#NewSpeciesAlert - 𝑆𝑝𝑖𝑛𝑖𝑝𝑡𝑒𝑟𝑢𝑠 𝑐𝑢𝑛𝑖𝑐𝑢𝑙𝑢𝑠, a new species of diminutive spiny driftwood catfish (Auchenipteridae), is described from the Guaporé River, a tributary of the Madeira River basin, Rondônia, Brazil. 🔓 scielo.br/j/ni/a/kh8TLkXnB36… "Many rivers of the southern Amazon experienced a severe drought in 2020, including portions of the Guaporé River, causing its channel to become narrow and shallow with widths reduced to approximately 60 m and depths ranging from 3 to 5 m. In one such section, a brittle lateritic block was taken from the riverbed. The block, measuring approximately 1.5 m in length, 60 cm in width, and weighing nearly 45 kg, contained a complex network of interconnected tunnels and galleries. The innermost, narrower tunnels were inhabited exclusively by small fishes, notably species of 𝑇𝑎𝑡𝑖𝑎 and the new species of 𝑆𝑝𝑖𝑛𝑖𝑝𝑡𝑒𝑟𝑢𝑠, herein described. In contrast, the outermost and wider tunnels were occupied by larger fish species (i.e., 𝐴𝑐𝑎𝑛𝑡ℎ𝑜𝑑𝑜𝑟𝑎𝑠 𝑠𝑝𝑖𝑛𝑜𝑠𝑖𝑠𝑠𝑖𝑚𝑢𝑠, 𝐴𝑔𝑎𝑚𝑦𝑥𝑖𝑠 𝑝𝑒𝑐𝑡𝑖𝑛𝑖𝑓𝑟𝑜𝑛𝑠, 𝐵𝑎𝑡𝑟𝑜𝑐ℎ𝑜𝑔𝑙𝑎𝑛𝑖𝑠 𝑟𝑎𝑛𝑖𝑛𝑢𝑠, 𝑃𝑒𝑐𝑘𝑜𝑙𝑡𝑖𝑎 𝑐𝑓. 𝑣𝑖𝑡𝑡𝑎𝑡𝑎, 𝑃𝑙𝑎𝑡𝑦𝑑𝑜𝑟𝑎𝑠 𝑎𝑟𝑚𝑎𝑡𝑢𝑙𝑢𝑠 and 𝑇𝑟𝑎𝑐ℎ𝑒𝑙𝑦𝑜𝑝𝑡𝑒𝑟𝑢𝑠 𝑠𝑝.). A total of more than 350 fish specimens were collected from the block, representing members of Auchenipteridae, Apteronotidae, Doradidae, Loricariidae, and Pseudopimelodidae." 𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲 A new species of diminutive spiny driftwood catfish 𝑆𝑝𝑖𝑛𝑖𝑝𝑡𝑒𝑟𝑢𝑠 (Siluriformes: Auchenipteridae) from the Madeira River system, Amazon basin, Brazil 𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻 Calegari, B. B., Ohara, W. M., Akama, A., & Zuanon, J. (2026). A new species of diminutive spiny driftwood catfish 𝑆𝑝𝑖𝑛𝑖𝑝𝑡𝑒𝑟𝑢𝑠 (Siluriformes: Auchenipteridae) from the Madeira River system, Amazon basin, Brazil. Neotropical Ichthyology, 24(3), e260022. doi.org/10.1590/1982-0224-20… 𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁 The genus 𝑆𝑝𝑖𝑛𝑖𝑝𝑡𝑒𝑟𝑢𝑠, a member of Auchenipterinae, was previously known from only two species: 𝑆. 𝑎𝑐𝑠𝑖, originally described from the Peruvian Amazon and later recorded from Juruá River in Brazil, and 𝑆. 𝑚𝑜𝑖𝑗𝑖𝑟𝑖, described from the Purus River basin. In a 2020 expedition to the Madeira River basin during an intense drought that exposed lateritic rocks in the Guaporé River bed revealed a diminutive, previously undescribed species of 𝑆𝑝𝑖𝑛𝑖𝑝𝑡𝑒𝑟𝑢𝑠. The new species differs from its congeners, 𝑆. 𝑎𝑐𝑠𝑖 and 𝑆. 𝑚𝑜𝑖𝑗𝑖𝑟𝑖, by the marbled body coloration, lower number of soft pectoral-fin rays, a longer head, a smaller interorbital distance, reduced maxillary barbels, and other osteological features. This new species, described herein, underscores the underestimated diversity within 𝑆𝑝𝑖𝑛𝑖𝑝𝑡𝑒𝑟𝑢𝑠, likely due to its habitat specificity and rarity in ichthyological collections, highlighting the importance of exploring unusual microhabitats in revealing hidden components of Neotropical fish diversity. A key to identification of the species of 𝑆𝑝𝑖𝑛𝑖𝑝𝑡𝑒𝑟𝑢𝑠 is provided. 𝗘𝘁𝘆𝗺𝗼𝗹𝗼𝗴𝘆 The specific epithet, 𝑐𝑢𝑛𝑖𝑐𝑢𝑙𝑢𝑠, comes from Latin and means hole or burrow, referring to the new species' habitat within lateritic blocks—an adjective. 𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁 Top - Live colouration of adult paratypes of 𝑆𝑝𝑖𝑛𝑖𝑝𝑡𝑒𝑟𝑢𝑠 𝑐𝑢𝑛𝑖𝑐𝑢𝑙𝑢𝑠, from Guaporé River, tributary of Madeira River basin, Rondônia, Brazil. Bottom - Portion of a larger lateritic block (approx. 45 kg, 1.5 m in length, 0.6 m in width) containing numerous interconnected tunnels, from which specimens of 𝑆𝑝𝑖𝑛𝑖𝑝𝑡𝑒𝑟𝑢𝑠 𝑐𝑢𝑛𝑖𝑐𝑢𝑙𝑢𝑠 were collected. The block was taken from the riverbed of the “Guaporé River (type locality),” Rondônia, Brazil. © 2026 the Author(s). Published in the journal Neotropical Ichthyology. An open access article, distributed under the terms of the Creative Commons Attribution 4.0 International (CC-BY-4.0) licence. creativecommons.org/licenses… #NewSpecies #Ichthyology #Taxonomy #Biodiversity #AquariumHobby #Fishkeeping #Aquarist #TropicalFish #FishTank #Spinipterus #Siluriformes #Auchenipteridae #Brazil #Neotropical #Catfishes #GuaporéRiver #Guaporé #MadeiraRiver #Rondônia #DriftwoodCatfish