Are Amazonian fish more sensitive to ammonia?

[bekateen]

This is paper never got into the forum before (as far as I can tell). It included data on

Corydoras(Ln9) schwartzi

. Since the paper old, I'll put it in Tank Talk rather than Science News:

Souza-Bastos, L. R., Val, A. L. & C. M. Wood. (2017). Are Amazonian fish more sensitive to ammonia? Toxicity of ammonia to eleven native species. Hydrobiologia, 789: 143–155.

https://link.springer.com/article/10.10 ... 015-2623-4

Abstract
Little is known about the tolerance of Amazonian fish to ammonia. However, elevated ammonia of anthropogenic origin may now occur. As Amazonian fish evolved in waters which are generally acidic (i.e., low NH3), we hypothesized that they would be more sensitive to ammonia than other freshwater fish. The acute (96-h) toxicity of NH4Cl was tested in native ion-poor soft water (pH 7.0, ~28 °C) using semi-static tests with 11 species. Species sensitivity distributions (SSDs) for LC5096 h and LC1096 h and calculations of the hazardous concentrations to the most sensitive 5% (HC5 values) were tabulated. Values of LC5096 h/LC1096 h (in mM total ammonia) ranged from 2.24/0.78 for

Paracheirodon axelrodi

(most sensitive) to 19.53/16.07 for Corydoras schwartzi (most tolerant). These results confirm our hypothesis that Amazonian fish are more sensitive to ammonia than other freshwater species. High levels of ammonia may be associated with hypoxia, especially during dry periods. Simultaneous hypoxia (15–20% saturation) exacerbated ammonia toxicity in the most sensitive species (P. axelrodi), but not in

Astronotus ocellatus

or Corydoras schwartzi, a facultative air-breather where prevention of air access doubled ammonia toxicity. The present data are useful in generating regulatory guidelines in Amazonian waters and indicate that further studies incorporating hypoxia and air access/denial are needed.

[TwoTankAmin]

Ammonia toxicity levels for various fish has been something I investigated in the past. I noticed the above paper includes cardinal tetras. I have a study bookmarked from some time back that deals with these fish.

Oliveira, Sarah Ragonha de, Souza, Rondon Tatsuta Yamane Baptista de, Nunes, Érica da Silva Santiago, Carvalho, Cristiane Suely Melo de, Menezes, Glauber Cruz de, Marcon, Jaydione Luíz, Roubach, Rodrigo, Ono, Eduardo Akifumi, & Affonso, Elizabeth Gusmão. (2008). Tolerance to temperature, pH, ammonia and nitrite in cardinal tetra, Paracheirodon axelrodi, an amazonian ornamental fish. Acta Amazonica, 38(4), 773-779.

https://doi.org/10.1590/S0044-59672008000400023

ABSTRACT

Poor water quality condition has been pointed out as one of the major causes for the high mortality of ornamental fishes exported from the state of Amazonas, Brazil. The purpose of the current study was to define water quality standards for cardinal tetra (Paracheirodon axelrodi), by establishing the lower and higher for lethal temperature (LT50), lethal concentration (LC50) for total ammonia and nitrite and LC50 for acid and alkaline pH. According to the findings, cardinal tetra is rather tolerant to high temperature (33.3o C), to a wide pH range (acid pH=2.9 and alkaline pH=8.8 ) and to high total ammonia concentration (23.7 mg/L). However, temperatures below 19.6o C and nitrite concentrations above 1.1 mg/L NO2- may compromise fish survival especially during long shipment abroad.
Full paper here http://www.scielo.br/scielo.php?pid=S00 ... ci_arttext

[bekateen]

Thanks TTA.

From the paper you linked:

The tests were carried out by adding a pre-established quantity of NH4Cl solution to the bath, which were evenly distributed into the chambers. The cardinal tetras were exposed to six concentrations: 0.9, 1.4, 8.5, 13.1, 18.6, 23.7 and 35.6 mg/L of total ammonia

23.7 mg/L NH4Cl is roughly 0.44mM. This is much lower than the limit tested in the paper above.

Cheers, Eric

[TwoTankAmin]

I am not familiar with mM. What I do know is the 1 mg/l = 1 ppm. Would that not mean they tested 35.6 ppm of Total Ammonia (TA)?

