Types of Aquatic Organisms - Freshwater Ecology: Concepts and Environmental Applications - page 121

TABLE 7.3 Terms Used to Classify Aquatic Organisms by Habitat

Habitat Description

Benthic On the bottom

Emergent Emerging from the water

Endosymbiotic Living within another organism

Epilithic On rocks

Epigean Above ground

Epipelic On mud

Epiphytic On plants

Episammic On sand

Hyporheic In groundwater influenced by surface water

Lentic In still water

Littoral On lake shores, in shallow benthic zone of lakes

Lotic In flowing water

Neustonic On the surface of water

Pelagic In open water

Periphytic (Aufwuchs, biofilm, Benthic, in a complex mixture including algae

microphytobenthos)
Profundal Deep in a lake

Symbiotic Living very near or within another organism

Stygophilic Actively use groundwater habitats for part of life cycle

Stygobitic Specialized for life in groundwater

indirect interactions are mediated by other species. The terms for interac-
tion types presented here are not all standard, but they allow for a very
general classification scheme. Exploitation is a general term for an inter-
action that harms one species and helps another. This term is not widely
accepted yet but includes interactions that may not be formally considered
predation or parasitism. For example, an epiphyte that harms a macro-
phyte but receives benefit from living on its leaves is exploiting the plant.
Mutualism is used to denote any positive reciprocal interaction. Others
have used various terms to denote mutualism, including symbiosis, syner-
gism, and protocooperation. Symbiosis refers to organisms that live close
together (but not to how they are interacting), and synergism and proto-
cooperation have not received widespread use outside of studies of animal
behavior.

TABLE 7.4 Classification of Interactions between Two Species (A and B)

Effect of A on B Effect of B on A Name of interaction

Positive Negative Exploitation (includes predation and

parasitism

Negative Negative Competition

Positive Positive Mutualism

None Positive Commensalism

None Negative Amensalism

None None Neutralism