The estuarine nudibranch Tenellia adspersa (Nordmann, 1845) was recorded for the first time in Portugal, while sampling for fouling fauna of artificial structures along the salinity gradient of the Guadiana estuary (SW Iberian Peninsula). Two specimens were found in association with the invasive hydrozoan Cordylophora caspia (Pallas, 1771) and kept in the laboratory for taxonomy purposes. After two days, batches of eggs were seen in C. caspia branches, while the nudibranchs were also actively feeding on the hydrozoan polyps. The fast generation times of T. adspersa, along with its food preference for C. caspia, might suggest a positive role of the nudibranch on controlling this invasive hydrozoan in the Guadiana estuary. Introduction routes and facilitation interactions are discussed.

中文翻译：

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Nudibranch Tenellia adspersa（诺德曼，1845年）在葡萄牙的首次记录，与入侵的水生脐带虫（Cordylophora caspia）有关（帕拉斯，1771年）

在葡萄牙首次记录了河口裸露的Tenellia adspersa（Nordmann，1845年），同时沿瓜迪亚纳河口（SW伊比利亚半岛）的盐度梯度对人造结构的结垢动物进行了采样。发现了两个与侵入性水生动物Cordylophora caspia相关联的标本（Pallas，1771），并保存在实验室中用于分类学目的。两天后，在C.caspia分支中看到了一批卵，而裸露的分支也活跃地以水生息肉为食。T. adspersa的快速生成时间，以及对C. caspia的食物偏爱可能暗示裸n科在瓜迪亚纳河口控制这种侵入性水生动物方面具有积极作用。介绍了引入途径和促进互动。