top of page


From late March to early April 2003, I participated in my first fish collecting expedition to South America – a trip that would yield many undescribed species and heavily influence my research for years to come. The purpose of this trip was to assist Dr. Donald Taphorn and his student Oscar Leon Mata – two people who have become longtime collaborators and were both then at the University of the Llanos, Ezequiel Zamora (UNELLEZ), in Guanare, Venezuela. Oscar's thesis focused on the environmental impact of ornamental fish harvests on fish populations around the confluence of the Orinoco and Ventuari rivers, an area that to this day remains a poorly studied biodiversity hotspot. To reach this area, Oscar and I drove from Guanare to Puerto Ayacucho and then to the port of Samariapo, where we met a boat that took us upriver to the community of Macaruco. Macaruco is situated on the south bank of the Orinoco River, right where the Ventuari River enters through a maze of islands and anastomose channels, making it the perfect base from which to launch our daily excursions. Specimens collected on this expedition are now cataloged at AUM and MCNG (field numbers NKL03-01–14), where they continue to yield important ichthyological discoveries. Published papers that benefited from collections and observations made during this trip include the following:


ABOVE: My first ever  Pseudoplatystoma (shovelnose catfish) and Serrasalmus (piranha), caught in a gillnet in the lower Guapuchi River, a right-bank tributary of the lower Ventuari.

RIGHT: A pair of Mylesinus schomburgkii (top right), and the popular aquarium fishes Hemigrammus rhodostomus (rummynose tetra, bottom left) and Hemiodus gracilis (right)  

ABOVE: My Clark jungle hammock – a comfortable home away from home during this and many subsequent expeditions. A field biologists should never leave home without one!

A small sample of the many beautiful cichlids that come from the upper Orinoco and are popular in the ornamental fish trade. CLOCKWISE FROM TOP-RIGHT: Hoplarchus psitticus (parrot cichlid), the earth-eater Geophagus taeniopareius, an undescribed pike cichlid (Crenicichla sp. 'Atabapo red'), Daemon's Satan cichlid (Satanoperca daemon) and an undescribed Heros sp. (sp.

'common'). All but the Geophagus were collected in Caño Maraya, a left-bank blackwater tributary of the lower Ventuari River, which in part explains their dark coloration. Since these specimens were collected, headwaters of Caño Maraya have been heavily mined for gold and the current status of these populations is unknown. The Geophagus was collected from Isla Caiman, a sandy island in the middle of the lower Ventuari River.  


This field work was sponsored by NSF grant DEB-0107751 to my PhD advisor Dr. Jonathan W. Armbruster

2003 Expedition to the Lower Ventuari, Venezuela

bottom of page