Creating a hybrid taxon with little source data

I’m wanting to create a new name for a hybrid Dwarf Angelfish - Centropyge heraldi × nox for this observation. I’m pretty sure this is the correct ID for the observation, but the problem is, this genus has an almost infinite number of possible hybrids with new ones being discovered all the time and it’s basically impossible to find literature sources for these outside of online articles, often written by aquarium hobbyists. But these hybrids are important, especially as concerns the aquarium hobby and study of these fish genera, so it’s not a waste of time to create these names and properly document them when possible. Is a source even needed in the case of hybrids?

Hello, I do not have much experience with fish so if I am totally wrong here please let me know.

I feel while it may seem like a good idea to create a new taxon without a scientific source for these hybrids as I agree they are important, adding a hybrid taxon to iNaturalist without proper scientific backing could be problematic. The reason for this is that if the hybrids you are trying to add were only described by hobbyists, they may not always have the expertise or experience required to correctly identify or classify hybrid species. For example, in my field of expertise, there are multiple Isopoda species that have been reported to create hybrids in the hobby; however, every one of them turned out to be incorrect. Fish of course hybridize more than Isopoda; however, I could see similar things happening. Moreover, as you have rightly pointed out, the sheer number of possible hybrids within a genus like Centropyge can make it difficult to find reliable literature sources for them, and relying solely on hobbyist articles could lead to errors or inconsistencies in naming and classification.

If you are confident an individual is a hybrid and there is no source or a hobbyist source I would say it would be best to flag the parent taxon and discuss adding the hybrid with other curators knowledgeable in that field.

Edit:

Here is a hobbyist article saying that it is not a hybrid: Black tailed Centropyge heraldi is just another one of numerous confusing variations

Here is one saying that it is: Centropyge Hybride (heraldi / nox)

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The problem here is that the hobbyists often are the experts. Joe_fish is a perfect example of this. He’s specifically written on the genus before. I’ve also personally worked in the aquarium industry and a lot of the more intricate information is only known to hobbyists - non-hobbyist scientists tend to be oblivious to the minutiae of hybridization and color morphs in aquarium fish genera, for example. Additionally, there are far too many hybrids to write papers on all the different combinations and most hybrids don’t have much literature behind them, though they’re known to exist. And in the genus Centropyge, we actually expect to find these hybrids. Even if a hybrid is mis-ID’d the hybrid names should be available to choose from. If I mis-ID a Flame Angel as a Coral Beauty, I can just go back and switch my ID. The same should be true with the hybrids in question. But they can’t be added to the system at all if there’s no “traditional” source. Many of the major sources such as WoRMS don’t even list hybrids so there’s nothing to reference.

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I posted before you added the article about the variants. I hadn’t read that, but a lot of those appear to be hybrids, though not necessarily F1 generation. The bicolor hybrid is obvious, but likely second generation.

It appears that this is widespread across numerous fields, and the Isopoda community is not an exception. In the context of the Isopod hobby, a single accurate identification is often accompanied by approximately ten erroneous ones, resulting in considerable perplexity and an overwhelming number of identification options. As evidenced by the sources cited in the previous post, a similar situation exists within the aquarium hobby as well. I feel it would be unwise to introduce this level of confusion to the iNaturalist platform, as that is not its intended purpose.

Also, many hobbyists do not realize it but they can submit to scientific journals; however, they would need to go through the peer review process that makes the scientific literature more accurate.

I think that’s taxonomy in general, honestly. Again, most of this doesn’t apply to hybrids, since they’re real entities that most organizations pretend don’t exist.

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I agree it is; this is why iNat uses taxonomic authorities (databases or individuals) and why I feel adding species based on data not supported by the taxonomic authorities should be added sparingly.

I kind of feel the opposite. If hybrid selections aren’t available, individual organisms can be misclassified, losing valuable information. I feel it’s safer to actually err on the side of marking an animal as a hybrid, as you can always walk it back. Not identifying a hybrid - nor in fact even having a name available to identify it with, however, just leaves that data in a hole and basically covers it with dirt. It’s similar to the fact that disagreements in identification carry more weight because they’re more likely to be correct.

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Are we talking mostly about wild or captive observations here? This has come up with plants before, and the consensus has been that hybrids only known from captivity probably shouldn’t be added because that’s not the point of iNat. I’ve added a few hybrids, but that’s only been in instances where they were documented in the literature and they were of wild individuals. With malacology at least, hobbyists are often extreme splitters and many of their names are dubious at best.

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Wild I believe.

I would also like to add here that after reading articles by multiple hobbyists it seems like no consensus was reached on Centropyge heraldi × nox with one of the last discussions on the topic from 2016 with someone saying that only molecular analysis could determine if it was a hybrid or aberrant. http://www.wetwebmedia.com/paracentfaqs.htm

As, I have stated I do not believe that this level of uncertainty is appropriate for iNat as the platform is more for educating and getting people involved with nature. If taxonomy is too complex the layperson may be turned away.

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Wild. Honestly, if they’re captive-bred hybrids, then the genetics are even more understood and there’s documentation.

