Shane's World Right Arrow GeographyRight Arrow The Venezuelan Diary Series, Part 13 • Rio Santo Domingo / Rio Tinaco :: Pt I

Article © Shane Linder, uploaded January 01, 2002.

Just returned from a fantastic day of collecting in Cojedes State. On Friday April 6, 2001 we drove from Caracas to Norbert Flauger's posada, Casa Maria in Carabobo State. We spent the evening discussing collecting and maintaining various fish. At some point, I mentioned Ingo Seidel and Norbert said that he thought Ingo would arrive Wednesday. Sure enough, Norbert checked his guest list and Ingo was scheduled to arrive this week. Ingo and I missed each other by two days! The next morning we left Casa Maria at 6:00 am to collect the Rio Santo Domingo and the Rio Tinaco. Norbert had claimed that the Rio Tinaco was the best place in Venezuela to collect loricariids, so I was very excited.

Rio Santo Domingo, Cojedes State 7 April 2001
In its lower course the Santo Domingo is called a Rio while the upper portion is reffered to as Cano Santo Domingo. The exact collecting location was on the dirt road that leads west from highway 8 at Cano Benito approximately 40km north of El Baul. Since it is the dry season, the Santo Domingo is not a river anymore, but a series of unconnected pools. We collected from a pool under the bridge and turned up some very interesting fish. The pH was measured at 7.0 and the conductivity at 1,100 mu. The temperature was about 84F and the water had almost no visibility. In a glass container the water was the color of weak tea. This area is northern most range of Apistogramma macmasteri. The substrate was thick leaf litter and driftwood with no aquatic plants.

Collecting the leaf litter turned up

  • Corydoras aeneus "black"
  • Corydoras septentrionalis
  • Corydoras habrosus (thousands!)
  • Small banjo cats
  • Rineloricaria (1 specimen)
  • Otocinclus (thousands!)
  • Trichomycterids (at least 2 spp)
  • Two spp. of small auchenipterids
  • Small Pimelodus

Collecting around larger pieces of driftwood we encountered:

  • Hypoptopoma sp.
  • Hypostomus plecostomus

It was possible with one sweep of a ten foot seine to capture 200 Otocinclus and / or C. habrosus (the two were always mixed). The two auchenipetrids were also very common and we thought we only had one sp. as the color patterns are very similar. Only later did we realize that one has a dorsal and adipose fin and the other only has a small single dorsal spine with no adipose. We also turned up a number of interesting tetras to include some beautiful hatchetfish. The prime predators in the pools were large Hoplias. The water was so full of fishes that it seemed to boil, especially when a large school of Corydoras came up for air at one time. Norbert and I joked that it would be impossible to fill a tank with dead leaves, heat it to 84F, throw in a few old cans, and place about two inches of fish to every gallon. If you tried to replicate this environment exactly, it would be cruelty to animals!

Notes on C. aeneus and C. septentrionalis: Fresh from the wild, both fish are bright emerald green. The only way to tell them apart in the net is by looking at the caudal. In a bucket, it is easy to spot the longer-nosed C. septentrionalis. C. aeneus "black" only turns this color after a few days in captivity. C. sp. aff. aeneus "Venezuela" (all Corydoras pg. 108) is the form from the Rio Chirgua while C. aeneus on pg. 104 look like the C. aeneus from the Rio Tuy. The interesting thing is that in the wild, all three look the same, bright emerald green, immediately after capture. The color change comes later in captivity.

The biotope:
This would be an easy and attractive tank to maintain. The other nice thing is that most of the fish are readily available. Lay down a substrate of about 3/4 inch fine sand. Cover this with two inches of old oak leaves. Along the back and the sides, place several pieces of driftwood. A long shallow tank (such as a 20 long) would be ideal. We caught C. habrosus and Otocinclus in 2-3 inches of water. Filtration should be very gentle such as that provided by a sponge filter. Throw in some 4-5 Apistogramma macmasteri, 10-15 C. habrosus (or smaller groups of the larger corys), 3 - 4 banjo cats, and top it off with some hatchet tetras.

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