Gutiérrez María Paz, Canel Delfina, Braicovich Paola E, Lanfranchi Ana L, Irigoitia Manuel M, Ivanovic Marcela L, Prandoni Nicolás I, Elena Beatriz, Timi Juan T
Laboratorio de Ictioparasitología, Instituto de Investigaciones Marinas y Costeras (IIMyC), Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Funes 3350, 7600, Mar del Plata, Argentina.
Instituto Nacional de Investigación y Desarrollo Pesquero (INIDEP), Paseo Victoria Ocampo N°1, Escollera Norte, 7600, Mar del Plata, Argentina.
Int J Parasitol Parasites Wildl. 2024 Aug 13;25:100974. doi: 10.1016/j.ijppaw.2024.100974. eCollection 2024 Dec.
The Argentine shortfin squid is one of the most important commercial species for the Argentine fisheries. The understanding of its stock structure is therefore necessary to ensure fishery sustainability and, given the relevance of squids in the regional food web, for biodiversity conservation. An overlap between parasitology and fisheries lies in the use of parasites as biological tags to identify the stock composition of exploited resources, however, the efficiency of this methodology has been questioned for stock assessment in cephalopods. In this work, the value of parasite assemblages of to discriminate between the co-occurring summer spawning stock (SSS) and south patagonic stock (SPS) in a mixing area over the Patagonian continental shelf during summer was evaluated for two cohorts. Five shortfin squid samples corresponding to SSS and SPS were examined for metazoan parasites. The squid size affected the parasite assemblage similarities, conversely, no gender effect on the infracommunities was observed. Multivariate analysis evidenced similarity in parasite assemblage composition and structure between both stocks captured in the mixing area on the same date. This similarity was related to the presence of short-lived trophically transmitted parasites, which are associated with their recently consumed food items and, indirectly, to the oceanographic conditions. The same set of host and environmental variables were identified as the most probable causes of the temporal variability observed in parasite assemblages between SPS cohorts and even intra-cohort. Despite the value of parasites as tags for discriminating squid stocks may have little value when cohabiting stocks are analysed, their variability could serve as a valuable indicator of environmental conditions. The use of parasites as biological tags to discriminate stocks needs to be verified at different spatiotemporal scales, including samples from other non-sympatric stocks in the analyses.
阿根廷短鳍鱿鱼是阿根廷渔业最重要的商业品种之一。因此，了解其种群结构对于确保渔业可持续性至关重要，而且鉴于鱿鱼在区域食物网中的重要性，对于生物多样性保护也很重要。寄生虫学与渔业的一个交叉点在于利用寄生虫作为生物标签来识别已开发资源的种群组成，然而，这种方法在头足类动物种群评估中的效率受到了质疑。在这项工作中，针对两个群体，评估了夏季巴塔哥尼亚大陆架混合区域内寄生虫群落区分同时出现的夏季产卵种群（SSS）和南巴塔哥尼亚种群（SPS）的价值。对对应于SSS和SPS的五个短鳍鱿鱼样本进行了后生动物寄生虫检查。鱿鱼大小影响寄生虫群落的相似性，相反，未观察到性别对群落内结构的影响。多变量分析表明，同一天在混合区域捕获的两种群的寄生虫群落组成和结构具有相似性。这种相似性与短期营养传播寄生虫的存在有关，这些寄生虫与其最近食用的食物有关，并且间接地与海洋学条件有关。同一组宿主和环境变量被确定为SPS群体之间甚至群体内部寄生虫群落中观察到的时间变异性的最可能原因。尽管寄生虫作为区分鱿鱼种群的标签的价值在分析共存种群时可能价值不大，但其变异性可作为环境条件的有价值指标。利用寄生虫作为生物标签来区分种群需要在不同的时空尺度上进行验证，包括在分析中纳入来自其他非同域种群的样本。
