Phylogenetic revision of Lasiancistrus

[bekateen]

José Luis Poveda-Cuellar, Cristhian Camilo Conde-Saldaña, Francisco Antonio Villa-Navarro, Nathan K Lujan, & Jorge Abdala Dergam dos Santos. (2023). Phylogenetic revision of whisker-cheeked suckermouth catfishes (Loricariidae: Lasiancistrus) from east of the Andes: five species where once there were two, Zoological Journal of the Linnean Society, 2023;, zlad042, https://doi.org/10.1093/zoolinnean/zlad042
https://academic.oup.com/zoolinnean/adv ... ogin=false

Abstract
We integrated large sample sizes, morphometric and molecular data, and phylogenetic and species delimitation analyses to test the 17-year-old hypothesis that only two species of whisker-cheeked suckermouth catfishes (genus

Lasiancistrus

) occur in river drainages west of the Andes Mountains. Our results reject this hypothesis, demonstrating that, in addition to the previously recognized

Lasiancistrus guacharote

from Lake Maracaibo, a Lasiancistrus clade from west of the Sierra de Perijá contains at least four allopatric, genetically differentiated and morphologically distinct lineages. One of these lineages had no previous name associated with it and is described here as the new species

Lasiancistrus wiwa

. Phylogenetic relationships and geographical distributions of all five trans-Andean lineages are concordant with watershed boundaries and major mountain ranges that form these boundaries, with the following five freshwater basins or regions each containing a single species: Lake Maracaibo (L. guacharote), Rancheria River basin (L. wiwa), Upper and Middle Magdalena River and lower Cauca River basins (

Lasiancistrus volcanensis

), Upper Cauca River basin (

Lasiancistrus caucanus

) and Pacific Coastal watersheds between central Colombia and central Panama (

Lasiancistrus mayoloi

). Evolutionary relationships among these lineages suggest that Andean uplift-mediated vicariance contributed significantly to the cladogenesis and allopatric distributions of these fishes.

Key words: Andes, biodiversity, biogeography, molecular phylogeny, South America, morphology, anatomy

[Shane]

Need to get access to this. We have Cat e log rearranging to do.

Under

Lasiancistrus cf_caucanus

are photos of Lasiancistrus I collected in the Magdalena.
-Shane

[bekateen]

Need to get access to this. We have Cat e log rearranging to do.

Under

Lasiancistrus cf_caucanus

are photos of Lasiancistrus I collected in the Magdalena.
-Shane

At work, we do subscribe to this journal digitally but there is a 1-year embargo on new issues.

Besides your cf. caucanus, I'd like to know if

Lasiancistrus sp(l386)

is among the species.

I notice that this paper revives two names which had been relegated to junior synonym status,

Lasiancistrus volcanensis

and

Lasiancistrus mayoloi

, both of which have been synonyms of

Lasiancistrus caucanus

. And with these authors putting L. mayoloi in Panama, this obviously kicks L. caucanus out of Panama.

Cheers, Eric

[Jools]

I missed this one, apologies. Paper attached. For sure L312 = L. volcanensis and I've made the switch - the last pic in there is a little off mind you. L386 (the pleco they named after a computer ) is a hard fish to find. Really only the picture in DATZ serves to ID it - it's a beauty but I am pretty sure it was overlooked by the review.

Jools

[bekateen]

L386 (the pleco they named after a computer ) is a hard fish to find. ... I am pretty sure it was overlooked by the review.

Jools

Circling back to the taxonomic changes here and L numbers, the solitary DATZ photo of

L386

is consistent with both

Lasiancistrus guacharote

and

Lasiancistrus mayoloi

. According to DATZ, L386 was coming from the Magdalena. This revision paper limits L. guacharote to the Lake Maracaibo drainages, and L. mayoloi to Pacific drainages from Colombia to Panama, plus some Caribbean drainages of Panama.

