Gammarus katagani is a species of freshwater amphipod, collected from Domaniç in Kütahya Province, Turkey.
Gardiner's frog is a terrestrial frog, feeding on small invertebrates including mites, sciarid larvae, ants, and amphipods.
Illinois Caverns is home to the federal endangered species Gammarus acherondytes (a.k.a. Illinois Cave Amphipod).
Offshore juveniles feed mainly on the hyperiid amphipod Phronima, also taking small numbers of other amphipods, copepods, and free-floating fish scales.
It is associated with other cave organisms, including the isopod Caecidotea recurvata, the amphipod Crangonyx antennatus, snails (genus Fontigens), and planarians (genus Sphalloplana).