zoology - Aside from cockroaches and other insects, which species (of all kinds) are 'immune' to ionizing radiation?

According to Paul Stamets, Gomphidius glutinosus is especially well suited to collecting Cesium-137:

G. glutinosus has been reported to absorb – via the mycelium – and
concentrate radioactive Cesium 137 more than 10,000-fold over ambient
background levels.

That article and Stamets' book Mycelium Running have more details on other species.