Talking about fauna

Megafauna[edit]
Main article: Megafauna


Australian and New Zealand fauna. This image was likely first published in the first edition (1876–1899) of the Nordisk familjebok.
Megafauna are large animals of any particular region or time. For example, Australian megafauna.
Meiofauna[edit]
Main article: Meiobenthos
Meiofauna are small benthic invertebrates that live in both marine and freshwater environments. The term meiofauna loosely defines a group of organisms by their size, larger than microfauna but smaller than macrofauna, rather than a taxonomic grouping. One environment for meiofauna is between grains of damp sand (see Mystacocarida).
In practice these are metazoan animals that can pass unharmed through a 0.5 1 mm mesh but will be retained by a 30–45 μm mesh,^[5] but the exact dimensions will vary from researcher to researcher. Whether an organism passes through a 1 mm mesh also depends upon whether it is alive or dead at the time of sorting.
Mesofauna[edit]
Main article: Soil mesofauna
Mesofauna are macroscopic soil animals such as arthropods or nematodes. Mesofauna are extremely diverse; considering just the springtails (Collembola), as of 1998, approximately 6,500 species had been identified.^[6]
Microfauna[edit]
Main article: Microfauna
Microfauna are microscopic or very small animals (usually including protozoans and very small animals such as rotifers). To qualify as microfauna, an organism must exhibit animal-like characteristics, as opposed to microflora, which are more plant-like.
Stygofauna[edit]
Main article: Stygofauna
Stygofauna are any fauna that live in groundwater systems or aquifers, such as caves, fissures and vugs. Stygofauna and troglofauna are the two types of subterranean fauna (based on life-history). Both are associated with subterranean environments – stygofauna are associated with water, and troglofauna with caves and spaces above the water table. Stygofauna can live within freshwater aquifers and within the pore spaces of limestone, calcrete or laterite, whilst larger animals can be found in cave waters and wells. Stygofaunal animals, like troglofauna, are divided into three groups based on their life history - stygophiles, stygoxenes, and stygobites.^[7]