Your internet guide to
all things catfish

Corydoras arcuatus  Elwin 1939

his member of the Callichthyidae family is a well known favourite amongst Corydoras lovers. The 'Skunk' or 'Arched Cory' is sometimes difficult to pick up in the shops and seems to come and go in periods so you have to snap them up when seen and of course the recently unfolding story of the true C. arcuatus is told below.

Corydoras arcuatus

Water conditions are of paramount importance on this species as the barbels are very susceptible and can very quickly wear away if the water changes are not adhered to and the bacteria builds up in the substrate, why this species of Corydoras is effected more than any other is a mystery to me.

In the following picture you can see the worn down barbels on this species. Sand would probably be a good bet for the bottom of their tank, just a light scattering should suffice.

Corydoras arcuatus

This species is sometimes confused with its longer nosed ‘cousin’ Corydoras narcissus, but the length of the snout is the main difference, and also the stripe in narcissus tends to be longer, running into the lower lobe of the caudal fin.

This species was given the CW-number (Corydoras World) of 36 as it had not previously been given a C-number. It is now thought (Grant, S. 2014) that this species, CW036, is the true Corydoras arcuatus instead of the shorter nosed C020.


Corydoras arcuatus = juvenile

Above is a young speciman, (C020) and as it grows the black spots will join up to show the adult black line.


UPDATE: It is now been proven (Grant, S. 2014) that CW036 is the true Corydoras arcuatus instead of C020.



Dorsal 1/7; Anal 1/6; 22-24 bony scutes in the upper lateral series, 20-22 in the lower.

Grey-yellowish to delicate grey-green; underside pure white. A broad, dark longitudinal band commences at the corner of the mouth and passes across the eye into an arched course following the profile of the back to the root of the tail where it turns abruptly downwards and, becoming narrower, continues along the lower edge of the caudal fin. No other markings. Fins colourless; caudal with fine dark spots and a blackish upper edge.

Will do well in a community setup with smaller tankmates such as Rasboras and Tetra's. Do not house with aggressive species or large Cichlids.

Not one of the easiest cory's to breed, but in one reported spawning a cold water change down to 60f (17c) induces spawning, with the eggs being laid in Java Moss. Eggs will hatch in 3 to 4 days. U.K. Corydoras breeder Ian Fuller of the Corydoras World web site has bred this species in 1980 and reported the usual Cory T-mating clinch fashion. 110 eggs were laid with about 65 of them in the Java moss the remainder were stuck on the sides of the tank mainly in the corners. Temperature was 68f (20c) and the eggs hatched in 3 to 4 days. There was a 95% hatch rate. 30 years later in 2010 In Scotland, aquarist Graham Ramsay has also bred this species. See breeding article on breeding the afore mentioned species C020 here

After the fry are 3 days old, feed microworm, fry flake then progress on to brineshrimp, keeping up the water changes. Adults can be fed on the usual good quality aquarium flake with tablet food and frozen bloodworm being a good diet.

Corydoras: Cory = helmeted; doras = leathery skin,(helmeted Doras) cuirass.
arcuatus :
Arched, like a bow, (referring to the stripe)

Lambourne, Derek, Corydoras Catfish, An Aquarists Handbook  1995
Sterba, Günther; Freshwater fishes of the World Vol.1 1973
Fuller, A.M. Ian,
Breeding Corydoradine Catfishes
Grant S., 2014, Catfish Study Group Journal V15 - I4

Photo Credits
© Ian Fuller @CorydorasWorld
Factsheet 004

Common Name:
Skunk Cory, Arched Cory
 Brazil, Rio Madeira, Humaita-region.
Male: 7.5 cm (3ins) Female: 8.0cm (3¼ins)
22-26°C (71-79°F)
6.5 - 7.2
If you found this page helpful you can help keep ScotCat running by making a small donation, Thanks. 

Donate towards my web hosting bill!


Print Friendly and PDF

























































                                                                                                                                              Factsheet 004 = updated December 14, 2018 , © ScotCat 1997-2018 Go to Top