1
|
Wood CM, Wang J, Jung EH, Pelster B. The physiological consequences of a very large natural meal in a voracious marine fish, the staghorn sculpin (Leptocottus armatus). J Exp Biol 2023; 226:jeb246034. [PMID: 37675481 DOI: 10.1242/jeb.246034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Accepted: 08/26/2023] [Indexed: 09/08/2023]
Abstract
Little information exists on physiological consequences when wild fish eat natural food. Staghorn sculpins at 10-13°C voluntarily consumed 15.8% of their body mass in anchovies. Gastric clearance was slow with >60% of the meal retained in the stomach at 48 h, and was not complete until 84 h. At 14-24 h post-feeding, pH was depressed by 3 units and Cl- concentration was elevated 2-fold in gastric chyme, reflecting HCl secretion, while in all sections of the intestine, pH declined by 1 pH unit but Cl- concentration remained unchanged. PCO2 and total ammonia concentration were greatly elevated throughout the tract, whereas PNH3 and HCO3- concentration were depressed. Intestinal HCO3- secretion rates, measured in gut sacs in vitro, were also lower in fed fish. Whole-animal O2 consumption rate was elevated approximately 2-fold for 72 h post-feeding, reflecting 'specific dynamic action', whereas ammonia and urea-N excretion rates were elevated about 5-fold. Arterial blood exhibited a modest 'alkaline tide' for about 48 h, but there was negligible excretion of metabolic base to the external seawater. PaCO2 and PaO2 remained unchanged. Plasma total amino acid concentration and total lipid concentration were elevated about 1.5-fold for at least 48 h, whereas small increases in plasma total ammonia concentration, PNH3 and urea-N concentration were quickly attenuated. Plasma glucose concentration remained unchanged. We conclude that despite the very large meal, slow processing with high efficiency minimizes internal physiological disturbances. This differs greatly from the picture provided by previous studies on aquacultured species using synthetic diets and/or force-feeding. Questions remain about the role of the gastro-intestinal microbiome in nitrogen and acid-base metabolism.
Collapse
Affiliation(s)
- Chris M Wood
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
- Bamfield Marine Sciences Centre, Bamfield, BC, Canada, V0R 1B0
- Department of Biology, McMaster University, Hamilton, ON, Canada, L8S 4K1
| | - Jun Wang
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
- Bamfield Marine Sciences Centre, Bamfield, BC, Canada, V0R 1B0
- College of Marine Life Sciences, Ocean University of China, Qingdao 266003, China
| | - Ellen H Jung
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada, V6T 1Z4
- Bamfield Marine Sciences Centre, Bamfield, BC, Canada, V0R 1B0
| | - Bernd Pelster
- Bamfield Marine Sciences Centre, Bamfield, BC, Canada, V0R 1B0
- Institute of Zoology, University of Innsbruck, 6020 Innsbruck, Austria
- Center for Molecular Biosciences, University Innsbruck, 6020 Innsbruck, Austria
| |
Collapse
|
2
|
Wen J, Chen SL, Xu WY, Zheng GD, Zou SM. Effects of high NaHCO 3 alkalinity on growth, tissue structure, digestive enzyme activity, and gut microflora of grass carp juvenile. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:85223-85236. [PMID: 37386223 DOI: 10.1007/s11356-023-28083-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 05/31/2023] [Indexed: 07/01/2023]
Abstract
With the gradual decrease in freshwater resources, the available space for freshwater aquaculture is diminishing. As a result, saline-alkaline water aquaculture has emerged as a crucial method to fulfill the increasing demand. This study investigates the impact of alkaline water on the growth performance, tissues (gill, liver, and kidney), digestive enzyme activity, and intestinal microbiology in grass carp (Ctenopharyngodon idella). The aquarium conditions were set with sodium bicarbonate (18 mmol/L (LAW), 32 mmol/L (HAW)) to simulate the alkaline water environment. A freshwater group was the control (FW). The experimental fish were cultured for 60 days. The findings revealed that NaHCO3 alkaline stress significantly reduced growth performance, caused alterations in the structural morphology of gill lamellae, liver, and kidney tissues, and led to decreased activity of intestinal trypsin and lipase amylase (P < 0.05). Analysis of 16S rRNA sequences demonstrated that alkalinity influenced the abundance of dominant bacterial phyla and genera. Proteobacteria showed a significant decrease under alkaline conditions, while Firmicutes exhibited a significant increase (P < 0.05). Furthermore, alkalinity conditions significantly reduced the abundance of bacteria involved in protein, amino acid, and carbohydrate metabolism, cell transport, cell decomposition, and environmental information processing. Conversely, the abundance of bacteria associated with lipid metabolism, energy metabolism, organic systems, and disease functional flora increased significantly under alkalinity conditions (P < 0.05). In conclusion, this comprehensive study indicates that alkalinity stress adversely affected the growth performance of juvenile grass carp, likely due to tissue damage, reduced activity of intestinal digestive enzymes, and alterations in intestinal microorganisms.
