Taxonomy & naming
The false network cory was described in 1986 by the Dutch ichthyologists Han Nijssen and Isaäc Isbrücker, in the Revue française d'Aquariologie, from material taken in the Río Yavarí (Yavari) drainage of Loreto, Peru — a tributary system on the Peru–Brazil border. The type locality is given precisely as the Caño de Guavariba in Lago Matamata, on the Río Yavarí. The specific name sodalis is Latin for 'companion' or 'comrade,' an allusion to how closely it accompanies — and resembles — its relatives.
For nearly four decades it sat in Corydoras Lacépède, 1803, the vast genus of South American armoured catfishes (family Callichthyidae) that holds most of the hobby's 'cory cats.' That genus had grown to well over 170 species and molecular work showed it was not a single natural lineage. In 2024 Dias, Tencatt and colleagues published a large phylogeny and revised classification of the Corydoradinae that split Corydoras into several genera — among them Brochis, Hoplisoma, Gastrodermus and Osteogaster. Under that scheme the false network cory becomes Brochis sodalis, and Eschmeyer's Catalog of Fishes now lists it as 'valid as Brochis sodalis (Nijssen & Isbrücker 1986).' The change is recent and the aquarium world still overwhelmingly says 'Corydoras sodalis,' so we keep that heading while recording the current combination. The species belongs to a cluster of net-patterned corys — alongside C. reticulata and the undescribed code species near them — that are persistently confused with one another in shops.
Morphology
This is a small, typically corydoradine catfish, deep-bodied and flat-bellied, reaching about 2 in in standard length (roughly 2.5 in including the tail). Like all members of the subfamily it is armoured rather than scaled: two rows of overlapping bony plates (scutes) run down each flank and the head is a hard, blunt helmet, with three pairs of sensory barbels fringing the downturned mouth.
The defining feature is the pattern. The ground colour is a pale silvery to greyish body overlaid with a dense, swirling network — a 'reticulation' — of fine dark lines that extends across the flank and into the dorsal fin, with darker bars or stripes marked on the caudal fin. It is told from the genuinely reticulated cory, C. reticulata, chiefly by its dorsal fin: C. reticulata carries a large, solid black blotch over much of the dorsal, whereas in C. sodalis that blotch is absent and the fin instead repeats the fine network. The overall patterning of sodalis is also softer and less boldly contrasted than in its namesake — which is exactly why the trade name 'false network' stuck. The dorsal, pectoral and adipose fins each bear a stiff, mildly venomous leading spine, the standard corydoradine defence.
Habitat
Corydoras sodalis is a fish of the western Amazon lowlands, recorded from the upper Amazon (Solimões) basin in the department of Loreto, Peru and the adjoining state of Amazonas in north-western Brazil, with its type series from the Río Yavarí on the border between the two. Within that range it occupies the shallow margins of streams, tributaries, pools and seasonally flooded forest, typically over soft sand with submerged wood and a litter of fallen leaves.
These are warm, soft, often tannin-stained blackwaters and clearwaters where aquatic plants are sparse and the bottom is the centre of activity. Reported tolerances are broad — temperatures of roughly 72–79 °F, a pH band from about 6.0 to 8.0 and soft to moderately hard water (around 2 to 25 °dH). Like other corydoradines it is a facultative air-breather, darting to the surface to gulp air and absorb oxygen through a vascularised hindgut, an adaptation that lets it survive in warm, low-oxygen pools and shrinking dry-season puddles.
Feeding
The false network cory is a benthic omnivore. In the wild it works the soft bottom continuously, burying its snout and barbels in sand to taste out small invertebrates, insect larvae, worms and crustaceans, along with fallen organic matter and some plant material, expelling cleaned sand through the gills as it goes. It is an opportunist rather than a specialist, which is part of its hardiness. In the aquarium it readily takes sinking pellets, granules and tablets as a staple, supplemented with frozen or live bloodworm, Daphnia, brine shrimp and Tubifex; the occasional blanched vegetable is accepted but not essential. As with all corys, it should never be left to subsist only on what its tankmates let fall to the bottom.
Mating
Corydoras sodalis is an egg-laying shoaler with no pair bond and the distinctive, well-studied corydoradine courtship. When a female is ripe the group becomes active and males begin to pursue her; she lets a male touch her with his barbels and the pair settle into the classic 'T-position,' the male at right angles to the female's head, where she appears to take his milt. Sperm is thought to pass rapidly through her gut to fertilise the few eggs she clasps in a basket formed by her pelvic fins. She then carries those one to four eggs to a cleaned surface — typically the aquarium glass, often near brisk flow — and presses them into place. The sequence repeats, a few eggs at a time, until the clutch is complete.
Breeding
Breeding follows the familiar Corydoras pattern and is reported as relatively straightforward. A group is conditioned on varied live, frozen and dried foods and skewed toward more males than females — around two males per female is a common recommendation. Spawning is triggered by emulating the rainy season: large water changes with notably cooler water, plus increased flow and oxygenation, repeated daily once the females are visibly full of eggs. The adhesive eggs receive no parental care and the adults will eat them, so breeders move either the eggs or the parents; the eggs are tough enough to be rolled gently up the glass with a finger. A little methylene blue helps hold off fungus, and any fungused eggs should be pulled. Eggs hatch in about three to five days, and the fry, after absorbing the yolk sac, take microworm and newly hatched brine shrimp. A thin layer of sand on the rearing-tank bottom is reported to keep the fry healthier than a bare base.
In the aquarium
The false network cory is an excellent, hardy community fish suited to beginners and experienced keepers alike, with the usual corydoradine requirements. First, it is a shoaling species and is genuinely stressed when kept alone or in twos — keep a group of six or more and they reward you with constant, confident activity along the bottom. They suit a tank with a good footprint; bottom area matters more than height.
Second, substrate is not decoration: provide soft sand or very smooth, rounded fine gravel, because corys feed by sifting and sharp or coarse grit erodes and infects their barbels, leaving stubby, blunted faces — one of the commonest signs of poor husbandry. An Amazon-style setup of sand, driftwood and leaf litter, with tannin-stained water and only sparse planting, mirrors the wild habitat, though they adapt happily to a planted community too. Water should be warm (about 72–79 °F), well-filtered and well-oxygenated, across a broad pH and hardness range. They are utterly peaceful and make ideal companions for tetras, peaceful barbs, rasboras, dwarf cichlids and other calm community fish, never anything large enough to bully them. Two standard cautions apply: the fin spines can catch in nets, so a cup is safer; and a distressed cory can release a skin toxin that, in the confined volume of a bag or bucket, can kill the whole group, so transport them with care.
Conservation
Corydoras sodalis is assessed by the IUCN as Least Concern, last evaluated in 2020. It is widespread across the western Amazon lowlands and tolerant of the warm, shallow, seasonally variable habitats it favours, and it is bred for the aquarium trade, which reduces collection pressure on wild stocks. None of that makes it immune to the broad pressures on Amazonian freshwaters — deforestation, agriculture, mining run-off and pollution all degrade the marginal habitats it occupies — but as a species it is in no danger. The more practical footnote is taxonomic and commercial: because it is so easily confused with C. reticulata and a cluster of similar net-patterned corys, fish are frequently traded under the wrong name, and clearer identification would benefit both hobbyists and any future assessment of the individual populations.