External morphology of Ludong (Cestraeus plicatillis) of perciformes: Mugilidae with emphasis on scale ultrastructure

• Main Authors: Calderon, Pacifico Eric E., Leon, Marivic A., Suarez, Anna Cristina V., Tamayo, Ma. Bida Olivia S., Valencia, Julie Ann M., Simeon, Emerita C.
• Format: text
• Published: Animo Repository 2006
• Subjects: Native fishes; Ultrastructure (Biology); Biology
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/12982
• Institution: De La Salle University

Ludong (Cestraeus plicatilis) also, known as "President's fish" is a rare species endemic to the Cagayan River system in the Philippines. It has been pronounced as "endangered" species by the Bureau of Fisheries and Aquatic Resources (BFAR) in 2002. With the dearth of literatures on its basic biology, conservation measures have suffered drawback. Hence, this study presents the unique descriptive morphology and morphometric profiles of ludong in reference to the other externally similar mullet species: banak (Valamugil seheli) and aligsin (Liza viridis and L. tade). Ludong exhibited variations chiefly in head morphology and internal squamation pattern of the scales. Its elasmoid scale showed unique ultrastructural pattern along the anterior, lateral and posterior margins. These results were inferred to their mode of aquatic adaptations to the various tensions on their kind during swimming, osmotic shock when they migrate from the marine to freshwater and other environmental influences.