Eggshell structure in Caiman latirostris eggs improves embryo survival during nest inundation.

Egg inundation often results in poor hatching success in crocodylians. However, how tolerant eggs are to submergence, and/or how eggshell ultrastructure may affect embryo survival when inundated, are not well understood. In this study, our objective was to determine if embryo survival in Caiman latirostris is affected by eggshell surface roughness, when eggs are submerged under water. Tolerance to inundation was tested early (day 30) versus late (day 60) in development, using eight clutches (four per time treatments), subdivided into four groups: (N = 9 per clutch per treatment; 9 × 4 = 36 eggs per group). 'Rough' eggshell represented the natural, unmodified eggshell surface structure. 'Smooth' eggshell surface structure was created by mechanically sanding the natural rough surface to remove surface columnar elements and secondary layer features, e.g. irregularities that result in 'roughness'. When inundated by submerging eggs under water for 10 h at day 30, 'smooth' eggshell structure resulted in more than twice as many dead embryos (16 versus 6, smooth versus rough; N = 36), and fewer than half as many healthy embryos (6 versus 13, smooth versus rough, respectively; N = 36). By contrast, at day 60, inundation resulted in very low hatching success, regardless of eggshell surface structure. Only two hatchlings survived the inundation, notably in the untreated group with intact, rough eggshells. Inundation produced a high rate of malformations (58% at day 30), but did not affect hatchling size. Our results indicate that eggshell roughness enhances embryo survival when eggs are inundated early in development, but not late in development. Apparently, the natural surface 'roughness' entraps air bubbles at the eggshell surface during inundation, thereby facilitating gas exchange through the eggshell even when the egg is submerged under water.

Mating System of Caiman yacare (Reptilia: Alligatoridae) Described from Microsatellite Genotypes.

The yacare caiman (Caiman yacare) is a reptile from South America and 1 of the 2 crocodilian species present in Argentina. The degradation of their natural habitat and strong hunting pressure led to a sharp numerical decline of wild populations. Nowadays, C. yacare is included in Appendix II of CITES, and ranching practices in some areas in Argentina are helping hatching success. In this context, it is important to better understand the population structure and mating system of the species. To do this, we amplified 10 microsatellite markers (SSRs) in 148 individuals of 13 C. yacare nests. All of the markers were polymorphic with 2­12 alleles per locus, with allelic sizes ranging between 154 and 400 bp and medium levels of polymorphism (Ho = 0.152­0.551 and He = 0.221­0.621). We were able to determine the maternal genotype in 9 out of 13 nests. In 6 of them we found more than 1 paternal genotype, with a maximum of 3 fathers for a single nest. This study is the first to provide evidence of multiple paternity behavior. These findings will be useful to improve management and conservation strategies for the species.

Increasing Population Status of Broad-Snouted Caiman (Caiman latirostris) Based on Sustainable Use Strategies in a Managed Protected Area in Santa Fe, Argentina.

People and crocodilians have engaged in interactions since the earliest human settlements. After many years of escalating non-regulated use, coupled with emerging threats such as habitat modification, environmental pollution, and the exponential growth of human populations, natural crocodilian populations have been pushed to the brink of extinction. To prevent this, various initiatives have implemented strategies to prevent local extinction. Reinforcing wild populations through reintroductions and head-starting programs has been considered the safest approach to recovering crocodilian populations. Subsequently, the concept of sustainability emerged. In the case of many historically exploited crocodilian species, it became evident that rational utilization need not adversely affect population status; on the contrary, there were clear signs of recovery when local communities were involved. In 1990, the broad-snouted caiman (Caiman latirostris) was in a critical state due to decades of poaching and the aforementioned threats. In response, the "Monitoring and restocking program of the broad-snouted caiman for management purposes", commonly known as Proyecto Yacaré, was established to study population abundance and assess the biological, ecological, and social response to this management methodology. As a result of the eggs's harvest, a proportion equivalent to or greater than what would have survived in natural conditions was released into the original habitat where the eggs were collected. The surplus was allocated for leather and meat production with a focus on economic and environmentally sustainable practices, without affecting biodiversity or threats to the managed species. The in situ work carried out by this program has been crucial for the recovery of broad-snouted caiman populations under the "incentives for conservation" system, whereby local communities receive benefits for nest identification and egg harvesting. Over time, conservation incentives have become significant contributors to regional economies. This study illustrates how C. latirostris populations increased due to the implementation of egg harvesting by local communities in a natural reserve for management purposes. This population increase was detected through continuous night monitoring and an analysis of the number of nests in the area. Currently, C. latirostris populations have transitioned from being among the most threatened to becoming one of the most abundant throughout their distribution area. Based on the analyzed information, we may affirm that the commercial value of these species is one of the most relevant aspects contributing to the sustainability of these programs, primarily due to the change in perception generated among local communities. Therefore, identifying and controlling factors affecting these programs are fundamental for the conservation of these species.

