Metabolic Rates of Rainbow Trout Eggs in Reconstructed Salmonid Egg Pockets
In situ evaluations of the metabolic rates (i.e., respiration and excretion) of salmonid eggs are mostly indirect, focusing on the sampling of hyporheic water from wild or artificial nests. Comparatively, experimental studies carried out under controlled, laboratory conditions are less abundant due...
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-02-01
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| Series: | Water |
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| Online Access: | https://www.mdpi.com/2073-4441/16/4/612 |
| _version_ | 1797296804582129664 |
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| author | Rudy Benetti Tobia Politi Marco Bartoli Nerijus Nika |
| author_facet | Rudy Benetti Tobia Politi Marco Bartoli Nerijus Nika |
| author_sort | Rudy Benetti |
| collection | DOAJ |
| description | In situ evaluations of the metabolic rates (i.e., respiration and excretion) of salmonid eggs are mostly indirect, focusing on the sampling of hyporheic water from wild or artificial nests. Comparatively, experimental studies carried out under controlled, laboratory conditions are less abundant due to methodological difficulties. This study presents a novel experimental setup aimed to address this issue and enable the measurement of oxygen and dissolved inorganic nitrogen fluxes in simulated rainbow trout (<i>O. mykiss</i>) egg pockets. The experimental setup consists of reconstructed egg pockets in cylindrical cores under flow-through conditions. Live and dead eyed-stage eggs were incubated in a natural, sterilised gravel substrate. Hyporheic water circulation was ensured using peristaltic pumps, with the possibility to collect and analyse inflowing and outflowing water for chemical analyses. Microcosm incubations, with closed respirometry of eggs in water alone, were also carried out in order to infer the importance of microbial respiration in the simulated egg pockets. The results show an increasing trend in oxygen demand, due to the development of biofilm in the reconstructed egg pockets and increased egg respiration rates. Moreover, egg pockets showed positive ammonium net fluxes connected with the advancing developmental egg stage, while nitrate removal peaked during the last phase of the experiment, mainly due to the formation of oxic-hypoxic interfaces, leading to couple nitrification–denitrification processes. The suggested approach enables to test a number of in situ situations, including the effects of extreme hydrological conditions, sediment clogging and sudden changes in water chemistry or temperature on the survival and metabolic performances of nests, at different egg development stages. |
| first_indexed | 2024-03-07T22:10:08Z |
| format | Article |
| id | doaj.art-660f2b32c0fc4942a9d6600f35df7086 |
| institution | Directory Open Access Journal |
| issn | 2073-4441 |
| language | English |
| last_indexed | 2024-03-07T22:10:08Z |
| publishDate | 2024-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Water |
| spelling | doaj.art-660f2b32c0fc4942a9d6600f35df70862024-02-23T15:38:06ZengMDPI AGWater2073-44412024-02-0116461210.3390/w16040612Metabolic Rates of Rainbow Trout Eggs in Reconstructed Salmonid Egg PocketsRudy Benetti0Tobia Politi1Marco Bartoli2Nerijus Nika3Marine Research Institute, Klaipeda University, 92294 Klaipeda, LithuaniaMarine Research Institute, Klaipeda University, 92294 Klaipeda, LithuaniaMarine Research Institute, Klaipeda University, 92294 Klaipeda, LithuaniaMarine Research Institute, Klaipeda University, 92294 Klaipeda, LithuaniaIn situ evaluations of the metabolic rates (i.e., respiration and excretion) of salmonid eggs are mostly indirect, focusing on the sampling of hyporheic water from wild or artificial nests. Comparatively, experimental studies carried out under controlled, laboratory conditions are less abundant due to methodological difficulties. This study presents a novel experimental setup aimed to address this issue and enable the measurement of oxygen and dissolved inorganic nitrogen fluxes in simulated rainbow trout (<i>O. mykiss</i>) egg pockets. The experimental setup consists of reconstructed egg pockets in cylindrical cores under flow-through conditions. Live and dead eyed-stage eggs were incubated in a natural, sterilised gravel substrate. Hyporheic water circulation was ensured using peristaltic pumps, with the possibility to collect and analyse inflowing and outflowing water for chemical analyses. Microcosm incubations, with closed respirometry of eggs in water alone, were also carried out in order to infer the importance of microbial respiration in the simulated egg pockets. The results show an increasing trend in oxygen demand, due to the development of biofilm in the reconstructed egg pockets and increased egg respiration rates. Moreover, egg pockets showed positive ammonium net fluxes connected with the advancing developmental egg stage, while nitrate removal peaked during the last phase of the experiment, mainly due to the formation of oxic-hypoxic interfaces, leading to couple nitrification–denitrification processes. The suggested approach enables to test a number of in situ situations, including the effects of extreme hydrological conditions, sediment clogging and sudden changes in water chemistry or temperature on the survival and metabolic performances of nests, at different egg development stages.https://www.mdpi.com/2073-4441/16/4/612salmonideggbiofilmmetabolismincubation |
| spellingShingle | Rudy Benetti Tobia Politi Marco Bartoli Nerijus Nika Metabolic Rates of Rainbow Trout Eggs in Reconstructed Salmonid Egg Pockets Water salmonid egg biofilm metabolism incubation |
| title | Metabolic Rates of Rainbow Trout Eggs in Reconstructed Salmonid Egg Pockets |
| title_full | Metabolic Rates of Rainbow Trout Eggs in Reconstructed Salmonid Egg Pockets |
| title_fullStr | Metabolic Rates of Rainbow Trout Eggs in Reconstructed Salmonid Egg Pockets |
| title_full_unstemmed | Metabolic Rates of Rainbow Trout Eggs in Reconstructed Salmonid Egg Pockets |
| title_short | Metabolic Rates of Rainbow Trout Eggs in Reconstructed Salmonid Egg Pockets |
| title_sort | metabolic rates of rainbow trout eggs in reconstructed salmonid egg pockets |
| topic | salmonid egg biofilm metabolism incubation |
| url | https://www.mdpi.com/2073-4441/16/4/612 |
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