body patterns from the moment they hatch. In comparison, other loliginid squid species do not produce complex body patterns at less than four months of age. The patterns produced by bigfin reef squids, however, are less diverse than those of the Caribbean reef squids. Bigfin reef squids do not possess photophores, and are thus not truly bioluminescent. Sexual dimorphism It is often difficult to superficially distinguish between male and female bigfin reef squids. Some authors say that females are generally smaller than males, but this distinction is not observed in other studies. Closer examination of sexually mature specimens, however, will usually distinguish males from females by the presence of the hectocotylus on the fourth left arm in males, and the nidamental glands and the pale ovaries within the mantle in females. Males also purportedly show a more conspicuous pattern of transverse streaks on their dorsal side. Ecology Distribution and habitat The bigfin reef squid is a neritic warm water-dwelling squid. They are usually found below the water's surface. They tend to remain close to the shoreline, near rocks and reefs. They are slightly more active during the night and will move to deeper waters or find cover in daytime. Large numbers of juveniles can often be found hiding beneath floating driftwood. The bigfin reef squid is the most widespread species in the genus Sepioteuthis. It is found in temperate and tropical regions of the Indian Ocean and the western Pacific Ocean. Their original range extends east to the Hawaiian Islands, west to the Red Sea, north to Japan, and south to Australia and New Zealand (42°N to 42°S and 32°E to 154°W). The range has also expanded to include parts of the Mediterranean Sea. In 2002, bigfin reef squids were first documented in the Gulf of İskenderun of the southeastern Mediterranean Sea. They may have already existed in significant populations in the area prior to their discovery in 2002, as they have acquired a common name among the fishermen of the Aegean Sea – (soupiocalamaro, literally "cuttlefish-like squid"). It is a Lessepsian migrant, reaching the Mediterranean Sea through the Suez Canal. Diet and predators The bigfin reef squid eats a variety of different marine organisms. Its main prey are usually prawns and other crustaceans, and fish. Captive specimens were observed to consume one fish every 2 to 25 hours. Bigfin reef squids are, in turn, preyed upon by tuna, marlin,