Genus Selenocosmia

[Theraphosid Research Team]

Hello Volker,
What Thrigmopoeus species looks this similiar to Arndsti???
This specimen photographed is still quite small with a leg span of roughly 1.5-2".
The light coloration can also be due to my horrible photographs hehe ;]
I received a group of these after loaning my male out to someone here in the USA with an adult female.I cant imagine they are hybrids...Can you share any more info about this Thrigmopoeus species you mention??
Thanks!
-Chris

Hi,

oh, I thought it would be a larger Specimen. But it's still curious, because it really looks like Thrigmopoeus truculentus (see attached file below).

Cheers, Volker

 

[Theraphosid Research Team]

Volker,
I have examined conspecifics from Samar which are apparently identical to the type. So, you think the spermathecae of this animal are not those of S.samarae?? I ask because I know most (but certainly not all, look at the spermathecae of the Orphnaecus type species as a clear example) are similar to the image, but I most certainly at no stage declared that the spermathecae were useful to identify species, what gave you that impression?

Hey Steve,

I'm sorry, I've misunderstood you. Of course you hadn't said that you can identify a Species only by the shape of the Spermathecae. You only said "Those are indeed identical to the spermathecae of S.samarae...", so I thought you had an impression of the Spermathecae from the Type Specimen, which is the only Specimen by which you can identify this Species for sure. But you mentioned that you haven't examined the Type ...

BTW, not in all circumstances is examination of a singular type needed to identify a species, only in some circumstances is this required. And quite often, the type is only a singular token representative of a species, true identification of a described species requires examination of possible conspecifics to determine stable traits IMO. Better a few than merely one, type or not.

An example: If you receive a group of Theraphosid Specimen from an island which named Samar. How can you identify this group of Spiders as "Selenocosmia samarae" without examining the Holotype of this Species? Actually I have a collection of round about 30 Specimen of Theraphosidae from Samar Island in my private collection (they were collected there from a colleague with which I'm preparing a revision of the genus Orphnaecus. I will do the morphological work, he has done the DNA stuff). Within this collection, we also have Sel. samarae, but also a lot of further Specimen, which belongs to other Species than to Sel. samarae. But I was only able to give the Name "Sel. samarae" to the right Specimen from Samar after examining the Type. Yes, I was able to distinguish the different Groups only by examining the Material in my collection by the help of a lot of useful taxonomical characters, but I was only able to give the right name to the right group, after examining the Typematerial of Sel. samarae. I have examining 99% of the Typematerial from the Ornithoctoninae and ca. 60% of the Selenocosmiinae and I can say that it is absolute neccessary to examine the Types to identify examined Material to Species level!

...not in all circumstances is examination of a singular type needed to identify a species

This argument is often used by Persons which do not have access to type Material but which have a lot of Material to examine. Here in Germany we also have a very old Person which used this Argument often in the past (you know about which Guy I'm talking about. ). I think I have declared why it is not possible to identify a Species for sure without examining the Type! So, to my opinion (based on the lots of Types I have examined up to now) it IS in all circumstances needed to examine a singular type to identify a Species!

...You ask for an image only of the stridulating organ, which is adequately illustrated in the original description by Giltay very well, to identify the species.

If you think that the illustration in Giltay's original description shows the real Stridulating Organ of the Type, okay, it's your opinion. But, please, accept that I follow my own exminations and pics which I've made from the Stridulating Organ of the Type!

Cheers, Volker

 

[John Kanker]

This argument is often used by Persons which do not have access to type Material but which have a lot of Material to examine. Here in Germany we also have a very old Person which used this Argument often in the past (you know about which Guy I'm talking about. ). I think I have declared why it is not possible to identify a Species for sure without examining the Type! So, to my opinion (based on the lots of Types I have examined up to now) it IS in all circumstances needed to examine a singular type to identify a Species!

This reminds me of G.aureostriata and P.maya which shows it still goes on and not just by an old guy in Germany. Too be honest I can't ever see it changeing either as more people get desperate to get their name on a paper!
Tarantula stardom rivals that of hollywood lol.