Detection and characterization of phospholipase A(2) (PLA(2)) in Caiman latirostris and Caiman yacare plasma.

Reptiles have proven to have a versatile and efficient nonspecific immune system adapted to the environments in which they commonly live. Phospholipase A(2) (PLA(2)) is important hydrolytic enzyme involved in the regulation of specific types of messengers, with significant roles in the innate immune response. A number of agents that exert effects on cellular receptors emit a series of signals leading to the increased activity of PLA(2). Phospholipase A(2) has been identified and characterized in temperature, plasma concentration, and kinetic dependence in two species of caiman. The results of these studies suggest that the high PLA(2) activities observed in caiman plasma may be an important component of a well-developed innate immunity. Based on the knowledge of their properties, this powerful immunologic component should be evaluated as a possible application in the veterinary or even human therapeutic industry. Additionally, this is another reason to consider these animals excellent models for the study of immune phylogenetic mechanisms.

Genetic, enzymatic and developmental alterations observed in Caiman latirostris exposed in ovo to pesticide formulations and mixtures in an experiment simulating environmental exposure.

In South America, economic interests in last years have produced a constant increase in transgenic soybean cropping, with the corresponding rise in pesticide formulated products. The aim of this study was to determine the effects of pesticides formulations and mixtures on a South American caiman, Caiman latirostris, after in ovo exposure. We conducted a field-like experiment which simulates the environmental exposure that a caiman nest can receive in neighbouring croplands habitats. Experimental groups were Control group, Treatment 1: sprayed with a glyphosate herbicide formulation, and Treatment 2: sprayed with a pesticide mixture of glyphosate, endosulfan and cypermethrin formulations. Results demonstrated genotoxicity, enzymatic and metabolic alterations, as well as growth delay in caimans exposed in ovo to Treatments 1 and 2, showing a higher toxicity for the mixture. Integral evaluation through biomarkers of different biological meaning is highly informative as early indicators of contamination with pesticides and mixtures in this wildlife species.

[Pulmonary cryptococcoma with involvement of the chest wall in an immunocompetent patient]. / Criptococoma pulmonar con invasión torácica en un varón inmunocompetente.

The pulmonary cryptococcosis in immunocompetent patients is unusual, and its presentation as large masses with involvement of the chest wall and the neighboring soft tissues has not been found in our bibliographic research. The variety gattii (serotype B/C) is limited geographically to tropical and subtropical regions and appears to affect particularly immunocompetent individuals. We describe the case of a 51-year-old man from the Northeast of Argentina, with a history of smoking 10 pack/year. He presented an increased volume of the left shoulder and reported that for the last six months he had been unable to move it due to the pain. A percutaneous biopsy of the mass provided a diagnosis of Cryptococcus neoformans, variety gattii. The patient was treated with antifungal therapy showing a favourable outcome with a progressive decrease of the mass.

Presence of Leptospira spp. in Caiman latirostris (Crocodylia, Alligatoridae) populations in Santa Fe, Argentina.

