ABSTRACT
This chapter provides an abundance of valuable first-hand information about the biology and ecology of portunid crabs. Carapace of portunid crabs may be hexagonal—transversely ovate to transversely hexagonal or almost circular. Adult habitats range from near shore estuarine to offshore open water and deep benthic environments. Dorsal surface is generally relatively flat and is often ridged or granulose. Front is broad and its margin is usually multidentate. The carapace of fresh specimens of certain portunid species have been observed to have fluorescing patterns which are of great use as a diagnostic character in species identification. In Portunus sanguinolentus, the mean monthly growth rates were found to be 10.3 m and 8.8 mm and attained a carapace width of 124.1 and 112.5 mm by males and females respectively on completion of one year. The crab uses its mouthparts to chop the food into small pieces and then the gastric mill ossicles further reduce the food to fragments.
