There is always some confusion about this family of fish. To the uninitiated like me, I would find it hard to differentiate between a kurau or a senangin. The English articles confuse me even more. So I hope the anglers would help me out, especially those who fish in West Malaysia and Singapore. The fishermen in Sarikei would probably be very well versed in these two kinds of fish, favourites of the Foochows.
However, here I will just stick to "Senangin or threadfins" are silvery grey perciform marine fish of the family Polynemidae. Found in tropical to subtropical waters throughout the world, the threadfin family contains nine genera and 33 species. An unrelated species sometimes known by the name threadfin, Alectis indicus, is properly known as the Indian threadfish (family Carangidae).
Ranging in length from 20 centimetres in the black-finned threadfin (Polydactylus nigripinnis) to 200 centimetres in fourfinger threadfins (Eleutheronema tetradactylum) and giant African threadfins (Polydactylus quadrifilis), threadfins are both important to commercial fisheries as a food fish, and popular among anglers. Their habit of forming large schools makes the threadfins a reliable and economic catch.
Their bodies are elongate and fusiform, with spinous and soft dorsal fins widely separate. Their tail fins are large and deeply forked; this is an indication of their speed and agility. The mouth is large and inferior; a blunt snout projects far ahead. The jaws and palate possess bands of villiform (fibrous) teeth. The most distinguishing feature of the threadfins are their pectoral fins: they are composed of two distinct sections, the lower of which consisting of between 3-7 long, thread-like independent rays. In Polynemus species there may be up to 15 of these modified rays.
(Source : Wikipedia)
Foochows are so paraochial.