Published online by Cambridge University Press: 21 July 2017
Ecology is the study of the relationships between organisms and their environments. For brachiopods living in marine habitats the main external factors of interest are temperature, water chemistry, light characteristics, and oxygen availability. However, organisms also modify their environments and in many cases the biotic environment may dictate changes or organism responses. Factors of importance here for animals are resources consumed (usually food items), predators that consume the species under study, organisms that compete for resources, organisms that provide benefits such as symbiotic arrangements or new habitat for colonisation, and those organisms which reduce the quality of the environment such as pathogens or parasites.