PHYLUM ECHINODERMATA

PHYLUM ECHINODERMATA

Echinodermata is a phylum of about 7000 living species distributed among five classes. It is any member of the phylum Echinodermata which comes from the Ancient Greek  ‘hedgehog’, and ‘skin’ of marine animals. Echinoderms are found on the sea bed at every ocean depth, from the intertidal zone to the abyssal zone. The phylum Echinodermata is the second-largest grouping of deuterostomes (a superphylum), after the chordates (which include the vertebrates, such as birds, fishes, mammals, and reptiles). Echinoderms are the largest phylum that has no freshwater or terrestrial members. The echinoderms are important both ecologically and geologically.

Echinoderms are important both ecologically and geologically. Ecologically, there are few other groupings so abundant in the biotic desert of the deep sea, as well as shallower oceans. Most echinoderms are able to reproduce asexually and regenerate tissue, organs, and limbs; in some cases, they can undergo complete regeneration from a single limb. Geologically, the value of echinoderms is in their ossified skeletons, which are major contributors to many limestone formations, and can provide valuable clues as to the geological environment. An interesting feature of the phylum Echinodermata is that all the organisms belonging to this phylum are marine.Till date, there have been no traces of any terrestrial or freshwater Echinoderms.These are multicellular organisms with well-developed organ systems. All the animals belonging to this phylum share the same characteristics features. They are colourful organisms with unique shapes.

The Echinoderms are found in sea-depths as well as in the intertidal zones. An interesting feature of the phylum Echinodermata is that all the organisms belonging to this phylum are marine. None of the organisms is freshwater or marine.The water vascular system present in echinoderms accounts for gaseous exchange, circulation of nutrients and waste elimination.

Echinoderms primarily use their tube feet to move about, though some sea urchins also use their spines. The tube feet typically have a tip shaped like a suction pad in which a vacuum can be created by contraction of muscles. This along with some stickiness provided by the secretion of mucus provides adhesion. Waves of tube feet contractions and relaxations move along the adherent surface and the animal moves slowly along.

The development of an echinoderm begins with a bilaterally symmetrical embryo, with a coeloblastula developing first. Gastrulation marks the opening of the “second mouth” that places echinoderms within the deuterostomes, and the mesoderm, which will host the skeleton, migrates inwards. The secondary body cavity, the coelom, forms by the partitioning of three body cavities. The larvae are mostly planktonic but in some species the eggs are retained inside the female and in some the female broods the larvae.

Echinoderms are globally distributed in almost all depths, latitudes and environments in the ocean. They reach highest diversity in reef environments but are also widespread on shallow shores, around the poles – refugia where crinoids are at their most abundant – and throughout the deep ocean, where bottom-dwelling and burrowing sea cucumbers are common – sometimes accounting for up to 90% of organisms. While almost all echinoderms are benthic – that is, they live on the sea floor – some sea-lilies can swim at great velocity for brief periods of time, and a few deep-sea sea cucumbers are fully floating.

CLASSIFICATION OF PHYLUM ECHINODERMATA

The phylum echinoderms is divided into five extant classes: Asteroidea (sea stars), Ophiuroidea (brittle stars), Echinoidea (sea urchins and sand dollars), Crinoidea (sea lilies or feather stars), and Holothuroidea (sea cucumbers).

CHARACTERISTICS OF PHYLUM ECHINODERMATA

1. They have a star-like appearance and are spherical or elongated.
2. They are exclusively marine animals.
3. The organisms are spiny-skinned.
4. They exhibit organ system level of organization. Most members have a circulatory system as well as a digestive system.
5. They are triploblastic and have a coelomic cavity.
6. The skeleton is made up of calcium carbonate.
7. They have an open circulatory system.
8. They respire through gills or cloacal respiratory tree.
9. They have a simple radial nervous system and the excretory system are absent.
10. The body is unsegmented with no distinct head. The mouth is present on the ventral side while the anus is on the dorsal side.

Economic importance of preservation

Microorganism  are economically important as these microorganisms are used by humans for many purposes. The beneficial uses of microorganism include the production of traditional foods such as fudge, yogurt, cheese, and vinegar. Microbes are also important in agriculture for the compost and fertilizer production.

Preservation has a positive economic impact on the communities that envision the potential benefits of thoughtful planning.

Preservation of open space, trails, parks and greenways creates jobs, enhances property values, expands local businesses, attracts new or relocating businesses, increases local tax revenues, decreases local government expenditures through the natural provision of ecosystem services, decreases the cost of recreation and promotes a sense of local community.

The following are economic importance of preserving microorganism:

1. Food processing: Sourdough bread is made to rise by fermentation, with a leaven that consists of microorganism, often combined with wild yeast enzymes.^[1] The milk-souring microorganisml genus Lactobacillus is used to make yogurt and cheese. Microorganism are also used to form organic acids in pickles and vinegar.
2. Biotechnology: Biotechnology involves the use of microorganisms including microorganism in the manufacturing and services industries. These include chemical manufacturing such as ethanol, acetone, organic acid, enzymes, and perfumes. Microorganism are important in the production of many dietary supplements and pharmaceuticals. For example, Escherichia coli is used for commercial preparation of riboflavin and vitamin K.^[3] E. coli is also used to produce D-amino acids such as D-p-hydroxyphenylglycine, an important intermediate for synthesis of the antibiotic amoxicillin.
3. Genetic engineering: Genetic engineering is the manipulation of gene. It is also called recombinant DNA technology. In genetic engineering, pieces of DNA (genes) are introduced into a host by a variety of techniques, one of the earliest being the use of a virus vector. The foreign DNA becomes a permanent feature of the host, and is replicated and passed on to daughter cells along with the rest of its DNA.^[5] Microorganisml cells are transformed and used in production of commercially important products. Examples include production of human insulin (used to treat diabetes)^[6] and human growth hormone (somatotrophin used to treat pituitary dwarfism).
4. Pest control: Microorganism can also be used in the place of pesticides in biological pest control. This commonly uses Bacillus thuringiensis (BT), a Gram-positive, soil-dwelling bacterium. This bacterium is used as a Lepidopteran-specific insecticide under trade names such as Dipel and Thuricide. Because of their specificity, these pesticides are regarded as environmentally friendly, with little effect on humans, wildlife, pollinators, or other beneficial insects.
5. Tanning Of Leather: Microorganism helps purify animal hides to make them easy, clean, and fit to use.

6.      Medicines: Microorganism are used to create multiple antibiotics such as Streptomycin from the microorganism streptococcus. Microorganism can also be used to create vaccines to prevent several diseases.

REFERENCES

1. Gadsby, P; Weeks, E. “The Biology of… Sourdough”. Discover. Discover Magazine. Retrieved September 16, 2019.
2. McGee, H (2004). On Food and Cooking: The Science and Lore of the Kitchen. New York: Scribner, pp. 291–296. ISBN 0-684-80001-2.
3. Healthwise, Incorporated (2010-06-28). “Throat Culture”. WebMD. Archived from the original on 2013-03-17. Retrieved 2013-03-10.
4. Old, D.C.; Duguid, J.P. (1970). “Selective Outgrowth of Fimbriate Bacteria in Static Liquid Medium”. Journal of Bacteriology. American Madigan, Michael T. (2012). Brock biology of microorganisms (13th ed.). San Francisco: Benjamin Cummings. ISBN 9780321649638.
5. Stöhr, Sabine (2014). “Echinodermata”. WoRMS. World Register of Marine Species. Retrieved 23 February 2014.Richard Fox. “Asterias forbesi”. Invertebrate Anatomy OnLine. Lander University. Retrieved 19 May 2012.