Spawning of Decapterus macrosoma (Bleeker, 1851) “Galunggong” in Tablas Island, Romblon, Philippines: with Inferences on its Reproductive Ecology and Management

Despite its significant contribution as a cheap source of protein and support to a large fishery industry, the biology and ecology of D. macrosoma (Galunggong) remain poorly understood. This study investigates the spawning characteristics vis a vis fisheries management of D. macrosoma in the waters of Romblon Province. The spawning peak in Romblon Pass is during the Hot (May) and Cold (December-January) Seasons, while during Rainy (October) and Hot (May) Seasons in Tablas Strait. The timing of peak spawning of D. macrosoma around Tablas Island varies with that of the South Sibuyan Sea, but generally similar to the breeding traits in Palawan Waters, Manila Bay, and other shortfin scads’ populations in Asian Waters. Initial findings argue that the variations in spawning characteristics of populations in this study are influenced by the rate of exploitation. Areas in Romblon Pass, Southwest Philippine Sea, and North Sulu Sea – show no sign of heavy exploitation. The common peak spawning months in MIMAROPA Waters are May and December, while May, October, and December in Romblon Waters. This can be used as the basis for management decisions to regulate the fishing efforts of D. macrosoma in the Fisheries Management Area no. 5.

Keywords: Spatial distribution, reproductive strategies, fisheries management areas