Archive for the 'Invertebrate Zoology' Category

Torsion in Gastropoda

One of the most significant modifications of the molluscan body form  in  the  gastropods  occurs  early  in  gastropod  development. Torsion is a 180°, counterclockwise twisting of the visceral mass, mantle, and mantle cavity. Torsion positions the gills, anus, and openings from the excretory and reproductive systems just behind the head and nerve cords, and twists [...]

Symbiotic relationship of protozoans

Many protozoa have symbiotic lifestyles. Symbiosis is an intimate association between two organisms. For many protozoa, these interactions involve a form of symbiosis called parasitism, in which one organism lives in or on a second organism, called a host. The host is harmed but usually survives, at least long enough for the parasite to complete [...]

How Entamoeba acts as harmful pathogen to human?

The infection of Entamoeba is more common in children and young adults. The trophozoites.by their amoeboid movement and also by the proteolytic enzyme, penetrate through the mucosa and burrow deeper and deeper by lysis of the tissue up to the submucous coat. They rapidly multiply here and cause destruction of the surrounding tissues. This results [...]

What are the harmful protozoa?

The protozoa are harmful in following ways : 1.         Pollution of water Drinking water in natural condition is made unpalatable by the reproduction of some free-living protozoa in it. For example, (Uroglenopsis brings fleshy odour like that of cod-liver oil. Peridinium emits smell resembling that of clam-shells. 2.         Destruction of animals of food value Bioluminescent [...]

What is economic importance of protozoa

The protozoa are acellular, microscopic organisms found everywhere, in water, soil, on the body of plants and animals. Although they are minute and apparently insignificant, but they are of considerable economic value to the mankind. The protozoa are useful in the following ways: 1.         Food Protozoa provide food for insect larvae, crustaceans and worms, which [...]