J. Davidsen, R. Knudsen, M. Power, A. Sjursen, L. Rønning, K. Hårsaker, T. F. Næsje, J. Arnekleiv
From 2011 to 2013, anadromous brown trout Salmo trutta (213−730 mm, total body length, LT) were collected during or shortly after their marine feeding migration at 7 different localities in central Norway. The mean volume of stomach content (%) of marine fish prey eaten by S. trutta captured in marine waters varied from 34 to 89%. There was a high prevalence (67−100%) for parasite groups potentially transmitted by marine prey fish (i.e. nematodes, cestodes and trematodes) at all sampling sites. There was a significant overlap in the signatures of both δ13C and δ15N in the muscle tissue between the 7 groups of S. trutta; however, individual variation within groups was large. A strong positive relationship between δ13C and LT indicated sizedependent niche selection, with smaller individuals feeding less on marine prey and more on brackish or freshwater invertebrates in the estuary. Short-term gut contents data and trophically transmitted parasites showed that all size groups were feeding on marine fish. However, an increased dependence upon marine prey fish by larger S. trutta was indicated by a strong positive relationship between LT and δ15N. Similarities in S. trutta feeding and time-integrated trophic tracers (stable isotopes and parasites) across the 7 localities supports the general view that S. trutta feed within similar marine trophic niches. This similarity in feeding niche requirements may make S. trutta populations vulnerable to anthropogenic ecosystem perturbations which reduce the diversity of potential marine prey items.
{"title":"Trophic niche similarity among sea trout Salmo trutta in Central Norway investigated using different time-integrated trophic tracers","authors":"J. Davidsen, R. Knudsen, M. Power, A. Sjursen, L. Rønning, K. Hårsaker, T. F. Næsje, J. Arnekleiv","doi":"10.3354/AB0689","DOIUrl":"https://doi.org/10.3354/AB0689","url":null,"abstract":"From 2011 to 2013, anadromous brown trout Salmo trutta (213−730 mm, total body length, LT) were collected during or shortly after their marine feeding migration at 7 different localities in central Norway. The mean volume of stomach content (%) of marine fish prey eaten by S. trutta captured in marine waters varied from 34 to 89%. There was a high prevalence (67−100%) for parasite groups potentially transmitted by marine prey fish (i.e. nematodes, cestodes and trematodes) at all sampling sites. There was a significant overlap in the signatures of both δ13C and δ15N in the muscle tissue between the 7 groups of S. trutta; however, individual variation within groups was large. A strong positive relationship between δ13C and LT indicated sizedependent niche selection, with smaller individuals feeding less on marine prey and more on brackish or freshwater invertebrates in the estuary. Short-term gut contents data and trophically transmitted parasites showed that all size groups were feeding on marine fish. However, an increased dependence upon marine prey fish by larger S. trutta was indicated by a strong positive relationship between LT and δ15N. Similarities in S. trutta feeding and time-integrated trophic tracers (stable isotopes and parasites) across the 7 localities supports the general view that S. trutta feed within similar marine trophic niches. This similarity in feeding niche requirements may make S. trutta populations vulnerable to anthropogenic ecosystem perturbations which reduce the diversity of potential marine prey items.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86241310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Helena Kling Michelsen, E. M. Nilssen, T. Pedersen, M. Reigstad, C. Svensen
The spatial patterns in abundance and composition of benthic invertebrate larvae (meroplankton), the correlation between these patterns and environmental variables (temperature, salinity and chl a) and the relative abundance of meroplankton in the mesozooplankton community were investigated in the sub-Arctic Porsangerfjord, Norway (70° N). Zooplankton samples and CTD-profiles were collected at 17 stations along the fjord in April 2013. A total of 32 morphologically different larval types belonging to 8 phyla were identified. Meroplankton were found at all stations, and their community and abundance differed significantly along the fjord. Meroplankton abundance in the inner and outer parts of the fjord was low and was dominated by Gastropoda and Echinodermata. The greatest numbers were recorded in shallow bays and the middle part of the fjord where Cirripedia and Polychaeta were dominant. Meroplankton contributed significantly to the mesozooplankton community in the bays (30 to 90%) and mid-fjord (13 to 48%) areas. These changes in community structure were attributed to spatial gradients in environmental variables such as chl a, salinity and temperature. The different communities suggested a seasonal succession in reproductive events from the fjord mouth toward the head. Considering that spring is an important season for reproduction in pelagic organisms, meroplankton may play a role in the pelagic ecosystem of high-latitude fjords as grazers and prey. Furthermore, the spatial dynamics and reproductive timing of benthic and holoplanktonic organisms are sensitive to local hydrographical features, illustrating their sensitivity to changing environments.
