The majority of snakes are non-poisonous and harmless animals. Some of the common poisonous snakes of Bangladesh are cobra, karit, pit-viper, rattle –snake, russls snake, corla-snake, and sea-snakes. The identification of poisonous and nonpoisonous snakes is very simple. The following key will serve to distinguish poisonous snakes from non-poisonous snakes:
If it is a marine snakes with the tail laterally compressed it is poisonous.
2. In a terrestrial snake the tail is rounded or cylindrical and not compressed. Examine its ventral scales.
Definition: Any animal or plant spends a portion or all of its life cycle intimately associated with another organism of a different species is considered as symbiont or symbiote and the relationship is designated as symbiosis. By employing the term symbiosis, no intent is meant to emply the occurrence or mutual or unilateral metabolic dependency.
In order to facilitate understanding, four subordinate categories of symbiotic relationships are commonly distinguished. Under the broad heading of symbiosis, types of associations known as phoresis, commensalisms, parasitism, and mutualism should be identified.
1).Phoresis: The term phoresis means, “to carry”. During this type of relationship, that which is usually the smaller fo the two species- the phoront –is mechanically carried in or on the larger species – the host. No metabolic interaction or dependency occurs. An example of phoresis is the transport of bacteria on the legs of flies. The fly host provides only involuntary transportation for the bacteria.