Under the light: high prevalence of haemoparasites in lizards (Reptilia: Squamata) from Central Amazonia revealed by microscopy

Abstract Blood samples from 330 lizards of 19 species were collected to investigate the occurrence of haemoparasites. Samplings were performed in areas of upland (terra-firme) forest adjacent to Manaus municipality, Amazonas, Brazil. Blood parasites were detected in 220 (66%) lizards of 12 species and comprised four major groups: Apicomplexa (including haemogregarines, piroplasms, and haemosporidians), trypanosomatids, microfilarid nematodes and viral or bacterial organisms. Order Haemosporida had the highest prevalence, with 118 (35%) animals from 11 species. For lizard species, Uranoscodon superciliosus was the most parasitised host, with 103 (87%; n = 118) positive individuals. This species also presented the highest parasite diversity, with the occurrence of six taxa. Despite the difficulties attributed by many authors regarding the use of morphological characters for taxonomic resolution of haemoparasites, our low-cost approach using light microscopy recorded a high prevalence and diversity of blood parasite taxa in a relatively small number of host species. This report is the first survey of haemoparasites in lizards in the study region. It revealed a high diversity of lizard haemoparasites and highlights the need to understand their impacts on hosts.

摘要：本研究采集巴西亚马逊州马瑙斯市周边高地（terra-firme）森林区域内19个物种共330只蜥蜴的血液样本，以调查血液寄生虫（haemoparasites）的感染情况。本次采样共在12个物种的220只（66%）蜥蜴体内检出血液寄生虫，其可分为四大类群：顶复门（Apicomplexa，涵盖血簇虫haemogregarines、梨形虫piroplasms与血孢子虫haemosporidians）、锥虫类（trypanosomatids）、微丝蚴线虫（microfilarid nematodes）以及病毒或细菌性病原。其中血孢子虫目（Haemosporida）的检出率最高，在11个物种的118只（35%）蜥蜴体内检出。在宿主蜥蜴物种中，裸耳蜥（Uranoscodon superciliosus）为被寄生率最高的宿主，共103只（87%；n=118）个体呈检测阳性。该物种同时拥有最高的寄生虫多样性，共检出6个寄生虫分类群。尽管诸多学者指出，利用形态特征开展血液寄生虫的分类鉴定存在诸多困难，但本研究采用低成本的光学显微镜（light microscopy）检测方法，在相对有限的宿主物种范围内仍检出了高检出率且多样性丰富的血液寄生虫分类群。本调查是该区域首次针对蜥蜴血液寄生虫的系统性调研，结果揭示了该区域蜥蜴血液寄生虫的丰富多样性，并强调了阐明其对宿主影响的必要性。