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Siroski P.A.,Laboratorio Of Zoologia Aplicada Anexo Vertebrados Fhuc Unl Maspyma | Merchant M.E.,Mcneese State University | Marco M.P.V.,Laboratorio Of Zoologia Aplicada Anexo Vertebrados Fhuc Unl Maspyma | Marco M.P.V.,CONICET | And 4 more authors.
Animal Biology | Year: 2011

Dipeptidyl peptidase IV (DPPIV) is a well-characterized protease with broad substrate specificity, functionally-related to the activity of many bioactive peptides. It plays an important role as physiological regulator of a number of peptides that serve as biochemical messengers within the immune system. Plasma DPPIV activity was characterized with respect to temperature, kinetics and concentration dependence in two species of caiman, the broad-snouted caiman (Caiman latirostris) and the black yacare (Caiman yacare). DPPIV activity showed a significant positive correlation from titrations carried out in the presence of different plasma concentrations. DPPIV activity was lower in C. yacare than in C. latirostris at all temperatures tested. C. yacare DPPIV activity showed a significant increase only at higher temperatures whilst C. latirostris plasma demonstrated a strong positive correlation starting at the lowest temperature, probably due to an adaptation for the tolerance of lower temperatures. Exposure of C. latirostris and C. yacare plasma at different time points showed that plasma DPPIV activities were time-dependent, and that the titer-dependent curves were different for the two species. These results revealed that plasma DPPIV activities were different between these two crocodilian species, which could contribute to the differences in susceptibility to infection between them. © 2011 Koninklijke Brill NV, Leiden.

Siroski P.A.,Laboratorio Of Zoologia Aplicada Anexo Vertebrados Fhuc Unl Maspyma | Poletta G.L.,Laboratorio Of Zoologia Aplicada Anexo Vertebrados Fhuc Unl Maspyma | Poletta G.L.,National University of Costa Rica | Fernandez L.,Laboratorio Of Zoologia Aplicada Anexo Vertebrados Fhuc Unl Maspyma | And 2 more authors.
Zoo Biology | Year: 2012

Sunlight is a key environmental factor in almost all ecosystems, and it is necessary for many physiological functions. Many vertebrates require ultraviolet (UV) radiation to perform different physiological processes. Artificial light is used to supplement UV in captive animals, through appropriate photoperiods and UV wavelengths. Previous studies reported that repeated exposure to artificial UV radiation may cause damage to the immune system. Taking into account the importance of UV effects and the serum complement system, the relationship between them was investigated. The study lasted 90 days and was carried out in plastic chambers. Ninety six broad-snouted caiman (C. latirostris) were assigned to four treatment groups with two replicates each: total darkness (TD), 8hr per day (8hr) and 16hr per day (16hr) of artificial UV/visible light exposure, and normal photoperiod of natural light (NP). Snout-vent length was measured to determine animal growth. Hemolytic assays were performed to evaluate the effects of artificial UV/visible light, TD, and NP on the serum complement system. Results showed that animals grew more in the NP group. The capacity of C. latirostris serum to hemolyze sheep red blood cells was higher in the NP group than when they are maintained in constant light-dark cycles (8 and 16hr) or in TD. These data demonstrate that artificial UV should be considered as a potential hazard for captive crocodilians if it is not properly managed, and this should be taken into account in the general design of facilities for reptilian husbandry. © 2011 Wiley Periodicals, Inc.

Nunez-Otano N.B.,CONICET | Nunez-Otano N.B.,Laboratorio Of Zoologia Aplicada Anexo Vertebrados Fhuc Unl Maspyma | Pina C.I.,CONICET | Pina C.I.,Laboratorio Of Zoologia Aplicada Anexo Vertebrados Fhuc Unl Maspyma | And 3 more authors.
Revista Mexicana de Biodiversidad | Year: 2013

There are few reports of cloacal mycobiota on wild reptiles, and in particular, fungal presence and function in Caiman latirostris remains unknown. Our objective was to describe the fungal community present in the cloaca of wild female broad-snouted caimans during their reproductive season determine whether the number of fungi has some relationship with the female's corporeal condition. Fungi were found in 9 out of 13 cloacal samples and 14 species of fungi were isolated and identified. Three of the species isolated had the highest occurrence values, and 2 of them are pathogenic. In this case, body condition index had no relationship with fungal frequency; the fungi found in this study may have originated from soil habitat and nest substrate that are in constant contact with the cloaca of the C. latirostris females. The findings in this work support the theory that reptiles are facultative carriers of fungi or their spores.

Simoncini M.S.,CONICET | Simoncini M.S.,Laboratorio Of Zoologia Aplicada Anexo Vertebrados Fhuc Unl Maspyma | Cruz F.B.,CONICET | Larriera A.,Laboratorio Of Zoologia Aplicada Anexo Vertebrados Fhuc Unl Maspyma | And 2 more authors.
Journal of Zoology | Year: 2014

Caiman latirostris has temperature-dependent sex determination and is potentially susceptible to environmental temperature fluctuations and, thus, to the global climate change phenomena. Considering the potential consequences of increasing temperatures for Ca.latirostris offspring, we examined the effects of climatic conditions on sex ratios produced by caimans in wild nests and in particular how climate variables affect nest temperature and the percentage of females produced. We also explored the potential consequences of a hypothetic 0.5 and 1.0°C increase in nest temperature on caiman populations. The proportion of females produced from nests in the wild varied among reproductive seasons, as mean nest temperatures varied between 27.1 and 33.9°C. However, after seven seasons the sex ratio biased toward females, and only during extreme events (strong El Niño Southern Oscillation event, La Niña) was there a reduction in the percentage of females produced in the wild. In the hypothetic scenarios of global warming, we predict a decrease of unisexual female nests, with nests containing both sexes or unisexual male nests becoming more frequent. Entire clutches might be lost if nest temperatures rise above 34.5°C for extended periods. However, it is possible that females modify their nesting timing and behavior to select thermally suitable nest environments. © 2014 The Zoological Society of London.

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