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This is a response to a pm from Eric. I thought it would be better to reply in the forum so the information remains available for posterity.

Going back through my logs and maps (2000-2002) I realized I recorded M. iheringi from two locations at opposite ends of the Valencia/Tuy basin.

M. iheringi was described in 1946 from the Rio Tumero. The Rio Turmero is a small river flowing (north to south) from the Cordillera de la Costa into the Lake Valencia basin. Before human intervention drained the lake for agriculture it was common for the waters of the Valencia and Tuy basins to mingle. In places tributaries of Valencia and the, now separate Tuy basin, are within 500 meters of each other. Keep in mind, the rio Tumero is maybe 25 kilometers in total length, so we are discussing a very small area compared to basins in the Amazon or Orinoco! The Valencia and Tuy basins share over 90% of the same species.

Both basins today have become heavily polluted making collection of them very difficult (Mikolji). Many of the locations I sampled 20 years ago are now destroyed.

Locations:
Rio Tumero within a kilometer of the holotype location. The area, 20 years ago, was used as a garbage dump by the locals. I did not do any collecting but did observe tetras and Chaetostoma living among the trash.

Rio Chirgua. A very strange tributary of Valencia. It flows north to south, hits the Serrania del Interior and flows south to north back up to the lake. As the crow flies, it is about 50 km west of the Tumero.

Hi Shane,

Thanks for this information. I sent another PM to explain my question, and why it was asked in a PM rather than in the forums.

Sorry in advance for the length of the PM... I am a tad windy.

Cheers, Eric

Part two (on mobile, did not want risk losing what I wrote).

Because the Chirgua is the westernmost feeder of the lake, it is away from the cities and towns of the Valencia/Tuy valley and is (or was) clean. I have in my collection notes that I collected Microglanis there.

Rio Capaya. The Capaya is a small independent drainage located in the Tuy valley that empties into a swamp on the Caribbean coast just 5 km north of where the Tuy flows into the sea. I collected M iheringi here near the village of Los Gonzalez. This drainage was clean as there are no major cities on the river.

So there you have it. A collection of M iheringi from the far west of the Valencia and the far east of the Tuy drainage. Despite sampling dozens of locations between these two occurrences I have no notes that I found it anywhere else.

This would leave me to believe M. iheringi is sensitive to environmental changes and is probably holding out only in a few Valencia/Tuy feeder streams isolating each of these populations.
-Shane

Also worth noting, this fella - - was from one of those - collected with Shane nearly 20 years ago. I think the Tuy, but I need to go check.

Jools

I forgot about that photo! My records indicate we caught it in the Chirgua. Note that it matches the M. iheringi photo in Romero's book. This is most certainly the "real" iheringi unless there are multiple Microglanis spp in that basin.
-Shane

Shane,

Your records will be correct, I didn't photograph it in the field. That photo was taken in Edinburgh. Eric - If it assists, here is the aforesaid book and picture with some info.

Jools

Jools wrote: ↑02 Mar 2021, 21:38Eric - If it assists, here is the aforesaid book and picture with some info.

Thanks Jools.

Shane also provided the photo from Roman's book in the other Microglanis thread (HERE), and you referenced the M. sp. `Venezuela` picture (HERE).

Unfortunately, much of the color pattern detail of M. sp. `Venezuela` fish is lost in the blues and blacks of the photo. Once (back in October) I "did that thing I do" with my phone where I tried image manipulation of the M. sp.`Venezuela` picture to improve the color and make its pattern more clear. I can say that seeing the traits more clearly was pretty useful but I didn't post the photo then; I can certainly do it now. Here are two attempts to improve the picture color:
Both of these fish show a character I also see in some of mine fish: That is the irregularly-shaped pale center to the subdorsal saddle, with a nearly horizontal (slightly posteroventrally slanted) dark pigmented line (following the lateral line?) through the pale area.

What I see different between these two photos is that on the sp.`Venezuela`, the dorsal blotch has a postero-ventral extension on the rear edge of the subdorsal saddle (maybe beyond the posterior edge of the dark pigmented spot at the base of the dorsal fin). I've outlined it in the paired photo with red ink. That same extension seems to be either absent or minimized in the fish shown in Roman's book, such that the same element of the color pattern on Roman's fish does not appear to extend beyond the dark dorsal fin spot above it. Alternatively, perhaps glare in the photo might be masking some of it, but I'm not leaning to conclude that now.
That said, I suspect there is considerable individual variation in phenotype (one of the reasons I'm buying so many of these fish to try to assess that), so this difference I point to may be critical or trivial taxonomically.

Finally, as just an observation, this fish in my collection bears a lot of similarity with the fish Shane brought back from Venezuela, with the same slant extending backwards and the thin line passing through the pale center spot. Cheers, Eric

Doh!, now it's my turn to forget! Perhaps what I can usefully do is go back to that old photo hi-res and see if it could be more usefully colour balanced.

Jools

Another noted collection location from 2000. This was in Jool's 2000 COTM.
-Shane

Collecting location: Venezuela, Estado Miranda, Rio Merecure, Rio Tuy Drainage. Collected from the Rio Merecure near the bridge that crosses the river on the road between Caucaqua and Higuerote. Water was very clear and flowed at a moderate to strong pace. Substrate was exposed bedrock and fist-sized stones. No aquatic vegetation present. Microglanis were collected in the riffles and along the banks among the root systems and overhanging terrestrial vegetation. Water chemistry: pH 7.2, 60 ppm GH, 76-80F (warmer in the shallows). Also collected were: one species of pike cichlid, Acara sp. (Blue Acara), Hypostomus sp. fry, various tetras (mainly Astynax bimaculatus), Hoplias tetras, and Characidium darter-tetras.

Biollania (1995) 12:49-62.
Recibido: 15-03-95, Aceptado: 17-10-95
NOTAS SOBRE LOS PECES DEL RÍO MERECURE, CUENCA DEL RÍO TUY:NUEVOS REPORTES, ASPECTOS SOBRE SU ECOLOGÍA Y SITUACIÓN ACTUAL.

"Bagres pimelódidos como Microglanis iheringi
y Pimelodella spp. y Loricariidos como
Chaetostoma spp. Ancistrus, spp., y Loricaria
spp. son de presenciahabitual; igualmente la anguila de ciénaga (Synbranchus marmoratus
, Synbranchidae) yprobablemente Sternopygus macrucrus
(Sternopigydae). "

Additional papers that should be searched:

Mago-Leccia, F. 1968. Notas sobre los peces del río Guaire en: Estudio de Caracas. EcologíaVegetal y Fauna. vol. 1. Ediciones de la bilioteca UCV. Caracas.

Mago-Leccia, F. 1970. Lista de los peces de Venezuela. Incluyendo un estudio preliminar sobrela ictiogeografía del país. MAC. Oficina Nacional de Pesca. Caracas. p. 283.

Marrero, C. y A. Machado-Alisson. 1990. Inventario y notas ecológicas de los peces de los ríosPanaquire, Urba y Yaguapa (Cuenca del río Tuy), Edo. Miranda, Venezuela.

Pearse, A. 1920. The fishes of Lake Valencia, Venezuela. Univ. Wisconsin Stud. Sci., 1:1-51.

Peeter, L. 1968. Origen y evolución de la cuenca del Lago de Valencia. Instituto deConservación del lago de Valencia. Caracas, Venezuela.

Thanks Shane. I'll look these up. Till now, as I've been updating the Microglanis CLOG entries, I've been selectively picking only articles with pictures of the fish. But as I get more involved with the actual research on their phylogenetic diversity, I'm going to need to go back and look at all records.

Cheers. Eric