A Study of the Relative Toxicity of Anions, with Polycelis Nigra as Test Animal

A brief review is given of existing knowledge regarding the physiological effects of anions, and literature dealing with their relative toxicity. The degree of toxicity of twenty-seven anions to Polycelis nigra (Müller) has been assessed, by determining in each case the molar concentration the animal survives for 48 hr. at 15-18° C. On this basis their order of increasing toxicity is as follows; commas separate ions of similar degree of toxicity: Cl<ClO3, acetate, Br <CO3 <tartrate <S2O3 <SO4, SO3 <I, NO3 <PO4, BO3 <BrO3 <citrate <CNS, C2O4 <AsO4 <CrO3 <IO3 <F <Fe(CN)6, Fe(CN)5NO <NO2, CN <S<OH. Generally speaking anions are very much less toxic than cations. Even the most toxic anion (OH) is far less toxic than ionic copper, silver or gold. The respiration rate of Polycelis is heavily depressed by cyanide, but the survival time is three days or longer, as long as the respiration rate is not less than about 16% of the normal value. With further depression the survival time shortens rapidly, and at 9% normal is under 4 hr. The normal respiration rate of Polycelis nigra is 0.165 c.c. O2/g./hr. This is not very much less than that of the trout. Polycelis is considerably the more resistant to cyanide. This is probably connected with its capability of surviving very many hours in water containing a very reduced supply of oxygen.

Download Full-text

The Effect of Ionic Copper on the Oxygen Consumption of Gammarus Pulex and Polycelis Nigra

Journal of Experimental Biology ◽

10.1242/jeb.18.2.153 ◽

1941 ◽

Vol 18 (2) ◽

pp. 153-161

Author(s):

J. R. ERICHSEN JONES

Keyword(s):

Oxygen Consumption ◽

Respiration Rate ◽

Copper Sulphate ◽

Muscular Activity ◽

Gammarus Pulex ◽

Cellular Respiration ◽

Appreciable Effect ◽

Normal Value ◽

Ionic Copper ◽

Effect Of Copper

The suggestion has been put forward that the oligodynamic action of certain heavy metals is the result of the destruction or inactivation of substances essential for cellular respiration. In a study of the effect of copper sulphate solutions on the oxygen consumption of Polycelis nigra it is found that solutions of concentration 0.001-0.01 N, fatal in 2 hr. or less, induce a marked preliminary rise in the respiration rate; this appears to be due to the inhibition of ciliary locomation and increased muscular activity. A similar increase is produced by increasing the activity of the animals by mechanical means, or by a muscle stimulant (barium chloride). Over the latter part of the survival time the respiration rate drops rapidly and disintegration of the animals begins when it falls to about 60% of the normal value. A 0.0004 N copper sulphate solutions does not inhibit ciliary locomotion, does not stimulate muscular activity, and the oxygen consumption undergoes a stedy decline. A 0.0002 N NaCN solution rapidly depresses the respiration rate to less than 20% of the normal value, but is not fatal, the animals surviving over 4 days. Hydrogen ions, at the concentrations resulting from the hydrolysis of the salt, have no appreciable effect on the oxygen consumption, but at lethal concentrations (pH 2.6, 2.8) effect a speedy depression. The results suggest that the depression of respiration rate observed is insufficient to account for the death of the animals, and is no more than a symptom of the toxic process. A similar general result was obtained in experiments with silver nitrate and mercuric chloride, and also in experiments on the comparative effect of copper sulphate and sodium cyanide solutions on the oxygen consumption of Gammarus pulex.

Download Full-text

The respiration and hypoxic tolerance of Nucula nitidosa and N. nucleus: factors responsible for determining their distribution?

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315402006471 ◽

2002 ◽

Vol 82 (6) ◽

pp. 971-981 ◽

Cited By ~ 7

Author(s):

Sebastian P. Holmes ◽

Nicola Miller ◽

Anke Weber

Keyword(s):

Body Size ◽

Metabolic Rate ◽

Survival Time ◽

Respiration Rate ◽

Standard Error ◽

Functional Strategy ◽

Mean Survival Time ◽

Hypoxic Tolerance ◽

The Mean ◽

Time Standard

Measurement of the respiration of Nucula nitidosa and N. nucleus determined that N. nucleus had a respiration rate approximately a third greater than that of N. nitidosa, 215·28 and 135·64 μl O2 gdfw−1 h−1, respectively. This was calculated to be equivalent to a metabolic rate of 0·648 J individual−1 24 h−1 for N. nitidosa and 1·752 J individual−1 24 h−1 for N. nucleus. Estimation of the production of N. nucleus, from its respiration rate, revealed that for comparable populations, N. nucleus was approximately a third more productive than N. nitidosa, 30 kJ g dry flesh weight (dfw)−1 m−2 y−1 as opposed to 20 kJ gdfw−1 m−2 y−1. Examination of the Kleiber's constant (β) obtained for each species, demonstrated that for N. nitidosa β fell in the range 0·75–1 and that for N. nucleus β fell in the range 1–1·25. This suggests, in combination with other data, that N. nucleus adopts an ‘exploitative’ functional strategy as opposed to N. nitidosa, which can be regarded as adopting a ‘conservationist’ functional strategy.Observations on the hypoxic tolerance of both N. nitidosa and N. nucleus revealed that N. nucleus had a hypoxic tolerance about twice that of N. nucleus. The mean survival time±standard error for N. nitidosa was 3·53±0·18 d in contrast to 7·72±0·21 d for N. nitidosa. The hypoxic tolerance of either species was not related to body size and was independent of any possible effects of starvation. These results are discussed with reference to their potential effects to determine the distribution of N. nitidosa and N. nucleus.

Download Full-text