{"title":"Spatial patterns of spring meroplankton along environmental gradients in a sub-Arctic fjord","authors":"Helena Kling Michelsen, E. M. Nilssen, T. Pedersen, M. Reigstad, C. Svensen","doi":"10.3354/AB00686","DOIUrl":"https://doi.org/10.3354/AB00686","url":null,"abstract":"The spatial patterns in abundance and composition of benthic invertebrate larvae (meroplankton), the correlation between these patterns and environmental variables (temperature, salinity and chl a) and the relative abundance of meroplankton in the mesozooplankton community were investigated in the sub-Arctic Porsangerfjord, Norway (70° N). Zooplankton samples and CTD-profiles were collected at 17 stations along the fjord in April 2013. A total of 32 morphologically different larval types belonging to 8 phyla were identified. Meroplankton were found at all stations, and their community and abundance differed significantly along the fjord. Meroplankton abundance in the inner and outer parts of the fjord was low and was dominated by Gastropoda and Echinodermata. The greatest numbers were recorded in shallow bays and the middle part of the fjord where Cirripedia and Polychaeta were dominant. Meroplankton contributed significantly to the mesozooplankton community in the bays (30 to 90%) and mid-fjord (13 to 48%) areas. These changes in community structure were attributed to spatial gradients in environmental variables such as chl a, salinity and temperature. The different communities suggested a seasonal succession in reproductive events from the fjord mouth toward the head. Considering that spring is an important season for reproduction in pelagic organisms, meroplankton may play a role in the pelagic ecosystem of high-latitude fjords as grazers and prey. Furthermore, the spatial dynamics and reproductive timing of benthic and holoplanktonic organisms are sensitive to local hydrographical features, illustrating their sensitivity to changing environments.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82074557","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Montalto, R. Bagarella, A. Rinaldi, G. Sarà, S. Mirto
Understanding the multifaceted nature of environmental fluctuations is crucial to predicting the physiological adjustments utilised by organisms in resisting or adapting to changes over time. Here we investigate the effects of 2 environmental stressors on tunicates, whose fitness can have important repercussions on the quality of habitat. Specifically, we report respiration rate (RR), clearance rate (CR), and assimilation efficiency (AE) of the ascidian Styela plicata in response to a range of temperatures and varying food availability. Temperature-dependent RR was observed only within a portion of the thermal window of the species. Significant differences in clearance rates were detected among organisms fed with varying algal concentrations, while no significant influence of food concentrations on AE was observed. This plasticity of the physiological rates and the development of ubiquitous mechanisms such as temperature-insensitive aerobic metabolism suggest a competitive advantage of this group. Such knowledge may allow for more accurate predictions of the physiological and evolutionary mechanisms driving current and future distribution of this species.
