The shallow brackish waters of the Dalyan River, which has a bed of fine sand and mud, form the ideal habitat for the blue crabs attracting the attention of both nature lovers and gastronomes. These large flamboyant crabs, originating from America and Canada, have legs and pincers of dark blue, rust colour joints projections on either sides of their bodies, and paddle with rear legs. The blue crabs that were brought to Turkey for their economic value and released in lagoons in the Northern Aegean and the Saros Bay reproduced and multiplied. However, probably because they were not able to find the natural conditions they required in this region, they migrated to the Southern Aegean and inhabited the Güllük and Dalyan lagoons, extending right over to the Karadeniz fish trap in Taşucu. Today a large number of blue crabs are hunted in the Dalyan delta and are served by restaurants with various sauces and cooking methods.

As is the case with other crustaceans, blue crabs change their shell as they grow, and protect themselves against their enemies by burying themselves in the sand-mud bed or hiding under rocks until their new shell hardens. Male crabs may reach a width of 9 cm and a length of 22 cm. For this they moult their shells a few times throughout their 3-year life. In contrast, however, females are smaller and have different abdominal hoops.

Female blue crabs can conceive only once after reaching sexual maturity. Their mating, which presents an interesting ceremony starts when the female blue crab releases a hormone in its faeces, which stimulates the male. The male crabs that compete for the female, the shell of which it has recently moulted and is still soft protect and carry the female. After this matrimonial ceremony where the toughest is the winner, the female stores the sperm and migrates to salty water after its shell hardens. During a period of 2-9 months following insemination, the blue crab secretes a sponge like orange hormone that fixes under its abdomen like a pillow and releases about 2 million eggs.

The eggs are protected by the female crab until the eggs hatch and spread into the water like a cloud of plankton. The development of the larvae, which are generally 0,25 mm wide, depends on saltiness and heat. The young, the width of which reach 2,5 mm in the shell formation stage, have the appearance of crabs, however with claws at the end of their legs; they prefer to live at the bottom although they are capable of swimming. At this stage the blue crabs gradually migrate to less salty water and mature by growing 1/3 of their current size at each moulting. Since male blue crabs prefer less salty water their migration may extend to upper parts of rivers.

For enthusiasts, blue crab hunting is very pleasant and profitable. A sinker and a piece of chicken skin or a dead fish attached to a largish hook is adequate. When the line you cast into the shallow water of the delta starts being pulled gently, you understand that the crab has taken the bait with its pincers. The only thing to do is to draw the line gradually without frightening the crab. Blue crabs are very stubborn and they do not let go of the bait until they reach the surface. However, it is necessary to put a net into the water to catch the crab as soon as it gets close to the boat. Another thing to be careful of is to avoid its large and strong pincers.