Sterbai Cory Factsheet

Common Name: Sterbai Cory

Scientific name:  Corydoras Sterbai.  Sterbai is a reference to Professor Dr. Günther Sterba, professor emeritus of zoology of Leipzig University who published a number of important books for fishkeepers in the 1970s and 1980s.

Sterbai Cory Size: 5cm to 6.5cm.

Sterbai Cory Minimum Tank size: 45cm/18”

Water parameters: pH 6-7.5: temperature 24-28°C/75-82°F; hardness 18-215ppm (very soft to moderately hard)

Sterbai Cory Origin:

Bolivia and Brazil. Specimens have been collected from the Rio Guaporé, a river located in Western Brazil and NE Bolivia that forms the border between the two countries. It also may be present in the Rio Araguaia, located further East in Brazil.

Diet:

The Starbai Cory is omnivorous and easy to feed as long as the food reaches the substrate where they forage.  They will accept any good quality sinking pellets and relish frozen or live food, particularly bloodworm.

Behaviour:

As with most Corydoras, Sterbai Corys are very peaceful and suitable for many community tanks. They should not be kept with any fish that are very large or aggressive, however, especially other fish which may establish territories in the lower part of the aquarium.  I have had problems keeping them with Rams as the cichlids attacked the Corys when they entered their territories to feed.  I would imagine any Cichlid that established territories in the base of the tank where the Corys will blunder into may be problematic. Always try to maintain Corydoras in groups as they’re far more confident and active in the presence of conspecifics. A group of at least six is good, although more is probably better. I have also noticed that they seem to prefer an area of substrate where they can forage free of décor.

Appearance:

The Sterbai Cory can be differentiated from most other members of the family by its bright orange pectoral fins.  They are superficially similar to C. haraldschultzi, but can be distinguished by examining the patterning on the head of the fish. In the case of the Sterbai this is composed of light spotted markings over a dark background, whereas in C. haraldschultzi the markings are dark and the background colour is light. C. haraldschultzi also has a more elongated snout.

Sexual Dimorphism.

At first glance, male and female Sterbai Corys look very similar, particularly when young.  When adult, however, the females are substantially larger than the males and look more rounded when viewed from above.

Breeding Sterbai Corys

Sterbai’s are considered to be one of the easier types of Cory to bread in the aquarium.  It is better to have a higher ratio of males to females and the fish should be conditioned on plenty of live or frozen food.  There are a number of triggers to spawning which may include time of year.  I have had success with fairly large water changes with cool water and plenty of frozen food, in order to replicate the wet season in the fish’s natural habitat.

During courtship, a number of males will chase a female around the aquarium until one male will pair up with the female and engage in the “T Position”.  Once the egg is fertilized, the female will carry it in her fins until she finds a suitable place to deposit it – this will likely be the aquarium glass but may also be the filter, broad leaved plants or wood.

Depending on what else is in the aquarium, some eggs are likely to survive and hatch a few days later at which point the fry will use up their yolk sacs before moving on to accept microworm and brine shrimp nauplii. I have had success in just feeding them using an old, decaying leaf from the aquarium (or more accurately, the organisms that feed on the leaves) followed by crushed flake.  Due to the likelyhood of predation of the fry in a community aquarium, I would recommend raising them in a breeding trap by collecting the eggs once they are lain.

Overview

The sterbai Cory is an easy to keep fish and a great one for beginners.  The most important requirements in my opinion are a soft or sandy substrate – they tend to struggle with sharp-edged gravel as it can erode their barbels – and a temperature that is a little higher than usual for most Corydoras.

They are not particularly fussy with regards to water hardness or pH, but they will prefer soft, acid water and are unlikely to breed in hard water.  As far as décor is concerned, I have found that they prefer a patch of clear substrate where they can forage and in their natural environment there is unlikely to be much in the way of plant life.  Having said that, they do seem to like broad leaved plants as they sometimes lay their eggs on the leaves.

A good biotope set up would be river sand covered in leaf litter with pieces of driftwood scattered around the substrate.  They would appreciate dim lighting or otherwise something to shelter them from bright light.

It is worth noting that as with all Corydoras, in Sterbai Corys the stiffened pectoral-fin spines are capable of piercing human skin and a ‘sting’ can be very painful, so care should be exercised when handling them. It is thought that secretions from the axillary glands at the base of each spine may even be mildly toxic or venomous.

These fish also have a modified intestine that has evolved to take-up oxygen in their natural environments so it is not uncommon to see them dash to the surface, take a gulp of air and then rush to the substrate again.  Unless this is taking place very frequently, it is not something to be concerned about.

It has also been noted that Corys can secrete a toxin as part of a defence mechanism that in high concentrations can be fatal to other fish.  This is particularly important to note when transporting the fish from the local fish shop and care should be taken to keep distress to an absolute minimum during transport.

In conclusion then, Sterbai Corys make great beginner fish.  They are very easy to keep and surprisingly hardy as long as they are kept on sand substrates and in fairly large numbers.  They also show a lot of interesting behaviours and are fairly easy to breed.