20/08/2026
Researchers in this study investigated catfish communities from the families Astroblepidae and Loricariidae in the headwaters of the Madre de Dios and Huallaga rivers in Peru, spanning elevations from 500 to 2,500 m. Using DNA barcoding and multiple species-delimitation methods, researchers identified 27 MOTUs (Metagenomic Operational Taxonomic Units), most of which could not be assigned to recognised species.
Examining diversity patterns, species co-occurrence, and phylogenetic community structure along the Andean slope, researchers developed a framework that evaluates how ecological processes—such as competition, niche partitioning, and ecological specialisation—shape community assembly.
"Combined with evidence of close phylogenetic relationships among MOTUs, our results highlight the likely importance of in situ diversification in driving species turnover and structuring catfish biodiversity across Andean elevational gradients."
𝗥𝗲𝘀𝗲𝗮𝗿𝗰𝗵 𝗧𝗶𝘁𝗹𝗲
Delimiting Andean catfish species of the families Astroblepidae and Loricariidae (Ostariophysi, Siluriformes) in the Peruvian Andes using DNA barcodes
Open-access - https://zookeys.pensoft.net/article/182593/
𝗖𝗶𝘁𝗮𝘁𝗶𝗼𝗻
De la Sota A, Hidalgo M, Estivals G, Faustino-Fuster D, Meza-Vargas V, Caminade P, Bêche L, Britzke R R, Steinke D, Hubert N (2026) Delimiting Andean catfish species of the families Astroblepidae and Loricariidae (Ostariophysi, Siluriformes) in the Peruvian Andes using DNA barcodes. ZooKeys 1290: 59-84. https://doi.org/10.3897/zookeys.1290.182593
𝗔𝗯𝘀𝘁𝗿𝗮𝗰𝘁
The Amazon Basin, the largest on Earth, hosts an exceptionally rich fish fauna shaped by its ancient evolutionary history, vast environmental heterogeneity, and steep altitudinal gradient. Despite this diversity, major taxonomic gaps persist, including the Linnean shortfall—the large number of undescribed species—and the Wallacean shortfall, reflecting limited knowledge of species distributions. During the past two decades, DNA barcoding using the mitochondrial COI gene has helped uncover substantial cryptic diversity in Amazonian fishes, particularly along the Andean slope, where Siluriformes exhibit striking levels of undocumented diversity.
In this study, we investigated catfish communities from the families Astroblepidae and Loricariidae in the headwaters of the Madre de Dios and Huallaga rivers in Peru, spanning elevations from 500 to 2,500 m. Using DNA barcoding and multiple species-delimitation methods, we identified 27 MOTUs, most of which could not be assigned to recognized species.
Our aim was to examine diversity patterns, species co-occurrence, and phylogenetic community structure along the Andean slope. This framework allows us to evaluate how ecological processes—such as competition, niche partitioning, and ecological specialization—shape community assembly. Combined with evidence of close phylogenetic relationships among MOTUs, our results highlight the likely importance of in situ diversification in driving species turnover and structuring catfish biodiversity across Andean elevational gradients.
𝗣𝗵𝗼𝘁𝗼 𝗖𝗿𝗲𝗱𝗶𝘁
Top left - Phenotypic variability and variations in colouration pattern of 𝐴𝑛𝑐𝑖𝑠𝑡𝑟𝑢𝑠 𝑠𝑝. (BOLD:AER0500; A–D) and 𝐴𝑛𝑐𝑖𝑠𝑡𝑟𝑢𝑠 𝑚𝑎𝑙𝑑𝑜𝑛𝑎𝑑𝑜𝑖 (E–H).
Top right - Phenotypic variability and variations in colouration pattern of 𝐶ℎ𝑎𝑒𝑡𝑜𝑠𝑡𝑜𝑚𝑎 𝑏𝑟𝑎𝑛𝑖𝑐𝑘𝑖𝑖 (A–D) and 𝐶ℎ𝑎𝑒𝑡𝑜𝑠𝑡𝑜𝑚𝑎 𝑚𝑖𝑐𝑟𝑜𝑝𝑠 (E–H).
Bottom left - Phenotypic variability and variations in colouration pattern of A–F. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 ℎ𝑢𝑎𝑙𝑙𝑎𝑔𝑎𝑒𝑛𝑠𝑖𝑠; G–L. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑠𝑝. (BOLD:AER0687).
Bottom right - Photographs of the 14 MOTUs delimited in the genus 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠, including A. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑠𝑝. (BOLD:AAM2932); B. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑠𝑝. (BOLD:AAM2933); C. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑠𝑝. (BOLD:AAN2234); D. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑠𝑝. (BOLD:AER0685); E. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑠𝑝. (BOLD:AER0686); F. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑠𝑝. (BOLD:AER0687, MOTU07); G. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑠𝑝. (BOLD:AER0687, MOTU17); H. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑠𝑝. (BOLD:AGY9904); I. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑠𝑝. (BOLD:AGY9906); J. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑠𝑝. (BOLD:AGY9907); K. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑠𝑝. (BOLD:AGY9908); L. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑞𝑢𝑖𝑠𝑝𝑒𝑖; M. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 ℎ𝑢𝑎𝑙𝑙𝑎𝑔𝑎𝑒𝑛𝑠𝑖𝑠; N. 𝐴𝑠𝑡𝑟𝑜𝑏𝑙𝑒𝑝𝑢𝑠 𝑠𝑝. (BOLD:AGY9903).
© 2026 the Author(s). Published in the journal ZooKeys. An open-access article, distributed under the terms of the Creative Commons Attribution 4.0 International (CC-BY-4.0) deed. https://creativecommons.org/licenses/by/4.0/