{"title":"Thermal adaptation and physiological responses to environmental stress in tunicates","authors":"V. Montalto, R. Bagarella, A. Rinaldi, G. Sarà, S. Mirto","doi":"10.3354/AB00685","DOIUrl":"https://doi.org/10.3354/AB00685","url":null,"abstract":"Understanding the multifaceted nature of environmental fluctuations is crucial to predicting the physiological adjustments utilised by organisms in resisting or adapting to changes over time. Here we investigate the effects of 2 environmental stressors on tunicates, whose fitness can have important repercussions on the quality of habitat. Specifically, we report respiration rate (RR), clearance rate (CR), and assimilation efficiency (AE) of the ascidian Styela plicata in response to a range of temperatures and varying food availability. Temperature-dependent RR was observed only within a portion of the thermal window of the species. Significant differences in clearance rates were detected among organisms fed with varying algal concentrations, while no significant influence of food concentrations on AE was observed. This plasticity of the physiological rates and the development of ubiquitous mechanisms such as temperature-insensitive aerobic metabolism suggest a competitive advantage of this group. Such knowledge may allow for more accurate predictions of the physiological and evolutionary mechanisms driving current and future distribution of this species.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89807531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To investigate the influence of HCO3 alkalinity on calcification in thalli of the genus Chara, we studied the effects of increased light level and additional HCO3 on calcification rate in C. vulgaris at various hours (30 min, 8 h, 12 h, 12.5 h, 20 h and 24 h after treatment) in a 24 h experiment (12 h light:12 h dark). We identified a significant Pearson’s correlation between exogenous dissolved inorganic carbon (DIC) concentrations and the utilization of DIC (μmol C g−1 fresh weight). Plotting the daily rhythm of DIC utilization produced negative quadratic curves. Furthermore, calcification rate (μmol Ca h−1 g−1) was linearly related to DIC utilization rate (DICuptake; μmol C h−1 g −1), indicating that the calcification rate is dependent on DICuptake. However, ratios of calcification to the utilization of DIC were decreased at high light intensity and increased with HCO3 addition, which was mainly ascribed to changes in the ratio of calcification to photosynthesis. Chlorophyll fluorescence results provided direct evidence for the promotion of photosynthesis in Chara thalli by both high light and DIC addition and their positive influence on maximum relative electron transport rate. These results suggest that calcification in calcareous C. vulgaris is mainly restrained by HCO3 alkalinity, which could explain the correlation between calcification of Chara thalli and alkalinity of water bodies in the field.
为了研究HCO3碱度对Chara属菌体钙化的影响，我们在24 h(光照12 h:黑暗12 h)试验中，研究了不同时间(处理后30 min、8 h、12 h、12.5 h、20 h和24 h)增加光照水平和添加HCO3对C. vulgaris钙化率的影响。我们发现外源溶解无机碳(DIC)浓度与DIC (μmol C g−1鲜重)的利用率之间存在显著的Pearson相关。绘制DIC利用的每日节律产生负二次曲线。钙化率(μmol Ca h−1 g−1)与DIC利用率(DICuptake;μmol C h−1 g−1)，表明钙化速率依赖于dici的摄取。然而，在强光下，钙化与DIC利用率之比降低，随着HCO3的加入而增加，这主要归因于钙化与光合作用之比的变化。叶绿素荧光结果为强光和DIC添加对查拉菌体光合作用的促进及其对最大相对电子传递速率的积极影响提供了直接证据。这些结果表明，钙质C. vulgaris的钙化主要受到HCO3碱度的抑制，这可以解释田间菌体钙化与水体碱度的相关性。
{"title":"Significance of HCO3- alkalinity in calcification and utilization of dissolved inorganic carbon in Chara vulgaris","authors":"Heyun Wang, L. Ni, Dan Yu","doi":"10.3354/AB00684","DOIUrl":"https://doi.org/10.3354/AB00684","url":null,"abstract":"To investigate the influence of HCO3 alkalinity on calcification in thalli of the genus Chara, we studied the effects of increased light level and additional HCO3 on calcification rate in C. vulgaris at various hours (30 min, 8 h, 12 h, 12.5 h, 20 h and 24 h after treatment) in a 24 h experiment (12 h light:12 h dark). We identified a significant Pearson’s correlation between exogenous dissolved inorganic carbon (DIC) concentrations and the utilization of DIC (μmol C g−1 fresh weight). Plotting the daily rhythm of DIC utilization produced negative quadratic curves. Furthermore, calcification rate (μmol Ca h−1 g−1) was linearly related to DIC utilization rate (DICuptake; μmol C h−1 g −1), indicating that the calcification rate is dependent on DICuptake. However, ratios of calcification to the utilization of DIC were decreased at high light intensity and increased with HCO3 addition, which was mainly ascribed to changes in the ratio of calcification to photosynthesis. Chlorophyll fluorescence results provided direct evidence for the promotion of photosynthesis in Chara thalli by both high light and DIC addition and their positive influence on maximum relative electron transport rate. These results suggest that calcification in calcareous C. vulgaris is mainly restrained by HCO3 alkalinity, which could explain the correlation between calcification of Chara thalli and alkalinity of water bodies in the field.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76712670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Tadasuke Tsunashima, M. Hagiya, Riko Yamada, Tomoko Koito, Nobuaki Tsuyuki, S. Izawa, Keita Kosoba, S. Itoi, H. Sugita
