Thursday, January 20, 2011

Adaptation Group 5

1. How do mangrove plats survive such as Avicennia obtain oxygen when their roots are buried in the mud?
  • Mangrove plants like the Avicennia is most commonly referred to as a black mangrove.
  • Each mangrove has an ultrafiltration system to keep much of the salt out and a complex root system that allows it to survive in the intertidal zone.
  • Some have snorkel-like roots called pneumatophores that stick out of the mud to help them take in air; others use prop roots or buttresses to keep their trunks upright in the soft sediments at tide's edge.

2. How are xerophytes apdapted to survive prolonged drought?
  • Xerophyte, any plant adapted to life in a dry or physiologically dry habitat (salt marsh, saline soil, or acid bog) by means of mechanisms to prevent water loss or to store available water.
  • Succulents (plants that store water) such as cacti and agaves have thick, fleshy stems or leaves.
  • Other xerophytic adaptations include waxy leaf coatings, the ability to drop leaves during dry periods, the ability to reposition or fold leaves to reduce sunlight absorption, and the development of a dense, hairy leaf covering.

3. About how the polar bear how they survive in regions where temperatures are always freezing
  • Polar bears have two types of fur: long oily guard hairs and short insulating hairs. Polar bears stay warm by combining the properties of these two hairs. They help to keep warmth under the skin.
  • Blubber also helps polar bears to stay warm by providing an insulating fat. Although they are not so effective, they still can provide food for the polar bear. Blubber traps little body heat lost by the bear and returns it back to the bear.
  • Polar bears stay warm by using the snow. Snow crystals trap small amounts of air, and polar bears will burrow in the snow to create an insulating blanket. This is sometimes combined with a biological process called winter sleep, which helps polar bears stay warm by slowing down metabolic processes.

4. How do deep-sea anglerfish locate it's prey in darkness?

  • Female anglerfish bear a piece of dorsal spine, which have a projecting structure above its mouth. This dorsal spine is similar to a fishing pole and it contains a lucent flesh at its tip, which makes it a perfect and natural tempter for preys. Anglerfishes can swallow a prey bigger than them because of their flexible body structure.
  • The male anglerfish is not equipped with any such luring organ like the female one. It is also comparatively small to the female ones. The only purpose of the male anglerfish’s life is to find a female angler and mate with it.
  • Any fish which passes before the angler fish’s eyes can be its prey. Anglerfish’s diet is filled with various genres of fishes. They eat almost all kind of sea worms, batfish, clams, copepods, and marine snails.
  • Instead of looking for prey actively, anglerfish have a brilliant hunting technique. They first camouflage their bodies to blend in well with the surroundings, and then they modify the foremost spine of their dorsal fins to look like a baited fishing rod. When wriggling it, anglerfish fool other fishes into believing that they have just caught a glimpse of a worm.
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5. Why can't a saltwater fish survive in a freshwater aquarium?What are the differences in pH between saltwater and freshwater?

Saltwater fish drinks a lot of saltwater to replace lost fluids and then excrete the extra salt.Their kidneys produces small volume of fluids that contains high concentration of salt to prevent water leaving the fish through osmosis. Thus,the saltwater fish is adapted to the saltwater environment.
A freshwater fish put in salt water would quickly lose water from its cells, with no way for it to be replaced, and perish.
The cells in a saltwater fish put in freshwater would quickly absorb water from the environment, and with no way to eliminate it, the cells would swell, burst and kill the fish.

Sources: Freshwater & Saltwater Fish |
  • pH in seawater is slightly more alkaline due to the presence of mono-ions like Mg+, Ca2+, etc.
  • pH of freshwater environs are highly variable due to runoff from rain, etc.


By Group 5_ Soe Yan Naung@Norman, Aaron Sng, Eugene Liow, Imran Khan, Ong Bing Jue

Posting for Aaron(Mac Crashed)

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