What are the aquatic adaptations of mammals?

What are the aquatic adaptations of mammals?

A few mammals that once lived on land have returned to the sea to continue their evolution. Some animals sought food, others fled from land enemies and some with their enormous bulk of weight were unable for swift land movement preferred swimming and modified their limbs into paddles and other aquatic adaptations during millions of years of evolution.

Of the warm-blooded animals that have returned to sea whales have successfully completed the evolutionary transition. Both sub orders of the Odontoceti that feed primarily upon fishes and Mystacoceti or Whalebone. Whales that feed by means of a peculiar brush like device of Whalebone, which strain out and shallow counter myriads of microscopic ocean animals and maintain a nutritious sea soup supply of unlimited quality. Together with Delphinus (the dolphin), Phocaena, Grampus, Orca (the killer), Monodon (waves) with a single senormous twisted tooth, Physeter (sperm whale) with teeth only in the lower jaw and Hyperodon (bootle nosed whale). Constitute the order cetacea, of infraclass Eutheria, in class-mammalia.

There are nine genera of fossil cetaceans and 27 genera of living ones, some of which are becoming scarce due to relentlessly man hunting. The animals of the order Cetaceans are to be found the largest animals that over lived. The animals are so well adapted to the realm of the sea that they had no need, as some other warm-blooded marine animals do, to go on land to bear, its young. They are remarkably stream-lined. They needs bones have become stabilizing fins and hind legs have completely disappeared. The only remains of external ear are openings on either side of the head just large enough to pass a pencil through. The nostrils have moved from the front to the very top of the head and have become either one or two blow holes which enable the whale to breath without raising itself more than a few inches above the surface of water. A thick layer of blubber conserves the body heat acts as thick blanket of heat retaining blubber under the skin enabling these gigantic animals to pursue their activities even in Arctic waters. It also improves streamlining and acts as a food reserve when the whale travels to warmer waters where its kind of food is not abundant. The largest ever caught female blue whale measured 113.5 feet long, weighted about 170 tons. Because the whale, fixed by the sea from force of gravity, its enormous size increases efficiency. Enormous size ultimately results in vastly greater volume enabling much space for muscles to generate swimming power required to over come the frictional force of water.

The female blue whale gives birth to a single calf every alternate year, their new born is the largest among all the terrestrial mammals example:- having 23 feet length at birth. For seven months the female blue whale supplies its baby with one ton of very rich milk per day. Studying wax plugs laid down in year by year layers inside whale’s ear membranes. The life of blue whale is estanited to 50 years.

Types of ecosystem of the world

In broad sense there are two major types of ecosystem namely terrestrial and aquatic. The terrestrial ecosystem is further divided into the following types of ecosystem-

1. Forest Ecosystem
2. Grassland Ecosystem
3. Desert Ecosystem.

Aquatic ecosystem is divided into two types of ecosystem-

1. Fresh water ecosystem
2. Marine or oceanic ecosystem.

The fresh water ecosystem is further divided into pond ecosystem, lake ecosystem, river ecosystem, and spring ecosystem.

Structure of Forest Ecosystem 

There are two main components an found in this ecosystems.

• (A) Abiotic Components – Forest ecosystem have the following abiotic components – soil, water, light etc.
• (B) Biotic components – Forest ecosystem consists of the following biotic components.

1. Producers – All the green plants of a forest ecosystem is producers. They are the main sources of food for forest animals. The plants of a top substratum are angiosperm our and gymnospermous plants. They utilize radiant energy in the greatest extent. Below the level of tress there is a layer of srube and below of its the grasses, hobs, lichens and mosses are found. These plants get least light.

2. Consumers – There are a number of consumers in an old dense forest. Consumers of the first order in the forest are grasshoppers, rabbit, deer, monkey, bird and many other wild herbivores, which utilize plants directly as their food. Secondary consumers are walves, phythons, jackal, etc. which consumes the flesh of herbivores, and lion, tiger, hawks are the consumers of the top level.

3. Decomposers and Transformers – They are microorganisms, chiefly bacteria and fungi, which attack dead bodies of producers and consumers and convert couples organic material into simpler materials. These free simpler materials again return to the abiotic components and are reutilized by producers in their nutrition.

Function of Forest Ecosystem

The components of an ecosystem are connected in a complex web. Function of forest ecosystem includes following cycles –

1. Energy Cycle: The sun starts the food pyramid by feeling the photosynthesis process. Trees and green plants begin all life processes with photosynthesis and the resulting production of plant biomass.

The sun’s energy constantly changes form as plants covert light into plant biomass, which is then consumed by other organisms. Plants perform an important action of energy fixation, which is the basis for all life.

2. Water Cycle: The water cycle collects, purifies, and distributes the world’s water. Without the water cycle, life on earth would be impossible. Trees and plants are part of this water cycle. Transpiration is the controlled evaporation process by which plants lose H2O through the pores in their leaf structures. A full grown tree can transpire hundreds of gallons of water a day during growing season.

3. Nutrient Cycle: Trees rely on nutrients like phosphorous and nitrogen for healthy growth and reproduction. Throughout a tree’s life stages, they constantly use and return nutrients to the soil. Nutrient cycles regularly transform nutrients from the non-living environment to the living environment and then back again.

IMPORTANT LINK

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• What is Competition Act, 2002?
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• What is Sustainable development?
• What is meant by competition Act, 2002 ? Provisions and Salient features of Competition Act, 2002
• Top 4 Components of Competition Act 2002
• Top 6 Limitations of Economic Growth

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