The order Polycladida comprises a highly diverse and cosmopolitan group of marine turbellarian flatworms. Owing to the great morphological diversity and the absence of a molecular phylogeny, the classification of this group has always been controversial. Here we seek to add resolution by reporting the results of molecular phylogenetic analysis based on sequences of the 28S ribosomal RNA gene, thus providing a framework for understanding relationships and the evolution of characters within the group. The phylogeny provides strong support for 10 and 7 distinct families within the suborders Acotylea and Cotylea, respectively. In addition, an analysis based on the mitochondrial gene sequences (cytochrome c-oxidase subunit I) reveals further details of the relationships within Acotylea, which were classified by morphological analysis, but not by 28S rRNA sequence-based analyses. These analyses also showed that several species corresponded to previously described genera based on morphological features and character combinations. We conclude that a classification of genera in Acotylea and Cotylea based on molecular phylogeny reflects the morphological diversity of these polyclad flatworms.
{"title":"A molecular framework for the taxonomy and systematics of Japanese marine turbellarian flatworms (Platyhelminthes, Polycladida)","authors":"Tadasuke Tsunashima, M. Hagiya, Riko Yamada, Tomoko Koito, Nobuaki Tsuyuki, S. Izawa, Keita Kosoba, S. Itoi, H. Sugita","doi":"10.3354/AB00682","DOIUrl":"https://doi.org/10.3354/AB00682","url":null,"abstract":"The order Polycladida comprises a highly diverse and cosmopolitan group of marine turbellarian flatworms. Owing to the great morphological diversity and the absence of a molecular phylogeny, the classification of this group has always been controversial. Here we seek to add resolution by reporting the results of molecular phylogenetic analysis based on sequences of the 28S ribosomal RNA gene, thus providing a framework for understanding relationships and the evolution of characters within the group. The phylogeny provides strong support for 10 and 7 distinct families within the suborders Acotylea and Cotylea, respectively. In addition, an analysis based on the mitochondrial gene sequences (cytochrome c-oxidase subunit I) reveals further details of the relationships within Acotylea, which were classified by morphological analysis, but not by 28S rRNA sequence-based analyses. These analyses also showed that several species corresponded to previously described genera based on morphological features and character combinations. We conclude that a classification of genera in Acotylea and Cotylea based on molecular phylogeny reflects the morphological diversity of these polyclad flatworms.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80052162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Macroscopic assessments of maturity from whole fish gonads are well established and routinely used in fisheries research and are important in the estimation of size-at-maturity and the impacts of size-selective fishing. Histological assessment of maturity is more accurate, but much slower, more expensive, and so less frequently conducted. We made a comparison between macroscopic and histological maturity classifications for a diandric protogynous hermaphrodite, blue cod Parapercis colias. The agreement between macroscopic and histological maturity classifications was low. Female and male L50 (length at which 50% of the fish are mature) was estimated from histological data as 23 and 26 cm, respectively. Female spawning frequency was 4.6 d, and mean ± SD relative batch fecundity was 6.5 ± 3.3 hydrated oocytes per gram body weight. A single gonad with both testicular and ovarian tissue was found. Many blue cod were assigned incorrect maturity classifications. These results warrant a study of early gonadal development in blue cod to elucidate if and how sex change takes place. Difficulties in determination of sex and maturity may be most pronounced for species, like blue cod, that have complex maturation patterns. For blue cod, a review of the macroscopic maturity classification key and more thorough technician training are called for.