Collapse
Affiliation(s)
- Jian Wen
- Genetics and Breeding Center for Blunt Snout Bream, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, 201306, China
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Song-Lin Chen
- Genetics and Breeding Center for Blunt Snout Bream, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, 201306, China
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Wen-Ya Xu
- Genetics and Breeding Center for Blunt Snout Bream, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, 201306, China
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Guo-Dong Zheng
- Genetics and Breeding Center for Blunt Snout Bream, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, 201306, China
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, 201306, China
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China
| | - Shu-Ming Zou
- Genetics and Breeding Center for Blunt Snout Bream, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, 201306, China.
- Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture and Rural Affairs, Shanghai Ocean University, Shanghai, 201306, China.
- National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai, 201306, China.
| |
Collapse
|
3
|
Jung EH, Brauner CJ, Wood CM. Do extreme postprandial levels of oxygen, carbon dioxide, and ammonia in the digestive tract equilibrate with the bloodstream in the freshwater rainbow trout (Oncorhynchus mykiss)? J Comp Physiol B 2023; 193:193-205. [PMID: 36656334 DOI: 10.1007/s00360-023-01475-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 12/20/2022] [Accepted: 01/06/2023] [Indexed: 01/20/2023]
Abstract
The gastrointestinal tract (GIT) lumen of teleosts harbors extreme conditions, especially after feeding: high PCO2 (20-115 Torr), total ammonia (415-3710 μM), PNH3 (79-1760 μTorr in the intestine), and virtual anoxia (PO2 < 1 Torr). These levels could be dangerous if they were to equilibrate with the bloodstream. Thus, we investigated the potential equilibration of O2, CO2, and ammonia across the GIT epithelia in freshwater rainbow trout by monitoring postprandial arterial and venous blood gases in vivo and in situ. In vivo blood was sampled from the indwelling catheters in the dorsal aorta (DA) and subintestinal vein (SIV) draining the posterior intestine in the fasting state and at 4 to 48 h following catheter-feeding. To investigate possible ammonia absorption in the anterior part of the GIT, blood was sampled from the DA, SIV and hepatic portal vein (HPV) from anaesthetized fish in situ following voluntary feeding. We found minimal equilibration of all three gases between the GIT lumen and the SIV blood, with the latter maintaining pre-feeding levels (PO2 = 25-49 Torr, PCO2 = 6-8 Torr, and total ammonia = 117-134 μM and PNH3 = 13-30 μTorr at 48 h post-feeding). In contrast to the SIV, we found that the HPV total ammonia more than doubled 24 h after feeding (128 to 297 μM), indicative of absorption in the anterior GIT. Overall, the GIT epithelia of trout, although specialized for absorption, prevent dangerous levels of PO2, PCO2 and ammonia from equilibrating with the blood circulation.
Collapse
Affiliation(s)
- Ellen H Jung
- Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
| | - Colin J Brauner
- Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Chris M Wood
- Department of Zoology, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| |
Collapse
|
4
|
Weinrauch AM, Hoogenboom JL, Anderson WG. A review of reductionist methods in fish gastrointestinal tract physiology. Comp Biochem Physiol B Biochem Mol Biol 2021; 254:110571. [PMID: 33556622 DOI: 10.1016/j.cbpb.2021.110571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Revised: 01/20/2021] [Accepted: 01/26/2021] [Indexed: 11/25/2022]
Abstract
A holistic understanding of a physiological system can be accomplished through the use of multiple methods. Our current understanding of the fish gastrointestinal tract (GIT) and its role in both nutrient handling and osmoregulation is the result of the examination of the GIT using multiple reductionist methods. This review summarizes the following methods: in vivo mass balance studies, and in vitro gut sac preparations, intestinal perfusions, and Ussing chambers. From Homer Smith's initial findings of marine fish intestinal osmoregulation in the 1930s through to today's research, we discuss the methods, their advantages and pitfalls, and ultimately how they have each contributed to our understanding of fish GIT physiology. Although in vivo studies provide substantial information on the intact animal, segment specific functions of the GIT cannot be easily elucidated. Instead, in vitro gut sac preparations, intestinal perfusions, or Ussing chamber experiments can provide considerable information on the function of a specific tissue and permit the delineation of specific transport pathways through the use of pharmacological agents; however, integrative inputs (e.g. hormonal and neuronal) are removed and only a fraction of the organ system can be studied. We conclude with two case studies, i) divalent cation transport in teleosts and ii) nitrogen handling in the elasmobranch GIT, to highlight how the use of multiple reductionist methods contributes to a greater understanding of the organ system as a whole.
