Fishes of the flooded savannas of Paz de Ariporo, Meta River, Orinoco basin

Study Extent

Our study site was located in Paz de Ariporo floodplains, at left side of Meta river and between lower Guachiría river and La Hermosa stream basins, Casanare department, Colombia (Fig. 1). This area corresponds to alluvial and eolic floodplains, which undergo a sinking, process during Pleistocene caused by a fault on which Meta river flow currently (Mora-Fernández et al., 2013, Osorio-Peláez et al., 2015).

Sampling

We characterized Fish community in floodplains in 13 stations and two climatic periods (ascending waters and descending waters), by the combination and standardization of different fishing arts and measure different environmental variables.

Method steps

1. Standardized samples were applied for both periods and study sites (Fig. 1): sampling included a 100 m transect, making five passes of a fence (7 m long, 2 m high and 0.1 cm mesh), 20 cast net shots (4 m diameter and 2.5 cm mesh) and fishing with hooks for three hours (hooks and lines of different sizes and types of bait). Two "stationary" gillnets (23 m long, 2 m high and 5 cm mesh) were used for 4 hours, and were revised every hour. After captured, fish were fixed in 10% formalin, and then transferred to 70% ethanol. The taxonomic list follows the classification system proposed by Reis et al. (2003) with recent modifications proposed by Oliveira et al. (2011) (characiform families), Thomaz et al. (2015) (Stevardiinae) and Betancur-R et al. (2016) (for osteichthyans in general), and valid species names were confirmed through queries on the Catalog of Fishes of the California Academy of Sciences (Eschmeyer et al., 2017). The species recorded were categorized as threatened (Mojica et al., 2012), migratory (Usma et al., 2013), endemic (DoNascimiento et al., 2017), and species subject of conservation (González et al., 2015).
2. Before fish sampling, in a 100-meter transect, environmental variables (sustrate, submerged vegetation, riparian vegetation and stream morphology) were measured following the protocols established in Rankin (2006). In each site, parameters were taken in-situ such as: dissolved oxygen, water temperature, pH and conductivity with previously calibrated apparatus (Hanna HI 9811-5). Likewise, a representative water sample was taken according to standard protocols for the analysis of the following chemical parameters: total nitrogen, total coliforms, total phosphorus and total solids.

In the 13 environments evaluated, 180 different species we recorded. The species were distributed in seven 7 orders, 34 families and 116 genera.

1. Acestrorhynchidae
   rank: family
2. Achiridae
   rank: family
3. Anostomidae
   rank: family
4. Apteronotidae
   rank: family
5. Auchenipteridae
   rank: family
6. Bryconidae
   rank: family
7. Callichthyidae
   rank: family
8. Chalceidae
   rank: family
9. Characidae
   rank: family
10. Chilodontidae
    rank: family
11. Cichlidae
    rank: family
12. Crenuchidae
    rank: family
13. Curimatidae
    rank: family
14. Cynodontidae
    rank: family
15. Doradidae
    rank: family
16. Erythrinidae
    rank: family
17. Gasteropelecidae
    rank: family
18. Gymnotidae
    rank: family
19. Heptapteridae
    rank: family
20. Hypopomidae
    rank: family
21. Iguanodectidae
    rank: family
22. Lebiasinidae
    rank: family
23. Loricariidae
    rank: family
24. Pimelodidae
    rank: family
25. Potamotrygonidae
    rank: family
26. Prochilodontidae
    rank: family
27. Pseudopimelodidae
    rank: family
28. Rhamphichthyidae
    rank: family
29. Sciaenidae
    rank: family
30. Serrasalmidae
    rank: family
31. Sternopygidae
    rank: family
32. Synbranchidae
    rank: family
33. Trichomycteridae
    rank: family
34. Triportheidae
    rank: family

Our study site was located in Paz de Ariporo floodplains, at left side of Meta river and between lower Guachiría river and La Hermosa stream basins, Casanare department, Colombia. This area corresponds to alluvial and eolic floodplains, which undergo a sinking, process during Pleistocene caused by a fault on which Meta river flow currently (Mora-Fernández et al., 2013, Osorio-Peláez et al., 2015).