Habit habitat and Economic importance of Arthropods.

Habit and habitat e of Arthropods

The arthropods are seen from 30,000 feet below to 20,000 feet above the sea level. This animal is bilaterally symmetrical,jointed legs, invertebrates may be marine, freshwater, terrestrial, subterranean, and aerial. Some arthropods like barnacles are sedentary.Innumerable crustaceans which live as planktons move passively in the current of water. But well-developed structures are present in many arthropods for moving effectively by swimming, crawling and flying. Some arthropods live within burrows, some are efficient diggers and many other build well-designed nests. Certain Arthropods like honeybees, ants, and termites are polymorphic and lead a complicated social life.All the food habits-herbivorous, carnivorous, and omnivorous are seen among arthropods and various food-getting are made within this group.

Some of the criteria for their success are

-1. Large number and variety of species, 2. A variety of habitats occupied 3. Widespread distribution,4. A variety of food habit, 5. The capability of defending against enemies, 6. The power of adapt themselves to changing conditions etc. Large numbers of Arthropods live as parasites, and structural changing occurs in them to adjust with the peculiar mode of life.Many Arthropods are well-known for their habit of migration. Some of them can produce sound and nearly all are equipped with efficient sense organs.Some forms exhibit a phenomenon-suspended animation, to overcome the unfavourable condition.Sexual reproduction is often accompanied by courtship dances.The members may either be oviparous or viviparous or ovoviviparous and some forms exhibit parental care. Parthenogenesis is quite common in Arthropods.

2. A variety of habitats occupied 3. Widespread distribution,4. A variety of food habit, 5. The capability of defending against enemies, 6. The power of adapt themselves to changing conditions etc. Large numbers of Arthropods live as parasites, and structural changing occurs in them to adjust with the peculiar mode of life.Many Arthropods are well-known for their habit of migration. Some of them can produce sound and nearly all are equipped with efficient sense organs.Some forms exhibit a phenomenon-suspended animation, to overcome the unfavourable condition.Sexual reproduction is often accompanied by courtship dances.The members may either be oviparous or viviparous or ovoviviparous and some forms exhibit parental care. Parthenogenesis is quite common in Arthropods.

Some structural and physiological patterns which have contributed to their big biological success are-1

1. The thick chitinous exoskeleton,

2. Jointedness of body and limbs.

3., Locomotion by small, striated, extrinsic muscle,

4. Various specialisations of somites, alimentary canal, and respiratory organ,

5. Cephalization with concentration of ganglia and sense organs in head, region,

6. Behaviour patterns ith primitive intelligence and social instinct in some group.

Economic Importance of Arthropods.

The economic importance of Arthropods is as described below.

A. Merostomata.

The American species (Limulas Polyphemus) is sometimes fed to chicken and pigs. The female are preferred on account of their eggs of which half-a-pint may be crowded into a cephalic shield. There is a belief that this diet makes the poultry lay mare eggs. Asian species of horseshoe crabs are consumed by human beings.

B. Arachnida.

Scorpion has belonged to an arachnid. In the trophic country, it enters the house and becomes a nuisance . Its bite can be very painful, sometimes results in death. But scorpion is beneficial to some extend, as they feed on unwanted insects like the cockroach, beetles etc.The venom of scorpion is used for biochemical, pharmacological, and immunological researchers. Certain mites cause damage to crops, fruits like apple, pear, and grapes.vegetable, etc.blister mice. Ticks suck the blood of man and domestic animals. They also act as a vector of protozoa causing Texas fever in cattle and tick fever in man.

C.Crustacea.

They are of importance economic significance to man. The group is a great valve for its health and economic progress.

1. As food.

Crustaceans like lobsters, prawn, crabs, and crayfishes etc are consumed by man. They form an important diet of a man with great nutritive value. They form an important diet of a man with nutritive value. Most edible portions are their tails almost all of which are composed of muscles. In mud crabs, the claws are the best part of the animal to eat. Smaller species of crustacean form the bulk of zooplankton which plays a vital role in food chains of both salt and freshwater fishes and other aquatic animals that eventually come to our table. Whales which are hunted by man for their various economic products depend on crustaceans for their food. Aquarium dealers collect the adults and eggs of Artemia and Daphnia and shell them as fish food.

2. As fish bait.

In most part of the America, the crayfishes, especially the soft shelled individuals are quite popular among fisherman as a fish bait. Soft shelled individuals are kept soft for a week or so on ice since refrigerator slows metabolism so that the shell develops slowly.

3. As scavengers.

Some crustacean such as crayfish, beneficial as they serve as an agency in the destruction of decaying vegetables and animal bodies in the water.

4. As intermediate host.

Although some crustaceans are parasites of aquatic animals, none is a parasite of man or other land animals. However, a handful of them serves as intermediate hosts to certain dangerous worm parasites of man and other vertebrates. Dreaded, human long-fluke, paragonimus westermani, used a crayfish for this purpose.Cyclops also serve as intermediate hosts for human guinea worm and for the great tapeworm.

5. As pests.

Certain crustaceans may become a serious pest when present in large number. Thus, crayfishes damage cultivated crops by eating young corn and cotton plants.Sow bugs and pill bugs, which also feed on vegetation, may turn pest in greenhouse and fields when sufficiently numerous. Some crustaceans bore into marine timber structures and destroys them causing loss of several crores of rupees.

D. Diplopoda.

Millipede may be useful as they are scavengers and can dispose of the dead organic matter. They cause damage to plants as they feed also on plants roots and destroy the greenhouses and gardens.

E. Chilopoda.

They are beneficial to man as well as they are feed on insects some of which may be injurious also.They are also reported to feed on snakes too. Some species are harmless to man, but some longer tropical ones infect a painful bite and cause fever, dizziness and headache.

F. Insecta.

Insecta is very well known for their economical value. A detailed study of their economic importance has been dealt separately.

Onychophora.

It forms a taxonomically important group as it forms a link between Annelida and Arthropoda. They are otherwise of no economic valve.

Reference.

Agrawal Sarita. A Text Book of Biology, New Delhi.: Madhuban Educational Books, 2011.

Bhamrah, H.S., and Kavita, Juneja. A Text Book of Invertebrates, New Delhi: Anmol Publications Pvt Ltd, 2011.

Jordan E.L. and P. S., Verma. Invertebrate Zoology, New Delhi,: S. Chand and Company Pvt. Ltd., 2011.

Kotpal, R. L.. Modern Text Book of Zoology: Invertebrates, New Delhi, India: Rastogi Publications,2011.