What Did You Call Me? - Yellowhump Eartheaters

The Yellowhump Eartheater (Geophagus pellegrini) does not have the most glamorous name, honestly you could call someone this as an insult, and it would probably land. On the plus side, this is a gorgeous fish, that is very active and engaging to watch in the home aquarium. Yellowhump Earth Eaters can be found in Colombia, where they are native to the Atrato, Baudó and San Juan River drainages. Here they have been collected in a variety of habitats, but always in rivers with some flow and at least partially sandy substrates, which is imperative to how Eartheaters forage for food.

Geophagus pellegrini was named for western science in 1912 by Charles Tate Regan, a British ichthyologist, who also classified hundred if not thousands of other species during his career, including the famous Betta Splendens (the example used in our recent binomial nomenclature article). The “Geophagus” part of the name is a reference to the “earth eating” habits of these fish, while “pellegrini” is a nod to a French scientist named Jaques Pellegrin. Pellegrin was a renowned zoologist at the Muséum national d'histoire naturelle, who, after naming more than 350 species, and authoring some 600 books, died fighting the Nazis at the age of 71 in 1944.

The scientific name for the group of fish we call “Earth Eaters” is “benthophage.” A benthophage is a fish that feeds by taking up mouthfuls of substrate and filtering it for edible items while the rest of the sand is then expelled through their gills. This is a strategy that happens in a variety of environments, there are even fish on the marine side of the fishkeeping hobby that employ it. The Yellowhump Eartheater feed exactly this way, and as a result, needs an aquarium with a fine enough substrate to be able to do it. They will also take food out of the water column, but even if their dietary needs are satisfied that way, will still engage in the sand filtering activity. This feeding style leaves them being omnivores. They get plenty of plant matter and algae, but they are mostly hunting for small invertebrates. We feed them a variety of thawed foods from Gamma, like mysis, tubifex, chopped prawn and bloodworms. We supplement this diet with pellets from Nutramar, and we use their Algae and color boost formula to help them get enough green in their diet. They will also greedily take live inverts, like small worms. In the wild, they would graze all day long, and so we recommend feeding them at least twice a day.

Displays for Yellowhump Eartheaters should be decent sized, as this is a fish that can get to be up to six inches long, though they are much more commonly four or five inches as adults. We suggest keeping a pair in an aquarium of no less than 55 gallons. Very clean water is a must for them so you should oversize the filtration, for a minimum turnover of five times per hour and ten would be better. This being said, because they also need a fairly fine substrate for their filter feeding habits, the flow must be diffuse enough to allow this sand to settle when it gets disturbed. They don't need a ton of sand, but an inch or so will give them enough work to do and make for a much more interesting display; look for sands with small grain sizes. They do like some cover, and driftwood would be our choice here. Flat smooth rocks should be included for those of you who are interested in trying to spawn these fish in captivity.

All Geophagus will move a bunch of substrates around, so they are not well suited for aquariums that have rooted plants. They'll be okay with things like java moss that are attached to other surfaces. They are a very peaceful fish (as long as they aren't overcrowded) and aren't much threat, even to fairly small fish. The list of things you could keep them with is long, just don't attempt to keep them with more aggressive fish as they will suffer from the bullying. For obvious dietary reasons, they should not be kept with decorative shrimp (unless you want to get rid of the shrimp!) They can be kept in pairs or small groups if the aquarium is large enough, this being said, you should only maintain one male per grouping.

As referenced, this is a fish that likes really clean water, so in addition to the oversized filtration, we recommend large, regular water changes to maintain a nitrate level under five ppm. They do best in softer water (under 50ppm, though up to 75 would be ok) and the water should have an acidic profile, pH should be between 5 and 6.5. Some of the rivers they are collected from are tea colored and if you are into this type of display, these fish will appreciate it. If not, think about utilizing lower light levels for them. Temperature wise, these fish will well anywhere from 75 to 85 degrees Fahrenheit, but it is easier to maintain higher oxygen levels at the lower end of this range.

Yellowhump Eartheaters do indeed have a yellow hump, that develops on the “forehead” of the mature males, an indication that they are old enough to reproduce. For those of you interested in this challenge, they are not the easiest fish to get this accomplished with, but very possible for the dedicated home aquarist. As previous referenced, they will need a flat smooth surface to lay eggs, and in breeding specific set ups, consider using deeper sand bed, up to three inches on average. Maintain the display at the low end of their temperature preferences, mid-seventies, perhaps even dropping to that temperature with a few larger than normal water changes. Some sources also indicate that they have better success inducing spawning at the higher end of their preferred pH range, around 6.5. These fish are mouthbrooders, and the female will pick up the fertilized eggs within a day or two, then carry them until they hatch. Fry will be stashed in caves and sandy holes (if the sand bed is deep enough) during the day, and collected by the female for protection at night, and this will happen for the first two to three weeks. After this, the fry will be big enough to consume fairly large foods like artemia, crushed flake and baby brine.

All of the Eartheaters are staff favorites around here, they are just so cool to watch. If you get them to successfully spawn in the aquarium, Yellowhumps have one of the most unique reproductions to witness. It's worth keeping them as a species-specific display. Luckily, they are also gorgeous enough to pull this off! These are fish that aren't difficult to keep but will need regular attention to water quality. If you love this stuff, then Geophagus pellegrini is one of the neatest fish you can keep. Head to your LFS and ask them to get you some Yellowhump Eartheaters from Aquatropic today!