Data_Sheet_1_Hematology and biochemistry reference intervals for American crocodiles (Crocodylus acutus) in South Florida.docx

The American crocodile (Crocodylus acutus) is considered a vulnerable species by the International Union for Conservation of Nature (IUCN) Red List across its range and classified as locally threatened in several countries. There is a lack of knowledge involving hematological and physiological parameters in American crocodile populations, limiting our understanding of what are considered “normal” blood analyte results for the species and how to link them with health assessments. In this study, we analyzed 40 hematological and biochemical parameters and estimated reference intervals (RIs) for 35 of them based on 436 clinically healthy wild American crocodiles caught in South Florida between 2015 and 2021. Crocodiles were captured across three areas with different levels of human influence [low = Everglades National Park (ENP), medium = Biscayne Bay Estuary (BBE), and high = Turkey Point Nuclear Power Plant (TP)]. There was very strong-to-strong evidence for an effect of where animals were caught on five analytes: basophils %, phosphorus, proportion of (pr) alpha-2 globulins, absolute count (abs) of gamma globulins, and corticosterone, so no reference values were estimated but general statistics are presented and discussed. From the remaining analytes, we found no evidence that sex or size class had an effect on red blood cell (RBC), azurophils and monocytes abs, triglycerides, and albumin abs. However, we did find moderate-to-strong evidence that sex influenced azurophils % and size class influenced white blood cell (WBC), heterophils %, monocytes %, basophils abs, creatine phosphokinase (CPK), potassium, glucose, bile acids, alpha-1 globulin abs, and alpha-2 globulin pr and abs. Finally, there was strong evidence that both sex and size class influenced PCV, lymphocytes % and abs, eosinophils % and abs, aspartate aminotransferase (AST), calcium, sodium, chloride, total protein, albumin/globulin (A/G) ratio, albumin pr, alpha-1 globulin, and beta globulin abs. Intraspecific analysis showed that size is the variable that most influenced analytes explaining up to 29% of the variation, which relates to our findings based on intraindividual analysis. We compared our results with blood parameters reported for conspecifics as well as closely related species and discussed implication of those results for clinical diagnosis and American crocodile conservation.

美洲短吻鳄（Crocodylus acutus）被国际自然保护联盟（IUCN）红色名录在其分布范围内列为易危物种，并在多个国家被归类为地方性濒危物种。关于美洲短吻鳄种群中的血液学和生理学参数，知识匮乏，这限制了我们对该物种被认为是“正常”的血液分析结果的理解，以及如何将这些结果与健康评估联系起来。在本研究中，我们分析了40项血液学和生化参数，并基于2015年至2021年在南佛罗里达州捕获的436只临床健康野生美洲短吻鳄，对其中35项参数估计了参考范围（RIs）。短吻鳄在三个不同人类影响程度的地域中被捕获[低影响=大沼泽国家公园（ENP）、中等影响=比斯坎湾三角洲（BBE）和高影响=土耳其角核电站（TP）]。有非常强烈的证据表明，动物的捕获地点对五种分析物产生了影响：嗜碱性粒细胞百分比、磷、α-2球蛋白比例、γ球蛋白绝对计数和皮质醇，因此未估计参考值，但呈现并讨论了一般统计学数据。从剩余的分析物中，我们没有发现性别或体型类别对红细胞（RBC）、嗜天青颗粒细胞和单核细胞绝对计数、甘油三酯和清蛋白绝对计数产生影响的证据。然而，我们发现性别对嗜天青颗粒细胞百分比有中到强的影响，体型类别对白细胞（WBC）、异嗜性粒细胞百分比、单核细胞百分比、嗜碱性粒细胞绝对计数、磷酸肌酸激酶（CPK）、钾、葡萄糖、胆汁酸、α-1球蛋白绝对计数和α-2球蛋白比例和绝对计数有中到强的影响。最终，有强有力的证据表明，性别和体型类别对红细胞压积（PCV）、淋巴细胞百分比和绝对计数、嗜酸性粒细胞百分比和绝对计数、天冬氨酸转氨酶（AST）、钙、钠、氯、总蛋白、白蛋白/球蛋白（A/G）比例、白蛋白比例、α-1球蛋白和β球蛋白绝对计数均有影响。种内分析表明，体型是影响分析物的主要变量，解释了高达29%的变异，这与我们的个体内分析结果相关。我们比较了我们的结果与同种以及密切相关的物种报道的血液参数，并讨论了这些结果对临床诊断和美国短吻鳄保护的意义。