Facultative parthenogenesis discovered for the first time in Jamaican boa (Chilabothrus subflavus) using novel microsatellite markers.

The mode of reproduction most often seen in snakes is sexual, but studies have noted facultative parthenogenesis in at least six families. Here, we provide evidence for the first observed case of facultative parthenogenesis in a captive Jamaican boa (Chilabothrus subflavus). A 7-year-old female Jamaican boa, isolated since birth, was found to have produced a litter of 15 offspring. To provide molecular DNA evidence of parthenogenesis, 13 new microsatellite loci were isolated in the species. All offspring were found to be homozygous at each locus and only possess alleles found in the dam, implicating that they were born from asexual reproduction. Several developmental abnormalities, including stillbirths and spinal deformities, were noted in the litter which may be explained by their increased level of homozygosity. To preserve genetic diversity in the captive population, research should be conducted to understand the prevalence of this mode of reproduction and to guide future management decisions of this IUCN listed Vulnerable species.

Action of Folliculinum 6cH on Folliculogenesis in the Snake Python Regius (Shaw, 1802) - Two Case Reports.

BACKGROUND: Folliculinum is a homeopathic sarcode medication that is mainly used for regulating the estrous cycle and reproductive function. In snakes, it is common to observe low frequencies of reproduction. Ovulation is related to follicular size and morphology, and follicle homogeneity may indicate the absence of problems such as dystocia (egg retention) or follicular stasis. OBJECTIVE: The objective of the present study was to report on follicular stage changes in two ball pythons, Python regius (Shaw, 1802), which were treated using Folliculinum 6cH in a zoological park setting. METHODS: Two female pythons - one weighing 2.8 kg, the other weighing 2.5 kg, and neither with a history of reproduction - were examined by ultrasound to enable viewing of ovarian follicles in different phases and sizes. Folliculinum 6cH, two globules diluted in 200 mL of water, was administered, targeted to the eyes and nostril regions. RESULTS: Even given the slow metabolism of reptiles, ultrasound revealed an improvement in follicle homogeneity between 6 and 15 days after the start of homeopathy in both snakes; there was also improved weight gain in both animals. The MOdified NARanjo Criteria for Homeopathy (MONARCH) score was +8 in each of the cases, suggesting a causal relationship between the use of homeopathic medicine and clinical outcome. CONCLUSION: Folliculinum 6cH may have promoted stabilization of follicle size and enabled folliculogenesis in two ball pythons.

Two records of xanthism in Corallus hortulana (Serpentes: Boidae) in Bolivia with comments on the yellow, patternless morphotype / Dos registros de xantismo en Corallus hortulana (Serpentes: Boidae) en Bolivia con comentarios sobre el morfotipo amarillo sin patrón

Snakes display a wide range of skin colors and patterns, acting in ecological, behavioral, and physiological roles. Xanthism has been reported in numerous snake species, including many neotropical taxa. Corallus hortulana is a polychromatic species widely distributed throughout South America. Yellow, patternless individuals, while rare, have been recognized as within the species' polychromatic range. We report the first yellow, patternless specimens of Corallus hortulana collected in Bolivia and discuss whether these individuals fit the criteria of xanthism.(AU)

Las serpientes muestran una amplia gama de colores y patrones de piel, actuando en roles ecológicos, de comportamiento y fisiológicos. Además, se ha informado xantismo en numerosas especies de serpientes, incluidos muchos taxones neotropicales. Corallus hortulana es una especie policromática ampliamente distribuida en América del Sur. Los individuos amarillos sin patrón, aunque raros, se han reconocido dentro del rango policromático de la especie. Reportamos los primeros especímenes amarillos sin patrón de Corallus hortulana recolectados en Bolivia y discutimos si estos individuos cumplen con los criterios de xantismo.(AU)

Brazilian Boidae hemipenis morphology: Macroscopic and histological aspects.

