Otothyris lophophanes or Schizolecis guntheri?

[Mike_Noren]

I am definitely no expert on these fish, and I don't think I've ever seen an Otothyris so I'm probably way off base here, but doesn't this look like a Schizolecis guntheri:
http://www.planetcatfish.com/catelog/im ... e_id=13546 ?

I thought the longitudinal rows of spikes was the hallmark of

Schizolecis guntheri

?

[Silurus]

The fish in question does look a lot more like S. guntheri than O. lophophanes as illustrated in Wels Atlas I, but all the illustrations of Otothyris there show the fish has having the longitudinal ridges on the dermal plates as well.

[MatsP]

Moved to "Cat-eLog Data issues".

--
Mats

[The.Dark.One]

I thought the same as you Mike when I saw the image update.

[Mike_Noren]

All righty then...

Here's a paratype of O. lophophanes from the original description by Garavello, Britski & Schaefer (1998):

Otothyris lophophanes, from: Garavello, Britski & Schaefer (1998). Their figure 3

The fish in the Cat-eLog photo is, IMO, not O. lophophanes, based on the lack of a pronounced supraoccipital crest, and head and body shape (e.g. more narrow peduncle).

Otothyris juquiae and Otothyris rostrata are both more similar to the fish in the cat-eLog photo, but having three strongly pronounced crests is a diagnostic character of Otothyris, and I'm not sure the fish in the photo have any. O. juquiae also have different caudal fin pigmentation (two vertical bars).

That said, O. rostrata is similar to the fish in the cat-elog photo:

Otothyris rostrata, from: Garavello, Britski & Schaefer (1998). Their figure 5

However, note the three crests (behind the eyes and median on the head). It is however possible they are easier to see in preserved fish. Other diagnostic characters (e.g. number of caudal fin rays) can not be evaluated from the photo.

So to sum up I don't think the fish in the cat-elog photo is O. lophophanes, although it may be Otothyris rostrata.

So, what about Schizolecis guntheri? I don't know. I can't find our Wels atlas, our other books were of no help, and our lone specimen in collection is not in its place, so I'm not sure how a guntheri is supposed to look. To Be Continued, maybe.

[The.Dark.One]

Based on your info here I am still in agreement that it is S. guntheri

[Jools]

Just to say I am tracking this topic, just haven't had the time to do the reading yet...

Jools

[Mike_Noren]

I've scoured the literature, and if the crests are as obvious on all Otothyris as it is on our preserved lophophanes then it's doubtful the fish in the cat-elog photo is any Otothyris at all. As far as I can tell Pseudotothyris lacks the crests, but apparently also the longitudinal ridges along the side, which would rule that genus out as well.
Confirming that it's a Schizolecis turned out to be more difficult: although there's lots of mentions of Schizolecis I haven't been able to find a single photo* or drawing of one.
I think the key citation is this...
Britski, H. A. and J. C. Garavello 1984 (28 Dec.). Two new southeastern Brazilian genera of Hypoptopomatinae and a redescription of Pseudotocinclus Nichols, 1919 (Ostariophysi, Loricariidae). Papéis Avulsos do Departamento de Zoologia (São Paulo) v. 35 (no. 21): 225-241.
...but I have not yet been able to find it on the net, and try to not involve the museum in my hobby endeavours, so if anyone happen to have this paper I'd be grateful if you could mail it to me.



* except the one in Wels atlas, which I don't know how reliable it is, and except this one, which is both tantalizingly inadequate and slightly doubtful for use in identification.

[The.Dark.One]

Hi Mike

I havent got access to any of those papers. I think we can rule out Otothyris or Pseudotothyris.

This was identified years ago by Ingo as Schizolecis guntheri.
http://www.scotcat.com/thedarkone/loric ... ntheri.jpg

I queried the slightly different pattern but he said they show up alongside the 'normal' ones:

[Mike_Noren]

This was identified years ago by Ingo as Schizolecis guntheri.
http://www.scotcat.com/thedarkone/loric ... ntheri.jpg

I queried the slightly different pattern but he said they show up alongside the 'normal' ones

But, apart from the extent of abdominal plating, how can one tell that's not an Otothyropsis marapoama? <pounds head against desk>

Compare to these fish I previously suspected were O. marapoama.

In related news one of the fish in D. & R. Lalkaka's cat-elog photos of Schizolecis guntheri show the three cranial crests diagnostic of Otothyris.

Either Hypoptopomatinae is a mess or I'm useless at this. Or both. I think it's time for my standard disclaimer: I am in no way, shape or form an expert on these fish, so please take everything I say with a generous helping of salt.

I will now shut up about these fish until I have something worthwhile to say.

[The.Dark.One]

I've had a look in Freshwater Fishes of Mata Atlantica. This has preserved or live images of (amongst others):

Otothyris juquiae
O. lophophanes
O. rostrata
O. travassosi
Pseudotocinclus juquiae
P. parahybae
P. tietensis
Pseudotothyris obtusa
S. guntheri

Based on those I would definitely say the images we questioned are not Otothyris lophophanes, but are S. guntheri. O. lophophanes in the book has a very short and humped head, short body, and prominent crest.

[Mike_Noren]

Based on those I would definitely say the images we questioned are not Otothyris lophophanes, but are S. guntheri.

Yes I agree: it is definitely not lophophanes or any other described Otothyris, and while I still have not seen a verified Schizolecis guntheri I can find no other described fish it could be.

So: the cat-elog photo of Otothyris lophophanes is misidentified, and probably shows a Schizolecis guntheri.

As an aside, I found some lophophanes in our collection. It's a tiny and distinctive fish. Here's the largest, 31 mm TL, 25 mm SL:

Otothyris lophophanes (NRM 33657). 25 mm SL. dorsolateral view.

Otothyris lophophanes (NRM 33657). 25 mm SL. ventral view.

The identifying character for lophophanes is the single row of enlarged, downward-pointing, odontodes around the rim of the snout, separated from the odontodes on the dorsal surface of the head by a discontinuity:

Otothyris lophophanes (NRM 33657). 25 mm SL. Approximately frontal view.

I apologize for the quality of the images; I had to shoot hand-held.

[Jools]

They're the best mages we have! I will move this over, would it be possible for me to use your correctly IDed pics to replace it?

Cheers

Jools

[Mike_Noren]

No need to ask; Planetcatfish has a blanket permission to publish any of my photos.

EDIT: Oh, I forgot - the fish in the photo is captured in the Rio São João drainage, in the state of Rio De Janeiro.

[Jools]

Thanks Mike. So, I've made the move and added the real deal. All OK?

Cheers,

Jools