The Octopuses

Today we decided to write about very fascinating sea creature - the octopuses. They inhabits many diverse regions of the ocean, including coral reefs, pelagic waters, and the ocean floor. They have numerous strategies for defending themselves against predators, including the expulsion of ink, the use of camouflage and demotic displays, their ability to jet quickly through the water, and their ability to hide. All octopuses are venomous, but only one group, the blue-ringed octopuses, is known to be deadly to humans. There are around 300 recognized octopus species, which is over one-third of the total number of known cephalopod species.

Octopuses are highly intelligent, likely more so than any other order of invertebrates. They have a highly complex nervous

Red Sea Coral and Marine Fish

Red Sea coral and marine fish

The rich diversity is in part due to the 2,000 km (1,240 mi) of coral reef extending along its coastline; these fringing reefs are 5000–7000 years old and are largely formed of stony a cropora and porites corals. The reefs form platforms and sometimes lagoons along the coast and occasional other features such as cylinders (such as the Blue Hole (Red Sea) at Dahab). These coastal reefs are also visited by pelagic species of red sea fish, including some of the 44 species of shark.

The Red Sea also contains many offshore reefs including several true atolls. Many of the unusual offshore reef formations defy classic (i.e., Darwinian) coral reef classification schemes, and are generally attributed to the high levels of tectonic activity that characterize the area.

The special biodiversity of the area is recognized by the Egyptian government, who set up the Ras Mohammed National Park in

How Are Coral Reefs Formed?

Reef-Building Corals

There are four taxa (formally classified groups) of corals that substantially assist in the deposition of calcium carbonates in the reef-building process. These are:

Scleractinian corals

Octocorals (a very few) Fire corals (Hydrocorals)

Stylasterine corals (Hydrocorals)

Shallow marine waters have high concentrations of calcium (Ca++) and bicarbonate (HCO3-) ions. Coral animals (polyps) have the ability to combine these two chemicals to form calcium carbonate (CaCO3), from which their protective skeletons are fashioned.

Crystal structure of calcite and

Red Sea Facts and figures

Length: ~2,250 km (1,398.1 mi) - 79% of the eastern Red Sea with numerous coastal inlets

Maximum Width: ~ 306–355 km (190–220 mi)– Massawa (Eritrea)

Minimum Width: ~ 26–29 km (16–18 mi)- Bab el Mandeb Strait (Yemen)

Average Width: ~ 280 km (174.0 mi)

Average Depth: ~ 490 m (1,607.6 ft)

Maximum Depth: ~2,211 m (7,253.9 ft)

Surface Area: 438-450 x 10² km² (16,900–17,400 sq mi)

Volume: 215–251 x 10³ km³ (51,600–60,200 cu mi)

Approximately 40% of the Red Sea is quite

Red Sea

The earliest known exploration of the Red Sea was conducted by Ancient Egyptians, as they attempted to establish commercial routes to Punt. One such expedition took place around 2500 BC, and another around 1500 BC ( by Hatshepsut ). Both involved long voyages down the Red Sea. The Biblical Book of Exodus tells the story of the Israelites' miraculous crossing of a body of water, which the Hebrew text calls Yam Suph. Yam Suph is traditionally identified as the Red Sea. The account is part of the Israelite escape from slavery in Egypt. Yam Suph can also been translated as Sea of Reeds.

In the 6th century BC, Darius the Great of Persia sent reconnaissance missions to the Red Sea, improving and extending navigation by locating many hazardous rocks and currents. A canal was built between the Nile and the northern end of the Red Sea at Suez. In the late 4th century BC, Alexander the Great sent Greek naval expeditions down the Red Sea to the Indian Ocean. Greek navigators continued to explore and compile data on the Red Sea. Agatharchides collected information about the sea in the 2nd century BC. The Periplus of the Erythraean Sea ("Periplus of the Red Sea"), a Greek periplus written by an unknown author around the 1st century AD, contain a detailed description of the Red Sea's ports and sea routes.

The Periplus also describes how Hippalus first discovered the direct route from the Red Sea to India.

Settlements and commercial centers in the vicinity of the Red Sea involved in the spice trade, as described in

The SS Thistlegorm.

The SS Thistlegorm was built by Joseph Thompson & Sons shipyard in Sunderland for the Albyn Line and launched in April 1940. It was powered by a triple-expansion steam engine rated to 365 hp (272 KW). The vessel was privately owned but had been partly financed by the British government and was classified as an armed freighter. She was armed with a 4.7-inch (120 mm) anti-aircraft gun and a heavy-calibre machine gun attached after construction to the stern of the ship. She was one of a number of "Thistle" ships owned and operated by the Albyn Line, which was founded in 1901, based in Sunderland, and had four vessels at the outbreak of World War II.

The vessel carried out three successful voyages after her launch. The first was to the US to collect steel rails and aircraft parts, the second to Argentina for grain, and the third to the West Indies for rum. Prior to her fourth and final voyage, she had undergone repairs in Glasgow. 

The Last Voyage