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February 08, 2013

Hello once again to all you fishy finantics. I know we had fun catching one of the world’s most sought after Loriicarid, Panaque cochliodon “Blue Eye Pleco”, in Colombia last week. I’ll be heading to San Jose this weekend to give a fish lecture on eartheaters to the Pacific Coast Cichlid Association and will need some time to prepare myself. Unfortunately, there are so many fish included in the family Geophagus that I won’t be able to cover all of it in about an hour. Why not cover some of this right here at home?

The South American cichlids of the family Gymnogeophagus are widespread throughout the countries of Argentina, Uruguay, and Paraguay. These fish are often collected and exported from the Ríos Paraná, Paraguay, and Uruguay in the Río de la plata Basin with the exception of Gymnogeophagus balzanii, which can be found in the Río Guaporé in the Amazonas Basin of Brazil. These countries are known for their cooler winters and scorching summers. The water temperatures should typically stay between 60-77° in the summer. During the winter months these plateau areas can drop down to as low as 40°! Because of this climate change, it is better to keep these cichlids in unheated aquariums – especially in the summer months. If you are planning on keeping the ‘naked eartheaters of the south’ than you will need to replicate these climate changes as best as you can. Fish that are exposed to warm conditions for longer periods of time often become listless and perish. Basically what this breaks down to is you really don’t need a heater for the aquarium. Setting up the aquarium is about as simple as you’d expect from most cichlid tanks. You really only need a few pieces of drift wood and some slate rocks for the fish to want to spawn on. You may place live plants, but be warned some species may consume them.

The reproduction of these miraculously beautiful cichlids can be broken down into two ways -the mouthbrooders and the substrate spawners. The substrate spawners choose a monogamous partner that bond for the entire length of the breeding process. Once a pair is formed both partners choose a flat and smooth spawning site which is cleaned before the eggs are laid. Then both parents guard their young until the fry are free enough to be on their own. The mouthbrooding gymnos allow for a single male to choose multiple females while guarding his terroitory. The eggs are kept in the mouth of the female, and she will care for the young. Mouthbrooding seems to be more common in Gymnogeophagus and seems to have higher survival rate.

Of the 10 described species, the most popular and well known is Gymnogeophagus balzanii. As mentioned previously, these cichlids can be found throughout Paraguay, Uruguay, Argentina, and southern Brazil. G. balzanii have a very tall body that has made them very sought after aquarium pets. They are also very peaceful and won’t uproot any plants that you may be trying to grow. The males typically grow to around 8”, and will display vivid colors during the spawning season. Like many Gymnogeophagus the males present a huge nuchal hump once mature. The females are typically a drab plain color that grows to around 5.5”. G. balzanii is part of the mouthbroodering family, and it is best to keep mulitiple females to every one male in a tank no smaller than 55 gallons.

 Gymnogeophagus balzani

Next, we have of on the most widespread cichlids of the Merín basin of Uruguay, Gymnogeophagus labiatus. Adult males of these dazzling colored cichlids are an array of oranges and blues, a glimmering striped dorsal and caudal fins, and thick lips to catch the eyes of potential females. Each location seems to be unique to each part of the country. Some locations exhibit elongated spots or stripes in the dorsal fin. The caudal fins can display different arrangements for the pattern. This particular batch was raised from the parents of a wild collecting point of the Río Olimar. Like G. balzanii, G. labiatus are mouthbrooding cichlids that should be housed in small groups.

Gymnogeophagus labiatus "Rio Olimar"

 Gymnogeophagus gymnogenys has the largest distribution of all the mouthbrooding eartheaters to the south. Each location has different colors, shapes, and designs. A lot of hobbyists and scientists feel that because of some of these differences can vary greatly, most feel that some of these forms can be potentially un-described members within the family Gymnogeophagus. Our batch was raised from parents of the Río Yerbolito. The males of this spectacular gymno have a black stripe that goes from the forehead and through the eye. The nuchal hump is a wonderful yellow color with a black “hockey stick” stripe right behind this. The fins display stunning red and blue stripes with the rest of the body being a tannish to yellow color.

Gymnogeophagus gymnogenys "Yerbolito"


Another tall bodied body gymno from the Río Negro in Uruguay is Gymnogeophagus meridionalis. There is much confusion with this species as it seems to come in under several trade names including G. sp. “Norte” or G. sp. “Blue Neon”. I believe that these are confused with the true G. meridionalis and are actually members of Gymnogeophagus rhabdotus. Adults are easily identified from the other variants by possessing a “high dorsal” that is covered in green and blue dots. The fish are covered with commanding blue and red stripes that run horizontal along the body. G. meridionalis are some of the smaller gymnos that grow to only around 4-5”. They are part of the substrate spawning group and a pair does become very aggressive when spawning. It’s advised if you are going to keep other cichlids with them I would have another aquarium set up to remove the others when this does happen.

Gymnogeophagus meridionalis 

 A lot of you know I pride myself in knowing a thing or two about South American eartheaters. If you live in the bay area you are more than welcome to come to the Pacific Coast Cichlid Association this Saturday night and I would love to enlighten you all about the rest of the family of eartheaters. I want to thank Dr. Ken Davis for the inspiration of this article. I hope to join him this November in Uruguay for our own collection trip.
If you’ve enjoyed this newsletter and want to learn more about the keeping of them, than I suggest going over our pricelist and picking some up for yourself. You can find all of these under the South American cichlid section on our pricelist.

Anthony Perry

Sales Manager