Formally, Corydoras orcesi is a synonym of Corydoras pastazensis. In the photos below you can see a difference in drawing of these species. Corydoras pastazensis has smaller dots instead of spots on the flank. The species do not occur jointly and because of the deviating drawing it cannot be ruled out that orcesi turns out to be a separate species.
The genus name Corydoras consists of two parts: Cory means “helmet” and doras means “skin”. The name is a reference to the double row of armored plates under the skin on the flank of this genus. These plates function as a kind of armor, hence the common name for this group of fish: Armored Catfish. Due to the possession of the leg plates, they do not need any further protection, so they do not have scales. The species name orcesi was chosen in honor of Dr. Gustavo Orcés-Villagomez.
Corydoras orcesi can reach a length of up to about seven centimetres. The ground colour is light brown with larger black spots on top. A vertical black band runs down from the first fin ray of the dorsal fin. A second band runs vertically across the eye.
The males are slimmer and smaller than the females. This is particularly visible from above. The fins of the males get slightly more pointed as they get older, the females are more rounded.
If you look closely at the snout of this species, you can see that they have a kind of saddle nose. It bend inwards a bit, instead of rounded outwards, like many other species.
Rio Tigre and Rio Conambo in Ecuador.
Using their barbels, Corydoras orcesi looks for something edible in the substrate. You can feed them with tubifex, red and black mosquito larvae, brine shrimp, Daphnia, sinking tablets and flake food are also eaten.
This peaceful schooling fish lives on the bottom. Despite their small size, they still need some space. We recommend keeping them in a group of at least six, but preferably more. For a group of six, you need an aquarium with a minimum length of about 80 centimetres.
Use rounded (filter) sand on the bottom so that they do not damage their barbels when looking for food. Create some hiding places by using lots of plants and wood. Leave some sand in the front and in the middle so that they can search for food and you can enjoy these active fish yourself.
The water can have a temperature of about 22 to 26 degrees at a pH of 6.0 to 7.5.
Suitable tankmates are peaceful Tetras swimming in the middle and top layers of the aquarium. Also hatchet fish are a great combination. A combination with bottom-dwelling dwarf cichlids such as Apistogramma is not recommended. These cichlids form a territory of which the group Corydoras orcesi does not care. Especially when the Cichlids have a nest of fry or eggs, this gives the Cichlids a lot of stress. The Corydoras often bulldoze through the nest with eggs.
Breeding aquarium and Conditioning
Breeding Corydoras orcesi proceeds as with most other Corydoras species. Prepare a breeding aquarium that is only furnished with a layer of sand on the bottom. Give the parents some hiding places in the form of some Java moss. Make sure there is sufficient flow and aeration in the aquarium and direct the flow towards the glass. This will usually be where the eggs are deposited.
Now add the parents in a ratio of 2 males to 1 female.
An important part of the conditioning of the fish is the food. Feed them meat-like food such as black mosquito larvae, tubifex, etc. Keep doing this until you see that the females are full of eggs.
The trigger for spawning, like many other Corydoras species, is a large water change of about 50%. Use water which is considerably colder than the aquarium water. The water should be soft and slightly acidic with a pH of 6.5 – 7.0. Repeat this large water change twice a week until the eggs are laid.
In some cases, a water change of 50% is not sufficient. In that case, increase the amount of fresh water to about 75% and increase the aeration and flow in the aquarium.
The dominant male chases a female. Eventually, they take the T position characteristic of Corydoras. With its pectoral fins, the Corydoras orcesi male grabs the female by her barbels. He pushes the female around hard. This is so rough that it can damage the female’s barbels. After a maximum of 10 seconds, she breaks free from the male. The female then releases an egg that she catches with her pelvic fins. With the egg clamped between her fins, she searches for a suitable place to stick the egg. This can be on the glass, but also in some Java moss.
The first few times the number of eggs is not very big, about 10 to 15 eggs. As the female gets more experience, this number increases to a maximum of about 30 eggs at a time.
Raising the fry
Unfortunately, you can not leave the eggs with the parents, because they will be eaten. You can place the parents back in their community aquarium, but most breeders leave the parents in the breeding aquarium and move the eggs. You can usually roll the eggs upwards with a finger over the glass. The advantage of leaving the parents behind is that they will likely spawn again a week later. You should then keep changing with cooler water twice a week.
Place the eggs in an aquarium with the same water as the parents and again ensure sufficient flow and aeration.
Corydoras eggs mould quickly. Remove the mouldy eggs to prevent them from igniting the other eggs. If the eggs continue to become mouldy, you can add a few drops of methylene blue to prevent mould. Unfortunately, this drug is often only available on prescription, but for instance, in Belgium, it can still be ordered freely.
The eggs hatch after 3 to 4 days. They then still eat their egg yolk. Only when they have eaten their egg yolk can you feed them with very fine food such as micro worms and Liquifry. Once a little bigger, around two weeks you can start feeding finely crushed flake food and freshly hatched brine shrimp.
It is important for the growth of the young Corydoras orcesi that a lot of water is changed frequently, up to about 50% per day. Please note that no large fluctuations in water values such as temperature and pH may occur.
Transport of Corydoras and Scleromystax
Many Corydoras species have a poisonous self-defence mechanism to prevent them from being eaten by larger fish. In case of danger, they can spread and lock the spines in their dorsal and pectoral fins. As a result, they get stuck in the attacker’s mouth or throat, they will think twice before trying to swallow a Corydoras. When catching a Corydoras with a net, they regularly get stuck with these spines in the net. Be careful when loosening, if the spine gets into your skin, it can partially break off and remain in the skin. These wounds are painful and often become inflamed.
In addition to the pointed spines, a number of Corydoras species can release a toxin into the water when they are stressed or in danger. If transported in too small an amount of water or too many Corydoras in the small space, this can lead to rapid mortality among the fish. Preferably transport the Corydoras only with other Corydoras and not too much in one bag. Since little research has been done on this poison, it is not clear whether this poison is spread from the gills or from the spines. It is thought that at least the Corydoras adolfoi, Corydoras arcuatus, Corydoras melini, Corydoras metae, Corydoras panda, Corydoras robineae, Corydoras rabauti, Corydoras atropersonatus, Corydoras sterbai and Corydoras trilineatus have this poison. But most likely other Corydoras species share this defence mechanism.
John de Lange