Cold X-Philes

Also known as psychrophiles, this group includes organisms with an optimal growth temperature equal to or less than ten degrees celsius (OGT≤15°C).

Cryophilic Archaea & Hyperpsychrotophic, Near-Cryophilic Archaeal Mesophiles
This group includes archaea with an optimal growth temperature equal to or less than ten degrees celsius (OGT≤15°C).

Cryophilic Bacteria & Hyperpsychrotroph, Near-Cryophilic Bacterial Mesophiles
This group includes bacteria with an optimal growth temperature equal to or less than ten degrees celsius (OGT≤15°C).

Here organisms are listed first by the upper end of their temperature range, then by OGT, then by the lower end of their temperature range, and for any organisms for which these properties are unknown or the same, they will be listed in alphabetical order.