Four genera of the Boidae family are found in Brazil: Eunectes, Corallus, Epicrates, and Boa. Male copulatory organs in snakes are located inside the tail and are called hemipenes. They are double structures in an inverted position that are exposed during copulation. This study describes the macroscopic and histological aspects of hemipenes in Boidae snakes. One Boa constrictor, three Epicrates cenchria, one Corallus hortulanus hemipenes, and one fragment of the muscular retractor penis magnus (m. retractor penis magnus) from Eunectes murinus were included in this study. The structures were evaluated macroscopically and photo-documented using a stereo microscope. Tissue fragments were included in glycol methacrylate plastic resin, cut into 3-µm-thick slices, and stained with 1% toluidine blue for microscopic evaluation. The macroscopic analysis showed that the arrangement and diameter occupied by the m. retractor penis magnus in the hemipenis and the internal and external cavernous bodies differ between species. The histological analysis showed that the hemipenis of B. constrictor, E. cenchria, and C. hortulanus has stratified epithelium in the external portion supported by dense connective tissue with blood vessels and muscle tissue. Although the literature reports the presence of skeletal musculature in the hemipenis, striated musculature with a centrally located nucleus in the fibre bundle, typical of cardiac musculature in mammals, was observed in the studied species.

Anatomic-radiographic aspects and gastrointestinal transit time in Boa constrictor amarali Stull, 1932 (Squamata, Boidae) / [Aspectos anátomo-radiográficos e tempo de trânsito gastrointestinal em jiboia-cinzenta Boa constrictor amarali Stull, 1932 (Squamata, Boidae)]

The goal of this study was to describe the gastrointestinal transit technique in the Boa constrictor amarali. For that purpose, we obtained simple radiographic images of seven serpents, subsequently administering a 25mL/kg dose of barium sulfate and establishing a radiographic sequence at the following times: 5 minutes; 1, 2, 3, 6, 9, 24, 48, 72 and 96 hours, extending to 120 and 126 hours for one animal. The mean esophageal transit was 26.71±19.48 hours; the mean gastric filling time was 28.57±27.22 minutes and the emptying time was 60±12 hours; the mean filling time of the contrast medium in the small intestine was 3±2.16 hours and the emptying time was 97±15.65 hours. We also obtained the mean filling time of the large intestine, which was 40±11.31 hours. We found that the mean passage time of the contrast medium through the cranial gastrointestinal tract - until the complete elimination of barium sulfate from the small intestine -was 97±15.65 hours. In addition to determining the gastrointestinal transit time, the technique used allowed for the morphological identification of the alimentary canal.(AU)

O objetivo deste trabalho foi descrever a técnica de trânsito gastrointestinal em Boa constrictor amarali. Para tanto, foram obtidas radiografias simples de sete serpentes, e, subsequentemente a essas, foi administrado sulfato de bário na dose de 25mL/kg. A partir disso, foi estabelecida a sequência radiográfica nos seguintes tempos: cinco minutos; uma, duas, três, seis, nove, 24, 48, 72 e 96 horas, e em um animal estendeu-se para 120 e 126 horas. O trânsito esofágico médio foi de 26,71±19,48 horas, o tempo médio de preenchimento gástrico foi de 28,57±27,22 minutos, e o esvaziamento de 60±12 horas; a média de tempo de enchimento do meio de contraste no intestino delgado foi de 3±2,16 horas e, por fim, o esvaziamento foi de 97±15,65 horas, e ainda obteve-se o tempo médio de enchimento do intestino grosso igual a 40±11,31 horas. Desse modo, verificou-se que a média do tempo de passagem do contraste pelo trato gastrointestinal cranial - até a completa eliminação do sulfato de bário do intestino delgado - foi de 97±15,65 horas. Além da determinação do tempo de trânsito gastrointestinal, a técnica empregada permitiu a identificação morfológica do canal alimentar.(AU)

Effects of feeding and digestion on myocardial contractility and expression of calcium-handling proteins in Burmese pythons (Python molurus).

