Friday, 27 June 2014

lampito mauritii is 8-21cm long and 3-4 mmwide
clitellum is present in 14-17 segments
dorsal pores commence from the 10th segment.through these segments the coelom communicates to exterior
three pairs of spermathecal openings are situated ventrolaterally b/w 6, 7 7,8 8,9
oviducal openings are pair on the ventral surfaces of the 14th segment
spermiducal opening 18th segment
nephridiopores in the14th segment
cuticle is secreted by epidermis
epidermis contain gland cells and receptor cells
muscles are of 2 types outer circular & inner longitudinal
when the circular muscles of the body contract body gets thin and elongates thereafter which results in forward movement
when the longitudinal muscles contract body becomes thick and shrinks
mouth occupies segment 1,2
pharynx occupies segment 3,4 and is surrounded by the pharyngeal glands
oesophagus lies in 5th segment
gizzard lies in 6th segment
intestine starts from 7th segment and upto 14segments it is narrow and the remaining part is sacculated
the dorsal wall of intestine is folded into th cavity as the typlosole
the dorsal longitudinal vessel runs above alimentary canal
while the ventral longitudinal vessel runs below the alimentary canal
dorsal b.v. has valves and is contractile in nature wherein blood flows forwards
the opposite is the case in ventral b.v.
in the anterior part of the body the dorsal vessel is connected with the ventral vessel by 8 commisural vessels or the lateral hearts lying in 6-13 segments. these vessels rum on the lateral sides of the body wall and
supply blood from dorsal b.v. to ventral b.v.
the dorsal vessel recieves blood from various organs and ventral vessel supplies blood to various organs
excretory system excretion in earthworm is through nephridia
a typical nephridia has an internal funnel like opening called nephrostome . it is fully ciliated.
nephridia terminates in nephridiopore
there are three types of nephridia found in megascolex
viz meganephridia , micronephridia , pharyngeal nephridia
besides nephridia there are specialised cells on the wall of intestine called chloragogen cells
they help nephridia in collection of excretory products
the brain in l.mauritii is formed of sopra pharyngeal ganglia and is bilobed , situated in the 3rd segment the ganglia found below the pharynx is sub pharyngeal ganglion ,both are connected through circum pharyngeal connectives they are situated laterally to pharynx
this leads in the formation of a nerve ring the double solid ventral nerve cord runs backward from the sub pharyngeal ganglion
in l.mauritii protandry is seen
male reproductive system
two pairs of testes and apair of vas deferense constitute male reproductive system
testes are found in 11-10 segmaents seminal vesicles are found besides testicular segments as lateral outgrowths
seminnal funnels are also present which are called as ciliary rosettes found beside testes
these ciliated funnels are connectec through vas deferens , the 2 vas differens run upto 18th segment where they open to the exterior through male genital opening
male genital apertures contain pineal setae , prostate glands in 18 & 19 segments prostate opens to the exterior through vas deferens...
the secretion of prostate help to arrange the sperms into bundles called spermatophores
female reproductive system
a pair of ovaries are seen in 13th segment. there are a pair of oviducts they open internally into the 13th segment and externally on the ventral surface of 14th segment
three pairs of spermathecae are present in 7,8,9 segments
after copulation the glandular cells of the clitellum secrete a thick fluid which hardens into a girdle surrounding the clitellum
which later seperates out from the body in the form of a cocoon
fertilization and development of the eggs into worms takes place within the cocoon
young worms come out of the cocoon after complete development

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