Archive for March, 2007



Caisons Disease

Friday 30 March 2007 @ 10:26 am

Caison disease pic Caisson disease Was the old name for decompression sickness. It is named after it appeared in construction workers when they left the caisson and had rapid decompression. It is caused by the same processes as decompression sickness in divers. The Brooklyn Bridge was constructed with the help of caissons, and several workers died of caisson disease. Caissons ar ehollow concrete blocks, which were sunk to the bottom of the seabed, filled with compressed air, to keep the water out, while the workers dug away at the mud in order to sink the concrete onto a firm base.

Decompression sickness happens when a diver ascends rapidly from a dive or does not carry out decompression stops after a long or deep dive. These situations cause inert gases, generally nitrogen, which are normally dissolved in the blood, body fluids and tissues, to come out of the dissolved state (i.e., outgas) and form gas bubbles.




Sea Anemone

Monday 26 March 2007 @ 4:45 am

Sea anemone The sea anemone has a foot which normally attaches itself to rocks or the sand. Some species attach themselves to kelp and others are free-swimming. Although they are not plants and therefore are incapable of photosynthesis themselves, many sea anemones form an important symbiosis with certain single-celled green algae species which live in the animals’ gastrodermal cells.




Clown Fish

Monday 26 March 2007 @ 4:41 am

Clown Fish Clownfish live in wide ranges of the warm waters of the Pacific and Indian Oceans. Some species ranges overlap others. Clownfish do not live in the Atlantic Ocean. Clownfish live in a symbiotic relationship with sea anemones, or in some cases settle in some varieties of soft corals, or large polypy stony corals. Once an anemone or coral has been adopted, the fish will defend it.




Sea Cucumber

Monday 26 March 2007 @ 4:36 am

Sea Cucumber Sea cucumbers are scavengers, feeding on debris in the benthic layer. Their food consists of plankton and other organic matter found on the seabed. One way they might get a supply of food is to place themselves in a current where they can grab food that flows by with their tentacles when they open. Also they sift through the bottom sediments using their tentacles. They can be found in large numbers beneath fish farms.




Parrot Fish

Monday 26 March 2007 @ 4:33 am

Parrot Fish Parrotfishes are named for their oral dentition: their many teeth are arranged in a tightly packed mosaic on the external surface of the jaw bones. This forms a parrot-like beak which is used to scrape algae from coral and other rocky substrates.




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