We discovered a new species of Porifera belonging to the genus Isodictya Bowerbank, 1864 during cruises aboard R/V Hesperides in Antarctica. Collected samples are mostly part of the surveys of the Spanish project BENTART whose main objective has been to study the benthic communities inhabiting sea bottoms of Livingston and Deception Island in the South Shetlands archipelago and the Antarctic Peninsula. Isodictya filiformis sp. nov., described here, is characterized by its fragile and thin morphology (very different from other known species in the area) and by having microxeas as additional microscleres. Three specimens were collected from Marguerite Bay, Low Island and Deception Island (Antarctic Peninsula) and one specimen at Peter I Island (Bellingshausen Sea). Its presence in Peter Island is quite relevant as this location is 390 km away from the nearest coast in the Bellingshausen Sea, an area that has scarcely been investigated in the past. However, results from the Bentart 03 Expedition seem to indicate that Peter I Island has a wide variety of benthic organisms, in contrast to the deep adjacent areas of Bellingshausen Sea. Apart from the morphological analyses, we place the new Isodictya species within its phylogenetic context using two nuclear markers (18S rDNA and 28S rDNA) and provide some information about the ecological preferences of the new species.

中文翻译：

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来自南大洋的一新种 Isodictya (Porifera: Poecilosclerida)

我们于 1864 年在南极洲的 R/V Hesperides 上航行时发现了一种属于 Isodictya Bowerbank 属的 Porifera 新物种。收集的样本主要是西班牙项目 BENTART 调查的一部分，该项目的主要目标是研究居住在南设得兰群岛和南极半岛利文斯顿和欺骗岛海底的底栖群落。Isodictya filiformis sp. 这里描述的 nov. 的特点是其脆弱而薄的形态（与该地区的其他已知物种非常不同），并且具有 microxeas 作为额外的 microscleres。从玛格丽特湾、低岛和欺骗岛（南极半岛）收集了三个标本，在彼得一世岛（贝灵斯豪森海）收集了一个标本。它在彼得岛的存在非常重要，因为该位置距离贝灵斯豪森海最近的海岸 390 公里，该地区过去几乎没有被调查过。然而，Bentart 03 远征的结果似乎表明，与贝灵斯豪森海的深层相邻区域相比，彼得一世岛拥有种类繁多的底栖生物。除了形态学分析外，我们还使用两个核标记（18S rDNA 和 28S rDNA）将新的 Isodictya 物种置于其系统发育环境中，并提供了有关新物种生态偏好的一些信息。与贝灵斯豪森海的深层相邻区域形成鲜明对比。除了形态学分析外，我们还使用两个核标记（18S rDNA 和 28S rDNA）将新的 Isodictya 物种置于其系统发育环境中，并提供了有关新物种生态偏好的一些信息。与贝灵斯豪森海的深层相邻区域形成鲜明对比。除了形态学分析外，我们还使用两个核标记（18S rDNA 和 28S rDNA）将新的 Isodictya 物种置于其系统发育环境中，并提供了有关新物种生态偏好的一些信息。