Leptospirosis is a disease caused by pathogenic spirochetes of the genus Leptospira, transmitted by wild and domestic animals. Rodents play a fundamental role in the transmission cycle of this zoonosis but the function of reptiles is unknown. For example, crocodilians could play an important role in the transmission of this disease by living in ideal environments (bodies of shallow water and high temperatures) for the colonization of this bacterium. However, few studies have documented the presence of zoonotic diseases in caiman populations. Our objective was to assess the prevalence of antibodies to leptospira and the presence of Leptospira spp. in wild and captive Caiman latirostris. Blood samples were taken from 45 individuals (20 wild and 25 captive). Before extraction, we cleaned each caiman's neck in order to prevent contamination of samples. We determined the presence of antibodies in serum by microscopic agglutination test (MAT) and polymerase chain reaction (PCR) to detect DNA of the bacteria. We excluded 9 of the 45 samples analyzed by MAT because 5 had lipemic serum and 4 were contaminated (colonized by other organisms). Of the 36 caimans studied by microscopic agglutination test (MAT), 56% (20/36) were considered reactive (titers ≥50). In 74% (14/19) of captive samples and 35% (6/17) of wild samples, antibodies to leptospira were detected by MAT. The serogroup with highest occurrence was Pyrogenes (85%, n = 17/20), presenting coagglutinations with Icterohaemorrhagiae (25%, n = 5/20). One sample from a captive animal was positive for PCR, and we could not isolate leptospires because of agar contamination. Of the 45 blood agar media, 17.8% were contaminated and the rest were negative. This work determined the presence of Leptospira spp. in one caiman and a high prevalence of antibodies in captive caiman relative to wild individuals.

Total and differential white blood cell counts in Caiman latirostris after in ovo and in vivo exposure to insecticides.

Agricultural activities associated mainly with soybean crops affect the natural environment and wildlife by habitat destruction and the extensive use of agrochemicals. The aim of this study was to evaluate immunotoxic effects of the insecticides cypermethrin (CYP) and endosulfan (END) in Caiman latirostris analyzing total blood cell count (TWBC) and differential white blood cell count (DWBC) after in ovo and in vivo exposure. Eggs (in ovo) and hatchlings (in vivo) from nests harvested in natural habitats were artificially incubated and reared under controlled conditions in the Proyecto Yacaré (Gob.Santa Fe/MUPCN) facilities. Exposure of embryos was performed by topication on the eggshell during the first stage of development. The treatments were distilled water (negative control; NC), ethanol (vehicle control; VC), four groups treated with different concentrations of CYP and four groups with END. In vivo exposure was performed by immersion; treatments were NC, VC, two groups exposed to CYP and two to END. After embryonic exposure to the insecticides, no differences were found in TWBC or DWBC among the neonates exposed to pesticides versus controls. In the in vivo scenario, similar results were obtained for TWBC, but DWBC data showed differences between NC hatchlings and CYP-1 hosts for heterophil, lymphocyte and monocyte levels, and between NC and END-1 hosts for lymphocyte and monocyte levels. Research on the effects of pesticide exposure on this species is of special interest not only to assess the impact on caiman populations, but also to further characterize the species as a potential sentinel of ecosystem health.

Effects of in vivo exposure to Roundup® on immune system of Caiman latirostris.

The present study aimed to evaluate the effect of Roundup(®) (RU, glyphosate-based formulation) on some parameters of the immune system and growth of Caiman latirostris. Seventy-two caimans (20-day-old) from Proyecto Yacaré (Gob. Santa Fe/MUPCN) were used. Two groups were exposed for 2 months to different concentrations of RU (11 or 21 mg/L; taking into account the concentration recommended for its application in the field), while one group was maintained as control. The RU concentration was progressively decreased through the exposure period to simulate glyphosate degradation in water. Animals were measured and weighed at the beginning and end of the experiment, and blood samples taken after exposure to determine total and differential white blood cell (WBC) counts as well as total protein concentration (TPC), and for performing protein electrophoresis. The results showed that, compared against control hosts, there was a decrease in WBC counts, a higher percentage of heterophils, a higher TPC (with a low percentage of F2 protein fraction), and a negative effect on growth in the young caimans exposed to RU. These results demonstrate that in vivo exposure to RU induced alterations in the selected immune parameters, plasma proteins, and growth of caimans, thereby providing relevant information about the effects of this type of pesticide in this important species in the Argentinian wetlands.

