B.Sc I - Sem I_Parasitic Helminthes Zoology Practical.pptx

this is of parasitic

1. To study and sketch museum specimens and permanent slides of parasitic H elminths

2. Fasciola hepatica Fasciola hepatica is commonly known Sheep liver fluke and cosmopolitan in distribution in India, China, Cuba, Argentina, Russia and U.S.A. and found as an endoparasite in the bile ducts of liver of sheep and other herbivorous mammals. Body is leaf like, dark brown and dorso -ventrally flattened. Anterior end bears oral and ventral suckers which later forms adhesive organ or acetabulam . Animal is hermaphrodite both male and female reproductive organs are present. Life cycle digenetic i.e. it is completed into two hosts sheep and man with an intermediate host snail ( Limnea truncatula ) completed through several larval stages. It is causative agent of a disease known as Liver rot .

3. Taenia solium Taenia solium is cosmopolitan in distribution, commonly called as Pork Tapeworm . The entire body of Taenia solium looks like a snake, about 4 to 6 meters in length and found as endoparasite in Man’s intestine. Body consists of Scolex or head with rostellum , neck and strobila or body segments. Scolex is the organ of attachment. It has 4 suckers and a rounded rostellum which contains double row of 28 to 32 hooks. Neck is long and unsegmented said to be an area of proliferation. Strobila consists of large number of segments about 800 to 1000. Each segment is known as proglottid .

4. Mature proglottid contains well developed hermaphrodite genital organs. Gravid proglottid contains branched uterus filled with onchospheres . Life cycle includes two hosts ( i ) Man as definitive host (ii) Pig as intermediate host. When Pig eats contaminated human faeces containing onchophores and becomes infected. Onchophores or hexacanth larvae develop into Cysticercous larvae or bladder worm which encyst in thigh, chest, shoulder muscles of the pig, such muscles is called as Measly pork. When measly pork is eaten by any man it leads to infection and development of adult Taenia solium in the intestine of the man. The disease caused is called as Taeniasis .

5. Cysticercus larva (Bladder worm) Bladder worm or Cysticercus larva of Taenia solium develops in the muscles of pig, the intermediate host. It is the infective stage of Taenia solium . The onchosphere first reaches the stomach of pig with faeces of Man. When onchosphere develops into encysted cysticercus larva seen as white spots between muscle fibers contaminated part of pig muscle is called as measly pork. Encysted larva consists of a sac or bladder- like structure, having invaginated proscolex measuring 6 to 18 mm in length. Proscolex contains suckers and hooks. Cysticercus larvae can be obtained after removing the cyst wall. If the larvae are kept in normal saline solution the scolex is eavaginated in 5 to 10 minutes .

6. Male and Female Round worm ( Ascaris lumbricoides ) Ascaris lumbricoides is found in the intestine of man and the pig. They are cosmopolitan in distribution generally in India, China, Philippines, Korea and Pacific Islands. The Ascaris is commonly known as Round worm. It causes ascariasis in man especially in children, infection occurs by eating raw and uncooked vegetables. Its body is elongated, cylindrical, pointed at both ends. The surface of the body is marked with four longitudinal lines. These are known as mid-dorsal, mid-ventral and two lateral lines. Mouth is situated at the anterior extremity which is guarded by one dorsal and two sub ventral lips.

7. 6. Excretory pore is small and lies on the ventral side about 2 mm away from the anterior end. 7. Ascaris shows well developed sexual diamorphism i.e. male is small and female is large. 8. Male is about 15 to 31 cm in length with posterior end curved. 9. Female is larger than male about 20 to 35 cm with posterior end straight and blunt. 10. Female genital aperture lies about one-third of the length of the body from the anterior end .

8. Redia larva Redia larva is the third larva of Fasciola hepatica , found in digestive glands of host. The unique feature of the larva is that, it develops from the germ balls present in sporocyst . Germ balls multiply and give rise to redia larva, it is elongated and sac like larva 1.3 to 1.6 mm in length. It anterior end bears the mouth leading into muscular pharynx, which finally leads into sac like intestine as well as there is a muscular ring like swelling called as collar just beneath the collar is birth pore. Posterior region is also provided with two stumpy processes knwon as lappets helpful in locomation . Flame cells increase in number and a number of twigs are formed and two excretory pore. Germ balls occupying major portion of the body, they differentiate into next larval stage called as Cercaria larva.

9. Cercaria larva Cercaria larva is the fourth larva of fasciola hepatica, it is a free swimming larva comes out from birth pore or bursting of body of redia at 9 to 26 °C. Body is covered by cuticle and body wall consists of cuticle, muscles and mesenchyme and it has higher grade of organization and considerably resemble the young fluke. Body is oval in shape with long simple tail, measuring 0.25 to 0.35 mm in length with a tail. It has two suckers, an anterior oral sucker surrounding the mouth and a ventral sucker situated in the middle of the body. Beneath the muscles layer and numerous unicellular cystogenous glands, which will form cyst wall of larva. Digestive system consists of mouth, oral sucker, pharynx, oesophagus and forked intestine and an acetabulum in the middle. Flame cells still increases in number with nephridial tubes unite to form excretory vesicle opens in nephridiopore . Cercaria larva after brief free life undergoes encycstment on water plants, the tail and cuticular spines are shed, cycstogenous gland from cyst and disappear and converted into metacercaria larva.

10. Taenia solium ( Scolex ) Classification – Phylum : Platyhelminthes Class : Cestoda Order : Taeniodea Genus : Taenia Species : solium Scolex of Taenia solium is th cephalic portion of the body it is knob like or just like an alpin head like measuring about 1 mm in diameter. It is the organ of attachment and also contains the brain and cephalic canals. In addition to suckers scolex contains rostellum which is pigmented and provided with double row of hooks. It is roughly quaderate in structure and has two distinct parts the proximal and distal. The proximal head bears 4 suckers which are adhesive. The distal part have small rostellum with smaller hooks 110 to 140 microns and longer hooks 160 to 180 microns respectively. The hooks are used as attachment organ of Taenia solium .

11. Taenia solium (Mature proglotid ) Mature proglottid or segment of taenia solium is square like, hermaphrodite with a single set of reproductive organs. Each mature proglottid or segment of Taenia solium is square like in shape. Each mature proglottid has complete set of male and female reproductive organs. Male reproductive consist of follicular testes, vas eference vas deference and cirrus or pennis . Testes are numerous spherical bodies distributed throughout the proglottid . Female reproductive system consist of ovarian lobes connected by Isthmus, oviduct, ootype , compact vitellaria and Mehil’s gland. Vagina carries the sperms.It starts from genital atrium and opens into ootype . It swells to from ootype and extend upword . Uterus arises from ootype and extend upwords .

12. Thank you