near the mouth of the Ji-Paraná River. The pygmy corydoras lives in a tropical climate in water with a 6.0 - 8.0 pH, a water hardness of 2 - 25 dGH, and a temperature range of . It feeds on worms, benthic crustaceans, insects, and plant matter. Breeding The pygmy corydoras lays approximately 100 eggs at a time. The female holds 2-4 eggs at a time in a pouch formed by her pelvic fins while they are fertilized by the male, which takes about 30 seconds. The female swims to a safe location with the fertilized eggs, where she attaches the sticky eggs to a surface, where they will remain. In the aquarium Pygmy corydoras are of commercial importance in the aquarium trade industry. It is a peaceful fish and can be kept in a community aquarium of smaller fish species such as ember tetras. It can be fed most sinking foods but may eat flakes. It enjoys frozen food and sinking wafers. It can be kept with small shrimp and snails. These cories should not be kept in tanks smaller than 10 gallons because they like room to swim around. In aquariums, they are often kept on fine grained substrate, such as sand. This is said to enable them to dig through the sand without injury. They are often kept at a pH of between 6.5 and 7.0. They are peaceful fish that are usually kept in groups of at least four and will also behave much more naturally in larger groups (10 or more). Unlike the larger more common Corydoras, they often swim in shoals around the mid water and lower regions of the tank. C. pygmaeus are good pets as they are fairly hardy. However, there are several things to keep in mind when planning to keep this species. They are inoffensive fish which will not thrive with aggressive tankmates. They are perhaps best kept in a planted species tank, or with shrimp such as Neocaridina spp. They seem to do best when offered live foods in addition to prepared food items. Appropriate foods include microworms or similar nematodes, as well as Artemia nauplii (newly hatched brine shrimp.) References Corydoras Taxa named by Joachim Knaack Fish described in 1966 Fish of South America