Thanks John

 

[Steve Nunn]

Hi Volker,
I think you simplify things a little. Not in all cases is examination of a type needed, it also critically depends on the geography, the original description, known congeners, prior knowledge, Pers.comm and all previous publications. Not in all cases are all factors needed, it greatly depends on value of evidence at hand. Sure, in many cases type exam or viewing is needed, I do not argue this, only that you simplify things by saying type exam and only type exam will solidify an identification in every circumstance. The "other person" we are talking about has several problems, lack of experience with types being one of them, I aboslutely agree with you. Even if he had experience with types, this may not help him out at all!

Type exam is not unequivocal, depending on additional types (jun.syn. in particular, but also lectotypes and some others), value of some descriptions (original types, neotypes and syntypes) and known conspecifics. Of critical importance is the increasing issue of singular types, due to pathology and teratology, the need to identify conspecifics is of utmost importance on many fronts. Ontogenetic phases are critical, part of teratological issues ie: a juvenile singular type may not show all traits of an adult species population. Geographical range and species vicariance are concerns that need to be understood if possible, to compare against a singular type, or indeed a group of types from a single location (or quite possibly, an adequate species description). As I said though, it depends again on the above factors I just mentioned. So it is a good tool no doubt, not as finite as you say. The above are just a portion of the problems with types as a be all and end all "solution".

Further, it can depend on what is being discussed where, as an example I can safely say within a hobby forum an image of P.metallica is indeed that species, because I've seen conspecifics in numerous images, I know what is within the hobby, I know no other conspecifics 'look' the same, so I can make a safe sssumption. I need not have examined the type to know this. An owner of a B.smithi on this forum knows it's a B.smithi, they need not have seen a type to know this. Personal communication suffices well and truly.

If I were publishing an article, I may want stronger evidence than that (unlike our friend) and may indeed look to a type, but not in all cases would this be the route (an example may be a species within an area where no congeners are found, or known to exist, in combination with supporting evidence). It also very much depends on the venue as to a prerequisite for species identification.

I hope you understand what I mean.

Thanks,
Steve

 

[Martin H.]

Hi Steve,

... An owner of a B.smithi on this forum knows it's a B.smithi, they need not have seen a type to know this. Personal communication suffices well and truly.

thanks for that example, I just wanted to ask for it! =;-)

What makes the people and also you so sure, that, what we lable "B. smithi" in the hobby is indeed that what was described by F. O. P.-Cambridge in 1897 as B. smithi? Only because it is labelled B. smithi in the hobby since a long time?

all the best,
Martin

 

[Theraphosid Research Team]

Hi Volker,
...Further, it can depend on what is being discussed where, as an example I can safely say within a hobby forum an image of P.metallica is indeed that species, because I've seen conspecifics in numerous images, I know what is within the hobby, I know no other conspecifics 'look' the same, so I can make a safe sssumption. I need not have examined the type to know this. An owner of a B.smithi on this forum knows it's a B.smithi, they need not have seen a type to know this. Personal communication suffices well and truly.

...

Hi Steve,

a short annotation which follows the argumentation from Martin. You told that you have "... seen conspecifics in numerous images (of P. metallica),...". But, how could you know that the "numerous images" indeed shows P. metallica? I can answer this rhetorical question myself: You have a clear "picture" of P. metallica in your mind, because one day in the past there was a Person (I think it was Andrew Smith) able to identify Material, which was collected in India, as belonging to Poecilotheria metallica, after the examination of- and the comparisson with the P. metallica Holotype. Thereafter, the offspring of this Material, identified as P. metallica, were sold worldwide under the Name P. metallica. So, that's the reason why you have a clear "picture" of what is P. metallica about. But in the beginning, there was the identification of the Material by comparing it with the Holotype! That should be always the beginning of an identification process, and so I'm STILL of the opinion: the examination and comparison of the Types is the only way for a correct identification!

I know no other conspecifics 'look' the same ...

Don't understand, because conspecifics of P. metallica belongs to P. metallica by definition and so they are obviously identical within their main characters.

Cheers, Volker

 

[Steve Nunn]

I meant congeners my apologies.

Lets just say I find a spider that allies with Raven's description of C.tropix, within the same locales that species is noted in. Are you meaning to say that only by type examination I can truly ID that species, and that the description cannot not suffice?? Tom Prentices A.paloma?? Interesting to me.

