Department of Zoology at ANDC/Zoology Museum/Museum specimens/Platyhelminthes

Phylum Platyhelminthes Date & Time : 22, November 2024 09:55 General Characteristics of Platyhelminthes Classification of Platyhelminthes A Few Examples 1.Planaria dorotocephala Common name- Dugesia Habitat- freshwater species, found in ponds, lakes and springs. Distribution- Cosmopolitan in distribution, found in India, Myanmar, U.K., U.S.A., and USSR. IDENTIFYING CHARACTERS:-- Body- Body is elongated, cylindrical and dorsoflattened. Body length- 2-15 mm. Body color- brown to black. Body division- It is divided into anterior head and posterior body. Head- It is triangular containing auricles (ear like) and eyes or ocelli (semicircular, one pair). Auricles and eyes both are sensory structures. Posterior body- it conmtains highly pointed end. Digestive system- complete, consisting of mouth, pharynx, proboscis and intestine (branched). Mouth- The mouth is situated in middle of the ventral surfaceand is surrounded by proboscis pore. Intestine- It has three branches in which one is extending upwards and other two are extending backwards. Genital pore- It is located posterior to the mouth. Reproduction- It reproduces sexually or asexually. Regeneration also occurs. 2. Taenia solium Common Name- Pork tapeworm. Habit and habitat- It is the parasite in the intestine of man. Distribution- it is found in India, China, Yogoslavia, and Germany. IDENTIFYING CHARACTERS:- Body- Body is about 4-5 meters in length. Segmentation- it consists of about 700-900 segments. Body division- It is differentiated intoscolex, neck and thenimmature, mature, gravid and malformed segments. Mature segments- They contain fully developed hermaphrodite genital organs. Scolex- It is adhesive in nature, consisting of four suckers and a rounded rostellum( surrounded by a double row of 28-32 hooks). Life cycle- Life cycle of T. solium isindirect. It requires an intermediate host pig for development. Diseases- It causes diseases like anaemia, secondary anaemia, eosinophilia, diarrhea, haemorrhage,abdominal pain and nausea etc. 3.Taenia saginata Common name- Beef tapeworm. Habit and habitat- It found in the posterior coils of the intestine. Distribution- It found in India, China and Germany. IDENTIFYING CHARACTERS;- Body- it is about 4-6 meters in length. Body color- whittish in color ( preserved). Body segments- Body is divided into about 1000 segments. Types of segments- There are four types of segments:-immature, mature, gravid and malformed segments. Body division- Body is divided into scolex, neck and strobila (segments). Scolex- It contain 4 suckers. But rostellum and hooks are absent. Life cycle- Life cycle is indirect. Buffalo is intermediate host. Diseases- It causes diarrhoea, nausea and insomnia and abdominal pain etc. 4.Fasciola hepatica Common name- Sheep liver fluke. Habit and habitat- It is a pathogenic parasite in the liver and bilary passage. Distribution- Cosmopolitan distribution. It found in sheep raising areas like India, U.S.A., Cuba and Syria etc. IDENTIFYING CHARACTERS:- Body- It has beef like and dorso-ventrally flattened body. Body length- 18-50 mm in length. Mouth- Mouth is small and ventrally situated at anterior extremity. Suckers- There are two types of suckers naming oral and ventral sucker. Oral sucker- It surrounds the mouth and located at the anterior extremity. Ventral sucker- It is also called acetabulum ( adhesive in nature) and is located a little behind to the mouth. Pores- gonopore and excretory pore.               (1)Gonopore is locatedbetween oral and ventral suckers              (2)Excretory pore is located at posterior extremity Cephalic cone- Anterior end consists of a conical projection. This is called cephalic cone. Hermaphrodite. Digestive system- It consists of mouth, oral sucker, pharynx, oesophagus and bifid intestine. Life cycle- Indirect and is completed in two hosts sheep and snail. 5.Catenula IDENTIFYING CHARACTERS:- Digestive tract- consist of simple pharynx. Excretory system- consist of single protonephredia (median). Nervous system- 4 pairs of longitudinal nerve cords and a statocyst. Reproduction- asexual by transverse fission. Habitat- freshwater. 6.Convoluta Habitat- exclusively marine form, lives under stones among algae. IDENTIFYING CHARACTERS- Body is small and ventrally curved. Anterior end contain frontal glands (many in number), eyes (one pair),  a single statocyst and mouth (ventrally situated). intestines are absent. excretory system is absent. 7.Schistosoma