Blueback Sprat

Spratelloides delicatulus

Blueback Sprat, also known as Spratelloides delicatulus, is a small, slender-bodied fish typically measuring between 5 and 7 cm in length, although some individuals can reach up to 17.8 cm. It has a laterally compressed, silvery body that often appears translucent, with a single dorsal fin and a forked caudal fin. These features facilitate its schooling behavior and sustained swimming in open coastal waters. The species can be distinguished from similar fish by its scale patterns and fin placement. This species is widely distributed across the tropical Indo-Pacific region, including areas such as northern Australia, the Great Barrier Reef, and Southeast Asia. It inhabits shallow coastal waters, lagoons, and reef shelf environments, typically at depths of up to 50 meters. The Blueback Sprat is a pelagic fish that forms large schools in areas with high plankton productivity. Feeding primarily on planktonic organisms, the Blueback Sprat plays a crucial role in the nutrient cycling of reef ecosystems. It is known to participate in feeding aggregations during coral reef spawning events. Although not a major target for commercial fisheries, it is often used as baitfish in small-scale operations. The species is classified as Least Concern by the IUCN.