Using my handy dandy ammonia calculator and the upper temperature (33.3C) and pH (8.8)limits and TA, I make the NH3 content of that TA to be 14.6628 ppm. I cannot imagine many FW fish surviving very long in that amount of ammonia, i.e. measured in minutes. My reading on this topic has led me to believe that ammonia as NH3 becomes an issue at about 0.05 ppm.

And now I am told that the initial paper tested even higher levels of ammonia?

[bekateen]

I am not familiar with mM. What I do know is the 1 mg/l = 1 ppm.

The units mM refer to millimoles per liter, where 1 mole is 6.022 x 10 (to the 23rd power) molecules of anything.

In both your study and the one I cited in OP, the researchers used NH4Cl to make their test solutions.

1 mole of NH4Cl weighs 53.491 grams, which is the combined masses of 1 nitrogen atom, 4 hydrogens, and 1 chlorine atom.

So if you have a 1 liter solution containing 53.491 grams of NH4Cl, then you've added one mole of NH4Cl to the water, and we say the solution is a 1 mole/L solution (or simply, 1 "molar" or 1 M) of NH4Cl.

From the study you shared, they said 23.7 mg/L NH4Cl was critical. 23.7 mg/L gets converted to molarity this way:

(23.7 mg/L) × (1g/1000mg) × (1 Mol/53.491g) × (1000mMol/Mol) = 0.44 mMol/L

Parts per million can be interpreted many ways, but commonly is used as mg/1000g in water, which is (roughly) mg/L.

As to what was tested in the OP, they were measuring LC50-96, in other words the lethal dose capable of killing 50% of the fish tested by 96 hours. Those fish survived 4 days!

Regards, Eric

[Bas Pels]

What is so nice about molar is it works out nicely with chemical reactions.

Let's say you want to neutrize a 1 M solution of NaOH with HCL. How much HCL solution wil you need? As the reaction is 1 to 1, you will need exactly the same solution, with exactly the same concentration.

In school the children learn to first put averyting into moles, and then do the calculation. For very gfood reasons

If you work with mg/l, or ppm, you would need 35,5 ppm to neutralize 40 ppm of NaOH - assuming I still know the molecular weights of the atoms involved - much more complicated

[TwoTankAmin]

I have never worked with moles, mostly because I never studied chemistry due to switching schools midway through 4 years of high school. The one I left gave chemistry in the third year and the new school gave it in the second year. I did take two years of physics. Unfortunately, I fulfilled my two semester college requirement for a science with geology. So on most of this stuff I am self taught.

I have done a little work using atomic weights, so I understand the difference between NH3 and NH4 and how the nitrogen scale is different from the total ion scale. But that is about the end of it.

Bear in mind that most hobbyists do not have the training and experience to go much beyond ppm and they barely understand that. The only calculation I have ever done for neutralizing was how effectively to block nitrite using chloride. There the calculation was determining how much sodium chloride to use to block a given level of nitrite.

Here is my one experience with ammonia tolerance and Amazonian fish. I brought wild Altum angels into an uncycled tank with a pH pf 4.2 and TDS in the low 20s. I had a plan to cycle filters to work at pH 6.0 in another tank and at the same time began bringing the pH in the angel tank towards 6. This was being done over about a 6 month period. As I approached the point where I had intended to move the cycled filters into the angel tank, the filters in that tank had already cycled and the water quality was fine. I never lost any fish during that process. That dispelled one of those urban aquarium myths that nitrification stops as the pH heads towards 6.0. While NH4 is way less toxic than NH3, fish will not do well in continuous NH4 especially at higher levels.

I do understand the LC kill concept. One can measure only the lethal level regardless of time or one can measure a given concentration with a given exposure time (usually in hours). For the tetra study I linked the issue under investigation involved shipping fish. It is rare this will involve 4 days in the bag. In many cases the time is under 24 hours and even when the fish are coming from Asia to America and all that entails, they are still not in bags for 96 hours. Plus there is the added factor of the bag water pH dropping during transit.

Most of the studies I find which deal with the toxicity of ammonia (nitrite or nitrate) to fresh water fish deal with food fish more than with the ornamentals.