{"title":"Assessing maturity, fecundity and hermaphroditism in blue cod Parapercis colias","authors":"K. Brandt, M. Dunn, S. Brouwer","doi":"10.3354/AB00679","DOIUrl":"https://doi.org/10.3354/AB00679","url":null,"abstract":"Macroscopic assessments of maturity from whole fish gonads are well established and routinely used in fisheries research and are important in the estimation of size-at-maturity and the impacts of size-selective fishing. Histological assessment of maturity is more accurate, but much slower, more expensive, and so less frequently conducted. We made a comparison between macroscopic and histological maturity classifications for a diandric protogynous hermaphrodite, blue cod Parapercis colias. The agreement between macroscopic and histological maturity classifications was low. Female and male L50 (length at which 50% of the fish are mature) was estimated from histological data as 23 and 26 cm, respectively. Female spawning frequency was 4.6 d, and mean ± SD relative batch fecundity was 6.5 ± 3.3 hydrated oocytes per gram body weight. A single gonad with both testicular and ovarian tissue was found. Many blue cod were assigned incorrect maturity classifications. These results warrant a study of early gonadal development in blue cod to elucidate if and how sex change takes place. Difficulties in determination of sex and maturity may be most pronounced for species, like blue cod, that have complex maturation patterns. For blue cod, a review of the macroscopic maturity classification key and more thorough technician training are called for.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87006657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Gristina, Simona Bertrandino, F. Cardone, D. Mentino, G. Corriero, G. Scillitani
Skin filaments are present on the heads of several Hippocampus species. Their clipping is a useful, non-lethal technique for marking individuals and sampling tissue. Little is known about the consequences of clipping on behaviour and details of regeneration. We present the results of a study on the effects of filament clipping on activity patterns and the regeneration of this structure at the macroscopic and microscopic level in Hippocampus guttulatus Cuvier, 1801 from the Gulf of Taranto (Apulia, Ionian Sea). Twelve individuals of both sexes underwent filament clipping, and their behaviour sequences (expressed as percent of total time spent swimming, resting, food searching, and swinging) were monitored for 10 wk in water tanks. In the first week, individuals spent significantly more time food searching and swimming compared to controls, whereas in the following weeks, no differences between groups were observed. Regeneration was observed in 12 other individuals reclipped after 3, 5, and 7 wk. Sections of paraffin-embedded filaments were stained with Mallory’s trichrome, alcian blue pH 2.5, periodic acid-Schiff (PAS), and PAS with diastase. Epidermal cells and basal membranes were the first to recover fully. Basal epidermal cells were filled with glycogen. In the dermis, the arrangement of bundles of fibres surrounded by melanocytes took longer to reconstitute. After 10 wk, the filaments grew to about 36.7% of their original length, whereas at the microscopic level, the tissues recovered fully. It is concluded that filament clipping does not significantly affect the general behavioural patterns of H. guttulatus, and regeneration at the microscopic level is fully accomplished.
