Mimics, lineages and chance of hybridization

[gossei]

After reading the Alexandrou, et al article "Competition and phylogeny determine community structure in Müllerian co-mimics" and the related chapter in Fuller and Evers "Identifying Corydoradinae Catfish Supplement 1", I was overcome by a bout of full-frontal nerdity and have become obsessed with setting up a tank featuring some corydoras mimics.

Is it reasonably safe to assume that fish from different lineages are less likely to hybridize than fish from the same lineage? Is it also safe to assume that the further apart the lineages are, the less likely the chance of hybridizing? My only existing mimics (or are they?) are

Corydoras paleatus

and

Corydoras ehrhardti

, both from the lineage 6.

Is it safe to pull the trigger on this, or is it folly?

Blaise

[MChambers]

Interesting question, Blaise. I'm just guessing, but I think it would be safe. Would seem that if the mimicry exists in nature there's no hybridizing.

I haven't actually read the full article, however, so someone who has thought more carefully about this should respond.

Matt

[Karsten S.]

Hi,

I have read the paper.
In my mind it is up to now the best approach to resolve the corydoradine phylogenetics.

It is reasonable to assume that the probability for hybridisation of two species is the higher the closer they are related.
Most of the known hybridisations within Corydoradinae happened in the same lineage, but there are a few exceptions.

Mimetic pairs are sharing in the same habitats, frequent hybridisation is obviously not happening there.
Therefore there has to be a barrier for a interspecific reproduction, this is not necessarily a biolocical or genetic one and it is not necessarily also present in our tanks. Just a few (rather theoretical) thoughts...

However, I would agree that there is only a minimum risk to keep two mimetic species.

Cheers,

[Coryman]

There are many species that at certain times of the year are found together, whether these species breed in the same locations is to a degree unknown. There are as we know a number on mimics i.e. C. opapoquensis/C. condisciplus, C. imitator/C. adolfoi/C. serratus, C. seussi/C. gossei. I have never seen or heard of hybridisation between species in any of these groups.

Personally I think there are far more differing ingredients in the species natural habitats which keep species separate, even in the same location, Things like preferred food items, substrate texture, water flow, depth. I an aquarium we force these fish into one set of conditions, which means that they have to rub shoulders with each other, like it or not.

We also see far more reports of hybridisation in tanks where there are many species but only in ones and two's, making the choice of mating partner almost impossible, the fish that come into breeding condition at the same time mate. In some of my stock tanks where I have 3 or 4 species groups of at least 6 of each species, I have had species spawn and only ever mated with their own kind.

Ian

[exasperatus2002]

I think in nature each species has its own queues for spawning, different niches & possibly different preferences for egg deposition, that they utilize, that act as barriers against hybridization. In the confines of an aquarium, there are no such barriers and hybrids are more likely to occur. Then, again is my opinion as I havent had the opportunity to read the articles in question.

[gossei]

Thanks for the responses. I'm not overly concerned about hybridization, as I, too, keep different species in the same tank without hybridization occurring. However, I have been fairly rigorous about not having similar species sharing a tank (e.g., no more than one lineage species per tank).

Blaise

[Tony C]

This seems like a good place to ask instead of starting a new thread. Are C. reticulatus and C. sterbai able or likely to cross breed, or could I keep them together safely?

[rmc]

If you can get C. reticulatus to breed at all let me know! lol I've been trying for about a year now and they don't do much besides eat and look pretty! I have bred C. sterbai however and in my experience they really only bred when they were the only Cory in the tank. Having tank mates (at least in my fishroom) seems to put a stop to their spawning, which when housed alone was quite often! Maybe others can share their different experiences, but if you have reasonable sized groups of each of those 2 species, I don't think there is much risk of hybridization there.

[Tony C]

Thanks for the info.