Pythons are important models of studies on postprandial metabolism because their physiological responses are exacerbated when digesting large prey. Prior studies of these animals have shown hypertrophy of the cardiac tissue 2 to 3 days after feeding, coinciding with the peak of the specific dynamic action (SDA), but the consequences of this remodeling in myocardial contractility have not been studied, which is the purpose of this work. Specimens of Python molurus were divided into two groups: a Digesting group (2 days after feeding, at the peak of SDA), and a Fasting group (28 days after feeding). When compared to the Fasting group, the Digesting group showed higher relative ventricular mass and calcium-handling protein expression such as sarcoplasmic reticulum Ca2+-ATPase (SERCA), phospholamban (PLB), and the Na+/Ca2+ exchanger (NCX). Digesting pythons also exhibited significant increases in the cardiac contraction force (Fc), rates of force development and relaxation, and cardiac pumping capacity. Therefore, the higher SERCA, PLB and NCX expression levels increased cytosolic Ca2+ transient amplitude, improving myofilament force. These changes are crucial to maintain cardiac output and a relatively high and continuous blood flow required by metabolic expenditure that occurs in postprandial animals.

Aspectos da biologia reprodutiva de Boa constrictor constrictor: um estudo histológico dos testículos nos períodos reprodutivos de quiescência e máxima atividade / Boa constrictor constrictor reproductive biology aspects: the testes histological study in the reproductive periods of quiescence and maximal activity

As serpentes pertencem ao segundo maior grupo dentro dos répteis, podendo apresentar sazonalidade quanto à espermatogênese, com produção descontínua ou contínua. O presente trabalho tem como objetivo caracterizar aspectos da biologia reprodutiva de Boa constrictor constrictor com base nos achados histológicos dos testículos nos períodos de máxima atividade (período de gametogênese) e quiescência. Os testículos de dois espécimes de Boa c. constrictor (7767 e 11752) foram cortados a uma espessura de 3µm em micrótomo, corados com azul de toluidina 1%, fotodocumentados e descritos. A presença de espermatozoides na luz do túbulo seminífero no indivíduo 7767 indica um período de máxima gametogênese, enquanto o lúmen dos túbulos seminíferos pouco evidentes, sem a presença de espermatozoides e de células gaméticas em divisão, caracteriza o indivíduo 11752 em período quiescente. Mediante os achados histológicos descritos no presente estudo, concluiu-se que Boa c. constrictor apresenta sazonalidade em relação à gametogênese, sendo esse padrão de sazonalidade associado ao período de cópulas relatado em literatura característico de serpentes com padrão pré-nupcial.(AU)

These snakes belong to the second largest group within the reptiles, being able to present seasonality regarding spermatogenesis, with discontinuous or continuous production. The present study aims to characterize Boa constrictor constrictor reproductive biology aspects from histological findings in testicles during periods of maximum activity (period of gametogenesis) and quiescence. The testicles of two specimens of Boa c. constrictor (7767 and 11752) were cut to a thickness of 3µm in microtome, stained with 1% toluidine blue, photodocumented and described. The spermatozoa presence in the seminiferous tubule lumen in individual 7767 indicates a period of maximum gametogenesis, whereas the seminiferous tubules lumen is not very evident without spermatozoa and the absence of dividing gametic cells characterizes individual 11752 in the quiescent period. Through the histological findings we concluded that Boa c. constrictor presents seasonality in relation to gametogenesis, and the pattern of reproductive seasonality observed along with the period of copulas reported in the literature resembles the pre-nuptial pattern.(AU)

Aspectos da biologia reprodutiva de Boa constrictor constrictor: um estudo histológico dos testículos nos períodos reprodutivos de quiescência e máxima atividade / Boa constrictor constrictor reproductive biology aspects: the testes histological study in the reproductive periods of quiescence and maximal activity

As serpentes pertencem ao segundo maior grupo dentro dos répteis, podendo apresentar sazonalidade quanto à espermatogênese, com produção descontínua ou contínua. O presente trabalho tem como objetivo caracterizar aspectos da biologia reprodutiva de Boa constrictor constrictor com base nos achados histológicos dos testículos nos períodos de máxima atividade (período de gametogênese) e quiescência. Os testículos de dois espécimes de Boa c. constrictor (7767 e 11752) foram cortados a uma espessura de 3µm em micrótomo, corados com azul de toluidina 1%, fotodocumentados e descritos. A presença de espermatozoides na luz do túbulo seminífero no indivíduo 7767 indica um período de máxima gametogênese, enquanto o lúmen dos túbulos seminíferos pouco evidentes, sem a presença de espermatozoides e de células gaméticas em divisão, caracteriza o indivíduo 11752 em período quiescente. Mediante os achados histológicos descritos no presente estudo, concluiu-se que Boa c. constrictor apresenta sazonalidade em relação à gametogênese, sendo esse padrão de sazonalidade associado ao período de cópulas relatado em literatura característico de serpentes com padrão pré-nupcial.(AU)