{"title":"Skin filament recovery after clipping in Hippocampus guttulatus: behavioural and histological aspects","authors":"M. Gristina, Simona Bertrandino, F. Cardone, D. Mentino, G. Corriero, G. Scillitani","doi":"10.3354/AB00680","DOIUrl":"https://doi.org/10.3354/AB00680","url":null,"abstract":"Skin filaments are present on the heads of several Hippocampus species. Their clipping is a useful, non-lethal technique for marking individuals and sampling tissue. Little is known about the consequences of clipping on behaviour and details of regeneration. We present the results of a study on the effects of filament clipping on activity patterns and the regeneration of this structure at the macroscopic and microscopic level in Hippocampus guttulatus Cuvier, 1801 from the Gulf of Taranto (Apulia, Ionian Sea). Twelve individuals of both sexes underwent filament clipping, and their behaviour sequences (expressed as percent of total time spent swimming, resting, food searching, and swinging) were monitored for 10 wk in water tanks. In the first week, individuals spent significantly more time food searching and swimming compared to controls, whereas in the following weeks, no differences between groups were observed. Regeneration was observed in 12 other individuals reclipped after 3, 5, and 7 wk. Sections of paraffin-embedded filaments were stained with Mallory’s trichrome, alcian blue pH 2.5, periodic acid-Schiff (PAS), and PAS with diastase. Epidermal cells and basal membranes were the first to recover fully. Basal epidermal cells were filled with glycogen. In the dermis, the arrangement of bundles of fibres surrounded by melanocytes took longer to reconstitute. After 10 wk, the filaments grew to about 36.7% of their original length, whereas at the microscopic level, the tissues recovered fully. It is concluded that filament clipping does not significantly affect the general behavioural patterns of H. guttulatus, and regeneration at the microscopic level is fully accomplished.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74715529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Swimming performance of fish is often improved following periods of moderate exercise training. To examine the effects of training regimes on swimming performance of juvenile bream Megalobrama pellegrini (5.10 ± 0.08 g), fish were held in slow-flowing water (control), or subjected to exercise training at 1 body length (BL) s−1, 2 BL s−1 or 4 BL s−1, or were given exhaustive chasing training daily for 5 wk at 25°C. Aerobic swimming performance was assessed by measuring critical swimming speed (Ucrit). Maximum metabolic rate (MMR), metabolic scope (MS), cost of transport (COT) and net cost of transport (COTnet) were assessed by measurement of oxygen consumption rates ( · MO2). Ucrit was significantly higher in the 4 BL s−1 training group than in the controls. The value of Ucrit was 5% greater for the exhaustive training group compared with the control group, although exhaustive chasing training did not have a significant effect on Ucrit. MMR and MS were not significantly different across treatments. · MO2 and COT of fish in the 4 BL s−1 and exhaustive training groups were significantly lower than in the control group in the swimming speed range of approximately 36−60 cm s−1. This suggests that high-intensity prolonged exercise training and exhaustive chasing training have a positive influence on the swimming performance of juvenile M. pellegrini, which may be related to elevated anaerobic metabolism and improved swimming efficiency.
