KARACHI – Around 15 feet long and four ton heavy whale was taken to the harbour by the Karachi Fish Harbour Authority (KFHA) on Friday.The KFHA has asked the marine research institutions to dissect the big sea creature to identify the cause of the fish’s death.KFHA spokesman Saghier Ahmed told TheNation that the fish harbour authority, through an official letter, had asked the Marine Fisheries Department of Pakistan and Center of Excellence in Marine Biology, University of Karachi (KU) to come forward and carry out research work on the giant sea creature so that some useful information could be obtained.He said that last year, 40 feet long and 30 ton heavy dead whale-shark was taken to the Karachi harbour, which was preserved in the Pakistan Museum of Natural History in Islamabad. The KFHA is still waiting for reports.During the last few years, dozens of whale sharks have been found dead in Pakistani waters.Talking to TheNation, KU Center of Excellence in Marine Biology Director Dr Jamal Prizada said that whale sharks were usually killed accidentally and it was not specific to Pakistani waters and could be found dead anywhere in the world and were sometimes hit by the ships. To a query, he said that study on dead species was usually academic domain, while the physical evaluation of the dead animal could identify the actual cause of the death, adding that the study on living whale shark was quite expensive for researchers.As per the website of National Geography, As the largest fish in the sea, reaching lengths of 40 feet (12 meters) or more, whale-sharks have an enormous menu from which to choose.Fortunately for most sea-dwellers—and us!—their favorite meal is plankton. They scoop these tiny plants and animals up, along with any small fish that happen to be around, with their colossal gaping mouths while swimming close to the water's surface.The whale shark, like the world's second largest fish, the basking shark, is a filter feeder.In order to eat, the beast juts out its formidably sized jaws and passively filters everything in its path. The mechanism is theorized to be a technique called “cross-flow filtration,” similar to some bony fish and baleen whales. The whale shark's flattened head sports a blunt snout above its mouth with short barbels protruding from its nostrils.Its back and sides are gray to brown with white spots among pale vertical and horizontal stripes, and its belly is white. Its two dorsal fins are set rearward on its body, which ends in a large dual-lobbed caudal fin (or tail).Preferring warm waters, whale sharks populate all tropical seas. They are known to migrate every spring to the continental shelf of the central west coast of Australia.The coral spawning of the area's Ningaloo Reef provides the whale shark with an abundant supply of plankton. Although massive, whale sharks are docile fish and sometimes allow swimmers to hitch a ride.They are currently listed as a vulnerable species; however, they continue to be hunted in parts of Asia, such as the Philippines.