Threadfin fishes occur in tropical and subtropical coastal waters and estuaries. There are also few freshwater species known to exist. They are mostly epibenthic forms found on sandy and muddy bottoms in depths less than 150 meters. These fishes generally feed on small fishes, crustaceans and some even depend on planktons. The pectoral filaments are most possibly helpful as a sense organ in search of food in muddy water. Hermaphrodites among threadfin fishes seem to be common since their sex change from male to female with growth. They probably breed in coastal waters and estuaries while the Mango fish of India is reported to ascend freshwater reaches of rivers for breeding purposes, Polydactylus sexfilis (Valenciennes) is known to occur near reef areas in vicinity of oceanic islands and so, seems to be not dependant on freshwater river inflow for breeding.
An attempt has been made to review the studies of polynemid fishes made in India along with examination of fresh and preserved specimens in order to avoid prevailing confusions, so that future workers will have proper guidance in the field of taxonomy as well as fisheries. Moreover, taxonomic confusions hinder collection of species-specific distributional as well as fisheries data. These fishes are considered as most highly esteemed food fishes and mostly contribute to the fisheries of regional importance.
1. Introduction
2. Review of Indian literature
3. Material and methods
4. Key to species
5. Systematic accounts
6. Discussion
Summary
Acknowledgements
References