Wild Rio Negro Conditions Information

[lemondiscus]

Ok, I had a whim of curiosity and decided to look up some information about the region itself where Heckels originate from (for some). I picked the Rio Negro as the region as that is where it seems MANY of the the Symphysodon Discus come from...

It is VERY hard to find water conditions on a monthly basis over the course of a year. I was curious about PH, Hardness and Water Temp over a one year period.... Finding the Negro's water parameters seems impossible UNLESS someone has documented all this information already... if so may I get a link?

I would assume that because of this that the Rio Negro DOES experience temperature fluctuations. If this is the case then what would they fluctuate from and to? Also again I need to ask, because of the rainy season which WOULD increase the PH and Hardness.... what would those parameters be compared to we will say the dry season...

Is there month to month info on this data?

[lemondiscus]

I did find this for the Air/Land Conditions

http://www.weather.com/outlook/trave...graph/BRXX0146

[wgtaylor]

Hey, you seen this site?
Lots of good information.
http://www.amazonian-fish.co.uk/
I have some others, have to dig them up, will try to get them within a couple days. Must be less organized than I thought.

Bill

[wgtaylor]

Here are links to Rio Negro watershed and others. More info than most would probably want to consume.


Black waters have ionic concentrations not much greater than that of rainwater.
They are, however, much more acidic and this results in black waters having an
aluminium concentration greater than that of the more neutral white waters.
The major difference is the concentrations of sodium, magnesium, calcium and potassium;
these are very low in black waters. This has considerable ecological implications.
Some animal groups, such as snails, need a lot of calcium with which to build their shells
and are not abundant in black waters. The lack of dissolved ions in black waters results
in a low conductivity, similar to that of rainwater.

http://www.wku.edu/~smithch/wallace/S011.htm
The mean temperature of the water of the Rio Negro in its lower part,
in the month of September, was, at 6 A.M., 85° 4' [85.4?--Ed.]; at 2 P.M., 86° 5';
and at 6 P.M., 86° 4'; giving very nearly 86° as the mean temperature for the month,
which is one of the hottest in the year. The mean temperature of the air for the same period
was, at 6 A.M., 76°; and at 2 P.M., 92° 5'. It is probable that at no time would the temperature
of the water in the lower part of the Rio Negro be less than 80°.

This is a link to archives here on Simply Discus
http://forum.simplydiscus.com/archiv...p/t-25886.html
The color of the water is mostly brown with a very high level of turbidity.
Fish must have to rely heavily on their lateral line to locate predators, obstacles, and other discus.
The water temperature was pretty steady at 82 F. Flow rate was variable depending on where you were.
Some places may have a few rapids while the next area proved to be extremely calm.
pH remained at about 4.5 but was as low as 3.9. Depth also was extremely variable but
for the most part in the collecting area was less than 5’.

Here are links with an almost endless amount of info about Amazon river, drainage areas, geography etc.
http://en.wikipedia.org/wiki/Amazon_River
http://en.wikipedia.org/wiki/Rio_Negro_(Amazon)
http://en.wikipedia.org/wiki/Blackwater_river

There is some good information on this link about water parameters and temperature.
Discus fish By Thomas A. Giovanetti
http://books.google.com/books?id=Gyk...tivity&f=false

Additional info on water parameters in 4 select tributories.
ftp://daac.ornl.gov/data/lba/nutrien..._Nutrients.pdf

[Kevin22]

thanks, Bill for the links

[wgtaylor]

thanks, Bill for the links

You are welcome Kevin.
I have wild brown, blue, green and heckels and have been researching their water parameters for a while.
Thank goodness for the internet and Simply Discus for being able to share information on all discus. Wilds steal my heart.
Bill

[lemondiscus]

You are welcome Kevin.
I have wild brown, blue, green and heckels and have been researching their water parameters for a while.
Thank goodness for the internet and Simply Discus for being able to share information on all discus. Wilds steal my heart.
Bill

Absolutely awesome! Thanks for the links. I thought it would be nice to research and find all the links we need all in one place instead of hunting the board for a link here or a link there and advice here etc....

[Genirous]

Ok, I had a whim of curiosity and decided to look up some information about the region itself where Heckels originate from (for some). I picked the Rio Negro as the region as that is where it seems MANY of the the Symphysodon Discus come from...

It is VERY hard to find water conditions on a monthly basis over the course of a year. I was curious about PH, Hardness and Water Temp over a one year period.... Finding the Negro's water parameters seems impossible UNLESS someone has documented all this information already... if so may I get a link?

I would assume that because of this that the Rio Negro DOES experience temperature fluctuations. If this is the case then what would they fluctuate from and to? Also again I need to ask, because of the rainy season which WOULD increase the PH and Hardness.... what would those parameters be compared to we will say the dry season...

Is there month to month info on this data?

It is a very interesting topic lemondiscus and I can say that I'm very interested on it! Although there are many links here, I couldn't find proper information -except those for temperature- about pH and conductivity. Does anyone have something on it?

[Bosse]

You can find that information in Heiko Blehers book "Bleher´s Discus".

[Apistomaster]

The water conditions of Heckels in the Rio Negro deviate little from what information WGTaylor has posted. Slightly higher ion content than rain water, high dissolved organic content and a low pH, 3.5 to 4.5 with 4.0 to 4.5 probably being the most common. Warm water rarely less than 80*F Discus usually in areas where the water is 84 to 86*F.

