An excerpt from the original description by Joachim Knaack published in: Aquaristik aktuell 4/2002 p. 50-56; translated and amended from German by Stephan M. Tanner.
belongs to the Corydoras elegans group sensu Nijssen
& Isbrucker consisting of C. elegans, C. hastatus,
C. undulatus, C. latus, C. pygmaeus, C. guapore,
C. nanus, and C. gracilis, as well as C. napoensis.
species presents with an obvious sexual dimorphism in size and
coloration that already becomes apparent in juveniles at 10 mm standard
length (SL). Females become considerably larger (max 55 mm SL) and
appear grayer in color. Males are smaller (max 44 mm SL) with a more
contrastful pattern due to the two name giving lateral stripes that can
vary from white to pale yellow. These are also visible in females but
appear more greenish-gray. The dorsal fin in males usually shows a black
blotch that can vary in size and form.
was collected in Bolivia, Departmento Santa Cruz, Cochabamba and Beni,
system of the upper Rio Marmor-14-18 degree S
and 62-68 degree W at an elevation of 161-327 m above sea level. The typus locality was a
large standing pool in October 2001 with dense floating plant cover of Pistia
stratiotes, Eichhornia, and Salvinia. The roots of Pistia
serve as substrate for egg laying. C. bilineatus from the typus
locality live in relatively cold-water temperatures of only 18-22 C
In contrast, specimens from the Northeastern low lands (Trinidad) live
in temperatures that about 3 C/F higher. The pH ranges from 6.04-8.40 with 20-1000 mS
depending on locality. C. bilineatus occurs in rather large
groups that contain hundreds of individuals.
C. bilineatus is an attractive and very active aquarium fish that prefers densely planted tanks with not too bright lighting. Given their natural behavior these fish should be kept in groups of no less than 8-10 individuals. To induce breeding the temperature should be lowered 2-3 C/F for 2-3 months. A fat-rich diet and increasing frequency of water changes with slightly warmer water will induce spawning which is quite productive. The numerous eggs are preferably stuck to swimming plant roots or egg mobs. Young C. bilineatus grow fast and reach 12 mm SL within four weeks. C. bilineatus eats any stable diet but prefers worm food such as tubifex, grindal, small mosquito larvae (blood worms), and brine shrimp, which can be offered frozen or live.