These snakes belong to the second largest group within the reptiles, being able to present seasonality regarding spermatogenesis, with discontinuous or continuous production. The present study aims to characterize Boa constrictor constrictor reproductive biology aspects from histological findings in testicles during periods of maximum activity (period of gametogenesis) and quiescence. The testicles of two specimens of Boa c. constrictor (7767 and 11752) were cut to a thickness of 3µm in microtome, stained with 1% toluidine blue, photodocumented and described. The spermatozoa presence in the seminiferous tubule lumen in individual 7767 indicates a period of maximum gametogenesis, whereas the seminiferous tubules lumen is not very evident without spermatozoa and the absence of dividing gametic cells characterizes individual 11752 in the quiescent period. Through the histological findings we concluded that Boa c. constrictor presents seasonality in relation to gametogenesis, and the pattern of reproductive seasonality observed along with the period of copulas reported in the literature resembles the pre-nuptial pattern.(AU)

Identification and mapping of real acupoints in the anatomical topography of Boa constrictor / Identificação e mapeamento de acupontos reais na topografia anatômica de Boa constrictor

Abstract Acupuncture is a therapy of the traditional Chinese medicine technique, which over the years has been widespread in the West. Defined as a needle-point treatment technique (acupoints), exactly preconfigured in the body to produce a specific physiological reaction to restore the balance between the function of conflicting states and homeostasis, alternating states of energy and thus maintain the ideal organ and body organization. Thus, the objective of this study was to map and describe the main points of acupuncture in the species Boa constrictor , and their indications to promote the balance of this species. The unprecedented result of the mapping was the discovery of specific acupoints with individual location indications without distribution in specific meridians and dispersedly distributed in the body.

Resumo A acupuntura é uma técnica terapêutica da Medicina Tradicional Chinesa, que ao longo dos anos tem sido muito difundida no Ocidente. Definida como uma técnica de tratamento com inserção de agulhas em pontos (acupontos) exatamente pré-estabelecidos sobre o organismo, para produzir uma reação fisiológica específica com o intuito de restabelecer o equilíbrio entre estados contraditórios de função e a homeostase, alternando os estados de energia e com isto mantendo a organização do órgão e do organismo. Com isso, o objetivo do presente trabalho foi mapear e descrever os principais pontos de acupuntura nas espécies Boa constrictore suas indicações para promover o equilíbrio dessa espécie. O resultado inédito do mapeamento foi à descoberta de pontos de acupuntura específicos com indicações de localização individuais sem distribuição em meridianos específicos e dispersamente distribuídos no corpo.

Predation of an American fruit-eating bat (Artibeus sp. ) by an Amazon tree boa (Corallus hortulanus) in the northern Brazilian Amazon / Predação de um morcego frugívoro (Artibeus sp. ) por uma suaçubóia (Corallus hortulanus) no norte da Amazônia brasileira

We report an observation of predation by an Amazon tree boa, Corallus hortulanus, on an American fruit-eating bat, Artibeus sp., in an area of seasonal forest close to a small stream in the northern Brazilian Amazon. While bats appear to be one of the main food items of C. hortulanus, our observation is only the fourth such event to be recorded in the Brazilian Amazon. The Artibeus sp. individual was observed making distress (agony) calls continuously over a period of three hours, much longer than recorded on previous observations. Records of this type are important to further our knowledge on bat predators, and the defensive behavior of bats. (AU)

Nós relatamos uma observação de predação por uma serpente Corallus hortulanus sobre um morcego do gênero Artibeus em uma área de floresta estacional perto de um córrego, no norte da Amazônia brasileira. Enquanto os morcegos parecem ser um dos principais itens alimentares de C. hortulanus, a nossa observação representa somente o quarto relato para a Amazônia brasileira. O indivíduo de Artibeus sp. foi observado vocalizando com chamados de distress (agonia) durante um período de três horas, o que representa uma duração muito maior do que o reportado em registros anteriores. Registros deste tipo são extremamente importantes para aumentar o nosso conhecimento sobre os predadores de morcegos e sobre o comportamento de defesa dos morcegos.(AU)

Identification and mapping of real acupoints in the anatomical topography of Boa constrictor.

