Updates on Identification and Distribution of the River Mullet “Ludong” in Northern Philippines

Abstract

“Ludong”, also known as the president’s fish, is a river mullet known to be found in Cagayan River, Northern Philippines. Unfortunately, this species has been heavily exploited over the years. As a conservation measure, the Department of Agriculture - Bureau of Fisheries and Aquatic Resources (DA-BFAR) issued the BFAR Administrative Circular (BAC) 247 of 2013, declaring a closed fishing season for “ludong” during its spawning from October 1 to November 15. Despite these efforts, the identity and distribution of “ludong” remain unclear. Here, the species identification and habitat range of “ludong” have been determined and updated by DNA barcoding using mitochondrial cytochrome c oxidase subunit 1 (CO1) as a marker. Twenty-five (25) “ludong” samples were collected from Cagayan River and Abra River traversing Regions 1, 2, and the Cordillera Administrative Region. BLAST, phylogenetic and pairwise analyses showed that all 25 specimens were Cestraeus goldiei. Consequently, the known distribution of C. goldiei has been extended from Cagayan River to Abra River, from Region 2 to Region 1 and CAR. Knowledge of the definitive species identification and distribution of “ludong” will contribute to further understanding of its biology and fisheries and boost its conservation.