Hirudinaria - ppt -indian cattle leech,,

Hirudinaria, commonly known as the Indian cattle leech, is a species of freshwater, blood-sucking leech belonging to the phylum Annelida and class Hirudinea. Found predominantly in South and Southeast Asia, these leeches are known for their hematophagous feeding habits, typically attaching to cattle or other large mammals.

Key Features: locomotion ,feeding ,physiology

1. Hirudinaria (leech)

2. Hirudinaria (Indian Cattle Leech) Hirudinaria is a species of leech commonly found in freshwater bodies in India and neighboring regions. It is known for its blood-sucking habit and is used in traditional medicine, including leech therapy. Below is a comprehensive guide on the morphology and physiology of Hirudinaria . Systematic position Phylum : Annelida Class : Hirudinea Order : Gnathobdellida Family : Hirudinidae Genus : Hirudinaria Species : Hirudinaria granulosa

3. MORPHOLOGY OF HIRUDINARIA External Structure Shape and Size : The body is elongated, dorsoventrally flattened, and segmented, ranging from 10-15 cm in length Body Segments : Though externally it looks like it has 33 segments, each segment is further subdivided into smaller annuli (rings), giving the appearance of more segments . Coloration : Typically dark olive green with orange-yellow stripes on the dorsum. The ventral surface is lighter. Anterior End : The mouth is located in the anterior sucker, which is used for attachment and feeding. Posterior End : The posterior sucker is larger and used for locomotion and attachment. Suckers : The leech has two suckers — an anterior sucker (smaller) and a posterior sucker (larger). These help in attachment to the host.

4. 2. Body Wall The body wall is muscular and consists of the following layers: Cuticle : A thin protective outer covering. Epidermis : Contains mucus glands, aiding in movement and protection. Musculature : The body has three main muscle layers: circular muscles, longitudinal muscles, and oblique muscles that help in movement. 3. Locomotion The leech moves using a "looping" or "inchworm" motion, with the anterior sucker attaching first, followed by the contraction of the muscles to bring the body forward, and then the posterior sucker attaching.

5. PHYSIOLOGY of Hirudinaria Digestive System Mouth : Located in the anterior sucker. Leeches have three jaws with tiny teeth for cutting into the host’s skin. Pharynx : A muscular pharynx helps suck blood from the host. Crop : The crop is a highly distensible region where blood is stored. It has lateral pouches or caeca to store large amounts of blood. Intestine : Following the crop, the undigested food moves into the intestine for nutrient absorption. Anus : Waste is expelled through the anus located near the posterior sucker.

6. 2. Feeding Hirudinaria is sanguivorous (feeds on blood). It secretes an anticoagulant enzyme called hirudin , which prevents blood clotting, allowing it to feed for long periods. It can store large amounts of blood in its crop and may not feed for several months. 3. Respiratory System Leeches lack specialized respiratory organs. Respiration occurs through the skin, where gases are exchanged between the environment and body fluids by diffusion. 4. Circulatory System Hirudinaria has a closed circulatory system. Hemolymph : The fluid in the body cavity acts as blood and transports nutrients and gases. Dorsal and Ventral Blood Vessels : The dorsal vessel pumps blood toward the anterior, while the ventral vessel circulates it toward the posterior .

7. 5. Nervous System The nervous system consists of a central nerve cord with segmental ganglia (nerve clusters). Ganglia : There are 21 pairs of ganglia in the ventral nerve cord, which control movement and sensory functions. Sensory Organs : Leeches have simple eyes (ocelli) that detect light intensity. They are also sensitive to vibrations and chemical changes in the environment. 6. Excretory System Nephridia : The excretory organs are nephridia, which are segmentally arranged. They collect waste from the body fluids and excrete it through pores. Excretory Pores : These open externally on the ventral surface.

8. 7. Reproductive System Hirudinaria is hermaphroditic , meaning it has both male and female reproductive organs. Male System : Testes produce sperm, which is stored in seminal vesicles and transferred to another leech through the penis. Female System : Ovaries produce eggs. Sperm from another leech fertilizes the eggs internally. Copulation : Occurs by direct transfer of sperm from one leech to another through copulation. Cocoon Formation : After fertilization, the leech secretes a cocoon where eggs are deposited. The cocoon is left in damp soil or water, and the young hatch after a few weeks .

9. 8. Sensory and Behavioral Adaptations Hirudinaria responds to mechanical stimuli (touch) and chemical cues (blood detection). It is sensitive to changes in the water current and temperature, helping it find hosts.

10. Economic and Medical Importance Leech Therapy : Medicinal leeches have been used in traditional and modern medicine for treating blood-clotting disorders, skin grafts, and even varicose veins. Their anticoagulant properties make them valuable for promoting blood flow in microsurgery. Agricultural Pest : In some regions, leeches can be a problem for livestock as they attach to animals and suck their blood, leading to reduced productivity.

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