An integrative framework to reevaluate the Neotropical catfish genus Guyanancistrus

[Karsten S.]

An integrative framework to reevaluate the Neotropical catfish genus Guyanancistrus (Siluriformes: Loricariidae) with particular emphasis on the Guyanancistrus brevispinis complex
Sonia Fisch-Muller, Jan H. A. Mol, Raphael l Covain

Abstract
Characterizing and naming species becomes more and more challenging due to the increasing difficulty of accurately delineating specific bounderies. In this context, integrative taxonomy aims to delimit taxonomic units by leveraging the complementarity of multiple data sources (geography, morphology, genetics, etc.). However, while the theoretical framework of integrative taxonomy has been explicitly stated, methods for the simultaneous analysis of multiple data sets are poorly developed and in many cases different information sources are still explored successively. Multi-table methods developed in the field of community ecology provide such an intregrative framework. In particular, multiple co-inertia analysis is flexible enough to allow the integration of morphological, distributional, and genetic data in the same analysis. We have applied this powerfull approach to delimit species boundaries in a group of poorly differentiated catfishes belonging to the genus Guyanancistrus from the Guianas region of northeastern South America. Because the species G. brevispinis has been claimed to be a species complex consisting of five species, particular attention was paid to taxon. Separate analyses indicated the presence of eight distinct species of Guyanancistrus, including five new species and one new genus. However, none of the preliminary analyses revealed different lineages within G. brevispinis, and the multitable analysis revealed three intraspecific lineages. After taxonomic clarifications and description of the new genus, species and subspecies, a reappraisal of the biogeography of Guyanancistrus members was performed. This analysis revealed three distinct dispersals from the Upper reaches of Amazonian tributaries toward coastal rivers of the Eastern Guianas Ecoregion. The central role played by the Maroni River, as gateway from the Amazon basin, was confirmed. The Maroni River was also found to be a center of speciation for Guyanancistrus (with three species and two subspecies), as well as a source of dispersal of G. brevispinis toward the other main basins of the Eastern Guianas.

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Link zum Paper

Die neue Gattung und die neuen Arten:

Cryptancistrus similis (Sipaliwini/Paru, Four Brother Mountains, Brasilien)

Guyanancistrus brownsbergensis (Saramacca River, Brownsberg, Surinam)
Guyanancistrus nassauensis (Marowijne River, Nassau Mountains, Surinam)
Guyanancistrus megastictus (Maroni River, Mitaraka Massif, FG)
Guyanancistrus tenuis (Jari River, Para, Brasilien)
Guyanancistrus teretirostris (Sipaliwini/Paru, Four Brother Mountains, Brasilien)

Außerdem wird die Typusart Guyanancistrus brevispinis (Typusfundort: Falawatra River, Surinam) in mehrere Unterarten aufgesplittet:

Guyanancistrus brevispinis brevispinis
Guyanancistrus brevispinis bifax (Crique Petit Laussat, FG)
Guyanancistrus brevispinis orientalis (oberer Oyapock, FG)

Ich müsste Bildmaterial von allen Unterarten von G. brevispinis haben. Die werde ich entsprechend demnächst in der DB ergänzen.

Gruß,
Karsten

[Karsten S.]

Hi,

ich habe Unterwasseraufnahmen aus dem Nickerie von der Nominalform von Guyanancistrus brevispinis hochgeladen, die anderen Unterarten waren ohnehin schon mit Bildern in der DB vertreten.

Unterwasseraufnahme von Guyanancistrus brevispinis brevispinis im Nickerie River in Surinam:





Die sind in der Natur recht scheu, aber schon eine wahre Pracht.

Gruß,
Karsten