New records of Microzonia velutina (Syringodermatales, Ochrophyta) in Isla Grande de Tierra del Fuego in the sub-Antarctic region

作者：Mauricio Alejandro Palacios, Julieta Kaminsky, ERASMO C MACAYA, Alicia Boraso, M. García Rodríguez, Mathias Hüne · 发表于：Botanica Marina · 年份：2025 · DOI：10.1515/bot-2025-0075 · 被引用次数：3 · 研究领域：Marine and coastal plant biology、Marine Biology and Ecology Research、Bryophyte Studies and Records

Abstract Sub-Antarctic coastal ecosystems are characterized by a high diversity of intertidal and subtidal macroalgae. Recent studies in this region have advanced knowledge of their composition and distribution, as well as adding new species records. During scientific diving expeditions in Isla Grande de Tierra del Fuego, we documented the subtidal brown macroalga Microzonia velutina , representing a new record for Chile and an additional record for Argentina. Field surveys were conducted at three sites, located in Aguirre Bay (Argentina) and Inútil Bay (Chile). Specimens were identified based on external and internal thallus anatomy, following diagnostic criteria established in studies along the Argentine Atlantic coast. The species occurred at depths of 3–6 m in subtidal habitats dominated by giant kelp forests ( Macrocystis pyrifera ). Diagnostic features included a fan-shaped thallus less than 3 cm in size, olive-brown coloration, uniseriate filaments bearing unilocular ovoid sporangia, occurring singly or in clusters. This finding expands the known distribution of M. velutina into sub-Antarctic ecosystems, highlighting Isla Grande de Tierra del Fuego, an important biogeographic region for macroalgal diversity. Future research should investigate the life cycle of the species and apply molecular approaches to clarify its phylogenetic position and evolutionary origins.