host
The organism from which a parasite obtains nutritional needs is called a host. The host is a food source and a home for the parasite.
If you count bacteria and viruses, a virus tends to feed off bacteria.
parasite
A parasite is an organisms that lives in or on another organism to obtain food directly.
It's called a "parasite".
It is called a Parasite. (Ex:Tapeworm.)
Parasite.
A Parasite
The correct term, in this instance, would be parasite.
Parasites. Animals that live on other animals aren't always parasites. It depends on the type of symbiosis is taking place; commensalism (the animal obtains food and shelter from the other animal without hurting or helping it), mutualism (both animals benefit, sort of a 'you scratch my back i'll scratch yours' kind of thing), and parasitism (the name speaks for itself).
it is called parasite
The organism a parasite lives on is called a "Host".