Puerto Inirida: the last contact with "civilisation“
Only accessible by boat and by plane, about 1.5 hours by plane east of Bogota, just before the border with Venezuela, lies the small town of Inirida on the Rio Inirida. Since this river resembles a brown broth, Inirida was the ideal starting point to regions with clearwater and blackwater, which were accessible by boat from there. Our group of 36 was divided into three small teams of 12 people each to visit the three out-of-town destinations in turns. We stayed overnight with the indigenous people, so Inrida was our last chance to spend money or buy anything we’d forgotten.
One biotope near Inirida, Cano Bonito, was worth seeing, because it had armored catfish in larger numbers. In the other biotopes, we only rarely found Corydoras species. But in the Cano Bonito they were there, in February at least. We were amazed when we saw the biotope again at the end of the rainy season: the water level had risen by several metres and flooded the whole area.
So the fish spread out over this larger amount of water and were found in much smaller numbers. But armored catfish are swarm fish. As soon as you spot one you know the others can't be far away! It was the perfect opportunity to test JBL PRONOVO CORYDORAS. Although the armored catfish were quite shy, they were very quick to eat the food, which was completely new to them!
It is interesting to compare the water parameters between the dry season in February and the end of the rainy season in November:
|
Feb 22 |
Nov 22 |
| Place / type of biotope |
Inirida, Caño Bonito, large |
Caño Bonito, large |
| GPS data: latitude |
03°53'41.4'' N |
03°53'41.4'' N |
| GPS data: longitude |
67°53'58.3 W |
67°53'58.3 W |
| Date |
Feb 05, 2022 |
Nov 17, 2022 |
| Time |
14:15 |
16:15 |
| Cloudiness |
patchy |
extremely cloudy |
| Visibility depth in cm |
approx. 200 |
approx. 60 |
| Water temperature in °C (surface) |
28 |
25.9 |
| Conductance in µS/cm |
9 |
12 |
| GH |
|
|
| KH |
|
|
| pH |
5.5 |
5 |
| Iron in mg/l |
|
|
| Oxygen in mg/l |
8 |
4 |
Presumably due to the low level of direct sunlight, the water temperature dropped by a good 2 °C to 25.9 °C at the surface. Not measured, but subjectively perceptible, was a lower temperature at a depth of about 1 m. The conductivity had risen, although the rain should actually have lowered it with its mineral-free water! Presumably the flooded soils dissolved multiple substances in the water that contributed to the increase in conductivity. The substances were unlikely to be minerals, as the GH and KH were still not measurable. The pH value had dropped from 5.5 to 5.0. The measurement result must, however, be viewed with caution, as all pH tests do not indicate accurately at KH 0. We will purchase a special soft water pH electrode for the next expedition! The lower oxygen content is easy to explain: Due to the floods, the organic matter of the surrounding rainforest undergo an infinite number of decomposition processes in the water, all of which consume enormous amounts of oxygen.
One team visited another biotope, which could not be visited in February due to the indigenous tribe living next to it and the Corona situation. The water level of the small River Sabanitas was also much higher, but it offered the team members interesting fish fauna. Only the altum angelfish we found in February were missing.
