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Technique for surgical implantation of transmitters in snakes
... Our understanding of the biology of adult Green Anacondas has improved in recent years. There have been comprehensive studies of their mating system (Rivas and Burghardt, 2001;Rivas et al., 2007a), general natural history (Rivas, 2000;Rivas et al., 2007b), conservation and sustainable use (Rivas, 2007(Rivas, , 2010, predation (Rivas et al., 1999Rivas and Owens, 2000), diseases (Calle et al., 1994, foraging (Rivas, 1998(Rivas, , 2004, and demography (Rivas and Corey, 2008), along with notes on field techniques (Rivas et al., 1995;Raphael et al., 1996;Rivas, 2008). Adult anacondas live in shallow, stagnant water that is often covered by aquatic vegetation (Rivas, 2000;Rivas et al., 2007b). ...
... Transmitters were implanted in two male and two female neonates. Subcutaneous infiltration of 0.03% lidocaine was used for local anesthesia, and the transmitters were implanted subcutaneously (Raphael et al., 1996). ...
Our knowledge of the biology of neonatal snakes has lagged behind that of adult animals, mostly due to the difficulty of finding and studying neonatal snakes in the wild. Traditional approaches view neonatal reptiles as miniature replicates of their adult counterparts. In this contribution, we present data on the natural history of neonatal Green Anacondas from opportunistic captures in the wild over a 17-year period, as well as from a brief study on captive-born radio-tagged individuals. Both approaches converge in presenting a picture of the ecology of neonatal anacondas showing many similarities between their natural history and that of adult anacondas in spite of the great size difference. The neonates' biology resembles that of adults, especially males, in their preference for birds in their diet, the relative prey size they choose, slow growth rates they experience, low feeding frequency, little mobility, and preference for similar habitats of stagnant, shallow water covered by aquatic vegetation. The conventional wisdom that neonatal reptiles are replicates of their adult counterparts seems to be largely on target in Green Anacondas. © 2016 by the American Society of Ichthyologists and Herpetologists.
... We measured snout-vent-length = SVL, and total length = TL with 1 cm precision, and body mass with a spring scale with 0.25 kg precision for captured animals. We equipped snakes (SVL > 150 cm) with radio transmitters <0.6% of snake mean body weight (∼27 g; Model F1850B, Advanced Telemetry Systems, Inc.), implanted subcutaneously using standardized procedures (Raphael et al., 1996). As mentioned, we relocated all the snakes found near homes in the largest wetland within Ibiato. ...
Understanding of snake ecology has increased over the past two decades, but is still limited for many species. This is particularly true for the recently described Beni anaconda (Eunectes beniensis). We present the results of a radio-telemetry study of nine (3M:6F) adult E. beniensis, including home range, and habitat use. We located the snakes 242 times in wet season, and 255 in dry season. Mean wet season home range (MCP) was 25.81 ha (6.7 to 39.4 ha); while mean dry season home range was 0.29 ha (0.13 to 0.42 ha). We found no relationship between home range size and either snout-vent length, weight, or sex. Beni anacondas seem to prefer swamps, and patujusal, while avoiding forest, and rice fields. However, habitat use by individual snakes seems to vary based on the habitats available within their respective home range. Notably, rice fields were avoided by most snakes, which suggests that this type of habitat is unsuitable for anaconda management.
... Individuals were sexed based on the presence or absence of claspers, fin clipped for genetic and isotopic analysis and tagged with passive integrated transponder (PIT) tags (FDXB transponders; Microchips Australia) for individual identification. Individuals were then sedated in a solution of tricaine methanesulfonate (MS-222; 150 mg mL À1 ) and an acoustic transmitter (Vemco V16) was implanted in their peritoneal cavity through a 2.5-cm incision, which was then sutured using five interrupted sutures and superglue (Mulcahy 2003). Transmitters were programmed with a nominal delay of 90 s and an expected battery life of 2805 days. ...
Knowledge of the broad-scale movement patterns of sharks is essential to developing effective management strategies. Currently there is a large bias in studies focusing on species that are either large apex predators or found in tropical to subtropical regions. There is limited knowledge of the movements and migrations of benthic and temperate shark species. The present study used passive acoustic telemetry to investigate the movement patterns of a benthic shark species, the Port Jackson shark (Heterodontus portusjacksoni). Individuals were tagged with acoustic transmitters between 2012 and 2014 and their movements were monitored within Jervis Bay and along the east Australian coastline for up to 4 years. Male and female Port Jackson sharks demonstrated high levels of philopatry to both Jervis Bay and their tagging location across multiple years. Although males and females did not differ in their arrival times, females departed from Jervis Bay later than males. Approximately half the tagged individuals migrated in a southward direction, with individuals being detected at Narooma, Bass Strait and Cape Barron Island. This study provides conclusive evidence of bisexual philopatry in a benthic temperate shark species, confirming previous hypotheses, and presents the most detailed migration route for Port Jackson sharks to date.
Reptiles can harbor pathogenic microorganisms asymptomatically and serve as potential reservoirs of infection for humans, domestic animals, and other reptiles. Infectious diseases are also problematic for free-ranging reptile populations and are an important consideration in reptile reintroduction and translocation projects. There have been limited serologic studies of free-ranging reptiles for evidence of exposure to potential pathogens. In the present study, serum or plasma samples from five male and five female free-ranging Venezuelan anacondas (Eunectes murinus) were screened for antibodies to eastern, western, and Venezuelan equine encephalitis viruses, vesicular stomatitis virus, ophidian paramyxovirus, 19 Leptospira interrogans serovars, and Cryptosporidium serpentes. Antibodies to these agents were not detected, or antibody titers were low and possibly nonspecific. These results for the limited number of anacondas surveyed suggest that they do not serve as significant reservoirs for these infectious agents at this location.
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