Sun Fish and Hammerheads, trip 10 (2021)

Our 10th liveaboard trip of 2021 with "Blue Force Fleet" at the Brothers Islands, Daedalus and Elphinstone (BDE). Wonderful reefs, caverns, sun fish, thresher shark, hammerhead sharks... HAMMERHEAD SHARKS are a group of sharks in the family “Sphyrnidae", so named for the unusual and distinctive structure of their heads, which are flattened and laterally extended into a "hammer" shape called a cephalofoil. Most hammerhead species are placed in the genus “Sphyrna", while the winghead shark is placed in its own genus, “Eusphyra". Many, but not necessarily mutually exclusive, functions have been proposed for the cephalofoil, including sensory reception, manoeuvering, and prey manipulation. Hammerheads are found worldwide in warmer waters along coastlines and continental shelves. Unlike most sharks, hammerheads usually swim in schools during the day, becoming solitary hunters at night. Some of these schools can be found near Malpelo Island in Colombia, the Galapagos Islands in Ecuador, Cocos Island off Costa Rica and near Molokai in Hawaii. Large schools are also seen in the waters off southern and eastern Africa and in the Red Sea. Hammerhead sharks are known to eat a large range of prey such as fish (including other sharks), squid, octopus, and crustaceans. Stingrays are a particular favorite. These sharks are often found swimming along the bottom of the ocean, stalking their prey. Their unique heads are used as a weapon when hunting down prey. The hammerhead shark uses its head to pin down stingrays and eats the ray when the ray is weak and in shock. The great hammerhead, tending to be larger and more aggressive than most hammerheads. SUN FISH. The Molidae comprise the family of the molas or ocean sunfishes, unusual fish whose bodies come to an end just behind the dorsal and anal fins, giving them a "half-fish" appearance. They are also the largest of the ray-finned bony fish, with the ocean sunfish Mola mola and southern sunfish, Mola alexandrini, both recorded at up to 4.6 m (15 ft) in length and 2,300 kg (5,100 lb) in weight. Molids mostly swim by using their anal and dorsal fins; the pectoral fins are probably just stabilizers. Sun Fish have been filmed interacting with other species. Since molids are susceptible to skin parasites, they make use of cleaner fish. A molid in need of cleaning will locate a patch of floating algae or flotsam that is home to halfmoons. The molid signals a readiness for cleaning by swimming almost vertically with its head near the surface of the water, and waits for the smaller cleaner fish to feed on the parasite worms. They feed mainly on soft-bodied animals, such as jellyfish and salps, although they also take small fish or crustaceans. BDE Route Week 5/11 September 2021 Filmed and Edited by Nino Del Duca www.blueforcefleet.com Music courtesy of Artlist https://www.ninodelduca.com/ Copyright © 2021 Nino Del Duca - All Rights Reserved

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