Thryssa mystax is silver, darker dorsally. There is a distinctive dark blotch behind upper part of gill opening, which can easily identify the species from other "Thryssa" species. Caudal fin is yellowish. It feeds on planktons, fish larva, and small crustaceans like shrimp larva. Thryssa mystax The moustached thryssa ("Thryssa mystax"), also known as Gangetic anchovy, is a species of oceanodromous ray-finned fish in the family Engraulidae. It is found in the tropical western Indo-Pacific region from India, Sri Lanka to Myanmar and south to Java, and Indonesia. It is a small schooling fish found in depth of 0-50m. Maximum length do
Fish fin keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to lure prey, and triggerfish avoid predators by squeezing into coral crevices and using spines in their fins to lock themselves in place.