Max Size: 4cm

Smudge Spot Corydoras (Corydoras similis)

The Smudge Spot Corydoras is very uncommon in the aquarium hobby, but it is in high demand due to its striking dark violet colouration as it matures. These Corys are spirited, distinctively patterned fish perfect for the nano, community, and planted aquarium.

The Smudge Spot Corydoras is a peaceful shoaling fish that is best kept in groups of at least six individuals. Keeping these Corys in more significant numbers will result in a much more natural-looking aquarium and makes for an interesting display.

You can house Smudge Spot Corydoras with most fish available in the hobby, including Dwarf Cichlids, Tetras, small to medium-sized Barbs, Gouramis and other peaceful Catfish. These Corys may prey on some smaller Dwarf Shrimp but are safe with larger shrimp and other ornamental invertebrates. However, you should avoid keeping these fish with larger, more aggressive fish as they will feel intimidated and get outcompeted for food.

Smudge Spot Corys will thrive in an aquarium set up to imitate an Amazon biotope. You will need a sandy or smooth gravelled substrate, a few driftwood branches, and some dried leaf litter to achieve this. You will not find aquatic plants in these Cory's natural habitats; instead, allow the wood and leaves to stain the water a brown colour, then remove old leaves and replace them every few weeks, so they don't decay and degrade the water. If a biotope setup is not your cup of tea, these Corys will also do well in a typical well-planted aquarium.

Smudge Spot Corys are sensitive to deteriorating water conditions, so it is essential that you have a good maintenance regime and avoid any sudden changes. It would be best to perform frequent water changes and not overfeed your Corys; other than that, these fish are undemanding and relatively easy to look after.

Smudge Spot Corys have cream colouration on the base of their bodies and periodic small brown spots on their heads. These spots continue down their bodies from their dorsal fin in consistent rows above their lateral line, decreasing in size the closer they get to the caudal peduncle.

The area of the body beneath the lateral line is tan-coloured, and these fish have a blueish blotch that begins behind the dorsal fin base, ending at the caudal peduncle. This blue blotch gets darker as it gets closer to the caudal peduncle. In addition, the ventral surface is whiteish-cream, and the fins are hyaline. Although their fins have no colour, their body colour is genuinely stunning when they are in spawning conditions.

Quick Facts
Scientific NameCorydoras similis
Year Described1991
Other NamesViolet Cory, Smudge Spot Cory
OriginsArgentina, Brazil
Aquarium LevelBottom
DifficultyBeginner - Intermediate
Best kept asGroups 6+
Lifespan3 - 5 years
Water Parameters
Water TypeFreshwater
PH5.5 - 7.5
GH5 - 20
72 - 79℉
22.2 - 26.1℃


Smudge Spot Corydoras
Smudge Spot Corydoras

Natural Habitat

You will find Smudge Spot Corydoras in the Rio Madeira, in the vicinity of the city of Ariquemes in Rondonia State, Brazil and Argentina in South America. These fish inhabit slow-flowing to almost still waters in pools, creeks and flooded forest areas with sandy or silty substrate.


Smudge Spot Corys are classic scavengers and will inhabit and feed on the aquarium floor. These Corys will accept most sinking dried foods such as algae wafers pellets and small live and frozen foods such as mosquito larvae, bloodworms, and Tubifex.

It would also benefit your Corys if you provided them with plenty of vegetable matter, as feeding a varied diet will ensure the fish are in optimum health and condition. However, you should not expect your fish to prevail on leftover food from other tank inhabitants or rely on them to clean the aquarium.

Sexual Dimorphism

It can be somewhat straightforward to differentiate between the male and female Smudge Spot Cory. The females are generally larger and more rounded than the males, the pectoral fins are more deeply convexed posteriorly, and they have larger ventral fins. In contrast, males are slimmer and slightly smaller than females.


Preparing a separate breeding tank would be best if you would like to breed Smudge Spot Corydoras. The breeding tank can be undecorated, but a soft substrate is a must, as your Corys will prefer to feed by foraging in the substrate for food.

The water should be mature, soft and acidic with a low light level, and it would be more beneficial if you added broad-leaved plants and had gentle aeration.

As females get close to spawning, you will notice them starting to clean the surface of leaves or the aquarium glass on which they will lay their eggs.

Large water changes with rainwater or cooler water, and conditioning them with live foods can mimic their natural spawning behaviour and encourage spawning.

Females may lay up to 100 eggs during one spawning. After that, the adults will take no further role in raising their offspring and may consume the eggs if given a chance, so it would be best to return them to their usual tank.

It typically takes between one and three days for the eggs to hatch, depending on the water condition and temperature and an additional two to three days for the yolk sacs to be consumed by the fry. Once these sacs are depleted, the fry will become free-swimming. Once they are free swimming, you can feed the fry with infusoria-type foods such as rotifers.

Once the fry starts to develop and won't be seen as a snack, you can introduce them into the community tank, where they will unite with the existing shoal. However, before moving the adolescent fish into the community tank, ensure you have balanced the water temperatures, decreasing the risk of triggering White Spot or other diseases.

Other Corydoras of interest

Adolfos Catfish(Corydoras adolfoi)
Agassizs Corydoras(Corydoras agassizii)
Albino Corydoras(Corydoras aeneus)
Armatus Corydoras(Corydoras armatus)
Axelrods Corydoras(Corydoras axelrodi)
Banded Corydoras(Scleromystax barbatus)
View all Corydoras
Date Added: 05/07/2022 11:26:20 - Updated: 05/07/2022 14:03:08