What is the need for parasites to develop special adarptations ? Mention some special adaptations developed by the parasites.

Explanation

Parasites have to evolve mechanisms to counteract and neutralize the host.s defence in order to be successful with in the host. For this purpose, the parasites have developed many special.adaptations such as the loss of unnecessary sensory organs, formation of organs for adhesion, high reproductive capacity, etc.
Parasitic adaptations : Parasites have evolved special adaptations to meet the requirements and lead successful life in the hosts.
i) In order to live in the host some parasites have developed structures like hooks, suckers, rostellum etc., for anchoring. e.g : Taenia solium.
ii) Some intestinal parasites have developed protective cuticle to with stand the action of the digestive enzymes of the host.e.g : Ascaris lumbricoides.
iii) Some intestinal parasites produce antienzymies to neutralize the effect of host.s digestive enzymes. e.g : Taenia solium.
iv) Some parasites live as obligatory anaerobes as the availability of oxygen is very rare for them. e.g: Entamoeba histolytica, Taenia solium etc.
v) Some intestinal parasites live as facultative anaerobes. I.e., if oxygen is not available, they live anaerobically and if oxygen is available, they respire aerobically.e.g: Ascaris lumbricoides.