<![CDATA[Abstract. Luthfi OM, Wiadnya DGR, Luthfi MAB, Isdianto A, Yamindago A, Tupas FP, Jaafar SN. 2026. The discovery of dendrophylliid scleractinian corals from Sempu Island, East Java, Indonesia. Biodiversitas 27 (9): d270902. https://doi.org/10.13057/biodiv/d270902. This study reports the first documented locality records of two dendrophylliid scleractinian corals, Duncanopsammia peltata and Turbinaria mesenterina, from the Sempu Island Nature Reserve and adjacent coastal waters, East Java, Indonesia. Previous coral surveys conducted within this protected area did not document either species, despite their widespread distribution throughout the Indo-Pacific region. Field surveys were conducted in November 2021 and July 2024 at seven reef-flat and reef-slope sites. Standardized searches were performed along 100-m transects covering approximately 200 m² per site, while snorkeling was used on the shallow reef flat at Kondang Merak Beach. Species identification was based on non-destructive in situ observations, scaled underwater photographs, and diagnostic skeletal characters, including colony growth form, corallite morphology, corallite diameter, septal arrangement, corallite density, and live colony coloration. A single juvenile colony of D. peltata was recorded on the shallow reef flat of Kondang Merak Beach, where it exhibited an encrusting form, tubular corallites, and a conspicuous dome-shaped columella. T. mesenterina was observed on sediment-influenced reef slopes, exhibiting encrusting, foliose, and vase-shaped growth forms with densely packed unifacial corallites. Visible sediment accumulation on several colonies further characterized the habitat conditions in which T. mesenterina occurred. Because no colonies or skeletal fragments were collected, identification relied exclusively on photographic and field-based morphological evidence. These records expand the documented coral inventory of the Sempu Island Nature Reserve and provide updated morphological documentation and baseline information to support field identification, biodiversity assessment, and future monitoring of dendrophylliid corals in tropical reef ecosystems.]]>