Acupuncture is a therapy of the traditional Chinese medicine technique, which over the years has been widespread in the West. Defined as a needle-point treatment technique (acupoints), exactly preconfigured in the body to produce a specific physiological reaction to restore the balance between the function of conflicting states and homeostasis, alternating states of energy and thus maintain the ideal organ and body organization. Thus, the objective of this study was to map and describe the main points of acupuncture in the species Boa constrictor , and their indications to promote the balance of this species. The unprecedented result of the mapping was the discovery of specific acupoints with individual location indications without distribution in specific meridians and dispersedly distributed in the body.

Manejo reprodutivo de jiboias e outros boídeos criados em cativeiro / Captive reproductive management of Boa constrictor snake and other boidae

Atualmente o mercado de animais exóticos movimenta bilhões de dólares, seja com o comércio de animais vivos ou produtos para sua manutenção. O aumento da popularidade das serpentes como animal de estimação é evidente, entretanto, tal explosão de popularidade não foi simultânea à evolução científica do manejo reprodutivo em cativeiro desses animais. O manejo reprodutivo de jiboias possui diversas particularidades que podem ser aplicadas para otimizar o desempenho da espécie, sempre buscando um manejo condizente. Os mecanismos fisiológicos da reprodução das serpentes não são totalmente elucidados, porém diversas características conhecidas devem ser exploradas para uma reprodução eficiente. A utilização de um manejo reprodutivo adequado, resulta em animais com alto grau de bem-estar, aumento de produção, possibilita o atendimento à demanda de mercado com animais legais nascidos em cativeiro e, portanto, colabora para a redução do tráfico e comercialização ilegal de animais.(AU)

Nowadays the exotic pet market represents a billionaire market worldwide, considering live animals sell and maintenance products. The increase in popularity of snakes as pets is evident, but this popularity increase was not simultaneous with scientific data production regarding husbandry of these species in captivity. The reproductive management of boas presents many particularities that must be considered for an adequate husbandry to optimize their reproductive performance. The reproductive physiological pathways of snakes are not completely elucidated; however the known characteristics may be explored for an efficient reproduction. The use of adequate techniques results in animals with improved welfare, increase in offspring production, and supply the demand for legal animals, therefore contributing against animal traffic and illegal commercialization.(AU)

Manejo reprodutivo de jiboias e outros boídeos criados em cativeiro / Captive reproductive management of Boa constrictor snake and other boidae

Atualmente o mercado de animais exóticos movimenta bilhões de dólares, seja com o comércio de animais vivos ou produtos para sua manutenção. O aumento da popularidade das serpentes como animal de estimação é evidente, entretanto, tal explosão de popularidade não foi simultânea à evolução científica do manejo reprodutivo em cativeiro desses animais. O manejo reprodutivo de jiboias possui diversas particularidades que podem ser aplicadas para otimizar o desempenho da espécie, sempre buscando um manejo condizente. Os mecanismos fisiológicos da reprodução das serpentes não são totalmente elucidados, porém diversas características conhecidas devem ser exploradas para uma reprodução eficiente. A utilização de um manejo reprodutivo adequado, resulta em animais com alto grau de bem-estar, aumento de produção, possibilita o atendimento à demanda de mercado com animais legais nascidos em cativeiro e, portanto, colabora para a redução do tráfico e comercialização ilegal de animais.

