Syno Dhonti

[Birger]

Is this not the same picture just reversed...with the bottom fish labeled differently in each


http://www.planetcatfish.com/catelog/im ... ge_id=2317

http://www.planetcatfish.com/catelog/im ... ge_id=2280

[Jools]

Yes it is, I've done this in a few cases for comparison reasons and the caption explains which is which. It's a good way to get two pictures/image credits in the catelog

However, you are asking if the fish is S. dhonti are you?

Jools

[Dave Rinaldo]

I believe Birger is saying the botom fish is ID'ed as both

Synodontis irsacae

AND

Synodontis dhonti

S. tanganyicae above,S. irsacae below

S. tanganyicae above,S. dhonti below

[Jools]

I can really be a muppet at times, I understand now...

Jools

[Richard B]

I can really be a muppet at times, I understand now...

Jools

All the best people are once in a while.... (at least that's my excuse & i'm stickin' to it! )

[Birger]

Okay...now that we have that straight...what do we think the lower fish is??

I think dhonti...but I am not 100 % on that...mostly due to the shape of the humeral process, identifications for both irsacae and dhonti are generally quite close but the pictures of humerals in Wright & Page(2006)show what seems to be a difference in shape. More narrow for irsacae I think.

We can not check the toothpad(split or unsplit) on this fish and I can't tell if it has a axillary pore(one does one does not) so that leaves me the humeral process.

[Jools]

I recently added some pictures under

Synodontis dhonti

, could we include these in this discussion. e.g. do you think they're akin to the "bottom fish"?

Cheers,

Jools

[Birger]

My turn to be a muppet...I am reading away in Wright & Pages paper...looking at the humerals...read again...trying without succeeding to see if there are axillary pore...read again...look at the mouths ...read again my head of course is starting to hurt by now and then I realize I was passing right by an important set of words in the text.

In table 1 & 2 where it says spots on body; for S.irsacae it has "Small"
where it says spots on body; for S dhonti it has "Absent"

Further in the text it once again goes on "Axillary pore present,large mandibular teeth22, body lacking spots, fin spines brown"

In all the pictures in this text if a fish is supposed to have spots it will have them on the preserved specimen but the preserved specimen used as an example for dhonti shows no spots, which it should not according to the text.

Even for tanganaicae It states "body with small or no spots" and the preserved specimen shows no spots at all.

Back to me being a muppet because now I have to say that what I thought was dhonti is not, according to this evidence.

Anyway I want to read up on the others some more yet.

Birger

[Richard B]

Isn't dhonti only known from the holotype...?

[Richard B]

If Jippo is out there (?) he has a photo of a fish which appears to be the closest thing to dhonti i've seen - the pic is in his album on a photo-share site somewhere that i can't access from work.

[Birger]

Isn't dhonti only known from the holotype...?

Yes, a single specimen, irsacae were for a time placed in synonymy with dhonti, must be why dhonti gets used so much when it should not.

If Jippo is out there (?) he has a photo of a fish which appears to be the closest thing to dhonti i've seen - the pic is in his album on a photo-share site somewhere that i can't access from work.

I think I saw the one you mention as well, but that fish had dots...unless we are thinking of different fish.

[Richard B]

I think I saw the one you mention as well, but that fish had dots...unless we are thinking of different fish.

it did indeed have dots - but was in a light environment, but was still a dark fish - i tentatively might suggest in a dark environment or as a dead specimen spots might not be obvious, then there is the thought that spots disappear with age/growth.....

Still an interesting individual worthy of inclusion & debate in this thread.

[Birger]

Still an interesting individual worthy of inclusion & debate in this thread.

Absolutely

[worton[pl]]

Hey,

in Wright and Page paper (if I'm remember things correctly - I don't have this paper right now in my hands, it would be also an article of Erwin Schraml for DATZ showing fish photographed by Lee Finley) is wrtten something about young specimens of dhonti having spots and totally different look than mature specimen - that's why we all are so confused about this species when irsacae comes to the game me thinks;).

