More than 350 species and subspecies of amphipods are endemic to the lake. They are exceptionally diverse in ecology and appearance, ranging from the pelagic "Macrohectopus" to the relatively large deep-water "Abyssogammarus" and "Garjajewia", the tiny herbivorous "Micruropus", and the parasitic "Pachyschesis" (parasitic on other amphipods). The "gigantism" of some Baikal amphipods, which has been compared to that seen in Antarctic amphipods, has been linked to the high level of dissolved oxygen in the lake. Among the "giants" are several species of spiny "Acanthogammarus" and "Brachyuropus" (Acanthogammaridae) found at both shallow and deep depths. These conspicuous and common amphipods are essentially carnivores (will also take detritus), and can reach a body length up to .