Nowadays the exotic pet market represents a billionaire market worldwide, considering live animals sell and maintenance products. The increase in popularity of snakes as pets is evident, but this popularity increase was not simultaneous with scientific data production regarding husbandry of these species in captivity. The reproductive management of boas presents many particularities that must be considered for an adequate husbandry to optimize their reproductive performance. The reproductive physiological pathways of snakes are not completely elucidated; however the known characteristics may be explored for an efficient reproduction. The use of adequate techniques results in animals with improved welfare, increase in offspring production, and supply the demand for legal animals, therefore contributing against animal traffic and illegal commercialization.

The influence of midazolam on heart rate arises from cardiac autonomic tones alterations in Burmese pythons, Python molurus.

The GABAA receptor agonist midazolam is a compound widely used as a tranquilizer and sedative in mammals and reptiles. It is already known that this benzodiazepine produces small to intermediate heart rate (HR) alterations in mammals, however, its influence on reptiles' HR remains unexplored. Thus, the present study sought to verify the effects of midazolam on HR and cardiac modulation in the snake Python molurus. To do so, the snakes' HR, cardiac autonomic tones, and HR variability were evaluated during four different experimental stages. The first stage consisted on the data acquisition of animals under untreated conditions, in which were then administered atropine (2.5mgkg-1; intraperitoneal), followed later by propranolol (3.5mgkg-1; intraperitoneal) (cardiac double autonomic blockade). The second stage focused on the data acquisition of animals under midazolam effect (1.0mgkg-1; intramuscular), which passed through the same autonomic blockade protocol of the first stage. The third and fourth stages consisted of the same protocol of stages one and two, respectively, with the exception that atropine and propranolol injections were reversed. By comparing the HR of animals that received midazolam (second and fourth stages) with those that did not (first and third stages), it could be observed that this benzodiazepine reduced the snakes' HR by ~60%. The calculated autonomic tones showed that such cardiac depression was elicited by an ~80% decrease in cardiac adrenergic tone and an ~620% increase in cardiac cholinergic tone - a finding that was further supported by the results of HR variability analysis.

Efeitos da administração do midazolam em doses diferentes em jiboias Boa constrictor Linnaeus, 1758 (Squamata: Boidae) / Effects of midazolam in different doses in redtail boa Boa constrictor Linnaeus, 1758 (Squamata: Boidae)

The objective of this study was to compare the effects of midazolam in Boa constrictor. We used 20 redtail boas, divided into two groups of ten animals each. Group 1 (G1) received 1 mg/kg of midazolam and group 2 (G2) 2 mg/kg, by intracelomic injection. The specimens of G1 presented reduction of head tone, muscle tone, manipulation, and locomotion for 233.50 ± 71.34 minutes and the representatives of G2 for 328.50 ± 125.35 minutes. No redtail boa belonging to both G1 and G2 presented absence of postural righting reflex or achieved analgesia. However, all specimens tested showed intense muscle relaxation and difficulty to move in. The turnaround time to pre-sedation conditions were 279 ± 73.55 minutes for G1 and 372 ± 142.27 minutes for G2. There were no statistical differences between evaluations of heart and respiratory rates in both groups tested. We concluded, therefore, in redtail boa, midazolam at the dosage of 1 mg/kg causes the same effect as 2 mg/kg, but with shorter recovery time, and it can be used to contain Boa constrictor, or in associations aimed at an effective muscle relaxation.(AU)

Objetivou-se comparar os efeitos de duas doses de midazolam em Boa constrictor. Utilizaram-se 20 jiboias, divididas em dois grupos. O grupo 1 (G1), composto por dez animais, recebeu 1 mg/kg de midazolam e o grupo 2 (G2), também com dez animais, 2 mg/kg, pela via intracelomática. Os animais do G1 apresentaram déficit de tônus da cabeça, tônus muscular, manipulação e locomoção por 3,89 ± 1,18 horas e os representantes do G2 por 5,47 ± 2,08 horas. Nenhuma jiboia, em ambos os grupos, manifestou ausência de reação postural de endireitamento ou alcançaram sedação profunda; entretanto, observou-se redução da agressividade, intenso relaxamento muscular e uma dificuldade de serpentear em todos os exemplares. O tempo de retorno às condições pré-sedativas foi de 4,65 ± 1,22 horas para o G1 e de 6,2 ± 2,37 horas para o G2. Não foram observadas diferenças significativas nas avaliações da frequência cardíaca e respiratória entre os grupos. Concluiu-se assim que 1 mg/kg de midazolam provoca nas jiboias o mesmo efeito que 2 mg/kg, porém na menor dose o tempo de recuperação é menor, podendo ser utilizado para a contenção farmacológica de Boa constrictor, ou em associações que visem um efetivo relaxamento muscular.(AU)

