Three new species of the family Canuellidae Lang, 1944 (Copepoda, Canuelloida) from the Western Pacific Ocean

Three new species of the copepod family Canuellidae Lang, 1944 (Copepoda, Canuelloida) are described from the Western Pacific Ocean, based on specimens collected from coastal waters of Korea (Jeju-do Island) and the Republic of Palau. This study provides detailed morphological descriptions and illustrations for Elanella jejuensis sp. nov ., Brianola coreana sp. nov ., and Scottolana picrca sp. nov . Key diagnostic characters differentiating them from congeners include the unique bulbous modification of caudal ramal seta IV in E. jejuensis sp. nov ., the presence of an inner seta on the P1 exopod-2 in B. coreana sp. nov ., and features including reduced urosome segmentation and a modified female caudal seta II that place S. picrca sp. nov . within the longipes -group. Molecular phylogenetic analysis using mitochondrial cytochrome c oxidase subunit I (COI) and nuclear 18S ribosomal RNA (18S rRNA) sequences recovers each new species as a distinct, well-supported lineage and resolves two major clades within Canuellidae: ( Elanella + Brianola ) and ( Scottolana + Canuella ). The phylogeny further indicates that Elanella and Brianola are sister taxa, and places S. picrca sp. nov . within the longipes -group; however, the placement of S. picrca sp. nov . as sister to S. wonchoeli is weakly supported (57% bootstrap). These findings significantly advance our understanding of Canuellidae diversity and evolution in the understudied Western Pacific region.