Last Update : Thursday 9 August, 2001 10:14 PM
Last Update : Thursday 9 August, 2001 10:14 PM |
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Combat Manta ray
BEGINNING
HER (2)
After these several years, she had grown up. She was 4 meters wide, measuring from wingtip to wingtip and could grow further to be more than 6 meters wide, weighing more than 1,600 kilograms.
Going back to the first day, after she had learned to swim she then learned to breathe. Most stingrays breathes by lying still on the seabed, sucking water in through spiracles passing through the gill.
But respiration system of manta ray is different from general stingrays. Manta ray does not have spiracles. So, she has to use water flow. When she swims forward, water would flow through the mouth-hole passing through gills under the body. Oxygen is separated from water for breathing and carbon dioxide is emitted. In some places where water flushes, she only keeps herself afloat, letting the water flows through.
Her mouth is different from other stingrays including eagle rays. They have mouths under the body. They have teeth to chew various crustaceans on the seabed. Their mouth cannot be used to filter the water to search for food. But for Manta ray, her mouth is in front of the body. Respiration is in relation to eating. A part of her pectoral fin becomes cephalic fins, adjusting the direction of water flow through her mouth. There are plankton, small fish or other crustaceans in the water flowing through. She uses specially developed gills to filter those creatures to eat. Since she does not use teeth in eating, her lower teeth are very small and covered by skin, whereas the upper teeth vanish.
1. Water flows in to the mouth with the assistance of cephalic fins.
2. Water flows to gills, which has been specially developed.
3. Oxygen in water is separated for respiration. Carbon dioxide is emitted.
4. Plankton and small creatures are filtered for food.
5. Water is drained out through gills underneath.She opened her mouth letting the water flow through happily. Some times food was scarce, she swam nearer to the shore where there were plankton and small creatures living in the sediments. She dived down to the seabed, flapped her wings to disperse sediments before pulling her head up quickly, unrolled her cephalic fins, open her mouth widely letting nourishing water flow through. Umm….delicious.
Apart from coming near the shore to search for food, she also came in other purposes, some time to relax, another time to look at new things, mainly to clear parasites. When coral reef with proper current was chosen, she swam down to the floor, lying still on the sand next to the coral reef, mouth opened, letting cleaner wrasse cope with parasites on the skin and around the gill area.
Cleaner Wrasse is in wrasse group. The well-known type is not more than 10 centimeters long. For Manta of several meters size, it would take them hours to clear away parasites. So, Manta has special Cleaner wrasse. This special cleaner wrasse is generally known as moonfish. They are in the large wrasse group. Normally, moonfish eat small creature in the coral reef. But when Manta comes in they would temporarily act as cleaner wrasse. With the length of almost 30 centimeters, largest fish among those with parasite devouring behavior, tens of moonfish around the coral reef spend less time in clearing away parasites on Manta ray.
Apart from entering coral reef area to be treated, there are times when Manta has medium size fish swimming around her to eat parasites. When the nurse cannot be found, Manta slides along the sand to clear parasites. Some time she might swim speedily and jump up above the water. Although parasite cannot be eliminated by this method, but it helps spinning off the Shark Sucker (Echeneis naucrates ) which has caused irritation. Yet, they will come back to make her jump for the second time.
Manta lives happily in the middle of the sea.
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