Efeitos da administração do midazolam em doses diferentes em jiboias Boa constrictor Linnaeus, 1758 (Squamata: Boidae) / Effects of midazolam in different doses in redtail boa Boa constrictor Linnaeus, 1758 (Squamata: Boidae)

The objective of this study was to compare the effects of midazolam in Boa constrictor. We used 20 redtail boas, divided into two groups of ten animals each. Group 1 (G1) received 1 mg/kg of midazolam and group 2 (G2) 2 mg/kg, by intracelomic injection. The specimens of G1 presented reduction of head tone, muscle tone, manipulation, and locomotion for 233.50 ± 71.34 minutes and the representatives of G2 for 328.50 ± 125.35 minutes. No redtail boa belonging to both G1 and G2 presented absence of postural righting reflex or achieved analgesia. However, all specimens tested showed intense muscle relaxation and difficulty to move in. The turnaround time to pre-sedation conditions were 279 ± 73.55 minutes for G1 and 372 ± 142.27 minutes for G2. There were no statistical differences between evaluations of heart and respiratory rates in both groups tested. We concluded, therefore, in redtail boa, midazolam at the dosage of 1 mg/kg causes the same effect as 2 mg/kg, but with shorter recovery time, and it can be used to contain Boa constrictor, or in associations aimed at an effective muscle relaxation.

Objetivou-se comparar os efeitos de duas doses de midazolam em Boa constrictor. Utilizaram-se 20 jiboias, divididas em dois grupos. O grupo 1 (G1), composto por dez animais, recebeu 1 mg/kg de midazolam e o grupo 2 (G2), também com dez animais, 2 mg/kg, pela via intracelomática. Os animais do G1 apresentaram déficit de tônus da cabeça, tônus muscular, manipulação e locomoção por 3,89 ± 1,18 horas e os representantes do G2 por 5,47 ± 2,08 horas. Nenhuma jiboia, em ambos os grupos, manifestou ausência de reação postural de endireitamento ou alcançaram sedação profunda; entretanto, observou-se redução da agressividade, intenso relaxamento muscular e uma dificuldade de serpentear em todos os exemplares. O tempo de retorno às condições pré-sedativas foi de 4,65 ± 1,22 horas para o G1 e de 6,2 ± 2,37 horas para o G2. Não foram observadas diferenças significativas nas avaliações da frequência cardíaca e respiratória entre os grupos. Concluiu-se assim que 1 mg/kg de midazolam provoca nas jiboias o mesmo efeito que 2 mg/kg, porém na menor dose o tempo de recuperação é menor, podendo ser utilizado para a contenção farmacológica de Boa constrictor, ou em associações que visem um efetivo relaxamento muscular.

Ecological specialization and morphological diversification in Greater Antillean boas.

Colonization of islands can dramatically influence the evolutionary trajectories of organisms, with both deterministic and stochastic processes driving adaptation and diversification. Some island colonists evolve extremely large or small body sizes, presumably in response to unique ecological circumstances present on islands. One example of this phenomenon, the Greater Antillean boas, includes both small (<90 cm) and large (4 m) species occurring on the Greater Antilles and Bahamas, with some islands supporting pairs or trios of body-size divergent species. These boas have been shown to comprise a monophyletic radiation arising from a Miocene dispersal event to the Greater Antilles, though it is not known whether co-occurrence of small and large species is a result of dispersal or in situ evolution. Here, we provide the first comprehensive species phylogeny for this clade combined with morphometric and ecological data to show that small body size evolved repeatedly on separate islands in association with specialization in substrate use. Our results further suggest that microhabitat specialization is linked to increased rates of head shape diversification among specialists. Our findings show that ecological specialization following island colonization promotes morphological diversity through deterministic body size evolution and cranial morphological diversification that is contingent on island- and species-specific factors.

