How do saprobes and parasites differ?
Saprobes derive their nutrition from dead and decaying organic matter; whereas parasites derive their nutrition from living host.
Saprobes are organisms which derive their nourishment from dead and decaying organic matter. These are also termed saprophytes** .
These secrete digestive enzymes externally, which digest the organic matter present in dead and decaying organisms. The digestion is external and the digested food is absorbed by the organism. e.g. Fungi such as Mucor, Rhizopus, etc.
Parasites are dependent upon the living host for their nutrition. These may be ecto-parasite (attached externally to the living host), e.g. Cuscutta, etc. These send parasitic roots inside the host meant for deriving nourishment from it.
Many bacteria are parasitic, living inside the host, absorbing digested food from it. These are endo-parasites .