Indeed, on that I agree with you. I think that happens often, where (as I've also been guilty of in this thread at different times) investigators try to identify fish they find based only on the existing species names, rather than being more open to the idea of their fish being a different species (not to say I advocate as a splitter; I tend to be a lumper myself). For example, here's a report of Microglanis cf. secundus in the Rio Trombetas, which I suspect is a misidentification (at least they had the wherewithall to use "cf"):Shane wrote: ↑Mon Jan 04, 2021 12:21 pm The entry in the Cat-elog for M. secundus in the Catatumbo is a mistake that needs to be fixed. I am sure it is based on a mistaken identification in Galvis et al's peces del Catatumbo. As you can see at a glance, the fish they found is not secundus.
So many "Fishes of" books and papers are riddled with mistaken identifications because the authors simply can not have expertise on every genera they encounter.
Also note that two distinct spp are shown. Is the Microglanis in the Catatumbo the fish in the line drawing or the photo? I can only guess that the line drawing is correct and the photo is simply of a Microglanis they found at an exporter in Bogota. Note the opposite patterns on the paired fins. The drawing shows dark fins with light edges. The photo shows a fish with dark fins that lighten near the body.
Perhaps unfortunately, these Rio Trombetas specimens are now accepted by at least some authors as M. secundus sensu stricto, as revealed in subsequent publications (e.g., Mori & Shibatta. 2006. Zootaxa, 1302, 31-42). I suppose, in that example, if the fish can just get over the mountains from Guyana, they might drop down into the Trombetas. While I know there have been papers written to explain why fish discovered in Guyana and Suriname should be expected to be present also in some Amazonian areas of Colombia and Brazil, I struggle to imagine that many of these applicable species have remained unified genetically over history.Ferreira, E. J. G. (1993). Composição, distribuição e aspectos ecológicos da ictiofauna de um trecho do rio Trombetas, na área de influência da futura UHE Cachoeira Porteira, Estado do Pará, Brasil. Acta Amazonica, 23, suppl. 1, 1-89. wrote:Tabela 11. Lista das especies exclusivas das regioes a montante da cachoeira Porteira (Rio Trombetas drainage): Microglanis cf. secundus
I also suspect, and I've mentioned it earlier in this thread, that this type of misidentification you describe (and the consequences of it in terms of future investigators simply taking a past author's word for an ID) applies to Microglanis poecilus also.
As to your recognition that the illustrations in Galvis et al.'s paper are mismatched and incorrectly ID'd, yes I think so too. In fact, I'd go farther and propose that neither image in Galvis et al. shows M. secundus based on Mees' original drawing. First, here again are the photo and drawing of "Microglanis secundus" from the Galviset al. paper; both images are retouched here for details. Next, I'll add the photo, just a few pages later in the same book, of Batrochoglanis acanthochiroides.
Notice the dark color fin markings on B. acanthochiroides - they almost exactly match the Galvis et al. drawing of M. secundus. Also notable is that the drawing of B. acanthochiroides on page 68 (which I did not reproduce here) bears no resemblance at all to the color pattern shown in the photo of B. acanthochiroides... Perhaps the M. secundus drawing is mismatched and belongs with B. acanthochiroides? If that is the case, then what kind of fish is the "M. secundus" photo?
Shane, you noted that the drawing shows a fish whose paired fins have a hyaline margin and that the photo doesn't show that. Myself, I'm inclined to take that with a grain of salt based on this single photo, since at least the pectoral fins in the photo are evidently damaged (perhaps not the pelvics); any hyaline margin might easily be lost, leaving the impression that the fins are dark to the margins. Conversely, what I see as most different between the photo and the drawing is the fact that in the photo, the tail is almost entirely hyaline but the drawing shows a very dark marked tail; while I've found a lot of variation in the tail color pattern in my Microglanis, that picture seems extreme. But perhaps the tail pigmentation is a growth-dependent trait (I know my Microglanis have developed more tail pigmentation just since I've had them, as is evident in my videos): Supporting that possibility, the museum specimens which Galvis has on file have been reexamined and identified as juvenile B. acanthochiroides: Here is an excerpt from a more recent paper on the Fishes of the Catatumbo:
Perhaps significantly, this paper reported NO Microglanis in the Catatumbo drainage. While I would not be surprised to find Microglanis in the Catatumbo drainage, for now I have no references to document them there.Ortega-Lara, A., Lasso-Alcalá, O. M., Lasso, C. A., de Pasquier, G. A., & Bogotá-Gregory, J. D. (2012). Peces de la cuenca del río Catatumbo, cuenca del Lago de Maracaibo, Colombia y Venezuela. Biota Colombiana, 13(1), 71-98. wrote:On the other hand, the records of Microglanis secundus are from a juvenile specimen of Batrochoglanis acanthochiroides (Ortega-Lara obs per.)...
All the above discussion aside (about the absence of M. secundus from the Catatumbo drainage), I'd like return to the point of my previous post, and that is this: Microglanis secundus bears no resemblance to M. poecilus, but rather it bears some resemblance to M. iheringi, both the true M. iheringi and to the Colombian "M. iheringi" (although how close cannot be reliably estimated due to the poor quality of specimens of both M. secundus and of true M. iheringi).