The Orange CPO Dwarf Crayfish, Cambarellus patzcuarensis, is a dwarf crayfish species native to Lake Pátzcuaro in Michoacán, Mexico. The species name CPO stands for Cambarellus Patzcuarensis Orange, referring to the vivid orange colouration of the selectively bred aquarium strain. Unlike their larger crayfish relatives, CPOs are remarkably small — reaching only around 4 cm — and display a notably more peaceful temperament that makes them compatible with many community fish and invertebrate species. The Orange CPO is an omnivore that forages actively through substrate and plant surfaces, consuming organic detritus, small food particles, algae, and occasional protein-rich morsels. Its small size makes it suitable for tanks from 30 litres and compatible with small peaceful fish including nano tetras, ember tetras, and other species too fast to be threatened by the crayfish. While peaceful by crayfish standards, CPOs may still interact aggressively with shrimp on occasion, particularly dwarf shrimp species, and close observation is recommended in mixed setups. Males display brighter orange colouration than females. CPOs are sexually dimorphic and relatively easy to breed in aquariums, with females carrying eggs under their tail until they hatch into miniature fully-formed juveniles. The species is considered threatened in its natural habitat and is primarily maintained through captive breeding.