鱼类的游泳能力通常在经过一段时间的适度运动训练后得到改善。为了研究不同训练方式对幼年佩莱格里尼巨鲷(Megalobrama pellegrini)(5.10±0.08 g)游泳性能的影响，研究人员将鱼置于慢流水中(对照组)，或进行1身长(BL) s - 1、2 BL s - 1或4 BL s - 1的运动训练，或在25°C下每天进行5周的穷力追逐训练。通过测量临界游泳速度(Ucrit)来评估有氧游泳成绩。通过测定耗氧量(·MO2)来评价最大代谢率(MMR)、代谢范围(MS)、运输成本(COT)和净运输成本(COTnet)。4 BL - 1训练组的Ucrit显著高于对照组。穷尽训练组的Ucrit值比对照组高5%，尽管穷尽追逐训练对Ucrit没有显著影响。MMR和MS在不同处理间无显著差异。·在游动速度约36 ~ 60 cm s−1范围内，4 BL s−1组和力竭训练组鱼的MO2和COT显著低于对照组。由此可见，高强度长时间运动训练和穷尽追逐训练对佩莱格里尼幼鱼的游泳成绩有积极影响，这可能与提高无氧代谢、提高游泳效率有关。
{"title":"Effects of prolonged exercise training and exhaustive chasing training on the swimming performance of an endangered bream Megalobrama pellegrini","authors":"Xiu-Ming Li, Xu Pang, Hua Zheng, Xiao-Jin Li, S. Fu, Yao-guang Zhang","doi":"10.3354/AB00681","DOIUrl":"https://doi.org/10.3354/AB00681","url":null,"abstract":"Swimming performance of fish is often improved following periods of moderate exercise training. To examine the effects of training regimes on swimming performance of juvenile bream Megalobrama pellegrini (5.10 ± 0.08 g), fish were held in slow-flowing water (control), or subjected to exercise training at 1 body length (BL) s−1, 2 BL s−1 or 4 BL s−1, or were given exhaustive chasing training daily for 5 wk at 25°C. Aerobic swimming performance was assessed by measuring critical swimming speed (Ucrit). Maximum metabolic rate (MMR), metabolic scope (MS), cost of transport (COT) and net cost of transport (COTnet) were assessed by measurement of oxygen consumption rates ( · MO2). Ucrit was significantly higher in the 4 BL s−1 training group than in the controls. The value of Ucrit was 5% greater for the exhaustive training group compared with the control group, although exhaustive chasing training did not have a significant effect on Ucrit. MMR and MS were not significantly different across treatments. · MO2 and COT of fish in the 4 BL s−1 and exhaustive training groups were significantly lower than in the control group in the swimming speed range of approximately 36−60 cm s−1. This suggests that high-intensity prolonged exercise training and exhaustive chasing training have a positive influence on the swimming performance of juvenile M. pellegrini, which may be related to elevated anaerobic metabolism and improved swimming efficiency.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81018346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Brodie, B. Roberts, Jessica I. Espinosa, K. Heilman, Stephen A. Borgianini, J. Welch, K. A. Reinsel
In 2014, the Atlantic mud fiddler crab Uca pugnax was found 80 km north of its previously known northern range limit. Two years before this shift was noted, we collected a total of 781 male and female specimens from 6 populations along a latitudinal transect extending from Wareham, Massachusetts (41.7615° N), to Tybee Island, Georgia (32.0139° N), USA. By assessing latitudinal and seasonal patterns in the hepatosomatic index (HSI; a measure of stored energy) and the reproductive status of females, we sought to determine whether adult physiological and reproductive limits might slow the northern expansion of U. pugnax. We did not find a latitudinal cline for HSI, suggesting that U. pugnax is a thermal generalist; however, both males and females in the southern part of the range showed greater seasonal fluctuations in HSI compared to northern conspecifics. Across the range, ovigerous females had a significantly reduced HSI, revealing the cost of reproduction. Ovigerous females were found in the May 2013 collection in Massachusetts be fore ocean conditions were permissible for larval development and earlier than previously reported for this species. U. pugnax is expected to closely track warming conditions in the Northwest Atlantic because adults in northern populations are able to maintain energy stores comparable to that of their southern conspecifics, and they release planktonic larvae in early spring, maximizing their dispersal potential.
