Inharmonious interspecific relations between different species in the same community have the same or very similar ecological niches, triggering a dispute mechanism for the same environmental resource, when it is not sufficient for both populations.
This mechanism can determine density control of the two populations that are interacting, extinction of one of them or even specialization of the ecological niche.
Relationship in which one species blocks the growth or reproduction of another species called amensal, through the release of toxic substances. Examples:
- The fungi Penicillium notatum eliminate penicillin, an antibiotic that prevents bacteria from reproducing.
- The substances secreted by Gonyaulax dinoflagellates, responsible for the phenomenon "Red tide", may determine the death of marine fauna.
- The secretion and elimination of toxic substances by the roots of certain plants prevents the growth of other species in the site.