To study rectal parasites in cockroach || Class Mastigophora || TrichonymphaI || Class Ciliata || NyctotherusI || Class Rhizopoda || Entameoba histolytica

Aim: To study rectal parasites in cockroach.

Requirements:

1. Biological- Cockroach

2. Insect saline, slide, coverslip, dissection box, Microscope

Procedure:

1. Prepare a cockroach for dissection.

2. Fix the cockroach to wax tray with the help of pins. 

3. Open the animal from its dorsal side so as to expose its alimentary canal.

4. Separate the intestinal portion and clean it in insect saline.

5. Gently press the separated intestinal portion and collect its content into the watch glass.

6. Take a drop of this gut content on clean slide and observe under microscope for presence of rectal.

Observations:

Following are the rectal parasites found:

I. Class Mastigophora: 

a. Trichonympha:

1. Measures about 30-50µ in length.

2. Body is divided in to anterior rostrum, intermediate and posterior region.

3. Rostrum is tapering, flagellated bearing apical cap.

4. Base of the rostral cap bears the hemispherical blespharoplasts.

5. Intermediate region is bell shaped and bears flagella.

6. Posterior region is round and non flagellated.

7. Single nucleus at the middle is present.

II. Class Ciliata:

b. Nyctotherus:

1. Body is kidney shaped or been like dorsoventrally compressed and is covered with cilia.

2. Protoplasm contains one macronucleus and one micronucleus, two contractile vacuole and many food vacuoles.

3. Peristome leads into curved cytopharynx which ends in the cytoplasm.

4. Permanent cytopgye is present.

I. Class Rhizopoda

a. Entameoba histolytica:

1. It is oval in shape and measures from 0.05-0.06mm in diameter.

2. Protoplasm contains single nucleus  and many food vacuole

3. Contractile vacuoles are absent.