Trophic ecology

thumb|300px|Cycle between autotrophs and heterotrophs. Autotrophs use light, [[carbon dioxide (CO2), and water to form oxygen and complex organic compounds, mainly through the process of photosynthesis (green arrow). Both types of organisms use such compounds via cellular respiration to generate ATP and again form CO2 and water (two red arrows).]]

thumb|300px|Overview of cycle between autotrophs and heterotrophs. [[Photosynthesis is the main means by which plants, algae and many bacteria produce organic compounds and oxygen from carbon dioxide and water (green arrow).]]

consumer-resource system

right|thumb|Terrestrial and aquatic phototrophs: plants grow on a fallen log floating in algae-rich water

A chemotroph is an organism that obtains energy by the oxidation of electron donors in their environments. These molecules can be organic (chemoorganotrophs) or inorganic (chemolithotrophs). The chemotroph designation is in contrast to phototrophs, which use photons. Chemotrophs can be either autotrophic or heterotrophic. Chemotrophs can be found in areas where electron donors are present in high concentration, for instance around hydrothermal vents.

A mixotroph is an organism that uses a mix of different sources of energy and carbon, instead of having a single trophic mode. Mixotrophs are situated somewhere on the continuum from complete autotrophy to complete heterotrophy. It is estimated that mixotrophs comprise more than half of all microscopic plankton. There are two types of eukaryotic mixotrophs. There are those with their own chloroplasts – including those with endosymbionts providing the chloroplasts. And there are those that acquire them through kleptoplasty, or through symbiotic associations with prey, or through 'enslavement' o

organism in an ecological food chain that receives energy by consuming other organisms

group of organisms, divided in relation to the nutrition mode according to the sources of energy and carbon, needed for living, growth and reproduction

thumb|Winogradsky column showing Photoautotrophs in purple and green Photoautotrophs are organisms that can utilize light energy from sunlight, and elements (such as carbon) from inorganic compounds, to produce organic materials needed to sustain their own metabolism (i.e. autotrophy). Such biological activities are known as photosynthesis, and examples of such organisms include plants, algae and cyanobacteria.

Photoheterotrophs (Gk: photo = light, hetero = (an)other, troph = nourishment) are heterotrophic phototrophs—that is, they are organisms that use light for energy, but cannot use carbon dioxide as their sole carbon source. Consequently, they use organic compounds from the environment to satisfy their carbon requirements; these compounds include carbohydrates, fatty acids, and alcohols. Examples of photoheterotrophic organisms include purple non-sulfur bacteria, green non-sulfur bacteria, and heliobacteria. These microorganisms are ubiquitous in aquatic habitats, occupy unique niche-spaces, and

Ophiophagy (Greek: , ) is a specialized form of feeding or alimentary behavior of animals which hunt and eat snakes. There are ophiophagous mammals (such as the skunks and the mongooses), birds (such as snake eagles, the secretarybird, coucals and some hawks), lizards (such as the common collared lizard), and even other snakes, such as the Central and South American mussuranas and the North American common kingsnake. The venomous king cobra (Ophiophagus hannah) is also named for this habit.

A mycotroph is a plant that gets all or part of its carbon, water, or nutrient supply through symbiotic association with fungi. A holomycotroph gets all its nutrition solely from a mycorrhizal symbiosis. The term can refer to plants that engage in either of two distinct symbioses with fungi: Many mycotrophs have a mutualistic association with fungi in any of several forms of mycorrhiza. The majority of plant species are mycotrophic in this sense. Examples include Burmanniaceae. Some mycotrophs are parasitic upon fungi in an association known as myco-heterotrophy.

A bacterivore is an organism which obtains energy and nutrients primarily or entirely from the consumption of bacteria. The term is most commonly used to describe free-living, heterotrophic, microscopic organisms such as nematodes as well as many species of amoeba and numerous other types of protozoans, but some macroscopic invertebrates are also bacterivores, including sponges, polychaetes, and certain molluscs and arthropods. Many bacterivorous organisms are adapted for generalist predation on any species of bacteria, but not all bacteria are easily digested; the spores of some species, such

mode of nutrition

Efficiency of energy transfer from one trophic level to next

biochemical pathways used by microbes to satisfy their energy needs and to assimilate nutrients