Too much brain time committed to understanding cory mimicry

[bekateen]

My brain is drifting with imagination and it leads me to a question:

• Are there any Lineage 1, 8 or 9 corys that have a strong color pattern resemblance to elegans or napoensis?

Sodalis gets close in Lineage 8, but even then not very. Considering all the mimicry among other color patterns, are there ANY real mimics in Lineages 1, 8, or 9 for the elegans types? I can't think of any great matches. Thanks for your help.

Cheers, Eric

[Mol_PMB]

Hi Eric,
Not my specialist subject, but I am interested in the Cory species in different lineages that have similar colour patterns.
Where these live together in the wild, is there evidence that one evolved to mimic the other, or simply that both species evolved to be well camouflaged in the local environment?
Where similar-coloured species don’t live together, can this be considered mimicry at all?
Also I note that there are several examples of mimicry with other species (including Brachyrhamdia and some characins).
With the elegans group having different habits (more mid-water dwelling than most corydoras) should you perhaps be looking for a characin mimic?

[bekateen]

Hi Paul,
Those are all good questions. To some, I don't think we have any answers yet. I'll do my best to summarize my understanding:

Where these live together in the wild, is there evidence that one evolved to mimic the other, or simply that both species evolved to be well camouflaged in the local environment?

This is a tough one to answer. The latter option is perfectly reasonable and may be sufficient to explain a lot of pattern similarity, but it wouldn't exclude an influence of the first idea. Also, there's no reason to discount the possibility that one idea may be the cause and the second occurs serendipidously.

Where similar-coloured species don’t live together, can this be considered mimicry at all?

No, I don't think mimicry would apply to species living in different locations, unless perhaps they are dealing with predators that are able to hunt both species (e.g., a migrating or wide-ranging predator). Taking into account my comment above, it's also been my impression that in many fish (in particular, we'll focus on corys and plecos here), I've noticed that certain genera and lineages seem to have above-the-species-level color patterns which I infer are genetic traits of the group, and this may pre-dispose fish that have shared ancestry to develop similar color patterns. What do I mean by this? Take a look at the

Panaqolus

or

Hypancistrus

or

Ancistrus

- there are certain color patterns which prevail in the genus (e.g., the scrolled lines on the face of many Panaqolus) which do not occur on plecos of other genera. Likewise, the black & white colors of many hypans are not recreated in Ancistrus or Panaqolus or other genera. These genetically determined patterns seem to be arch-typical of subgroups within each genus. In that sense, I am not surprised to see the re-occurrence of patterns like those of

Corydoras trilineatus

,

Corydoras sodalis

or

Corydoras duplicareus

in a variety of cory species, even if they don't live side-by-side. So is that mimicry or merely relatedness? Even if it is relatedness, it does not exclude any benefits of mimicry (but as you point out, if the two species do not live together, it's difficult to call the color match "mimicry" since, what are they mimicking?)

Also I note that there are several examples of mimicry with other species (including Brachyrhamdia and some characins). With the elegans group having different habits (more mid-water dwelling than most corydoras) should you perhaps be looking for a characin mimic?

True, you might expect that, but I'm asking about mimicry within the corys between different lineages. I suppose you could argue that all of the corys WITHIN the

Corydoras elegans

group are mimicking each other, but I'm thinking about all the corys that have mimics in other lineages. Perhaps because the elegans group species tend to be midwater swimmers and most other lineages of corys are not, that might predispose them to NOT mimicking the elegans-type corys. If that were the single explanation, I would find that fascinating.

Of note, @The.Dark.One observed that

Corydoras zygatus

can resemble some of the females in the elegans group. This is true. I was thinking of male elegans types when I asked my question, but the female comment should not be overlooked.

Cheers, Eric

[panaque]

I assume you are aware of this paper Eric, but others may not be: https://www.nature.com/articles/nature09660

[bekateen]

I assume you are aware of this paper Eric, but others may not be: https://www.nature.com/articles/nature09660

Yes, it's from this paper I started thinking about this. Thank you for reposting the link.

Cheers, Eric

[panaque]

From that paper...