UFO - South America

[Viktor Jarikov]

Another vaillantii, presumably: http://www.monsterfishkeepers.com/forum ... -ID-Please

[FerocactusLatispinus]

I've been reviewing this post just today, and I realize I was off in my opinion as to the ID of this cool fish. I want to share some of my observations and give my personal verdict as to this cat's genus and species:

Regarding the image in the initial post. Is that "dorsal extension" a filament or a continuation of the ossified leading ray? It strikes me as rather rigid: looking closely, it seems to me that the right maxillary barbel passes behind that "extension", with the "extension" transecting it and creating a very acute angle with the same barbel (2D perception); that large, ossified leading ray seems like a consistent P. albicans characteristic.

Regarding the third posted image, the caudal peduncle seems to have a more angular shape, the dorsal containing a greater mass, as is seen here: http://www.planetcatfish.com/forum/down ... &mode=view; whereas in this P. albicans, its peduncle's upper and lower lobes (and the rays' basal integument and muscles) are seemingly equivalent: http://www.planetcatfish.com/common/ima ... e_id=14733.

The second image posted shows the length of the two ossified pectoral fin rays to be shorter than their succeeding rays; here, http://www.planetcatfish.com/common/ima ... e_id=15081, the leading pectoral rays are slightly longer than the first soft rays; however, this P. albicans is also a sub-adult as compared to the fish-in-question, which looks somewhat like the juvenile B. vaillantii seen here: http://www.planetcatfish.com/common/ima ... ge_id=6633.

Most prominent, the dorsal profile of this fish is also quite depressed and elongate when compared to a P. albicans'.

I initially thought it might be a B. vaillantii, but the "dorsal extension" changed that in favor of P. albicans, but most of the fish's characteristics point to a B. vaillantii. After all this, I now believe this fish to be a "brachy", Brachyplatystoma vaillantii, rather than a "pimmy".


*If you're wondering, my usage of technical terms is really due to my studying of Dr. Warren Burgess', An Atlas of Freshwater and Marine Catfishes. It's a terrific book that goes through each of the Siluriforme's 32 families! I highly recommend it!!

*The several edits are mostly punctuation, sorry 'bout that!

[Silurus]

I was wondering why

Duopalatinus peruanus

was not considered at all as a possible ID.

[Viktor Jarikov]

Thanks HH. I see the likeness. I think the OP fish and others, which I linked in the foregoing, are well over the (current?) 6" SL max but I cannot be 100% sure. So little is reported on this catfish. It may indeed grow larger, no?

[Viktor Jarikov]

Couple more recent cases of vaillantii identity crises:

http://www.monsterfishkeepers.com/forum ... -d.673058/

http://www.monsterfishkeepers.com/forum ... st-7565844 - this one looks closer to Rob's fish imho.