Criptococoma pulmonar con invasión torácica en un varón inmunocompetente / Pulmonary cryptococcoma with involvement of the chest wall in an immunocompetent patient

La criptococosis pulmonar en pacientes inmunocompetentes es una entidad poco habitual y su presentación como masas de gran tamaño, con compromiso de la pared torácica y de los tejidos blandos vecinos, no la encontramos descriptas en nuestra revisión bibliográfica. La variedad gattii (serotipoB/C) está acotada geográficamente a regiones tropicales y subtropicales y parece afectar preferentemente a individuos inmunocompetentes. Presentamos el caso de un hombre de 51 años proveniente del noreste de la Argentina, fumador de 10 atados/año que consulta por aumento del volumen del hombro izquierdo e impotencia funcional por intenso dolor de seis meses de evolución. Mediante una biopsia percutánea de la masa, se diagnostica Cryptococcus neoformans, variedad gattii. El paciente recibe terapéutica antifúngica, mostrando una evolución favorable con disminución progresiva de la masa.

The pulmonary cryptococcosis in immunocompetent patients is unusual, and its presentation as large masses with involvement of the chest wall and the neighboring soft tissues has not been found in our bibliographic research. The variety gattii (serotype B/C) is limited geographically to tropical and subtropical regions and appears to affect particularly immunocompetent individuals. We describe the case of a 51-year-old man from the Northeast of Argentina, with a history of smoking 10 pack/year. He presented an increased volume of the left shoulder and reported that for the last six months he had been unable to move it due to the pain. A percutaneous biopsy of the mass provided a diagnosis of Cryptococcus neoformans, variety gattii. The patient was treated with antifungal therapy showing a favourable outcome with a progressive decrease of the mass.

Food conversion rate (FCR) in Caiman latirostris resulted more efficient at higher temperatures / La tasa de conversión alimenticia (FCR) de Caiman latirostris resulta más eficiente a temperaturas altas / A Taxa de conversão do alimento (FCR) do Caiman latirostris é mais eficiente a temperaturas mais elevadas

The effects of temperature on the growth of Caiman latirostris were investigated in order to evaluate the efficiency of food conversion at 29 and 33°C. Sixty-eight captive raised animals, two months old, taken from four nests, were used. All groups were maintained up to 70 or 72 days in similar environmental treatments except for temperature. Animals maintained at 33°C reached greater body mass (BM) and total length (TL) than those maintained at 29°C. A more efficient nutritional conversion rate was found in animals kept at 33°C. The increase of temperature could improve the amount of energy extracted from food, producing a more efficient FCR.

El efecto de la temperatura sobre el crecimiento de Caiman latirostris fue estudiado a fin de evaluar la eficacia de la conversión alimenticia en cautiverio a 29 y 33°C. Fueron utilizados 68 animales cautivos de dos meses de edad, provenientes de cuatro nidadas. Todos los grupos fueron mantenidos hasta por 70 o 72 días en tratamientos ambientales similares, a excepción de la temperatura. Los animales mantenidos a 33°C alcanzaron mayor peso y longitud total que aquellos mantenidos a 29°C. Una tasa de conversión alimenticia más eficiente fue encontrada en los animales criados a 33°C. El aumento de la temperatura podría mejorar la cantidad de energía extraída del alimento, produciendo un FCR más eficiente.

Para avaliação de um método econômico na criação em cativeiro de Jacaré-de-Papo-Amarelo (Caiman latirostris) estudio-se o consumo de ração, a taxa de conversão e o efeito da temperatura de cria no crescimento da espécie. Para este estudo foram utilizados 68 jacarés de dois meses de idade, nascidos de quatro ninhos coletados na natureza e incubados artificialmente. Durante o experimento os animais foram mantidos a duas temperaturas: 29ºC e 33ºC até 70 ou 72 dias. Como esperado, os animais mantidos a 33ºC mostraram maior taxa de crecimento (comprimento total e peso), e maior consumo de ração que aqueles mantidos a 29ºC. A taxa de conversão de alimento também foi mais efetiva quando a temperatura de cria foi maior. Concluí-se que o aumento da temperatura poderia melhorar a quantidade de energia extraída da ração, produzindo uma taxa de conversão mais eficiente.