South American Journal of Herpetology Impact Factor & Information

Publisher: Sociedade Brasileira de Herpetologia

Journal description

Current impact factor: 0.00

Impact Factor Rankings

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5-year impact 0.00
Cited half-life 0.00
Immediacy index 0.00
Eigenfactor 0.00
Article influence 0.00
Other titles South American journal of herpetology (Online)
ISSN 1808-9798
OCLC 81146246
Material type Document, Periodical, Internet resource
Document type Internet Resource, Computer File, Journal / Magazine / Newspaper

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: Studying the mating system of wild populations of American crocodiles, Crocodylus acutus, has important conservation implications. We conducted a preliminary analysis of the mating system of C. acutus in Las Baulas (2007 and 2008), Santa Rosa (2007) and Palo Verde (2008 and 2009) National Parks in Guanacaste, Costa Rica. We captured hatchlings during crocodile surveys and analyzed them with nine polymorphic microsatellite loci to determine relatedness values. High relatedness values indicated that full and half siblings were sampled in a single locality and season. We found full siblings between the years that hatchlings were collected in Las Baulas and Palo Verde National Parks, which suggested mate fidelity. The mate fidelity and high relatedness values could be a consequence of the smaller number of adult crocodiles found within these areas or indicative of a small number of dominant males in the populations. Our results support the need to conduct future studies describing the mating system and nesting success within populations of C. acutus. Understanding of these population factors is crucial to the continued success and maintenance of viable populations of C. acutus.
    South American Journal of Herpetology 04/2015; 10(1):4-9. DOI:10.2994/SAJH-D-14-00022.1
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    ABSTRACT: In some reptiles, gonadal outcome is regulated by temperature during a critical period of the embryonic development. Gonadal steroid hormones are seen as effectors of the gonadal differentiation process. Recently, stress and glucocorticoids (GCs), stress-related hormones in vertebrates, have been considered as potential modulators of the sex determination process in some vertebrates that present temperature-dependent sex determination (TSD). In reptiles, corticosterone is the main GC produced, and its administration to eggs causes a bias in sex ratio in some lizards. In this context, we aim at assessing whether dexamethasone (Dex), a potent synthetic glucocorticoid, can modify the sex ratio in Caiman latirostris, a species with strong TSD. As a first step, we incubated embryos at masculinizing temperatures (33°C; 100% males). Different doses of Dex were topically applied to the eggshell at stage 20, prior to gonadal differentiation. We assessed embryonic development at stages 22 and 25 and evaluated some physiological and morphological hatchling traits. Embryonic mortality was not affected by dexamethasone manipulation. No effects of Dex on sex ratio were found and all animals analyzed histologically possessed testes. However, older embryos and hatchlings from Dex treated eggs were heavier, larger, and hatched earlier than control individuals. Our results do not account for Dex involvement in the process of ovarian differentiation, at least under a strong masculinizing temperature. Nevertheless, they suggest that Dex might accelerate embryo development by enhancing intermediate metabolism and/or by stimulating growth hormone secretion.
    South American Journal of Herpetology 04/2015; 10(1):41-49. DOI:10.2994/SAJH-D-14-00027.1
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    ABSTRACT: Male intromittent organs serve two primary reproductive functions: the physical entry into the female body during copulation and the effective delivery of gametes resulting in internal fertilization. Here we present a histological examination of the adult male American alligator phallus semen delivery apparatus, the sulcus spermaticus. While the highly collagenous basal crurae and more distal shaft of the alligator penis contain the rigid structures that facilitate cloacal intromission, the sulcus is more functionally intricate. Here we show the sulcus spermaticus (an open groove that runs along the ventral aspect of the phallic shaft) to be a spatially heterogeneous reproductive structure containing a complex architecture of multiple tissue types. Sulcus morphology markedly changes from its proximal origin between the crurae to its distal exit from the phallus tip. At the proximal origin of the sulcus, the ductus deferens vent semen into an expanded lumen lined by a convoluted secretory epithelium. Along the length of the phallic shaft, an arrangement of longitudinally and radially oriented smooth muscle bundles may act via rhythmic contractions to produce peristaltic sperm conveyance through the sulcus. An extensive vascular network of blood and lymph vessels putatively engorges the sulcus tissues during reproductive activity, increasing tension on an internal network of connective tissues and leading to localized inflation and increased tissue rigidity. We hypothesize that this engorgement works to seal the sulcus groove and allow the structure to convey semen through a functionally closed tube. Further, numerous epithelial secretory cells contribute seminal fluids to the ejaculate and may aid in as yet uncharacterized aspects of sulcus functioning. Together, these observations establish that the sulcus spermaticus is far more than a simple furrow in the phallus shaft for sperm conduction: it contains elements that form a complex functional gamete delivery system.
    South American Journal of Herpetology 04/2015; 10(1):32-40. DOI:10.2994/SAJH-D-14-00037.1
