Tintinnid community structure was investigated by plankton net (20 mu m) sampling in the water column (0-200 m) at 33 stations during the spring inter-monsoon (10 March to 9 April 2012) in the eastern equatorial Indian Ocean. A total of 126 species belonging to 32 genera were recorded. Tintinnid abundance and biomass in the range of 193-2983 ind. m(-3) and 0.99-14.75 mu g C m(-3) were positively related to integrated chlorophyll a (chl a) concentration. Taxonomic and morphological diversity were not significantly related to integrated chl a concentration and size diversity, estimated by size-fractionated chl a concentration in the water column of 0-200 m, but were negatively correlated to the depth of the deep chlorophyll maximum. Species abundance distributions at most stations (31 of 33) and in the 3 zones-the northern zone of the equator, the southern zone of the equator (SEQ) and the equator (EQ)-followed a typical lognormal distribution. The geometric distribution gave the best fit for the distribution of lorica oral diameter size-classes in the NEQ and SEQ. Our results suggest that the community structure of tintinnids is governed by the underlying water column environment rather than by the neutral theory of random colonization from a large species pool.
{"title":"Tintinnid community structure in the eastern equatorial Indian Ocean during the spring inter‑monsoon period","authors":"Cuixia Zhang, Jun Sun, Dongxiao Wang, Shu-qun Song, Xiaodong Zhang, Sonia Munir","doi":"10.3354/AB00677","DOIUrl":"https://doi.org/10.3354/AB00677","url":null,"abstract":"Tintinnid community structure was investigated by plankton net (20 mu m) sampling in the water column (0-200 m) at 33 stations during the spring inter-monsoon (10 March to 9 April 2012) in the eastern equatorial Indian Ocean. A total of 126 species belonging to 32 genera were recorded. Tintinnid abundance and biomass in the range of 193-2983 ind. m(-3) and 0.99-14.75 mu g C m(-3) were positively related to integrated chlorophyll a (chl a) concentration. Taxonomic and morphological diversity were not significantly related to integrated chl a concentration and size diversity, estimated by size-fractionated chl a concentration in the water column of 0-200 m, but were negatively correlated to the depth of the deep chlorophyll maximum. Species abundance distributions at most stations (31 of 33) and in the 3 zones-the northern zone of the equator, the southern zone of the equator (SEQ) and the equator (EQ)-followed a typical lognormal distribution. The geometric distribution gave the best fit for the distribution of lorica oral diameter size-classes in the NEQ and SEQ. Our results suggest that the community structure of tintinnids is governed by the underlying water column environment rather than by the neutral theory of random colonization from a large species pool.","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":"86267498","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}
Haiqing Wang, Guodong Wang, Jianguang Fang, Zengjie Jiang, M. Du, Yaping Gao, Jinghui Fang
Sulphide accumulates in sediment due to global aquaculture development and is very harmful to aquatic and benthic ecosystems. Perinereis aibuhitensis inhabits coastal areas and is often exposed to fairly high sulphide concentrations. The present study investigated the tolerance of P. aibuhitensis to sulphide to evaluate its potential application in sulphide remediation and sustainable aquaculture. We assessed the toxicity of sulphide on P. aibuhitensis in a 96 h acute sulphide exposure experiment under different temperature and salinity conditions. Two-way ANOVA showed that increasing salinity did not influence the LC50 of P. aibuhitensis exposed to sulphide. In contrast, increasing temperature significantly augmented the LC50 value (p < 0.05). The results showed a negative relationship between mortality and temperature, and between mortality and exposure time. Subsequently, we performed 2-way ANOVA analysis of the antioxidant (superoxide dismutase [SOD], catalase [CAT] and total antioxidant capacity [T-AOC]) responses of P. aibuhitensis during 96 h exposure to sub-lethal sulphide concentrations (0, 80, 160, 320, and 640 μmol l−1), and a sub sequent recovery period. The activation of this antioxidant defense system appeared to depend on sulphide concentration and exposure duration and their interaction. SOD, CAT, and T-AOC showed obvious differences at the beginning and end of exposure. They were steadily restored during the recovery period. The results indicated that P. aibuhitensis adjusts its antioxidant defense system to cope with sulphide contamination. Therefore, these indexes of P. aibuhitensis could be applied to environmental monitoring and bio-restoration at mudflat or intensive aquaculture areas with high sulphide concentrations.
