Morphological and Molecular Identification of Padas (Siganus spp.) in Northwestern Luzon, Philippines

This study aimed to identify the species and population structure of siganid juveniles, locally known as padas, in Northwestern Luzon using morphological and molecular identification methods. A hundred padas samples were collected from four provincial sites, and their morphological traits were evaluated. The study identified four species of padas: Siganus spinus, Siganus canaliculatus, Siganus argenteus, and Siganus fuscescens , with Siganus spinus being the most dominant. Phylogenetic analysis revealed strong homology between the identified padas samples and known Siganus NCBI sequences. The fixation index indicated genetic differentiation and similarities among Siganus spinus populations from different provinces, while populations of Siganus canaliculatus displayed some differentiation.