heterotoper

Heterotoper (plural form used in some languages) refers to organisms that rely on pre-formed organic carbon for growth and do not fix inorganic carbon through photosynthesis or chemosynthesis. They obtain energy by oxidizing organic molecules derived from other organisms, and must continuously ingest or absorb organic matter to sustain metabolism.

Most heterotrophs feed by ingesting or absorbing organic material. They use phagotrophy (engulfing solid particles), osmotrophy (absorbing dissolved organic compounds), or saprotrophy (digesting external organic matter, typically fungi and some bacteria). Some organisms are mixotrophic, combining photosynthesis with heterotrophy depending on conditions.

Heterotrophs occupy diverse ecological roles: animals and fungi are classic examples; many bacteria and protists are heterotrophs as decomposers, scavengers, parasites, or predators. They form the second trophic level in food webs and drive nutrient cycling by breaking down complex organic matter into simpler compounds.

Heterotrophs occur across all domains of life, from unicellular microbes to large multicellular species, in virtually every habitat. Their reliance on organic carbon links them to primary producers and other consumers, shaping energy flow and ecosystem dynamics.