|Effects of mine acid on the longevity and reproductive rate of the gastrotrich Lepidodermella squammata (Dujardin)|
Faucon, A.S.; Hummon, W.D. (1976). Effects of mine acid on the longevity and reproductive rate of the gastrotrich Lepidodermella squammata (Dujardin). Hydrobiologia 50(3): 265-269
In: Hydrobiologia. Springer: The Hague. ISSN 0018-8158, more
Acids; Mineral industry; P; Pollution effects; Reproduction; Fresh water
|Authors|| || Top |
- Faucon, A.S.
- Hummon, W.D.
Effects of mine acid on longevity and reproductive rate of the parthenogenic gastrotrich L. squammata were studied under lab culture conditions. Water from unpolluted and polluted streams was used, directly or mixed, to establish a series of test conditions at pH 8.1, 7.1, 6.4, 5.2, 4.6 and 3.3. Eggs, cultured individually under each test condition, were observed at 12 h intervals for hatching, daughter egg laying and death. Data representing 50 animals under each test condition were used in the construction of a series of life tables. From these were calculated maximal life expectancy (ex), net reproductive rate per individual lifetime (Ro) and intrinsic rate of natural increase (rmax). Values of ex, Ro and rmax were maximal at pH 7.1 and were reduced slightly at the higher pH; ex was greatly reduced and Ro zero at pH 6.4 and 5.2; and ex was zero at pH 4.6 and 3.3. Analysis of variance tests indicate significant differences between exvalues of L. sqummata cultured at pH 8.1 and those cultured at pH 7.1, but no differences between Ro or rmax>. Associated with the decrease in pH was an increase in total conductivity and a decrease in carbonate alkalinity and hence in carbonate conductivity. It appears that L. squammata is capable of living and reproducing at pH 6.0 to 6.5 under field conditions low in carbonates, providing noncarbonate ions are not abundant, or under field conditions high in non-carbonate ions, providing sufficient carbonated are present.