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    ABSTRACT: Very little is known about the attainment of puberty in reptiles. In the American alligator (Alligator mississippiensis) males are assumed to be sexually mature at about 1.8 m in total length, but it is not clear at what size they produce testosterone, spermatozoa and mate successfully. We re-examined this question by studying plasma testosterone levels in blood samples from a large sample of alligators (∼1,500) collected every month of the year and ranging in size from approximately 61 cm (2 ft) to 360 cm (11.5 ft). Testosterone values ranged from 0.05-115.41 ng/mL. All size classes of alligators exhibited a seasonal cycle in testosterone levels, but the concentrations were size-dependent: the larger the alligator the higher the testosterone. In all size-classes testosterone reached a peak in the breeding season (March-May). Mean testosterone in the largest size-class during breeding was 75 ng/mL whereas in the smallest size-class peak testosterone was less than 3 ng/mL. The smallest size-class (59-89 cm) showed an additional rise in testosterone in late summer. The attainment of sexual maturity in alligators appears to be closely associated with growth and is a gradual process lasting several years. Sexually immature alligators show a seasonal pattern of testosterone secretion similar to that of adults, but the values are significantly lower.
    South American Journal of Herpetology 04/2015; 10(1):58-63. DOI:10.2994/SAJH-D-15-00005.1
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    ABSTRACT: A new salamander of the genus Chiropterotriton is described from the Sierra Madre Oriental in southwestern Tamaulipas, Mexico. This genus is widespread in the Sierra Madre Oriental, its range extending from Tamaulipas to northern Oaxaca, and it occurs into central Mexico along the mountains associated with the Transverse Volcanic Axis. The species described herein is one of the northernmost species. Previously a few species of Chiropterotriton have been reported from the mountains of Tamaulipas and adjacent Nuevo León, but this new salamander is easily distinguished by its enlarged nares. It also differs from all congeners by a combination of characters including size, limb length, hand and foot morphology, color pattern, and dental morphology.
    South American Journal of Herpetology 12/2014; 9(3):228-234. DOI:10.2994/SAJH-D-14-00042.1
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    ABSTRACT: Estimating total systemic blood flow based on measurements from a single aortic arch is common practice in cardiovascular studies on reptiles to avoid heavy instrumentation and consequent stress responses. This practice requires the validation of a specific correction factor that expresses the relationship between the measured blood flow and the blood flow to be estimated. Misleading estimations may occur when correction factors are used in different conditions from those they were originally measured. Despite recognized as a problem, such misleading estimations are common in physiology. In the present study, we derived values for correction factors to estimate systemic blood flow in the South American rattlesnake, Crotalus durissus, following recovery from anesthesia, using serial measurements of blood flow in the three main systemic arteries, left or distal right aortic arches and the carotid artery. Blood flow recorded in the left aortic arch provided the most reliable and less variable correction factors. Different from previously published, blood flow distribution in the systemic circulation varied with temperature. We suggest the use of the specific correction factors present in this paper for different experimental protocols and temperatures. Furthermore, we can affirm that unilateral left vagotomy, which effectively ablated control of right-left shunts, does not affect systemic blood flow distribution, so the same correction factors can be used.
    South American Journal of Herpetology 12/2014; 9(3):171-176. DOI:10.2994/SAJH-D-14-00012.1
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    ABSTRACT: The anole lizards represent a conspicuous group of vertebrates due to their high species number and abundance in different habitats. Despite the high richness of anoles in Mexico (48 species), to date only a few studies have been performed on their ecology. Because different groups of parasites can provide ecological information on their hosts, we studied the helminths parasitizing Anolis uniformis, one of the most common anoles from southern Mexico. We examined individuals from the tropical rainforest in Laguna Escondida, Los Tuxtlas, Veracruz and we found eight parasitic taxa: seven nematodes (Acuariidae gen. sp., Aplectana sp., Oswaldocruzia sp., Physocephalus sp., Piratuba sp., Rhabdias tobagoensis, and Strongyluris panamaensis) and one acanthocephalan (Centrorhynchus sp.). All taxa represent new records for the host. Additionally, the genera Centrorhynchus, Oswaldocruzia, Physocephalus and Strongyluris are new records for Mexican anoles, while the genus Aplectana is a new record for all anoles. At the genus level, the taxonomical composition of the helminth fauna of A. uniformis is similar to that reported for Central and South American anoles. The life cycles of the parasites found suggest that these lizards may acquire most nematodes from the forest floor while hiding. Life cycles also support that A. uniformis has a mainly insectivorous diet and reflect the presence of mosquitoes that transmit microfilariae to the lizards when feed on their blood.
    South American Journal of Herpetology 12/2014; 9(3):183-189. DOI:10.2994/SAJH-D-14-00035.1
  • South American Journal of Herpetology 08/2014; 9(2):154-169. DOI:10.2994/SAJH-D-14-00018.1
  • South American Journal of Herpetology 08/2014; 9(2):142-150. DOI:10.2994/SAJH-D-13-00039.1