Fish Division expedition to Suriname in South America’s Guiana Shield
Written by: Samuel Borstein and Hernán López-Fernández, Published 3/25/2020
In February and March of 2020, the Division of Fishes, in partnership with Conservation International Suriname, Anton de Kom University and the Amerindian village of Tepu led an expedition to the Upper Tapanahony River in Suriname, northern South America. The Tapanahony is the largest tributary of the Marowjine (also known as the Maroni) River, which serves as the border between the remote region of southern Suriname’s Sipaliwini District from French Guiana. Our expedition expanded the assessment of fish diversity of the Upper Tapanahony in only the second large exploration of the basin since 1999 and one of the very few ever made to the area. The Upper Tapanahony River is close to the headwaters of several other river systems in the region, which could allow faunal exchanges between rivers draining the Amazon basin and the Atlantic Ocean through the Tumucunaque mountains at the southern edge of the Guiana Shield. When geological events cause these rivers to come into contact they open pathways for fish to move naturally into new river systems. While the Tapanahony River is in pristine condition, expanding gold mining activities in Suriname threaten the overall health of the river and surrounding habitats. Gold mining can increase erosion and sedimentation, changing river flow dynamics and altering fish communities. Gold mining also contaminates the water and sediments with heavy metals and chemicals used during gold extraction.
We collected more than 2,600 specimens from over 140 species of fishes during the expedition. These include several species that are only found in the Tapanahony River, many of which are new to the UMMZ fish collection. The expedition yielded several likely undescribed species. One such species is a suckermouth catfish in the genus Pseudolithoxus that is a vibrant green, matching the color of the aquatic plants it lives among in high flow areas. Another is possibly a new species of pacu, which are herbivorous relatives of piranhas. This pacu is similar to species known only from distant river systems in Brazil and Venezuela. The expedition highlighted the fish diversity in the currently pristine Upper Tapanahony River and contributed to the still incomplete inventory of fish diversity in the Guiana Shield. The Tapanahony added valuable samples to several research projects in collaboration with Surinamese institutions, ranging from biodiversity discovery and conservation to historical biogeography and analyses of the evolutionary origin of the incomparably diverse freshwater fish fauna of South America. Given the success of the expedition, the Fish Division and its local partners at Conservation International Suriname are already discussing plans to continue the inventory of this very remote region of South America.