Collapse
Affiliation(s)
- Alyssa M Weinrauch
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
| | - J Lisa Hoogenboom
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
| | - W Gary Anderson
- Department of Biological Sciences, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
| |
Collapse
|
5
|
Goodrich HR, Bayley M, Birgersson L, Davison WG, Johannsson OE, Kim AB, Le My P, Tinh TH, Thanh PN, Thanh HDT, Wood CM. Understanding the gastrointestinal physiology and responses to feeding in air-breathing Anabantiform fishes. JOURNAL OF FISH BIOLOGY 2020; 96:986-1003. [PMID: 32060920 DOI: 10.1111/jfb.14288] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Revised: 12/16/2019] [Accepted: 02/13/2020] [Indexed: 06/10/2023]
Abstract
The Mekong Delta is host to a large number of freshwater species, including a unique group of facultative air-breathing Anabantiforms. Of these, the striped snakehead (Channa striata), the climbing perch (Anabas testudineus), the giant gourami (Osphronemus goramy) and the snakeskin gourami (Trichogaster pectoralis) are major contributors to aquaculture production in Vietnam. The gastrointestinal responses to feeding in these four species are detailed here. Relative intestinal length was lowest in the snakehead, indicating carnivory, and 5.5-fold greater in the snakeskin, indicating herbivory; climbing perch and giant gourami were intermediate, indicating omnivory. N-waste excretion (ammonia-N + urea-N) was greatest in the carnivorous snakehead and least in the herbivorous snakeskin, whereas the opposite trend was observed for net K+ excretion. Similarly, the more carnivorous species had a greater stomach acidity than the more herbivorous species. Measurements of acid-base flux to water indicated that the greatest postprandial alkaline tide occurred in the snakehead and a potential acidic tide in the snakeskin. Additional findings of interest were high levels of both PCO2 (up to 40 mmHg) and HCO3 - (up to 33 mM) in the intestinal chyme of all four of these air-breathing species. Using in vitro gut sac preparations of the climbing perch, it was shown that the intestinal net absorption of fluid, Na+ and HCO3 - was upregulated by feeding but not net Cl- uptake, glucose uptake or K+ secretion. Upregulated net absorption of HCO3 - suggests that the high chyme (HCO3 - ) does not result from secretion by the intestinal epithelium. The possibility of ventilatory control of PCO2 to regulate postprandial acid-base balance in these air-breathing fish is discussed.
Collapse
Affiliation(s)
- Harriet R Goodrich
- School of Biological Sciences, The University of Queensland, St Lucia, QLD, Australia
- College of Life and Environmental Sciences, The University of Exeter, Exeter, Devon, UK
| | - Mark Bayley
- Department of Bioscience, Zoophysiology Aarhus University, Aarhus, Denmark
| | - Lina Birgersson
- Department of Biological and Environmental Sciences, University of Gothenburg, Göteborg, Sweden
| | - William G Davison
- College of Life and Environmental Sciences, The University of Exeter, Exeter, Devon, UK
| | - Ora E Johannsson
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Anne B Kim
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| | - Phuong Le My
- Department of Agriculture, Bac Lieu University, Bac Lieu, Vietnam
| | - Tran H Tinh
- Aquaculture and Fisheries, Department of Animal Sciences, Wageningen University and Research, Wageningen, The Netherlands
| | - Phuong N Thanh
- College of Aquaculture and Fisheries, Can Tho University, Cần Thơ, Vietnam
| | - Huong Do Thi Thanh
- College of Aquaculture and Fisheries, Can Tho University, Cần Thơ, Vietnam
| | - Chris M Wood
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|