CLASSIFICATION OF EARTHWORM (LUMBRICUS TERRESTRIS)

 CLASSIFICATION OF EARTHWORM (LUMBRICUS TERRESTRIS)

Earthworm is a tube-shaped, segmented worm found in the phylum annelida. They are common found living in soil, feeding on live and dead organic matter.

SCIENTIFIC CLASSIFICATION

Kingdom – Animalia

Phylum – Annelida

Class – Oligochaeta

Sub-class – Haplotaxida

Order – Megadrilacea

Sub-order – Lumbricina + maniligastrida

Family – Lumbricidae

Species – Lumbricina

Earthworm is a tube-shaped, segmented worm found in the phylum annelida. They are common found living in soil, feeding on live and dead organic matter. Its digestive system runs respiration through its skin. An earthworm has a double transport system composed of coelomic fluid that moves within the fluid-filled coelom and a simple closed blood circulatory system. They have a central and a peripheral nervous system. The central nervous consist of two ganglia above the mouth, one on either side, connected to a nervous cord running back along its length to motor nervous and sensory cells in each segment. Large numbers of chemoreceptors are concentrated near it mouth circumferential and longitudinal muscles on the periphery of each segment enable the worm to move.

Similar sets of muscles line the gut, and their actions move the digesting food toward the worm anus (Hickman et al;1984)

Earthworms are hermaphrodites each individual carried both male and female sex organs. They lack either an internal skeleton or exoskeleton but maintain their structure with fluid filled coelem chambers that function as a hydrostatic skeleton. Earthworm is the common name for the largest number of oligochaeta (which is either a class or a sub-class depending on the author). In classical system, they were placed in the order opisthopora, on the basis of the male pores opening posterior to the female pores trough the internal male segments are anterior to the female. Theoretical cladistics studies have places them, instead in the suborder lumbricina of the order Haplotaxida, but this may again soon change folk names for the earthworm include “dew-worm”, “rain-worm”, “night crawler”, and angle worm (due to its use as fishing balt). Larger terrestrial earthworms are also called magadriles (or big worms) as opposed to the microdiles (or small worms) in the semi aquatic familiesTubificidae, bumbriculidae, and enchytracidae among others. The magadriles are characterized by having a distinct clitellum (which is more extensive than that of microdriles) and a vascular system with true capillaries.

Earthworms are farless abundant indisturbed environment and are typically active only if water is present (Bandy et al ; 2009).earthworms do not called “light cells of Hess. Those photo receptor cells have a central intracellular cavity (Phoasome) filled with microvilli. As well as the microvilli, these are several sensory cilia in the phaosome which are structurally independent of the microvilli (Rohlich, 1970) the photoreceptors are distributed in most parts of the epidermis but are more concentrated on the back and sides of the worm. A relatively small number occur on the ventral surface of the first segment. They are most numerous in the prostomium and reduce in density in the first three segments; they are very few in number past the third segment.