How Alkaline Water Affects the Gills of River Prawns

Jim Crocker
7th August, 2024

How Alkaline Water Affects the Gills of River Prawns

Image Source: Natural Science News, 2024

Key Findings

  • The study focused on the oriental river prawn, Macrobrachium nipponense, and its response to alkali treatment
  • Alkali treatment increased antioxidant enzymes like malondialdehyde, glutathione, and glutathione peroxidase in the prawn's gills
  • High alkali concentrations (above 8 mmol/L) damaged gill membranes and hemolymph vessels, impairing respiratory functions
Alkali tolerance in aquatic species is a critical factor for successful aquaculture, especially in regions with high saline-alkali water sources. The oriental river prawn, Macrobrachium nipponense, is a significant commercial species in China, yet its alkali tolerance is insufficient for cultivation in such environments. A recent study conducted by the Chinese Academy of Fishery Sciences aimed to analyze the effects of alkali treatment on the gills of M. nipponense after 96 hours of exposure to various alkaline concentrations[1]. The study employed several methods to understand the impact of alkali exposure: histological observations, measurement of antioxidant enzymes, metabolic profiling analysis, and transcriptome profiling analysis. The findings revealed that alkali treatment stimulated the contents of malondialdehyde, glutathione, and glutathione peroxidase in the gills. These antioxidant enzymes play essential roles in protecting the organism from alkali-induced damage. However, high alkali concentrations (greater than 8 mmol/L) resulted in damage to the gill membrane and hemolymph vessels, affecting normal respiratory functions. Metabolic profiling analysis identified several enriched metabolic pathways, including the biosynthesis of secondary metabolites and amino acids, which are consistent with previous studies examining environmental stress factors[2]. Transcriptome profiling revealed that a 12 mmol/L alkali concentration had the most significant regulatory effects on gene expression. KEGG analysis identified key metabolic pathways such as Phagosome, Lysosome, Glycolysis/Gluconeogenesis, Purine Metabolism, Amino sugar and nucleotide sugar metabolism, and Endocytosis. These pathways are involved in immune response and energy metabolism, suggesting their role in alkali adaptation in M. nipponense. Quantitative PCR analyses confirmed the accuracy of the RNA-Seq data, showing significant stimulation of differentially expressed genes (DEGs) in the Phagosome and Lysosome pathways. This suggests that these pathways and their associated genes are crucial for alkali tolerance in M. nipponense. The findings of this study are in line with previous research on the molecular mechanisms of acid-base regulation in other aquatic species. For instance, a study on the cyprinid fish Leuciscus waleckii, which tolerates highly alkaline environments, revealed that genes involved in ion transportation and ammonia transportation play significant roles in acid-base homeostasis under alkaline stress[2]. Similarly, the current study on M. nipponense identified key metabolic pathways and antioxidant enzymes that are vital for alkali tolerance. Furthermore, the study on the oriental river prawn's androgenic gland transcriptome identified numerous sex-determination related genes and potential markers for genetic studies[3]. This comprehensive genetic information can be leveraged for the genetic improvement of alkali tolerance in M. nipponense, providing a foundation for further research and practical applications in aquaculture. In summary, the study by the Chinese Academy of Fishery Sciences provides valuable insights into the effects of alkali treatment on M. nipponense. By identifying key metabolic pathways and antioxidant enzymes involved in alkali tolerance, this research offers a pathway for genetic improvement in this commercially important species.

BiochemAnimal ScienceMarine Biology

References

Main Study

1) Identification of the effects of alkalinity exposure on the gills of oriental river prawns, Macrobrachium nipponense

Published 6th August, 2024

https://doi.org/10.1186/s12864-024-10659-7

Related Studies

2) Transcriptome and expression profiling analysis of Leuciscus waleckii: an exploration of the alkali-adapted mechanisms of a freshwater teleost.

https://doi.org/10.1039/c3mb70318e

3) Transcriptome analysis of androgenic gland for discovery of novel genes from the oriental river prawn, Macrobrachium nipponense, using Illumina Hiseq 2000.

https://doi.org/10.1371/journal.pone.0076840


Related Articles

An unhandled error has occurred. Reload 🗙