You are on page 1of 6 Search inside document A. EstrEllA et al. Abstract: The dipsadid genus Helicops comprises sixteen species ocurring in all South American countries, with the exception of Chile. Such aquatic snakes inhabit rivers and lagoons of Tropical areas; all species have enlarged rear teeth, although a sulcus is absent, reason why they are considered aglyphous snakes. Nonetheless, a well developed Duvernoy gland is present. The main objective of this study was to investigate the proteolytic and neurotoxic activities of the venom of H.
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You are on page 1of 6 Search inside document A. EstrEllA et al. Abstract: The dipsadid genus Helicops comprises sixteen species ocurring in all South American countries, with the exception of Chile.
Such aquatic snakes inhabit rivers and lagoons of Tropical areas; all species have enlarged rear teeth, although a sulcus is absent, reason why they are considered aglyphous snakes. Nonetheless, a well developed Duvernoy gland is present. The main objective of this study was to investigate the proteolytic and neurotoxic activities of the venom of H.
The crude venom lethal dose fifty LD 50 was of 5. Six peaks were obtained by Superose 12 size exclusion chromatography with neurotoxic activity in peak 3. The neurotoxic clinical manifestations produced death in INH mice eight minutes postinjection with crude venom and its fractions.
The proteolytic activities tested on gelatin and casein were positive with crude venom and size exclusion peak 1. Hemorrhagic activity was not present in the crude venom nor in its fractions.
Helicops angulatus should be considered a middly venomous dipsadid snake. Key Words: aglyphous, aquatic snake, Venezuela, Helicops, neurotoxic, proteolytic, venom.
Estrella, A. La dosis letal cincuenta del veneno crudo fue de 5. Helicops angulatus debe ser considerada una serpiente dipsadida moderadamente venenosa.
Zug et al. However, recent phylogenetic studies provided considerable refinement of this system, recovering several monophyletic groups to be recognized at the familial status, such as the Colubridae sensu stricto and the Dipsadidae Vidal et al. In spite of the modern classifications mentioned above, studies focused on the venom activities of snakes species other than vipers, elapids and atractaspidids were based in the orthodoxal classification, considering species currently allocated in other families as belonging to the Colubridae sensu lato e.
Colubridae sensu lato. The genus Helicops comprises sixteen species of aquatic snakes occuring in moist habitats associated to brookes, rivers and lagoons of most South American countries, to the exception of Chile. Diet of Helicops species is mostly composed by frogs and fishes Marques et al. Since biting is one of the most important defensive strategies of these snakes, accidents to humans have already been recorded for at least one species of the genus Albolea Despite the presence of enlarged teeth that follow a diastema, such teeth in Helicops lack any traces of distinctive sulcus, characterizing an aglyphous dentition.
Nonetheless, serous secretions are produced by a well differentiated Duvernoy gland. The species approached in this study is H. This work comprises first experimental study of the neurotoxic and proteolitic action of the venom of H. Other Helicops species were studied by Albolea Neurotoxic clinical symptoms were observed in mice injected with venom samples of H.
Most of these venom toxins have not been considered clinically important in envenoming because they are less than 30 kDa, and detect specific receptors often located on cell membranes Chippaux and Goyffon Their response can be hemostatic, neurological, muscular, cardiovascular or undifferentiated.
Their mode of action and objectives are mainly neurotoxins, but cardiotoxins, myotoxins and hemostatic toxins are also present Nkinin et al. Animals were acclimated for about one week before beginning each experiment and received water and food ad libitum.
Specimens of H. The venom was extracted with a capillary tube. From each extraction, approximately 0. Protein determination We followed the method of Lowry et al. A total of 0. The endpoint of lethality was calculated after 48 h. Venezuelan specimen of Helicops angulatus. Ejemplar venezolano de Helicops angulatus. The relative masses were estimated by the Multi-Analyst PC version 1.
Views Read Edit View history. A study system for the evolution of viviparity helicips squamate reptiles Zoologischer Anzeiger Sixth contribution to the herpetology of Tropical America. Helicopsin — Helicops angulatus South American water snake Reviewed — Annotation score: Ventrally, it is yellowish in alcohol with black crossbands or black spots. Check List 10 4: This colubrid snake article is a stub. The dorsal scales are strongly keeled, even on the occiput and nape, and are arranged in 19 rows. The algorithm is described in the ISO standard.
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