[BWDave]

While researching the properties of humic substances in the Rio Negro, I came across this:

http://www.scielo.br/pdf/jbchs/v18n4/27.pdf

Has a nice table with monthly values for temperature (25-35 deg C), pH (4.5-5.0), conductivity (9-13 uS/cm), rainfall (mm/month) and water depth (M).

Regarding fluctuations over the course of one day, I found the following:

http://www.scielo.br/pdf/bjb/v62n4b/a03v624b.pdf

“Temperature and oxygen measurements in the Rio Negro were determined with an oxygen meter YSI, model 55. The measurements were made near the drift nets in the Lago do Prato, Anavilhanas archipelago, at several depths, and every 4 h for one day.”

“Oxygen levels usually were in the 5.0-6.5 mg/ L range, and temperature range was 29.7-34.3oC. Higher oxygen levels and temperature were observed at 12:00-16:00 h, while lower values were determined at 4:00 h. Depth of water column did not influence temperature, but oxygen levels were 0.3-1.0 mg/L higher at surface than bottom (0.5-1.0 m).”

[wgtaylor]

While researching the properties of humic substances in the Rio Negro, I came across this:

Lots of good info on water parameters on this link, great info everyone.
BWDave, you are a hero with your first post, good links, thanks a bunch.
Bill

[BWDave]

I think temperature variability is a fruitful area to explore. I actually work with an aquatic turtle endemic to the Rio Negro, Podocnemis erythrocephala. I look to the Heckel community for biotope ideas.

One observation with my turtles: When I “upgraded” my heater to a precise digital model, all breeding activity ceased. Prior to that, I used a couple of underpowered ebo-jager heaters that resulted in the tank water temperature varying a fair amount with ambient.

I now vary temperatures both seasonally and daily. I run two heaters: one set for the nighttime low, and the other set for the daytime peak. The daytime heater is on a timer. As soon as I started using the timer, they started showing interest in each other again.

[Apistomaster]

I think temperature variability is a fruitful area to explore. I actually work with an aquatic turtle endemic to the Rio Negro, Podocnemis erythrocephala. I look to the Heckel community for biotope ideas.

One observation with my turtles: When I “upgraded” my heater to a precise digital model, all breeding activity ceased. Prior to that, I used a couple of underpowered ebo-jager heaters that resulted in the tank water temperature varying a fair amount with ambient.

I now vary temperatures both seasonally and daily. I run two heaters: one set for the nighttime low, and the other set for the daytime peak. The daytime heater is on a timer. As soon as I started using the timer, they started showing interest in each other again.

Your methodology with keeping your turtles makes perfect sense to me. It is odd but I have never applied these principals to my own wild Discus when I do use them all the time to stimulate breeding Hypancistrus species, Peckoltia sp L134 and most Corydoras species.
For some reason, most wild discus keepers, including myself, are remarkably rigid about their husbandry methods. It makes no sense to keep the Discus in a steady state and expect to breed them.

I have kept juvenile Amazon turtles, the type with yellow spots on their heads, many years ago when they could still be imported. I don't know if they were the same species you are working with. I don't think they were one of the larger species.

[BWDave]

Yellow spotted sidenecks are the same genus, but a different species. The red-headed sidenecks that I keep are the smallest species of the genus and live exclusively in the blackwater Rio Negro basin. That is why I think of them as the “Heckel” of the turtle world. A number of keepers of the redheads are similarly rigid in temperature range, never letting their tanks get below 85 deg F.

If we are going to expose our specimens to a more varied environment, what ranges are acceptable? The red-headed sidenecks are much more susceptible to shipping losses than most species, probably caused by exposure to low temperatures. I found a study that explored the tolerance of cardinal tetras of the Rio Negro to a range of high and low temperatures.

http://www.scielo.br/pdf/aa/v38n4/v38n4a23.pdf

They were held at a constant temperature for 96 hours. Significant losses were experienced at 19 deg C and below. On the high end, the paper states:

“The tests with high temperatures (25 to 35 oC), showed 100% fish survival at 29 and 31 oC, resulting in total fish mortality above 35o C.”

This seems to conflict with Table 2 where it appears that some losses were experienced even at 29 and 31 deg C (the temperature of the fish collection waters).

I’m not sure how to reconcile the cardinal tetra paper with the Rio Negro seasonality paper I posted earlier where temperatures as high as 35 deg C were reported in the dry season. Perhaps exposure to a peak temperature during the 4 hottest hours of the day is quite different than constant exposure for 96 hours.

There’s probably no need to push the upper limits with fish. With the turtles however, I think that the sharp rise in temperature at the end of the rainy season is probably a breeding trigger since they nest at the low water stage. I’m guessing that with fish, a larger difference between day and night temp at the beginning of the rainy season could be important. (Though I don’t have any Rio Negro data to back that up…)

In summary,
I have been running my “Rio Negro” turtle tank in the ranges of

Hottest months: 88-90 deg F daytime peak, 85 deg F nights
Start of rainy season: Still run 88 deg in the day, but let the nights drop to about 82.
Coldest two months: 82 deg F daytime, 78-79 deg F nights