I had to dig a bit but this is why I always figured they are palys…
Thank you for the response. You can recite from memory or your book or a website, all of the visible characteristics that you wish. Doing so does not change the fact that identification is ambiguous at best in person and meaningless from a photo where even coloration can't be verifiably determined (if coloration was even a deciding factor). Again, this is due to the fact that there are biological variations and a rather complex lineage that ties all of these animals together and creates a high degree of visual ambiguity.
Almost any actual scientific study on the animals will get you headed in the right direction. There are literally dozens of sources, many behind paywalls or in offline journals and books but a few should be freely available.
The sample size was minuscule and therefore can't logically be extrapolated to entire order. Many of you are myopically hanging your hat on it as the law of the land without digging any deeper. I assume confirmation bias has something to do with this.
Now only "cryptic" palythoa? Sorry, but I think you are digging a deeper hole.
You keep repeating "Well defined" but it has been established that physical features alone do not define these animals. So back to square one, you are making an educated guess by using a photograph to identify them. That is fine in the context of hobby names and general conversation, but it is meaningless when it comes to differentiation with regard to biology and specifically toxicity.
The key takeaway (Reimer, as mentioned above) is that the for distributed siblings are almost indistinguishable but still differ and often carry different Symbiodinium and as such may or may not have or produce palytoxin.
I can send you a PDF if you want. Joe sent it to me himself.I had to dig a bit but this is why I always figured they are palys…
When I got them they were misidentified/ mislabeled. I guess the old method, small is Zoa, large is Paly…
Learn something new all the time.
I am eyeing the book you mentioned “Indo pacific corals”… but the $$$ is steep….
Regardless very educational discussion on zoa vs paly…
That is only talking about the Atlantic/Indo-Pacific species pairs, which I acknowledged in my last reply: you can tell them apart by collection locality. Of course, collection locality is usually not provided for captive species, which is why I (should have) put "cf" in my Zoanthus identifications
Please note the last line (though the entire passage is relevant):
I suggest reading any of the work by Reimer (noted above).
Furthermore, if you read these studies for context (not cherry picking what you want to hear), the recurring theme is that identification without genetic testing is nearly impossible and the mechanism for the production of palytoxin is not fully understood. Some lineages have the building blocks, but don't produce it, while others do. The new understanding is that lineage of these animals is much more complex than previously thought.
I see. Now do you have any evidence as to Zoanthus containing palytoxin? Maybe like a study that finds toxic amounts of palytoxin in Zoanthus species? All this time you have been saying "we have not enough evidence" or "the study does not have enough samples."
I did not say "only" cryptic Palythoa species. And I asked a coral taxonomist/biologist about this; he said that the Palythoa species are relatively easy to identify, and that the Zoanthus species are irrelevant.
By "well-defined," I mean the morphospecies are distinct from each other, which they are. About the "educated guess" thing--that is what EVERYBODY is doing when they identify corals morphologically.
You can't keep splitting hairs here and be somehow be correct. This is getting further and further from the point.
Sorry, I should have worded it better. I meant between the two Zoantharian genera commonly found in the hobby, Palythoa is the only genus that contains toxic levels of palytoxin; Zoanthus does not have Palytoxin.You can't keep splitting hairs here and be somehow be correct. This is getting further and further from the point.
Your argument:
The body of science date does not support that.
The specimen in question was genetically confirmed to be Parazoanthus sp. and clocked in at near 3mg/g of palytoxin... that is insanely high. Exposure was in an aquarium and the patient experience severe symptoms, lucky to be alive as it were.
Check your phylogenetic tree showing where Parazoanthus sits in relation to your "safe" Z. vietnamensis or the toxic paly's that sit in proximity.
Still no.
Do you have any evidence for Zoanthus containing Palytoxin?
This might not necessarily be true— there are a lot of factors that can contribute to toxicity, such as coral diet (which could be synthesized into a toxin), environmental conditions, presence of predators. This could lead two distantly related palythoas to adopt similar levels of toxicity. Similar to how the development of tetrodotoxin in pufferfish is seemingly unrelated to their lineages, and some species in a group may express greater toxicity than others in that same group (outlined in many research papers such as the one by Zhu et al.) While I’m not an expert in the phylogeny of zoanthid toxicity, I’d have to imagine it would follow a rather similar pattern.
I simply paraphrased what I have read in the studies that I have looked at.
Those are the very points being made, that so many here balk at.
I think if you look into some of these reports, you will find that the event directly correlates to manipulation of the zoa/paly. Anything is anecdotal unless it is proven in a controlled environment. The point is/was that there are numerous human illness incidents that have been documented and some of those coincide with tank deaths as well. The overarching point is that made numerous times here... treat them all as if they are toxic. That's all.
You are correct in a literal sense—technically, no species can be identified fully without DNA evidence. However, species identification exists with the purpose of individuals being able to identify things visually. @encrustingacro has correctly identified a species based on the observations and experiments of scientists. If every time we stumbled upon an animal and tested its DNA to confirm in was indeed a particular species, biological science would be a lot slower than it currently is. You also seem to be confusing the term species with the term morph. There are hundreds of zoanthid breeds which have all sorts of crazy names, but they all fall under an umbrella species name. Similar to identifying dog breeds, the only way of knowing exactly what it is would be through DNA testing. However, Z. vietnamensis is a distinct species, not a morph. So your country of origin analogy is irrelevant, because all humans are the exact same species. You don’t need DNA evidence to prove that.
I stand correctedDeeds, et al. 2011
Some of the the samples tested in THIS study showed palytoxin. There are others.
You are now going to split hairs and try to compare "weakly toxic" to "highly toxic" but will be again missing the point. If you read the research, these are interspersed side by side with siblings that contain high levels and those that contain none. They have only tested a tiny fraction of the known species.
You, at every juncture of this conversation appear to have ignored the facts in favor of your opinion.
There is no need to be obtuse, it obfuscates the point. IDing these things by looks is fine for general conversation, sale, whatever. The problem is that it is NOT close enough with regard to positive identification for the sake of determining toxicity, origin, etc.
I am not confusing anything. Both my be intermingled here in conversation by various parties or segments of hte conversation, but the issue (again) is that one can't tell by looks alone which morph is or is not toxic and many morphs are ambiguous when physical traits such as color, number of tentacles, disc size, etc. are considered.
Thank you. Enjoy your zoa's and be safe!
Sure, but when someone has expertise in the matter, they are able to tell such distinct differences. I should think that being able to correctly identify a species by morphology would be less obfuscating than repeatedly saying “we can’t know unless we have the DNA”. Given that we’re not going to conduct such analyses with each ID thread, the best we can do is make an educated observation based on the data that we do have. To consider this method of identification as objectively wrong is simply irrational and damaging to the conversation.
