Austraolheros and Geophagus questions.

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Aladyne

Feeder Fish
MFK Member
Dec 14, 2016
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Missouri, USA
Is there a difference between Australoheros facetus and Australoheros oblonga?

My google searches have been getting mixed results. Some say oblonga was renamed to be included into facetus, others I see they're still different species.

My question on geophagus is is it possible to have breeding colonies of different geophagus species or any of the other "earth eaters"? If so, what species? Will they interbreed? Also, how many of each species and what ratio? I've gotten really confused with trying to research this so decided to ask the experienced ones here.

Thank you.
 
No one really knows, oblongum has never been found in the wild after that first import of them, so they have never been formally described. They seem to take higher temps which might mean they are found further north, possibly in Brazil? We may never know.
 
Don't know on the Austaloheros question. As for geos, I've seen people report similar types interbreeding, two suriname types or a suriname and altifrons, for example. But I've also seen people keep similar species in the same tank and only spawn within their species.

Speaking generally, both from what I've seen and personal experience, when keeping similar species together tank size helps as does having available mates within the same species. But there's also an element of randomness with individual behavior of individual fish, so maintaining order might require some intervention.

Even more general: It's well documented that "species" has different definitions among scientists or that the term or its usefulness has been debated. So the most common definitions you might see aren't that simple in the real world and nature doesn't always play by these classifications.

http://www.askabiologist.org.uk/from_the_lab/species-concepts
 
"Oblongum" is a trade name.
As darth pike mentions, the fish known as "oblongum" in the hobby is an unknown.....nobody seems to know where this fish originates from.
The name Australoheros oblongum is considered to be a synonym of Australoheros facetus.
But that fish doesn't have much to do with the "oblongum" in the hobby.....as we really don't know where it comes from.
"Oblongum" could be an undescribed species. Or it could be a regional variant of one of the 29 described species. Some have even speculated that it is hybrid developed in the far east, though I sort of doubt that.
 
If you keep multiple individuals of each Geo species you shouldn't see interbreeding. But if they do not have one of their own to spawn with, they'll gladly choose another, as I found out with a lone male G. parnaiba and a female orangehead.

 
By multiple is it just a pair or does geos prefer more of a "community" type of setting where they are with multiple of their own kind? If so, which ones would you recommend and how many of each should I be looking to add for a group?

As for the australoheros, I've seen videos of a few different species on the internet, but realistically how easy are they all to get ahold of? Are there any that I should be shooting for over others?
 
A. facetus is the type species for the genus. Facetus grow quite large (close to a foot) and are pretty robust, aggressive fish. They're quite cold tolerant. I collected them from the type locality (where Darwin collected them too at a place called Laguna del Diario near Maldonado in Uruguay) a few years ago and they would breed in the spring when it warmed up from the mid-50s (in a tank on the floor of my basement to the upper 60s/lower 70s).

The fish known as A. oblongum are much smaller and, while cold tolerant and appreciate a winter cool down, in my experience, much smaller and less aggressive. Largest I've seen are about 5-6". They have really interesting breeding behavior and hang their fry in the plants. I don't think that their true origin in the wild is known but they've been around the hobby for a couple of decades.

Both are well worth keeping.

Matt
 
I didn't realize Facetus got so big. The research I found they were 7-8" TL. That's why even after research I would rather ask on here. I feel that experienced keepers would know more than whatever I find on google searches.
 
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