, diagnosis of IBD is based on the light microscopic identification of eosinophilic intracytoplasmic inclusion bodies in hematoxylin and eosin stained tissues or blood smears. An antigenically unique 68 KDa protein was identified within the IBD inclusion bodies, called IBD protein. A validated immuno-based ante-mortem diagnostic test is needed for screening snakes that are at risk of having IBD. In this study, despite difficulties in solubilizing semi-purified inclusion bodies, utilizing hybridoma technology a mouse anti-IBD protein monoclonal antibody (MAB) was produced. The antigenic specificity of the antibody was confirmed and validated by western blots, enzyme-linked immunosorbent assay, immuno-transmission electron microscopy, and immunohistochemica
-
Immunohistochemical detection of a unique protein within cells of snakes having inclusion body disease, a world-wide disease seen in members of the families boidae and Pythonidae
PLoS ONE, 2013Co-Authors: Li-wen Chang, Ann Fu, Marjorie Chow, Diane G. Duke, Karen Kelley, Linda Green, Edward Wozniak, Jorge A Hernandez, Elliott R JacobsonAbstract:Inclusion body disease (IBD) is a worldwide disease in captive boa constrictors (boa constrictor) and occasionally in other snakes of the families Boidae and Pythonidae. The exact causative agent(s) and pathogenesis are not yet fully understood. Currently, diagnosis of IBD is based on the light microscopic identification of eosinophilic intracytoplasmic inclusion bodies in hematoxylin and eosin stained tissues or blood smears. An antigenically unique 68 KDa protein was identified within the IBD inclusion bodies, called IBD protein. A validated immuno-based ante-mortem diagnostic test is needed for screening snakes that are at risk of having IBD. In this study, despite difficulties in solubilizing semi-purified inclusion bodies, utilizing hybridoma technology a mouse anti-IBD protein monoclonal antibody (MAB) was produced. The antigenic specificity of the antibody was confirmed and validated by western blots, enzyme-linked immunosorbent assay, immuno-transmission electron microscopy, and immunohistochemical staining. Paraffin embedded tissues of IBD positive and negative boa constrictors (n=94) collected from 1990 to 2011 were tested with immunohistochemical staining. In boa constrictors, the anti-IBDP MAB had a sensitivity of 83% and specificity of 100% in detecting IBD. The antibody also cross-reacted with IBD inclusion bodies in carpet pythons (Morelia spilota) and a ball python (python regius). This validated antibody can serve as a tool for the development of ante-mortem immunodiagnostic tests for IBD. [ABSTRACT FROM AUTHOR]
-
Inclusion Body Disease, A Worldwide Infectious Disease of Boid Snakes: A Review
Journal of Exotic Pet Medicine, 2010Co-Authors: Li-wen Chang, Elliott R JacobsonAbstract:Abstract A disease called inclusion body disease (IBD) is seen worldwide in snakes that are members of the families Boidae and Pythonidae. Snakes affected by this disease often have neurological signs. A diagnosis is based on light microscopic examination of tissues for the presence of intracytoplasmic inclusions that consist of a unique protein that has been termed inclusion body disease protein (IBDP). In some cases, inclusions are found exclusively in the central nervous system, whereas in others they may be diffusely disseminated in multiple tissues. In a few cases, the IBD inclusions have overlapped in appearance with other types of nonviral intracytoplasmic inclusions. The specific etiologic agent of IBD remains unknown. Because the underlying cause of IBD is unknown, recent research has focused on understanding the formation and nature of IBDP. A monoclonal antibody has been developed against IBDP and is currently being used in immunodiagnostic assays to develop a reliable diagnostic test for IBD. This monoclonal antibody is going through rigorous validation testing and will provide more specificity and sensitivity than currently available routine histological diagnostics. Because large numbers of boas and pythons are being bred and sold for the pet trade, better diagnostic tests are needed to help develop IBD-free breeding colonies of these snakes. Further, because IBD is one of the few worldwide diseases of captive snakes, there is concern in many countries (e.g., Australia, where it has been identified in captive pythons) that it will become established in native wild populations. Thus, there is conservation value in developing better diagnostic tools for screening snakes intended for release as part of reintroduction programs.
Andrew Williams - One of the best experts on this subject based on the ideXlab platform.
-
Geographic variation in sexual size dimorphism within a single snake species (Morelia spilota, Pythonidae)
Oecologia, 2002Co-Authors: David Pearson, Richard Shine, Andrew WilliamsAbstract:Unusually among reptiles, Australian carpet pythons ( Morelia spilota ) display substantial geographic variation in mating systems and sexual size dimorphism. We studied a population of the south-western subspecies ( M . s . imbricata ) of this widely distributed taxon, on Garden Island near Perth, Western Australia. Our data greatly expand the range of variation previously documented for populations of this species. Unlike eastern Australian populations where sex differences in mean adult body size are relatively minor [
-
geographic variation in sexual size dimorphism within a single snake species morelia spilota Pythonidae
Oecologia, 2002Co-Authors: David Pearson, Richard Shine, Andrew WilliamsAbstract:Unusually among reptiles, Australian carpet pythons (Morelia spilota) display substantial geographic variation in mating systems and sexual size dimorphism. We studied a population of the south-western subspecies (M. s. imbricata) of this widely distributed taxon, on Garden Island near Perth, Western Australia. Our data greatly expand the range of variation previously documented for populations of this species. Unlike eastern Australian populations where sex differences in mean adult body size are relatively minor [<10% in snout-vent length (SVL), <30% in mass], female M. s. imbricata grow to over twice the length and more than 10 times the mass of adult males. Mean adult size averages 104 cm SVL (305 g) for males versus 214 cm SVL (3.9 kg) for females. This sex difference is a consequence of cessation in growth by males, in turn due to a reduced rate of feeding. Males display low feeding rates even in captivity, suggesting that their "dwarf" sizes reflect genetic control rather than local prey availability. Observations of free-ranging snakes suggest that males do not engage in overt agonistic interactions during the mating season, and that larger body size does not enhance male mating success. These results fit well with previous interpretations of the relationship between mating systems and sexual size dimorphism in snakes, including other populations of carpet pythons. M.s. spilota displays the greatest geographic variation in sexual size dimorphism yet recorded for any vertebrate species.
