An annotated list of brown seaweeds (Phaeophyceae) from Nakadori Island (northern Goto Islands, Nagasaki, Japan) Author Belleza, Dominic Franco C. 0000-0002-0141-7495 Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki 852 - 8521, Japan & Department of Biology, University of San Carlos, Nasipit, Talamban, Cebu City, 6000, Philippines dfcbelleza@gmail.com Author Tateishi, Hiroto Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki 852 - 8521, Japan caprellidae315@gmail.com Author Tanimae, Shin-Ichiro Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki 852 - 8521, Japan cyphonautes@gmail.com Author Kobayashi, Taishun Faculty of Fisheries, Nagasaki University, Nagasaki 852 - 8521, Japan taishun8125@gmail.com Author Aota, Tomoyuki Faculty of Fisheries, Nagasaki University, Nagasaki 852 - 8521, Japan tommarine290@gmail.com Author Urasawa, Toshiki Faculty of Fisheries, Nagasaki University, Nagasaki 852 - 8521, Japan tu1118kr@gmail.com Author Nishihara, Gregory N. Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki 852 - 8521, Japan & Faculty of Fisheries, Nagasaki University, Nagasaki 852 - 8521, Japan text Phytotaxa 2025 2025-03-18 694 1 1 24 https://doi.org/10.11646/phytotaxa.694.1.1 journal article 10.11646/phytotaxa.694.1.1 1179-3163 16722860 Sargassum siliquastrum (Mertens ex Turner) C. Agardh, 1820 Japanese name: ヨレモク (yoremoku) Type locality: — Nagasaki Harbor, Nagasaki , Japan Description and remarks: —The specimen has a robust discoid holdfast with two branches arising from it. The main axis is 2.5 mm wide and has three angles on its cross-section (i.e., triquetrous). The leaves are dense around the upper parts of the thallus and can reach lengths of up to 7 cm , with widths of about 2–3 mm and have serrate or dentate margins. The midribs are also distinct on the leaves. The vesicles are located on upper, secondary branches and are borne on stalks, 3–5 mm long. The vesicles are avoid and may be observed with leaflets on their apices. This species is common in Yokoura in mid spring and has been found along the exposed and shallow rocky areas near the wave breaker. Material examined: —18ECS1-3-2