What does autotroph mean?
An autotroph is any organism that can manufacture its own food from simple inorganic substances, without needing to eat other living things. The word comes from Greek roots meaning "self-feeding" and is the standard biological counterpart to "heterotroph," the term for organisms such as animals and fungi that must consume organic matter to survive. Most autotrophs are photosynthetic — green plants, algae, and cyanobacteria use sunlight, carbon dioxide, and water to build sugars — while some, known as chemoautotrophs, draw energy from chemical reactions involving compounds such as hydrogen sulfide, often near deep-sea vents. Because they create the organic material on which all other life ultimately depends, ecologists often describe autotrophs as the primary producers of an ecosystem, anchoring the base of virtually every food chain. The term appears mainly in biology, ecology, and science education.
nounAn organism that produces its own food from inorganic substances, using light or chemical energy rather than consuming other organisms.
- An organism capable of synthesizing its own organic nutrients from inorganic substances, typically via photosynthesis or chemosynthesis.
"Plants, algae, and cyanobacteria are autotrophs, forming the base of nearly every food chain on Earth."
"As an autotroph, the phytoplankton converts sunlight into the sugars that sustain the entire marine food web."
"Deep-sea bacteria are chemosynthetic autotrophs, thriving around hydrothermal vents where no light ever reaches."
The standard plural; commonly used when discussing groups of self-feeding organisms within ecosystems.
"Autotrophs such as grasses and trees capture solar energy that flows upward through the food web."
Every meal you've ever eaten traces back to an autotroph — organisms like plants and algae that literally feed themselves using nothing but sunlight, air, and water.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of autotroph
The word "autotroph" was coined in the late 19th century from the Greek elements "autos" (self) and "trophē" (nourishment, food), literally meaning "self-feeding." It was introduced as a precise scientific label for organisms that sustain themselves without consuming others, contrasting with "heterotroph" (from "heteros," other). Its adjective form is "autotrophic," and related terms such as "phototroph" and "chemotroph" share the same Greek root for nourishment.
Related word forms
How autotroph is actually used
A technical term used chiefly in biology, ecology, and education; it is uncommon in everyday conversation but standard in scientific writing and textbooks.
Easily confused with autotroph
An autotroph makes its own food from inorganic sources, whereas a heterotroph must obtain energy by consuming other organisms or organic matter.