Di Azevedo Maria Isabel N, Carvalho Vitor L, Iñiguez Alena M
LABTRIP, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz-FIOCRUZ, Pavilhão Rocha Lima, Sala 518. Av. Brasil 4365 Manguinhos, Rio de Janeiro. RJ, 21040-900, Brazil.
Associação de Pesquisa e Preservação de Ecossistemas Aquáticos, AQUASIS, Caucaia, Ceará, 61627-210, Brazil.
Parasitol Res. 2017 Nov;116(11):3105-3116. doi: 10.1007/s00436-017-5622-8. Epub 2017 Oct 3.
Anisakidae are represented mainly by species of Anisakis Dujardin, 1845, Pseudoterranova Krabbe, 1878, and Contracaecum Railliet and Henry, 1913. Integrative taxonomy, based on morphological and genetic approaches, can provide a precise identification of species, increasing the knowledge of their systematics, biology, and evolution. In this study, integrative taxonomy was applied in order to identify, at generic and/or specific taxonomic level, 245 anisakids from 63 cetaceans of 12 different species, which stranded in the Brazilian coast. Parasites from nine hosts were preserved by freezing and, from 54 hosts, were fixed in 70% ethanol (n = 43) or alcohol-formalin-acetic (n = 11) for a period varying from 6 to 19 years. The morphological analysis allowed the identification of 171 specimens at genus level: 120 as Anisakis sp. clade I, 47 as Anisakis sp. clade II, and four as Pseudoterranova sp. From those 15, specimens were identified at species level, seven as Anisakis typica, seven as Anisakis paggiae and one as Anisakis brevispiculata. Moreover, 74 specimens were identified as belonging to Anisakidae family. The genetic analysis based on cox2 gene allowed the identification/confirmation of Anisakis typica (n = 33), Anisakis paggiae (n = 1), and for the first time in the Brazilian coast, Anisakis brevispiculata (n = 4) and Anisakis ziphidarum (n = 1). Additionally, a probably new Anisakis species, genetically close to A. paggiae, is reported infecting a dwarf sperm whale. The results clearly indicated that the preservation of nematodes influenced significantly on the level of taxonomic definition, in both morphological and, mainly, genetic analyses. Pseudoterranova sp. was identified for the first time in the spinner dolphin, Stenella longirostris. The detection of nine A. paggiae specimens, in three Kogia breviceps animals, substantiates the austral occurrence of this species. The identification of A. brevispiculata in Kogia sima and K. breviceps confirms Kogiidae whales as their most common hosts. Anisakis typica was corroborated as a generalist species, the most widely distributed in the Brazilian coast, infecting a broad variety of Delphinidae and Kogiidae, with two new geographical records in Stenella frontalis and Lagenodelphis hosei. The study showed a new scenery of parasite diversity of marine anisakids, updating the Anisakis species distribution.
异尖科主要由1845年杜雅尔丹命名的异尖线虫属、1878年克拉贝命名的拟新地蛔属和1913年拉耶与亨利命名的对盲囊线虫属的物种代表。基于形态学和遗传学方法的综合分类学能够精确鉴定物种，增加对其系统学、生物学和进化的了解。在本研究中，应用综合分类学在属和/或种的分类水平上鉴定来自巴西海岸搁浅的12个不同物种的63头鲸类动物身上的245条异尖科线虫。来自9头宿主的寄生虫通过冷冻保存，来自54头宿主的寄生虫用70%乙醇（n = 43）或酒精 - 福尔马林 - 乙酸（n = 11）固定，保存时间从6年到19年不等。形态学分析在属水平上鉴定出171个标本：120个为异尖线虫属I分支，47个为异尖线虫属II分支，4个为拟新地蛔属。其中15个标本在种水平上被鉴定出来，7个为典型异尖线虫，7个为派氏异尖线虫，1个为短刺异尖线虫。此外，74个标本被鉴定为属于异尖科。基于cox2基因的遗传分析鉴定/确认了典型异尖线虫（n = 33）、派氏异尖线虫（n = 1），并且在巴西海岸首次发现了短刺异尖线虫（n = 4）和齐氏异尖线虫（n = 1）。此外，还报告了一种可能的新异尖线虫物种，在基因上与派氏异尖线虫接近，感染了一头小抹香鲸。结果清楚地表明，线虫的保存对分类定义水平有显著影响，无论是在形态学分析还是主要在遗传学分析中。拟新地蛔属首次在长吻飞旋海豚中被鉴定出来。在3头小抹香鲸中检测到9个派氏异尖线虫标本，证实了该物种在南半球的存在。在小抹香鲸和小拟小抹香鲸中鉴定出短刺异尖线虫，证实了小抹香鲸科鲸鱼是其最常见的宿主。典型异尖线虫被确认为广布种，在巴西海岸分布最广，感染多种海豚科和小抹香鲸科动物，在东方飞旋海豚和霍氏海豚中有两个新的地理记录。该研究展示了海洋异尖科寄生虫多样性的新景象，更新了异尖线虫属物种的分布。
