Elsevier

Aquaculture

Volume 218, Issues 1–4, 27 March 2003, Pages 613-623
Aquaculture

Effects of pH on survival, growth, molting and feeding of giant freshwater prawn Macrobrachium rosenbergii

https://doi.org/10.1016/S0044-8486(02)00265-XGet rights and content

Abstract

The 24-, 48-, 72- and 96-h LC50s (median lethal concentrations) of pH on Macrobrachium rosenbergii juveniles (0.13±0.01 g) were 4.00, 4.05, 4.07 and 4.08, respectively. Survival rates of M. rosenbergii juveniles (2.65±0.06 g) following 56 days exposure to pH 8.2, 7.4, 6.8, 6.2 and 5.6 were 100%, 88.9%, 94.4%, 94.4% and 94.4%, respectively. After 42 days of exposure, the body weight and total length of prawns placed in pH 5.6 were significantly lower (p<0.05) than those placed in pH 8.2. The 42- and 56-day EC50s of pH (pH level that reduced weight gain by 50% of that of the controls) were pH 5.61 and 6.25, respectively. After 56 days of exposure, M. rosenbergii juveniles placed in pH 6.8 exhibited significantly lower molting frequency and body weight gain. Feeding rate was reduced in M. rosenbergiijuveniles (2.06±0.10 g) exposed to pH 6.8 and lower. The minimum acceptable pH levels were 6.2 and 7.4 based on growth and feeding, respectively.

Introduction

The giant freshwater prawn, Macrobrachium rosenbergii is a common inhabitant in rivers and in estuaries throughout the Indo-Pacific regions. This species is of commercial importance for food due to its fast growth in subtropical and tropical regions (New, 1995). The optimal temperature and optimal pH range for the growth of M. rosenbergii are 29–31 °C and 7.0–8.5, respectively.

In freshwater ponds, pH levels fluctuate from 6.6 to 10.2 because of the removal of carbon dioxide due to photosynthesis of plants during daytime and the release of carbon dioxide by both plants and animals during the night (Boyd, 1990). Acid precipitation and its effect on forestry, agriculture and aquaculture have gained attention in the world. In Taiwan, acid rain with a pH level range of 4.06–4.57 in urban and 4.5–5.24 in rural areas has been reported (Her, 1994). The pH level of rain is usually high in July and low in January, and a pH level as low as 4.10 has been observed in Keelung during year 2000 (Fig. 1). Acid precipitation has been also reported to lead to decreased pH in natural freshwater environments (Haines, 1981). Low pH may also occur when water interacts with acid-sulfate soil which contains iron pyrite, and when water receives acidic effluent and seepage (Boyd, 1990).

The acute toxicity of pH on decapod crustaceans has been studied in several species of crayfish Morgan and McMahon, 1982, France, 1984, Distefano et al., 1991 and tiger shrimp Penaeus monodon (Allan and Maguire, 1992). Low pH water has been reported to cause retarded growth in P. monodon (Allan and Maguire, 1992), disturbed ion regulation in crayfish and tiger shrimp Morgan and McMahon, 1982, Allan and Maguire, 1992 and acid–base imbalance in crayfish and freshwater prawn Morgan and McMahon, 1982, Chen and Lee, 1997. However, nothing is known regarding the chronic effect of pH on M. rosenbergii. This paper provides information of survival, growth, molting and feeding of M. rosenbergii when exposed to different pH levels in the laboratory.

Section snippets

Materials and methods

Three experiments were conducted. The first experiment was a study of the acute toxicity of pH for M. rosenbergii. The second experiment evaluated chronic effects on growth and molting, and the third studied the effect on feeding.

Lethal effect

All prawns survived in pH 4.4 for 96 h, and all prawns survived in pH 4.2 for 12 h. However, all prawns placed in pH 3.6 and pH 3.7 died by 24 and 96 h, respectively (Table 1). The 24-, 48-, 72- and 96-h LC50 values and their 95% confidence limits (in parenthesis) of pH for M. rosenbergiijuveniles was 4.00 (3.94, 4.05), 4.05 (4.00, 4.11), 4.07 (4.02, 4.13) and 4.08 (4.02, 4.15), respectively (Fig. 2).

Effect of pH on growth

All prawns survived for 56 days in pH 8.2. The prawns placed in pH 7.4, 6.8, 6.2 and 5.6

Discussion

The pH level below 5.0 may kill several species of DaphniaHavas et al., 1984, Havas, 1985. The acute toxicity of pH on decapod crustaceans has been studied by several scientists and results are given in Table 6. M. rosenbergii is considered to be more sensitive to low pH as compared to other decapod crustaceans. Concerning the toxicity of pH to crayfish, adults are more tolerant to low pH than juveniles France, 1984, Distefano et al., 1991. It is expected that the adult prawns may show a lower

Acknowledgements

We are very grateful for the grant supported by Science Council of Agriculture, Republic of China. We thank Dr. S.Y. Cheng for creating graphs and Mr. R.U. Wang for his assistance in the experiments.

References (26)

  • E.S. Chang

    Endocrine regulation of moulting in crustacea

    Rev. Aquat. Sci.

    (1989)
  • J.C. Chen et al.

    Effects of nitrite exposure on acid–base balance, respiratory protein, and ion concentration of giant freshwater prawn Macrobrachium rosenbergii at low pH

    Arch. Environ. Contam. Toxicol.

    (1997)
  • R.J. Distefano et al.

    Response of the crayfish Cambarus bartonii bartonii to acid exposure in southern Appalachian streams

    Can. J. Zool.

    (1991)
  • Cited by (78)

    • Low water pH depressed growth and early development of giant freshwater prawn Macrobrachium rosenbergii larvae

      2022, Heliyon
      Citation Excerpt :

      These conditions negatively impact the health status and/or more seriously result in mass mortality (Breeze, 2017), as evident in giant freshwater prawn farms (Kawamura et al., 2015; Masse et al., 2017; Amaral et al., 2020). The effects of acidification have been previously reported in post-larva (PL), juvenile, young and adult stages of M. rosenbergii (Chen and Chen, 2003; Kawamura et al., 2015, 2018). However, to our knowledge, the effect of acidification on larval M. rosenbergii remains unclear, most probably due to the handling difficulty during the delicate larval stage.

    • Effects of heat shock protein 70 knockdown on the tolerance of the brine shrimp Artemia franciscana to aquaculture-related stressors: Implications for aquatic animal health and production

      2022, Aquaculture
      Citation Excerpt :

      Changes in pH from the normal ranges not only affect fish growth and reproduction (Zweig et al., 1999), but also the survival of larvae (Zelennikov, 1997; Keinnnen et al., 2003). Other studies reported that low water pH has cause retarded growth in tiger shrimp Penaeus monodon (Allan and Maguire, 1992), imbalance of acid base and ion regulation in crayfish Procambarus clarkii (Morgan and McMahon, 1982), and reduced growth, molting frequency, feeding rate and survival of giant freshwater prawn Macrobrachium rosenbergii (Chen and Chen, 2003). Furthermore, high pH levels increase the solubility of elements and compounds, the toxicity of chemicals, and the risk of toxic compound absorption by aquatic organisms (Hickin, 1995).

    View all citing articles on Scopus
    View full text