1
|
Li H, Zhang J, Ge X, Chen S, Ma Z. The Effects of Short-Term Exposure to pH Reduction on the Behavioral and Physiological Parameters of Juvenile Black Rockfish ( Sebastes schlegelii). BIOLOGY 2023; 12:876. [PMID: 37372160 DOI: 10.3390/biology12060876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/18/2023] [Accepted: 06/13/2023] [Indexed: 06/29/2023]
Abstract
Coastal areas are subject to greater pH fluctuation and more rapid pH decline as a result of both natural and anthropogenic influences in contrast to open ocean environments. Such variations in pH have the potential to pose a threat to the survival and physiological function of offshore fishes. With the aim of evaluating the impact of short-term pH reduction on the behavioral performance and physiological response of costal fish, the black rockfish (Sebastes schlegelii), one of the principal stock-enhanced species, was examined. In the present study, juveniles of the black rockfish with a mean body length of 6.9 ± 0.3 cm and weight of 8.5 ± 0.5 g were exposed to a series of pHs, 7.0, 7.2, 7.4, 7.6, 7.8, and normal seawater (pH 8.0) for 96 h. At the predetermined time points post-exposure (i.e., 0, 12, 24, 48, and 96 h), fish movement behavior was recorded and the specimens were sampled to assess their physiological responses. The results indicate that the lowered pH environment (pH 7.0-7.8) elicited a significant increase in highly mobile behavior, a decrease in immobile behavior, and a significant rise in the metabolic levels of the black rockfish juveniles. Specifically, carbohydrate metabolism was significantly elevated in the pH 7.2 and 7.4 treatments, while lipid metabolism was significantly increased in the pH 7.0, 7.4, and 7.8 treatments. The results of the present study indicate that short-term reductions in pH could ramp up boldness and boost energy expenditure in the black rockfish juveniles, leading to an increased metabolic cost. Additionally, the present investigation revealed that the black rockfish juveniles were capable of adapting to a short-term pH reduction. The findings may provide insight into the underlying physiological mechanisms that govern fish responses to potential decreases in seawater pH in the future.
Collapse
Affiliation(s)
- Haixia Li
- Key Laboratory of Environment Controlled Aquaculture, Ministry of Education, Dalian 116023, China
- College of Marine Technology and Environment, Dalian Ocean University, Dalian 116023, China
| | - Jia Zhang
- Key Laboratory of Environment Controlled Aquaculture, Ministry of Education, Dalian 116023, China
- College of Marine Technology and Environment, Dalian Ocean University, Dalian 116023, China
| | - Xiaoyu Ge
- Key Laboratory of Environment Controlled Aquaculture, Ministry of Education, Dalian 116023, China
- College of Marine Technology and Environment, Dalian Ocean University, Dalian 116023, China
| | - Songmeng Chen
- Key Laboratory of Environment Controlled Aquaculture, Ministry of Education, Dalian 116023, China
- College of Marine Technology and Environment, Dalian Ocean University, Dalian 116023, China
| | - Zhen Ma
- Key Laboratory of Environment Controlled Aquaculture, Ministry of Education, Dalian 116023, China
- College of Marine Technology and Environment, Dalian Ocean University, Dalian 116023, China
| |
Collapse
|
2
|
Domingos JA, Shen X, Terence C, Senapin S, Dong HT, Tan MR, Gibson-Kueh S, Jerry DR. Scale Drop Disease Virus (SDDV) and Lates calcarifer Herpes Virus (LCHV) Coinfection Downregulate Immune-Relevant Pathways and Cause Splenic and Kidney Necrosis in Barramundi Under Commercial Farming Conditions. Front Genet 2021; 12:666897. [PMID: 34220943 PMCID: PMC8249934 DOI: 10.3389/fgene.2021.666897] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/19/2021] [Indexed: 01/31/2023] Open
Abstract
Marine farming of barramundi (Lates calcarifer) in Southeast Asia is currently severely affected by viral diseases. To better understand the biological implications and gene expression response of barramundi in commercial farming conditions during a disease outbreak, the presence of pathogens, comparative RNAseq, and histopathology targeting multiple organs of clinically “sick” and “healthy” juveniles were investigated. Coinfection of scale drop disease virus (SDDV) and L. calcarifer herpes virus (LCHV) were detected in all sampled fish, with higher SDDV viral loads in sick than in healthy fish. Histopathology showed that livers in sick fish often had moderate to severe abnormal fat accumulation (hepatic lipidosis), whereas the predominant pathology in the kidneys shows moderate to severe inflammation and glomerular necrosis. The spleen was the most severely affected organ, with sick fish presenting severe multifocal and coalescing necrosis. Principal component analysis (PC1 and PC2) explained 70.3% of the observed variance and strongly associated the above histopathological findings with SDDV loads and with the sick phenotypes, supporting a primary diagnosis of the fish being impacted by scale drop disease (SDD). Extracted RNA from kidney and spleen of the sick fish were also severely degraded likely due to severe inflammation and tissue necrosis, indicating failure of these organs in advanced stages of SDD. RNAseq of sick vs. healthy barramundi identified 2,810 and 556 differentially expressed genes (DEGs) in the liver and muscle, respectively. Eleven significantly enriched pathways (e.g., phagosome, cytokine-cytokine-receptor interaction, ECM-receptor interaction, neuroactive ligand-receptor interaction, calcium signaling, MAPK, CAMs, etc.) and gene families (e.g., tool-like receptor, TNF, lectin, complement, interleukin, chemokine, MHC, B and T cells, CD molecules, etc.) relevant to homeostasis and innate and adaptive immunity were mostly downregulated in sick fish. These DEGs and pathways, also previously identified in L. calcarifer as general immune responses to other pathogens and environmental stressors, suggest a failure of the clinically sick fish to cope and overcome the systemic inflammatory responses and tissue degeneration caused by SDD.
Collapse
Affiliation(s)
- Jose A Domingos
- Tropical Futures Institute, James Cook University, Singapore, Singapore.,Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, QLD, Australia
| | - Xueyan Shen
- Tropical Futures Institute, James Cook University, Singapore, Singapore
| | - Celestine Terence
- Tropical Futures Institute, James Cook University, Singapore, Singapore
| | - Saengchan Senapin
- Faculty of Science, Fish Health Platform, Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp), Mahidol University, Bangkok, Thailand.,National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Pathumthani, Thailand
| | - Ha Thanh Dong
- Faculty of Science, Fish Health Platform, Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp), Mahidol University, Bangkok, Thailand.,Faculty of Science and Technology, Suan Sunandha Rajabhat University, Bangkok, Thailand
| | - Marie R Tan
- School of Applied Science (SAS), Republic Polytechnic, Singapore, Singapore
| | - Susan Gibson-Kueh
- Tropical Futures Institute, James Cook University, Singapore, Singapore
| | - Dean R Jerry
- Tropical Futures Institute, James Cook University, Singapore, Singapore.,Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, QLD, Australia
| |
Collapse
|