With 700 known fish species, Guyana is arguably the best studied country in the Guayana Shield from an ichthyologic perspective, followed by French Guiana. However, within Guyana there is still a scarcity of information as many regions remain unstudied mainly due to inaccessibility. this is perhaps the main reason for the Lower Essequibo River to be well-studied, while the upper reaches is largely unknown.
This survey is the first comprehensive study of the fish and crustacean aquatic life of the Acarai Mountains and Sipo, Kamoa, and Essequibo rivers upstream from the Amaci Falls.
Methods
Fishes, crustaceans, and mollusks were collected both day and night by several methods. Gill nets were put out in the morning and evening and minnow traps were used to catch small fish and crustaceans and Seine nets were used in the small creeks.
Scientists also collected fish manually using dip nets and, for the rapids, a cast net. On one occasion, the team tried a traditional Wai-Wai fishing technique using a native plant extract, from lianas of hiari (Derris elliptica).
Results
A total of 113 species of fish were identified, from six orders and 27 families. The order Characiformes, which includes tetras and piranhas, was the most diverse with 61 species, followed by catfish (Siluriformes) with 32 species. Four species likely new to science were recorded. Half of the fish species recorded are considered important subsistence resources.
Ten species of aquatic macroinvertebrates were found, from the classes of Crustacea, Gastropoda (snails), and Bivalvia (mussels).
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Accumulation curve for ichthyological species added to the overall species
list per day of study during the 2006 RAP survey of the Acarai Mountains,
Sipu, Kamoa and Essequibo rivers, Konashen Indigenous District of
Southern Guyana. |
Although the sampling by the fish team was very effective, statistical analysis tells us that there are likely many more species to be found. The number of species found each day continued to increase up to the end of the expedition.
On a graph, this yields a curve that does not level off which suggests that more sampling is necessary to record species that were not found in the short time the fish team was in the field.
IN DEPTH: See more graphs, tables and figures by downloading the full report (PDF - 3.67 MB).
What it Means
All of the areas studied were in pristine condition, likely as a result of being within the Konashen COCA. As expected, the most inaccessible streams were the best conserved. The results from the RAP survey brought the number of species that are used by the Wai-Wai community up to 50.
LEARN MORE: Meet some of the fish of the Konashen, Guyana.
Although these species are important for conservation reasons (they are endemic) as well as being important for food, the populations are healthy and abundant and show no evidence of overexploitation. Fishing pressure could be a problem if performed repeatedly at the same sites, but the Wai-Wai have well-established fishing seasons and subsistence fishing practices.
More study is recommended to identify all the species present in the Konshen’s streams, ponds, and rivers. It is also important to study the aquatic density at different seasons of the year, as the low water season will likely yield different conservation results.
| Ant Team | Dung Beetle Team | Katydid Team | Fish Team |
| Reptile and Amphibian Team | Bird Team | Mammal Team |