Earth worm presentation
EARTH WORM
EARTH WORM
EARTH WORM
Phylum: AnnelidaClass: OligochaetaGenus: MegascolexSpecies: mauritii
HABIT
NEGATIVELY PHOTOTACTICNOCTURNALLOCOMOTIONBURROWINGFEEDINGBREEDINGREGENERATION
Earthworms are terrestrial animals inhabiting the moist soil. They are usually found in the upper layer of soil to a depth of 30-40cm. They are nocturnal and in day time they live in the burrows.During rainy season they come out and crawl on the ground. During winter they close the burrows by leaves and debris. This is to warm the burrows. Their presence is marked by the occurrence of worm cast, the faecal deposit of earthworm. There are about 500 species of earthworm. Of which 13 are found in India. Common varieties are Pheretima and Lumbricus
EXTERNAL MORPHOLOGY
A fully grown earthworm measures about 150mm in length and 3-5mm width The body is cylindrical and elongated. The anterior end is pointed , while the posterior end is rounded.
EARTHWORM
Body SegmentsProstomiumPeristomium
14-16 segments: Clitellum Glandular tissue coveringMetameres 100-120Dorsal side- dark mid dorsal lineVentral side- genital openingsAnt. End- Mouth, Prostomium, Peristomium
Body apertures
Spermathecal PoresFemale genital PoresMale genital poresNephridioporesDorsal pores Anus
INTERNAL MORPHOLOGY
Cuticle, Epidermis, Two muscle layers, Coelomic Epithelium
The body wall is covered externally by a thin non-cellular cuticle. It is followed by two muscle layers and an inner most coelomic epithelium.The epidermis consists of single layer of columnar cells.Secretory gland cells are also found among the columnar cells
T.S. of bodywall showing Setae
All segments except first and last bear a ring of microscopic S-shaped chitinous setae ,help in locomotion.by gripping on the soil
Digestive system
It is a straight tube and runs from the first to the last segments. It consists of mouth(peristomium),buccal cavity , pharynx, oesophagus,a muscular gizzard, stomach, intestine and anus
Circulatory system
In earthworm ,the circulation is closed type.The circulatory system consists of heart, blood vessels, capillaries and blood glands
Excretory system
Segmentally arranged nephridia are the excretory organs.There are three types of nephridiaseptal,integumentary and pharyngeal.
NERVOUS SYSTEM
The nervous system consists of segmentally arranged ganglia and a ventral nerve cord. A ganglion is a mass of nerve cells.
Nerve ringVentral Nerve cordSense Organs
Reproductive system
Earthworm is hermaphrodite or bisexual.
Male reproductive organsTestisSeminal vesiclesSeminal funnelsVasa differentiaProstate glands
Female reproductive system
OvariesOviducal funnelsOviductsSpermatheca
INTERACTION WITH MANKIND
WORM CASTVERMI COMPOSTINGFOODMEDICINE