A. reticuosa vs A. urteagai

[madrededios]

All,

I was just checking into Tom and Martin's website and noticed the photos of these two fishes. I have collected many fish in the Madre de Dios that I THOUGHT were the latter, but now I'm not so sure. However, I am having trouble seeing what external characteristics are being used to differentiate between them. What am I missing?

Thanks,

Brian Perkins
www.wildperu.net

 

[madrededios]

All,

I was just checking into Tom and Martin's website and noticed the photos of these two fishes. I have collected many fish in the Madre de Dios that I THOUGHT were the latter, but now I'm not so sure. However, I am having trouble seeing what external characteristics are being used to differentiate between them. What am I missing?



Bp

Thanks,

Brian Perkins
www.wildperu.net

I wish I could type!!! That should have been "resticulosa"................. :O/

 

[Mike Wise]

Brian, A. (cf.) resticulosa (there are many different forms) and A. urteagai are closely related. I believe that A. urteagai is an offshoot of the resticulosa-complex and in my species list it is listed as 'resticulosa-complex?' Genetic studies indicate that it is related to the resticulosa- and caetei-complexes. A. urteagai is a more robust, deeper-bodied, species like caetei-complex species. Like caetei-complex species, A. urteagai often shows a Bar 7 that is darker below the lateral band. Resticulosa-complex species are more slender species that typically have a uniformly pigmented Bar 7. The caudal fin of A. urteagai shows a more distinct and more extensive pattern of markings than resticulosa-complex species. Here is part of an email I sent Tom when he showed me 40 images of the 2 species:

"The first fish (DSCF3695 - 3709) has all of the features diagnostic for A. urteagai: vertical bars wider than inter spaces; abdominal streaks only visible just below the lateral band; complete rows of spots on the caudal fin; narrow cheek stripe. The blue face color is very different from most A. urteagai. This may be the same fish as A. sp. Kosho-Kosho. I am still not certain if Kosho-Kosho is a different species. Brian Perkins sent photos of fish from the same location that Jeff Cardwell and Vin Kutty collected the high fin specimen. None of his fish show the high fin. It is possible that Jeff & Vin's fish was a super-specimen and that Kosho-Kosho is only a blue color morph of A. urteagai.

Wow, this is interesting! I've never seen a A. urteagai with that much blue color in the face. I will for sure ask XXXXX to keep some of this last ones for us! And if we take a trip with Brian Perkins, we might find some ourselves....

The second fish (DSCF 3710 - 3733) has features diagnostic for A. resticulosa: abdominal streaks extend almost to the ventral edge of the abdomen and the caudal fin shows only a few rows of spots on the posterior half. Do you know if these fish were collected together? If this is a form of A. resticulosa, then it is the first to be collected in the Río Madre de Dios. It has a caudal spot very similar to that on the specimen Heiko Bleher collected in the Lagoa Abunã (Brazil/Bolivia border). I know of a report of a resticulosa form from the Río Beni, too, but XXXXX's fish is from much farther west.

Very interesting. I asked XXXXX where they were collected, and he answered "Around Puerto Maldonado". So I don't know if they were collected together, or exactly where they were collected."


My guess is that the A. resticulosa form was not actually collected in the Madre de Dios system, but in the upper Abunã system.


I probably won't be at the CAS meeting tomorrow night. I will be at a Colorado Rockies game. I should be able to make the RMCA meeting on Sunday. Look forward to talking to you in person.