Mud crab (scylla serrata.)this important food crab is common in mangroves where fishermen hook them out of their burrows using long iron rods. They are also found in rocky areas with muddy substrates. Their colours vary from dark green (mangrove habitat) to bluish green (open waters). They feed on any animal matter available, preferring shelled molluscs. Because of their bulk, they use their paddle-like last pair of legs to burrow rather than swim. They are able to stay out of water for long periods. (width of shell up to 23cm). 250 - 350 g (small) 350 - 500 g (medium) 500 - 750 g (large) 750 - 900 g (ex-large) 900 and above (xxl)