It would be easy to identify dhonti if it would be just spotless, brown fish ;).

What about this movie guys?

I would say it is not mature dhonti and fish in catelog was exactly the same in look and movements as this in the movie ;).
I have very similar fish in my tank right now but it is very small and doesn't grow...

Yeah, headache is all you get when identifying Tang synos ;)

[Dinyar]

My impression from Wright and Page and other discussions is that S dhonti is a large brown fish known only from the holotype, and all museum specimens and fish in the aquarium trade that were called "dhonti" are in fact "irsacae". The images in question were contributed by Gregg Pierson well before the Wright and Page monograph, so "dhonti" may have been the appropriate name at the time. As to whether these are irsacae or something else again - possibly undescribed - I'm not 100% sure, but I would call it irsacae for now.

I recall that within what was called "dhonti", there was lots of variation (as there is within "petricola" and even "polli"), and lots of guesses as to the distinctions between dhonti, tanganyicae, putative lacustircolus, etc. Further research might show that there are multiple subtly differentiated species in this flock of irsacae lookalikes.

[Birger]

After going through the Wright & Page paper a few times and taking a long look again at some of these pictures that have come up I would have to go the same opinion as Dinyar, these what look to me as long nosed,sloped forhead, high backed fish that are labeled Dhonti (unless someone can show me one that loses it's spots,gains an axillary pore and attains the length cited for Dhonti) I would now consider them Irsacae.



Birger

[Richard B]

Maybe a liitle unusual bur based on...

First, it is extremely unlikely that S. dhonti has ever entered the hobby. Wright and Page borrowed pretty much every museum specimen of fish labeled as dhonti, petricola, polli, etc., that they could get their hands on, and concluded that the only specimen of dhonti that they saw was the type specimen.

...would we wish to reconsider the Id's of the fish labelled S. Dhonti in cat-e-log?

[Birger]

Maybe a liitle unusual bur based on...

First, it is extremely unlikely that S. dhonti has ever entered the hobby. Wright and Page borrowed pretty much every museum specimen of fish labeled as dhonti, petricola, polli, etc., that they could get their hands on, and concluded that the only specimen of dhonti that they saw was the type specimen.

...would we wish to reconsider the Id's of the fish labelled S. Dhonti in cat-e-log?

I agree, It has been discussed in this thread and my opinion still stands. http://www.planetcatfish.com/forum/view ... =3&t=27345

Birger

[MatsP]

And I've just merged the topics - they aren't EXACTLY related, but I think they can and should be dealt with together...

--
Mats

[Dinyar]

Boulenger described dhonti. Matthes came along some five decades later and described irsacae. This was thrown into synonymy with dhonti -- don't remember by who -- when it was claimed that Mathhes' "irsacae" was just the juvenile form of dhonti. Then Wright & Page came along another five decades later and resurrected irsacae, reporting that in all the specimens they examined (hundreds, I believe), they did not find any that matched the type specimen of dhonti, and the non-type specimens labeled as "dhonti" were in fact irsacae.

Both dhonti and tanganicae are very large, monochrome brown Synos, based on their descriptions. The fish that many of us have kept for years as dhonti and tanganicae have neither grown very large nor very brown, which suggests to me that they are not what we thought.

[Jools]

Absolutely fine with reasoning above and happy to move pictures. I will find a S. dhonti drawing to go there.

a) Does someone wish to capture this in a data submissions or two? And

b) Where do I move the pictures that are

Synodontis dhonti

?

Synodontis irsacae

?

Jools

[Birger]

a) Does someone wish to capture this in a data submissions or two?

I will do it.

b) Where do I move the pictures that are Synodontis dhonti? Synodontis irascae?

Moving them to S.irsacae is what I was thinking.


Birger

[Jools]

OK, let's do it!

Jools