Table 2 Brief natural history of tiger parasites. Most of the information is generic and comes from related hosts or captive carnivores. Reliable and specific information on species in tigers and their effects on the host is unavailable at present.

Paragonimus

Paragonimidae

These are ovoid with a spiny tegument and are parasitic in the lungs (lung flukes).

The eggs are laid in the cyst in which the worms live and escape in the respiratory system. Animals swallow the cysts along with the mucus which pass in the faeces. The miracidium escapes and penetrates into an amphibian snail. After escaping the snail, the cercariae swim about in the water and on meeting a suitable crab or crayfish, penetrate into it. The final host becomes infected by eating infected crustacea.

Diphyllobothrium Diphyllobothriidae

occurs in the small intestine of man, cat, pig and fish eating mammals. Large tapeworms, The scolex has instead of suckers, narrow, deep, weakly muscular grooves called 'bothria'.

A typical life cycle includes free living coracidium (a ciliated embryo), a procerciod occuring in the first intermediate host, copedid crustaceans; a plerocerciod found in the second intermediate hosts, fish and definitive hosts (amphibia, reptiles birds or mammals) contain the adult stage. Life cycle of the tiger species (if there is a different one) is not completely known.

Taenia

Taeniidae

Large tapeworms, Gravid proglottids are longer than they are wide, Rostellum with a double row of small and large hooks

Species found in wild carnivores, commonly have herbivores as intermediate hosts. Some of the species form hydatid cysts in the secondary host. Hydatids are frequently found in herbivore viscera of the study area.

Hookworm

Ancylostomatidae

These are hookworms with a well developed buccal capsule with chitinous cutting plates.

Direct. No intermediate hosts involved. Infective larvae enter through water or by active penetration of the skin.

Toxocara & Ascaris

Ascarididae

Relatively large worms with three well developed lips. There is no buccal capsule or pharynx. Cervical alae give their anterior ends an arrow like appearance. For this reason they are sometimes called arrow worms or arrow headed worms.

The infective stage is the egg containing second stage larva. They grow in the intestine of the host.

Lungworm

Filaroididae

Parasites of respiratory system of mammals

Direct. No intermediate hosts involved.

Capallaria

Capillariidae

The worms are closely related to Trichuris worms (whip) but they are small and slender and the posterior part of the body is not conspicuously thicker than the anterior part.

The lifecycle may be direct or indirect. The eggs are unsegmented when laid and develop into larval stages which then infect the definitive host if the life cycle is indirect.