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I don’t put a great deal of faith in most genetic testing methods. Most use mtDNA, which is straight pseudoscience. mtDNA testing techniques have three major flaws - 1: mtDNA is not the DNA of the organism and tells you nothing about its actual traits, 2: mtDNA is typically (though not always) derived exclusively from the mother, heavily skewing results away from nuclear results and 3: And this is the worst part - most genetic testing techniques - mitochondrial or nuclear only use tiny snippets of genes to try to sort out relationships, which gives wildly inaccurate results. The genetic testing techniques currently en vogue are great if you’re trying to publish lots of papers and chop up taxa like a sushi chef, but they’re not good for much else, and they’ve created an entire universe of confusion and misunderstanding in the taxonomic community. I exclusively advocate for full genome apples-to-apples comparisons in any genetic testing. Anyone using anything less than that when it comes to genetic testing I refuse to take seriously. I’ve just seen these techniques go wrong far too many times to consider them scientifically useful.

Edit: Also, the default position you’re taking isn’t the neutral one. Calling a coywolf Canis lupus, because it’s “less confusing to newbies” is straight up feeding those same users inaccurate information.

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I agree with your position, buf e.g. for fX hybrids of Herring ang Caspian gulls I will call them by the species they’re more close to, hybrid observations never get a second id, most hybrids look pretty nuch like Herring gulls and with the whole population being affected by hybridization, it’s just what local Herrings are, a mess of a gull.

Yeah I can see that, and gulls flock in huge numbers which makes it more difficult. The difference with Centropyge species is we’re expecting hybrids to be seen. Most people interested in this genus have backgrounds in the aquarium hobby. And Centropyge species never travel in groups of more than about 1-3 individuals as they’re harem animals so they’re easy to pick out.

I can understand your concerns about genetic testing methods and your preference for full genome comparisons; however, it’s important to recognize that genetic testing methods are not pseudoscience, and they have provided important insights into a wide range of scientific fields.

While it’s true that mtDNA may not tell you anything about the organism’s actual traits, it can still provide valuable information about the evolutionary relationships and history of a particular species or population. In addition, while mtDNA is typically maternally inherited, there are other genetic markers that can be used to study paternally inherited traits. It’s also important to note that while some genetic testing methods use only small snippets of genes, these methods have been validated and are widely used in many areas of genetics research. They may not provide a complete picture, but they can still provide valuable insights into genetic relationships and variations.

When studying fish genetics, researchers often use a combination of different molecular markers to gain a better understanding of genetic relationships and population structures. AFLPs (Amplified Fragment Length Polymorphisms), microsatellites, direct nucleotide sequence variation, and SNPs (Single Nucleotide Polymorphisms) are among the most commonly used markers.

Morphological analysis can be just as inaccurate as molecular analysis, particularly when it comes to identifying and classifying species.

The phenomenon of phenotypic plasticity due to factors such as environmental variation or individual differences can make it difficult to accurately identify and classify species based solely on their physical features. Another reason is cryptic speciation, in which some species may appear very similar in morphology, but be genetically distinct and evolutionarily separate. This can lead to misidentification of species if only morphology is used for classification. Hybridization between species can also lead to intermediate forms with characteristics that do not match those of either parent species, making it difficult to accurately identify them based on morphology. Human error is also a factor in the accuracy of morphological analysis. This method requires a high level of expertise, and even experts can make mistakes or misinterpret characters due to subjectivity or bias.

Overall, while morphological analysis is still an important tool for studying organisms, it can be just as inaccurate as molecular analysis, particularly when used in isolation. For the most accurate species identification and classification, it’s often necessary to use multiple approaches, including morphology, molecular analysis, and other lines of evidence such as geographic distribution, behavior, and ecology.

Yes, I agree to call a coywolf Canis lupus, because it’s “less confusing to newbies” is inaccurate information; however, those hybrids have scientific literature on them, not based on “guesswork” as Lemon Tyk put it.

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The iNat Curator’s Guide is pretty clear that hybrids should be avoided and only really used when supported by the scientific literature. It says, in part:

“Given their vague morphological delineation and taxonomic uncertainty, use of hybrid taxon concepts should be avoided whenever possible. Adding IDs of higher-level taxa is usually sufficient. In those rare cases when some external authority actually supports a named hybrid, we will tolerate it, but please abide by the following guidelines.”

Given the links presented above, it seems like adding a hybrid taxon in this situation would not be justified under the guidelines.

On a side note, as someone who has done research on hybridization, identifying hybrids using nuclear DNA is not that difficult in most species. If they have unusual numbers of chromosomes or genome structure, things can get wonky, but in these situations, strong evidence would be needed even more to determine what the heck is going on. mtDNA is not “psuedoscience” but it doesn’t provide good evidence for hybridization since it will almost always be inherited from one parent. I don’t think scientists currently studying hybridization would base a study around mtDNA though it might have been done decades ago when mtDNA was really the only thing being sequenced for logistical reasons.

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Obviously mtDNA isn’t pseudoscience. It’s a part of mitochondria. I’m absolutely not going to agree with you on the current trendy techniques such as COI barcoing not being pseudoscience. They’re simply trendy, even when they give totally wrong results. I personally have plenty of experience trying to undo the incorrect ideas scientists get from using genetic tools that are designed around ease of use rather than accuracy. I’m not a fan. As far as the hybrid names issue goes, I guess I have my answer - avoid them unless they’re specifically published.

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Obviously this was in reply to the wrong post.

As someone currently working through sequencing 1500 samples (with multiple genes for each), this is neither feasible nor a good use of money when individual genes are just as helpful at differentiating species.

This is simply not true, at least for the groups I’ve worked with (mollusks and fungi).

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