You missunderstand me, I know that type exam is often criticial in identification, but by no means is it a be all and end all.

And thanks for the replies about B.smithi and P.metallica, I did say Pers.comm is enough in some cases, and of more importance, it depends on the venue (which is of course what I was refering to in that context). I know at some stage somebody most likely saw the type and did the ID, but in many cases this is not the case, certainly not always.

My point is simply an argument that type exam is not always required, often it may be, but NEVER always without question. That is just incorrect in my opinion. If it was every bit as critical as you say, don't you think the ICZN would have by now stamped all over their silly rules for type deposit (hence stopping the deposit of exuviae etc..)??

Steve

 

[Theraphosid Research Team]

Hi Steve,

I see your arguments and I agree. Indeed it is not neccessary in every (identification)case to examine a Holotype. Especially in the newly described Species, it should be enough to use the original description, because today the descibers use many drawings and pictures to illustrate the keycharacters of the described Species. For example, I was recently able to identificate a Selenocosmia jiafu from Laos (deposited in SMF) only by using the very good original descrption of that Species made by Prof. Zhu in 2008. BUT, in the case we are discussing here, i.e. in the identification of Selenocosmia samarae, I can tell that it is neccessary to examine the Type to get a safe result!

Cheers, Volker

 

[Theraphosid Research Team]

I meant congeners my apologies.

Lets just say I find a spider that allies with Raven's description of C.tropix, ...

BTW, if Robert would have examined the Types from Coremiocnemis, he would have recognized that his Coremiocnemis tropix has nothing to do with Coremiocnemis. When he visited me before some Years ago, I've showed him my examination results and pictures fom the Holotypes of all the Coremiocnemis Species and he agreed to my opinion, that C. tropix is obviously not nearer related to the other Coremiocnemis Species. So, it's another good example, why it is neccessary in most cases to examine the available Types.

Cheers, Volker

 

[syndicate]

I also remember reading somewhere that C.tropix was not a Coremiocnemis...Off topic here but any idea what genus it belongs in?
-Chris

 

[Theraphosid Research Team]

...but any idea what genus it belongs in?
-Chris

Yes! But because of several reason I will not discuss this here!

Cheers, Volker

 

[Steve Nunn]

Hi Volker,
Yes, I understand what you're saying and I do agree with you. There are many traits in C.tropix that vary compared to the W.Malaysian Coremiocnemis. As you would know, Raven is currently working on the correction. Interesting you mention S.jiafu, because there is another species with dubious placement. Regardless, conspecifics can be (as you said) identified from the description.

Cheers,
Steve

 

[syndicate]

Hi Volker,
Yes, I understand what you're saying and I do agree with you. There are many traits in C.tropix that vary compared to the W.Malaysian Coremiocnemis. As you would know, Raven is currently working on the correction. Interesting you mention S.jiafu, because there is another species with dubious placement. Regardless, conspecifics can be (as you said) identified from the description.

Cheers,
Steve

Steve what should we label the tropix in the hobby now as we know they don't belong to Coremiocnemis?
-Chris

 

[syndicate]

One of my favorite spiders in this genus!

Selenocosmia arndsti
Female

 

[MaDhAcK]

Hi

0.1 Selenocosmia arndsti

Greetz
Dustin

 

[Steve Nunn]

Steve what should we label the tropix in the hobby now as we know they don't belong to Coremiocnemis?
-Chris

Hi Chris,
Their current status is still Coremiocnemis tropix, however the placement is recognised as dubious and will be changed in the not-too-distant future

You could call them "Selenocosmiinae sp. tropix", which is appropriate.

Chers,
Steve

 

[TiogaWhiteTiger]

Hi

0.1 Selenocosmia arndsti

Greetz
Dustin

I will only say so : Wow! :drool:

 

[syndicate]

You could call them "Selenocosmiinae sp. tropix", which is appropriate.

Hi Steve,
Thanks for the reply!I was thinking this would be the best temporary name for now.
-Chris

 

[syndicate]

Selenocosmia peerboomi
Sub-Adult Female

 

[Philth]

Selenocosmia peerboomi ultimate male

Later, Tom