If the paper's survey was pretty thorough (and it says it was), what does this mean for L386? There were no "dark bodied, light spotted" Lasiancistrus reported from the Magdalena in this paper. So either the investigators missed a dark bodied, light spotted variety in the Magdalena (as Jools suggested may have happened), or it means the reported collection source for L386 was inaccurate. With that info, can we make any inference about whether a reported Magdalena distribution is more consistent with a Pacific coast distribution or a Lake Maracaibo distribution?

As an alternative approach to resolving this, there is the anatomical difference: The paper says that L. guacharote can be differentiated from L. mayoloi by the presence vs. absence (respectively) of abdominal plates between the pectoral fins. Do we know whether L386 has abdominal plates?

Cheers,
Eric

[Jools]

It's not clear-cut for me. Here's some data, starting with a translation of what was written when L386 was introduced in DATZ.

"L-Numbers A "new" Harnischwels from the Río Magdalena
As early as autumn 2003, Transfish (Planegg near Munich) imported a Lasiancistrus species from the Colombian Río Magdalena, which was first introduced to the Datz special issue "L-Numbers".

Typical features of L 386, in addition to its flat shape, are the uniform, coarser from front to back, yellow-white-dot pattern on a grey-brown ground, which covers not only the head and body but also the pectoral and ventral fins. On the other hand, the edges of the paired fins and the dorsal and caudal fins bear a pattern of orange/brown, elongated spots.*

The specimen shown here has a total length of around ten centimetres; with this size, it should be (almost) fully grown."

*They look like stripes to me!

Some of the early L-numbers were introduced with pretty random locations. By the time we get to 2003/4, and L386 or so it was a lot more organised. The fish was unusual in so far it's not been, AFAIK, exported since. It would be unlikely to be exported from the Maracaibo basin or the coast (no other fishes exported from there). Could it be a collection site somewhere between where they get Arius shark cats and Bogota? Seems unlikely. Could it be a mistake and is it a by-catch of L387 from the Meta - seems plausible until you realise DATZ grouped those two as they were both from Colombia. One was imported by Transfish / Andreas Hartl, and one by Aqua Global/ Ingo Seidel. Both reliable sources who would say "unknown" rather than publish bad data - although they likely went on what the exporter said and knew the fishes came from a particular company dealing in particular fishes from a region.

We don't know about abdominal plates.

My guess is this paper missed it, and why not? It's one fish photographed from a huge river and might not even be that river. Lasiancistrus tend to have fairly wide distributions in whatever river system, so perhaps is a specially coloured individual. Maybe, but where are the dull ones?

Maybe L386 is not a Lasiancistrus and so was not overlooked, just not included. Looks like one to me but there are similar genera.

So, an unusual distribution, and a new species or at least chromotype, seems like the most likely theory?

Jools

[bekateen]

It's not clear-cut for me. Here's some data, starting with a translation of what was written when L386 was introduced in DATZ.

On the other hand, the edges of the paired fins and the dorsal and caudal fins bear a pattern of orange/brown, elongated spots.* "

*They look like stripes to me!

Indeed, these "orange/brown, elongated spots" do align to form a vertical bar/stripe, but it's a broken stripe at best. I sent you an email with some comparison photos. Let me know what you think.

We don't know about abdominal plates.

I expected as much. Thanks.

My guess is this paper missed it, and why not? It's one fish photographed from a huge river and might not even be that river. Lasiancistrus tend to have fairly wide distributions in whatever river system, so perhaps is a specially coloured individual. Maybe, but where are the dull ones?

Maybe L386 is not a Lasiancistrus and so was not overlooked, just not included. Looks like one to me but there are similar genera.

So, an unusual distribution, and a new species or at least chromotype, seems like the most likely theory?

Jools

Check out the photos I sent you. I think they are compelling to, at the very least, keep this fish in Lasiancistrus. I do wish however that the DATZ photo gave a better impression of the length of the pectoral fins (and now in hindsight, the abdomen)... perhaps this DATZ individual was a female with smaller pectorals?

Cheers, Eric