Sunday, August 28, 2011
Ambergris occurs as a biliary secretion of the intestines of the sperm whale and can be found floating upon the sea, or in the sand near the coast. It is also sometimes found in the abdomens of whales. Because the beaks of giant squids have been found embedded within lumps of ambergris, scientists have theorized that the substance is produced by the whale's gastrointestinal tract to ease the passage of hard, sharp objects that the whale might have eaten.
Ambergris is found in lumps of various shapes and sizes, weighing from 15 g (½ oz) to 50 kg (100 pounds) or more. When initially expelled by or removed from the whale, the fatty precursor of ambergris is pale white in color (sometimes streaked with black), soft, with a strong fecal smell. Following months to years of photo-degradation and oxidation in the ocean, this precursor gradually hardens, developing a dark gray or black color, a crusty and waxy texture, and a peculiar odor that is at once sweet, earthy, marine, and animalic. Its smell has been generally described as a vastly richer and smoother version of isopropanol without its stinging harshness.
Ambergris has been mostly known for its use in creating perfume and fragrance much like musk. While perfumes can still be found with ambergris around the world, American perfumers usually avoid it because of legal ambiguities. It was banned from use in many countries in the 1970s, including the United States, because its precursor originates from the sperm whale, which is an endangered species. However, it has been legal since 2005 because of strict monitoring of distributors who ensure that only ambergris that has been naturally washed to shore is sold. Ancient Egyptians burned ambergris as incense, while in modern Egypt ambergris is used for scenting cigarettes. The ancient Chinese called the substance "dragon's spittle fragrance". During the Black Death in Europe, people believed that carrying a ball of ambergris could help prevent them from getting the plague. This was because the fragrance covered the smell of the air which was believed to be the cause of plague.
This substance has also been used historically as a flavouring for food, and some people consider it an aphrodisiac. During the Middle Ages, Europeans used ambergris as a medication for headaches, colds, epilepsy, and other ailments.
Sunday, August 21, 2011
Jellyfish Lake is a marine lake located on Eil Malk island in Palau. Eil Malk is part of the Rock Islands, a group of small, rocky, mostly uninhabited islands in Palau's Southern Lagoon, between Koror and Peleliu. There are about 70 other marine lakes located throughout the Rock Islands. Jellyfish Lake is one of Palau's most famous dive (snorkeling only) sites. It is notable for the millions of golden jellyfish which migrate horizontally across the lake daily.
Jellyfish Lake is connected to the ocean through fissures and tunnels in the limestone of ancient Miocene reef. However the lake is sufficiently isolated and the conditions are different enough that the diversity of species in the lake is greatly reduced from the nearby lagoon. The golden jellyfish, Mastigias cf. papua etpisoni, and possibly other species in the lake have evolved to be substantially different from their close relatives living in the nearby lagoons.
Snorkeling in Jellyfish Lake is a popular activity for tourists to Palau. Several tour operators in Koror offer trips to the lake. Eil Malk island is approximately a 45 minute boat ride from Koror. The lake is accessed by a short trail from the beach on Eil Malk to the lake.
Although both species of jellyfish living in the lake have stinging cells (nematocytes), they are not in general powerful enough to cause harm to humans. It has been reported that it is possible to notice the stings on sensitive areas like the area around the mouth. The Fish n' Fins tour guide recommended that people with allergies to jellyfish consider wearing protective clothing.
Sunday, August 14, 2011
Bobtail squid (order Sepiolida) are a group of cephalopods closely related to cuttlefish. Bobtail squid tend to have a rounder mantle than cuttlefish and have no cuttlebone. They have eight suckered arms and two tentacles and are generally quite small (typical male mantle length being between 1 and 8 cm). Sepiolids live in shallow coastal waters of the Pacific Ocean and some parts of the Indian Ocean as well as in shallow waters on the west coast of the Cape Peninsula off South Africa. Like cuttlefish, they can swim by either using the fins on their mantle or by jet propulsion. They are also known as dumpling squid (owing to their rounded mantle) or stubby squid.
Bobtail squid have a symbiotic relationship with bioluminescent bacteria (Vibrio fischeri), which inhabit a special light organ in the squid's mantle. The bacteria are fed a sugar and amino acid solution by the squid and in return hide the squid's silhouette when viewed from below by matching the amount of light hitting the top of the mantle. The organ contains filters which may alter the wavelength of luminescence closer to that of downwelling moonlight and starlight; a lens with biochemical similarities to the squid's eye to diffuse the bacterial luminescence; and a reflector which directs the light ventrally.
Sunday, August 7, 2011
Scientists at Dalhousie University in Halifax, Canada, collected samples of the R.M.S. Titanic's icicle-like rust formations, called rusticles, in 1991.
Although the formations were teaming with life, nobody had identified the specific microbes on the ship, instead grouping them into broad categories such as bacteria or fungi.
So Henrietta Mann and then graduate student Bhavleen Kaur, now of the Ontario Science Centre, decided to isolate and identify one species of bacteria from the mess of microscopic life-forms.
The one they chose turned out to be a new species, which the pair dubbed Halomonas titanicae. The bacteria is part of a family that had never been seen before in waters as deep as those in which the Titanic sits, about 2.4 miles (3.8 kilometers) below the surface, Kaur said.