Predation of a squirrel monkey (Saimiri sciureus) by an Amazon tree boa (Corallus hortulanus): even small boids may be a potential threat to small-bodied platyrrhines.

Predation has been suggested to play a major role in the evolution of primate ecology, although reports of predation events are very rare. Mammalian carnivores, raptors, and snakes are known predators of Neotropical primates, and most reported attacks by snakes are attributed to Boa constrictor (terrestrial boas). Here, we document the predation of a squirrel monkey (Saimiri sciureus) by an Amazon tree boa (Corallus hortulanus), the first record of the predation of a platyrrhine primate by this boid. The event was recorded during a nocturnal herpetological survey in the Piratuba Lake Biological Reserve, in the north-eastern Brazilian Amazon. The snake was encountered at 20:00 hours on the ground next to a stream, at the final stage of ingesting the monkey. The C. hortulanus specimen was 1620 mm in length (SVL) and weighed 650 g, while the S. sciureus was a young adult female weighing 600 g, 92 % of the body mass of the snake and the largest prey item known to have been ingested by a C. hortulanus. The evidence indicates that the predation event occurred at the end of the afternoon or early evening, and that, while capable of capturing an agile monkey like Saimiri, C. hortulanus may be limited to capturing small platyrrhines such as callitrichines.

Sex allocation and secondary sex ratio in Cuban boa (Chilabothrus angulifer): mother's body size affects the ratio between sons and daughters.

Secondary sex ratios of animals with genetically determined sex may considerably deviate from equality. These deviations may be attributed to several proximate and ultimate factors. Sex ratio theory explains some of them as strategic decisions of mothers improving their fitness by selective investment in sons or daughters, e.g. local resource competition hypothesis (LRC) suggests that philopatric females tend to produce litters with male-biased sex ratios to avoid future competition with their daughters. Until now, only little attention has been paid to examine predictions of sex ratio theory in snakes possessing genetic sex determination and exhibiting large variance in allocation of maternal investment. Cuban boa is an endemic viviparous snake producing large-bodied newborns (∼200 g). Extremely high maternal investment in each offspring increases importance of sex allocation. In a captive colony, we collected breeding records of 42 mothers, 62 litters and 306 newborns and examined secondary sex ratios (SR) and sexual size dimorphism (SSD) of newborns. None of the examined morphometric traits of neonates appeared sexually dimorphic. The sex ratio was slightly male biased (174 males versus 132 females) and litter sex ratio significantly decreased with female snout-vent length. We interpret this relationship as an additional support for LRC as competition between mothers and daughters increases with similarity of body sizes between competing snakes.

Fatal attack on black-tufted-ear marmosets (Callithrix penicillata) by a Boa constrictor: a simultaneous assault on two juvenile monkeys.

Here we report the first witnessed attack on a marmoset by a constrictor snake. The incident occurred mid-morning in a gallery forest within an altered landscape of the Cerrado region of central Brazil and refers to a fatal attack by a Boa constrictor on two juvenile black-tufted-ear marmosets (Callithrix penicillata) simultaneously. The snake captured both individuals at a height of ~ 4 m while a group of eight marmosets traveled through the subcanopy. The actual strike was not seen. After 2 min, the boa fell to the ground with both marmosets in its coils and proceeded to kill one animal at a time through constriction. Two adult marmosets immediately descended to where the snake held its victims on the ground and attacked it. The snake showed no apparent reaction, and after ~ 1-2 min, the adults rejoined the remaining group members that were mobbing and vocalizing from 5 to 6 m above. The group left the scene ~ 7 min after the onset of the attack and was not seen again. The snake loosened its coils 10 min after its initial strike, left the two carcasses on the ground and stayed behind a nearby tree. Thus, we are not sure if the victims were in fact ingested. This report confirms that marmosets are vulnerable to boid snakes and capable of highly organized and cooperative antipredation behavior. It also suggests that snakes pose a greater threat to callitrichids than previously thought.