Today was a follow up of the last class we had at the Kovalam beach. Last class we learned about wave currents, marine life and more. However, today is a more detailed description of what you can find in the sea/ocean.
Many sea creatures are mistaken for fish when they are not, especially star fish, jelly fish and cuttle fish. To find weather a creature is a fish it must meet these points.
1- It must be vertebrates.
2- It must have gills/fins.
3- It must lay eggs.
If the sea creature meets any of these points it is a fish. These are some of the creatures we listed into groups.
Sharks- features of a fish
Sea horse- It has a dorsal fin
Clown fish- Features of a fish
Cat fish- Features of a fish
Sardines- Features of a fish
Piranha- Features of a fish
Pom fish- Features of a fish
Mud skipper- Features of a fish
Dolphin- It has lungs
Jelly fish- Soft body
Bi-valves and univalves- In- animate
Star fish- in-vertebrate
Cuttle fish- Does not have features of a fish
Groups of fish-
1- Jaw less
Jaw less fishes do not have jaws, so they can suck their prey to consume it, they have an adaptation to avoid getting peeled off from the prey’s body and they can produce large amounts of mucus.
Cartilaginous fishes are flexible and have joints.
3- Apex predators
Apex predators stalk their prey and devour them when least expected.
4- Boney fish
Boney fishes are the basic kind of fishes, the kind that we humans usually draw-
There are different layers on the ocean, each of the layers are categorized by how much light is found there.
1- Pelagic zone (Sunlit zone)
In the pelagic zone it is usually warm so more vegetation grows there, so that means more marine organisms live there. In the pelagic zone a process called counter shading takes place, counter shading means that the part of a marine organism which is exposed to sunlight will be a darker color than the bottom. This way when you look down at the ocean ,the marine organism will remain camouflaged.
2- Meso pelagic (twilight zone)
The mid layer in the ocean is the meso pelagic zone also known as the twilight zone. The reason it is called “meso” pelagic is because this layer is not very bright nor very dark.
3- Ocean floor
The ocean floor is the last layer where it is pitch black, most the marine organisms in this zone have an adaptation to glow, on the ocean floor the water pressure is very intense,so the marine organisms are usually flat. Previously, we learned that where it is bright there is more vegetation, so if the ocean floor is pitch black there will not be a lot of vegetation. Luckily the organisms there eat left overs, this means if a dead creature-such as a shark or whale,sinks to the ocean floor the marine organisms will feed on it.
Water bodies inside water bodies-
This might not make sense the first time you think about it ,but when you look into the facts, you will be surprised. A water body inside a water body is formed when there is too much salt concentrated on an area, this separates that area from the rest of the ocean, because of this the water will look foggy. Many marine organisms look for food inside the salt water body, and will die. There are very rare cases in which an organism survives, but usually the level of salt is too much in that area that the creatures that go inside it will get a toxic shock and die.
By Ishaal Azeez, Grade 6