{"title":"Acute sulphide toxicity in Perinereis aibuhitensis under different salinities and temperatures: LC50 and antioxidant responses","authors":"Haiqing Wang, Guodong Wang, Jianguang Fang, Zengjie Jiang, M. Du, Yaping Gao, Jinghui Fang","doi":"10.3354/AB00674","DOIUrl":"https://doi.org/10.3354/AB00674","url":null,"abstract":"Sulphide accumulates in sediment due to global aquaculture development and is very harmful to aquatic and benthic ecosystems. Perinereis aibuhitensis inhabits coastal areas and is often exposed to fairly high sulphide concentrations. The present study investigated the tolerance of P. aibuhitensis to sulphide to evaluate its potential application in sulphide remediation and sustainable aquaculture. We assessed the toxicity of sulphide on P. aibuhitensis in a 96 h acute sulphide exposure experiment under different temperature and salinity conditions. Two-way ANOVA showed that increasing salinity did not influence the LC50 of P. aibuhitensis exposed to sulphide. In contrast, increasing temperature significantly augmented the LC50 value (p < 0.05). The results showed a negative relationship between mortality and temperature, and between mortality and exposure time. Subsequently, we performed 2-way ANOVA analysis of the antioxidant (superoxide dismutase [SOD], catalase [CAT] and total antioxidant capacity [T-AOC]) responses of P. aibuhitensis during 96 h exposure to sub-lethal sulphide concentrations (0, 80, 160, 320, and 640 μmol l−1), and a sub sequent recovery period. The activation of this antioxidant defense system appeared to depend on sulphide concentration and exposure duration and their interaction. SOD, CAT, and T-AOC showed obvious differences at the beginning and end of exposure. They were steadily restored during the recovery period. The results indicated that P. aibuhitensis adjusts its antioxidant defense system to cope with sulphide contamination. Therefore, these indexes of P. aibuhitensis could be applied to environmental monitoring and bio-restoration at mudflat or intensive aquaculture areas with high sulphide concentrations.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85054946","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}
J. Shao, W. Luo, Q. Wei, Feng Wang, Wei Guo, H. Ye, Zhipeng Chu, Jinming Wu, Shuhuan Zhang
We evaluated the use of microsatellite markers to identify parentage in Brachy mystax lenok tsinlingensis Li, 1966, an endangered salmonid. Computer simulations showed that when no parent information was available, or when information was only available from 1 parent, then exclusion probabilities ranged from 23.6 to 45.1% and from 25.9 to 52.4%, respectively; combined exclusion probabilities for the 8 loci investigated were 97.7 and 98.4%, respectively. However, a breeding experiment with known parental and filial information resulted in 91.28% of progeny being exclusively assigned to their correct parent pair. Our data demonstrate that microsatellitebased parentage assignment is a reliable means with which to obtain information pertaining to genealogical relationships and could therefore benefit genetic conservation of this species.
{"title":"Assignment of parentage by microsatellite analysis in the endangered Brachymystax lenok tsinlingensis (Salmonidae)","authors":"J. Shao, W. Luo, Q. Wei, Feng Wang, Wei Guo, H. Ye, Zhipeng Chu, Jinming Wu, Shuhuan Zhang","doi":"10.3354/AB00675","DOIUrl":"https://doi.org/10.3354/AB00675","url":null,"abstract":"We evaluated the use of microsatellite markers to identify parentage in Brachy mystax lenok tsinlingensis Li, 1966, an endangered salmonid. Computer simulations showed that when no parent information was available, or when information was only available from 1 parent, then exclusion probabilities ranged from 23.6 to 45.1% and from 25.9 to 52.4%, respectively; combined exclusion probabilities for the 8 loci investigated were 97.7 and 98.4%, respectively. However, a breeding experiment with known parental and filial information resulted in 91.28% of progeny being exclusively assigned to their correct parent pair. Our data demonstrate that microsatellitebased parentage assignment is a reliable means with which to obtain information pertaining to genealogical relationships and could therefore benefit genetic conservation of this species.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88092025","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}
Huan-Zhi Xu, Lulu Liu, Yuqi Su, Ye Liang, Jiaxin Yang
The mechanistic target of rapamycin (mTOR) coordinates a complex signal pathway from translation to autophagy that is a key regulator of not only growth and proliferation but also metabolism and aging. mTOR is sensitive to many environmental and endocrine stimuli. We investigated the influence of TOR signaling on aging and reproduction of the rotifer Brachionus calyciflorus using rapamycin as an exogenous inhibitor. We found that 2 and 4 μM rapamycin extended B. calyciflorus life span by 15 and 22%, respectively compared with controls (p < 0.05). The reproductive peak was significantly delayed by rapamycin at 2 and 4 μM (p < 0.01), but the preand post-reproduction periods were not significantly different from controls (p > 0.05). Partial cDNAs coding 375 bp for TOR and 951 bp for S6 kinase (S6K) were obtained from B. calyciflorus expressed sequence tags. The identities of the deduced amino acid sequences of B. calyciflorus cDNAs to their human orthologs were 58% for TOR and 68% for S6K. TOR and S6K mRNA expression were upor down-regulated by different rapamycin concentrations (0.5, 1, 2, 4, 8, and 16 μM) and treatment intervals (control, 12, 24, 36, and 48 h). The results indicated that TOR inhibition acted additively to extend rotifer life span, with upand down-regulation simultaneously impacting reproduction and gene expression.
