In June 2003 I joined my PhD advisor Dr. Jonathan W. Armbruster, labmates Paul Pera and David Werneke, and Venezuelan colleague Oscar Leon Mata from the University of the Llanos Ezequiel Zamora (UNELLEZ) on an overland fish collecting expedition to the Gran Sabana in southeastern Venezuela. We drove across almost the entire country from Guanare in the west to Santa Elena de Uairén near Venezuela's tricorner border with Brazil and Guyana. Most of our collecting was conducted in tributaries of the lower Caroni River (Orinoco drainage) and headwaters of the Cuyuni River (Essequibo drainage). The Cuyuni headwaters were especially interesting becuase they hold many species and genera that have long been isolated from the lowlands by waterfalls and rapids along the eastern escarpment of the western Guiana Shield (e.g., 'Ammocryptocharax' vintonae, Neblinichthys, and Exastilithoxus). Samples from this expedition are now cataloged at AUM and MCNG (field numbers VEN03-01–26) where they continue to yield import discoveries. Publications that benefitted from collections and observations made during this fieldwork include the following:
Lujan, N.K., J. Armbruster, N. Lovejoy and H. López-Fernández. 2015. Multilocus molecular phylogeny of the Loricariidae (Pisces: Siluriformes) with a focus on subfamily Hypostominae. Molecular Phylogenetics and Evolution 82A:269–288.
Lujan, N.K. and J.W. Armbruster. 2011. The Guiana Shield. pp. 211-224 In: J. Albert, R. Reis, eds. Historical Biogeography of Neotropical Freshwater Fishes. University of California Press, Berkeley.
'Ammocryptocharax' vintonae from headwaters of the Cuyuni River. This is the largest of all species in the South American darter family Crenuchidae. This species differs markedly from the type species of the genus (A. elegans) and likely represents an undescribed genus. Specimens of this species collected during our 2003 trip to the Gran Sabana now form part of the foundation of a micro- to macroevolutionary investigation of the Crenuchidae being conducted by Devin Bloom, Brian Sidlauskas, Hernán López-Fernández and myself.
This field work was sponsored by NSF grant DEB-0107751 to my PhD advisor Dr. Jonathan W. Armbruster.