{"title":"Seasonal and latitudinal variations in the energy reserves of the mud fiddler crab Uca pugnax: implications for the response to climate change","authors":"R. Brodie, B. Roberts, Jessica I. Espinosa, K. Heilman, Stephen A. Borgianini, J. Welch, K. A. Reinsel","doi":"10.3354/AB00683","DOIUrl":"https://doi.org/10.3354/AB00683","url":null,"abstract":"In 2014, the Atlantic mud fiddler crab Uca pugnax was found 80 km north of its previously known northern range limit. Two years before this shift was noted, we collected a total of 781 male and female specimens from 6 populations along a latitudinal transect extending from Wareham, Massachusetts (41.7615° N), to Tybee Island, Georgia (32.0139° N), USA. By assessing latitudinal and seasonal patterns in the hepatosomatic index (HSI; a measure of stored energy) and the reproductive status of females, we sought to determine whether adult physiological and reproductive limits might slow the northern expansion of U. pugnax. We did not find a latitudinal cline for HSI, suggesting that U. pugnax is a thermal generalist; however, both males and females in the southern part of the range showed greater seasonal fluctuations in HSI compared to northern conspecifics. Across the range, ovigerous females had a significantly reduced HSI, revealing the cost of reproduction. Ovigerous females were found in the May 2013 collection in Massachusetts be fore ocean conditions were permissible for larval development and earlier than previously reported for this species. U. pugnax is expected to closely track warming conditions in the Northwest Atlantic because adults in northern populations are able to maintain energy stores comparable to that of their southern conspecifics, and they release planktonic larvae in early spring, maximizing their dispersal potential.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-08-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76159114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Karbalaei, A. Karami, M. Ebrahimi, M. F. Jahromi, A. Ismail, J. Liang, S. Simpson, Sharifah Norkhadijah S. Ismail, Y. Goh
There is a paucity of information about the influence of ploidy status on physiological parameters in organisms following contaminant stress. Also, little is known about the changes in nutritional values of fishes in response to the exposure to contaminants. Full-sibling juvenile Clarias gariepinus were exposed to 3 levels (mean measured 8.9, 17.5, or 28.0 μg l−1) of chlorpyrifos for 21 d. The levels of 3 fatty acids (FAs) in the muscle were significantly different between unexposed diploid and triploid fish. In the chlorpyrifos-exposed fish, the levels of most amino acids (AAs), some FAs, protein, and moisture content were affected in the muscle of diploids, while the levels of some FAs and ash content were changed in the muscle of triploid fish. This work represents the first study of changes in FAs and proximate composition in triploid animals in response to environmental stressors. Fewer changes of nutritional values in triploid C. gariepinus under chlorpyrifos exposure may indicate higher adaptability of triploids than diploids towards environmental stressors. Significant changes in the muscle protein content and AA and FA compositions in diploid Clarias gariepinus in response to chlorpyrifos exposure suggest their application as sensitive indicators of aquatic environmental pollution.
{"title":"Changes in nutritional parameters in diploid and triploid African catfish Clarias gariepinus following chlorpyrifos exposure","authors":"S. Karbalaei, A. Karami, M. Ebrahimi, M. F. Jahromi, A. Ismail, J. Liang, S. Simpson, Sharifah Norkhadijah S. Ismail, Y. Goh","doi":"10.3354/AB00678","DOIUrl":"https://doi.org/10.3354/AB00678","url":null,"abstract":"There is a paucity of information about the influence of ploidy status on physiological parameters in organisms following contaminant stress. Also, little is known about the changes in nutritional values of fishes in response to the exposure to contaminants. Full-sibling juvenile Clarias gariepinus were exposed to 3 levels (mean measured 8.9, 17.5, or 28.0 μg l−1) of chlorpyrifos for 21 d. The levels of 3 fatty acids (FAs) in the muscle were significantly different between unexposed diploid and triploid fish. In the chlorpyrifos-exposed fish, the levels of most amino acids (AAs), some FAs, protein, and moisture content were affected in the muscle of diploids, while the levels of some FAs and ash content were changed in the muscle of triploid fish. This work represents the first study of changes in FAs and proximate composition in triploid animals in response to environmental stressors. Fewer changes of nutritional values in triploid C. gariepinus under chlorpyrifos exposure may indicate higher adaptability of triploids than diploids towards environmental stressors. Significant changes in the muscle protein content and AA and FA compositions in diploid Clarias gariepinus in response to chlorpyrifos exposure suggest their application as sensitive indicators of aquatic environmental pollution.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90111367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：