Relationship in which individuals of one species produce toxins that inhibit or impede the development of others. Ex .: Red tide, snake (poison) and man, fungus penicillium (penicillin) and bacteria.

THE Penicillin was discovered in 1928 when Alexander Fleming, in his laboratory at St Mary's Hospital in London, noticed that one of his cultures of Staphylococcus had been contaminated by a mold Penicillium, and that around the fungus colonies there were no bacteria. He demonstrated that the fungus produced a substance responsible for the bactericidal effect, penicillin.

THE Red tide It is the proliferation of some species of toxic algae. Many of them are reddish in color, and usually occur occasionally in seas all over the planet. We found these plants only at the bottom of the sea. In situations such as temperature changes, changes in salinity and sewage discharge into sea waters, they multiply and rise to the surface, where they release toxins that kill large numbers of fish, shellfish and other marine life.
When this happens, large red spots are seen on the surface of the water. Beings contaminated by these toxins become unfit for human consumption.

Red tide


Individuals hold captive individuals of another species for advantage. Ex .: ants and aphids.

The aphids are parasites of certain vegetables, and they feed on the elaborate sap they take from the plant's libertine vessels. The elaborate sap is high in sugars and low in amino acids. Because they absorb a lot of sugar, aphids eliminate their excess through the anus. This eliminated sugar is used by the ants, who even caress the aphids' abdomen with their antennas, causing them to eliminate more sugar. The ants carry the aphids to their anthills and place them on delicate roots to remove the elaborate sap from them.

Ants often take care of the aphids offspring so that in the future, enslaving them, they get sugar. When taking into account the fact that ants protect ladybugs aphids, the interaction is harmonic, being a type of protocooperation.