Resumo Na Argentina, a distribuição mais austral do jacaré-de-papo-amarelo (Caiman latirostris Daudin 1802) ocorre na Provincia de Santa Fe, sendo que suas populações são manejadas pelo “Proyecto Yacaré” desde 1990. Entre os anos de 1997 e 2016, nós capturamos 77 fêmeas nidificantes do jacaré-de-papo-amarelo em Santa Fe. Nossos resultados sugerem que as classes de tamanho definidas para o jacaré-de-papo-amarelo não representam a realidade dos animais capturados no presente estudo. Portanto, propõe-se uma alteração nas classes de tamanho para o jacaré-de-papo-amarelo. Nós também observamos que as fêmeas reintroduzidas pelo “Proyecto Yacaré” representaram 32% das fêmeas capturadas. Estes resultados indicam que fêmeas reintroduzidas pelo programa de manejo estão sobrevivendo e reproduzindo na natureza por, pelo menos, 20 anos.

Abstract The southern distribution of the Broad-snouted Caiman (Caiman latirostris Daudin 1802) in Argentina occurs in Santa Fe Province, where its population has been under management by “Proyecto Yacaré” since 1990. From 1997 to 2016, we captured 77 nesting female Broad-snouted Caimans in Santa Fe Province. Our results suggest that previously defined size classes for Broad-snouted Caiman do not adequately describe the reproductively mature female segment of the population. Here we propose to change size ranges for general size classes for Broad-snouted Caiman. In addition, we have observed that reintroduced reproductive females by Proyecto Yacaré represent about 32% of captured females. These results indicate that reintroduced females by the management program are surviving and reproducing in the wild at least up to 20 years.

Blood samples were collected from 180 healthy specimens of the South American rattlesnake, Crotalus durissus terrificus, in captivity. All animals were in good clinical condition. Normal biochemical reference values were established for the following: total proteins, albumin, globulins, uric acid, creatinine, urea, glucose, triglycerides, cholesterol, total lipids, calcium, phosphorus, potassium, sodium, chloride, magnesium, GOT (AST), GPT (ALT), and alkaline phosphatase (ALP). Samples were obtained by venipuncture of the ventral tail vein. Values were compared with published data for Boidae, Elapidae, and Viperidae.

Blood samples of 50 healthy specimens from each of the following species: Bothrops alternatus, Bothrops jararacussu, Bothrops moojeni, and Bothrops neuwiedi diporus all kept in captivity were taken to determine the hematocrit (PCV) value, red blood cell count (RBC), total leukocyte (WBC) and differential leukocyte count, thrombocyte count, mean corpuscular volume (MCV), hemoglobin concentration (HbC), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). These hematological parameters were compared to those obtained from other Bothrops species. PCV values, RBC, hemoglobin, WBC count, and differential leukocyte count are within the range of values reported for other Bothrops species, while the thrombocyte count was significantly lower. All the hematological parameters obtained from the four studied Bothrops species were higher than those described for B. ammodytoides.

The immunochemical reactivity and neutralizing capacity of polyvalent Vipera antivenom (Vipera ammodytes, Vipera aspis, Vipera berus, Vipera lebetina, and Vipera xanthina) were tested on the enzymatic and biological activities of Crotalus durissus terrificus and the following Bothrops venoms from Argentina (Bothrops alternatus, Bothrops ammodytoides, Bothrops neuwiedii, Bothrops jararaca, Bothrops jararacussu, and Bothrops moojeni). The Vipera antivenom reacted weakly when tested by double immunoprecipitation (DIP) and reacted with all the venoms when tested by ELISA. Several components in all the venoms studied were recognized in Western blots. Vipera antivenom deactivated to different degrees in vitro procoagulant, (indirect) hemolytic, and proteolytic activities in all the venoms studied. Preincubation of Bothrops alternatus venom with Vipera antivenom neutralized a lethal potency of 4.5 LD50 in mice with an ED50 of 1.25 <FONT FACE="Symbol">±</FONT> 0.25 <FONT FACE="Symbol">m</FONT>l per <FONT FACE="Symbol">m</FONT>g of venom, and with 1.0 <FONT FACE="Symbol">m</FONT>l/<FONT FACE="Symbol">m</FONT>g inhibited 54% of the hemorragic activity and 48% of necrotic activity. Vipera antivenom (2.0 <FONT FACE="Symbol">m</FONT>l per <FONT FACE="Symbol">m</FONT>g toxin) inhibited the phospholipase A2 activity of purified crotoxin and decreased its lethal potency by 60%, while the neutralizing capacity on the lethal potency of crude Crotalus durissus terrificus venom was poor even at a level of 5.0 <FONT FACE="Symbol">m</FONT>l/<FONT FACE="Symbol">m</FONT>g of venom.