{"title":"Effects of rapamycin on life span and on expression of TOR and S6K in Brachionus calyciflorus (Rotifera)","authors":"Huan-Zhi Xu, Lulu Liu, Yuqi Su, Ye Liang, Jiaxin Yang","doi":"10.3354/AB00673","DOIUrl":"https://doi.org/10.3354/AB00673","url":null,"abstract":"The mechanistic target of rapamycin (mTOR) coordinates a complex signal pathway from translation to autophagy that is a key regulator of not only growth and proliferation but also metabolism and aging. mTOR is sensitive to many environmental and endocrine stimuli. We investigated the influence of TOR signaling on aging and reproduction of the rotifer Brachionus calyciflorus using rapamycin as an exogenous inhibitor. We found that 2 and 4 μM rapamycin extended B. calyciflorus life span by 15 and 22%, respectively compared with controls (p < 0.05). The reproductive peak was significantly delayed by rapamycin at 2 and 4 μM (p < 0.01), but the preand post-reproduction periods were not significantly different from controls (p > 0.05). Partial cDNAs coding 375 bp for TOR and 951 bp for S6 kinase (S6K) were obtained from B. calyciflorus expressed sequence tags. The identities of the deduced amino acid sequences of B. calyciflorus cDNAs to their human orthologs were 58% for TOR and 68% for S6K. TOR and S6K mRNA expression were upor down-regulated by different rapamycin concentrations (0.5, 1, 2, 4, 8, and 16 μM) and treatment intervals (control, 12, 24, 36, and 48 h). The results indicated that TOR inhibition acted additively to extend rotifer life span, with upand down-regulation simultaneously impacting reproduction and gene expression.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89020432","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}
Remarkably few studies on the effects of PCBs on wild turtles have been conducted. We contrasted population-level parameters of 2 species of freshwater turtles, the snapping turtle Chelydra serpentina and the painted turtle Chrysemys picta, across a strong PCB concentration gradient in the upper Hudson River, New York State, USA. Our study employed standardized capture methods that yielded 465 turtles during 1968 trap-nights over 2 yr (2006 and 2007) at 246 trapping sites. Individuals of both turtle species were relatively heavier in a contaminated river segment, but PCB concentration did not otherwise influence relative abundance of turtles, probabilities of habitat occupancy or detection, sex or age ratios, body size, incidence of deformities, external parasite occurrence, or several movement parameters in a manner consistent with adverse impacts to wild turtles. This lack of spatial trend in parameters of wild populations of aquatic turtles across a strong gradient of PCB contamination contrasts with predictions of adverse impacts derived from population modeling, dose-response studies, and tissue residue analyses.
{"title":"Population status of freshwater turtles across a PCB contamination gradient","authors":"J. Gibbs, S. Rouhani, L. Shams","doi":"10.3354/AB00676","DOIUrl":"https://doi.org/10.3354/AB00676","url":null,"abstract":"Remarkably few studies on the effects of PCBs on wild turtles have been conducted. We contrasted population-level parameters of 2 species of freshwater turtles, the snapping turtle Chelydra serpentina and the painted turtle Chrysemys picta, across a strong PCB concentration gradient in the upper Hudson River, New York State, USA. Our study employed standardized capture methods that yielded 465 turtles during 1968 trap-nights over 2 yr (2006 and 2007) at 246 trapping sites. Individuals of both turtle species were relatively heavier in a contaminated river segment, but PCB concentration did not otherwise influence relative abundance of turtles, probabilities of habitat occupancy or detection, sex or age ratios, body size, incidence of deformities, external parasite occurrence, or several movement parameters in a manner consistent with adverse impacts to wild turtles. This lack of spatial trend in parameters of wild populations of aquatic turtles across a strong gradient of PCB contamination contrasts with predictions of adverse impacts derived from population modeling, dose-response studies, and tissue residue analyses.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73055361","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}
Righting behavior has been used extensively in laboratory studies of sea urchins as an indicator of stress under various environmental conditions. In situ measurements of the natural righting response of sea urchins would serve to place such laboratory measurements in an ecological context as well as potentially validate laboratory control conditions. We investigated the righting response of the sea urchin Lytechinus variegatus in seagrass and sand bottom habitats of Saint Joseph’s Bay, Florida. Field-measured righting times (other than the exception mentioned below) in L. variegatus were similar to those measured in laboratory studies. Moreover, as seen in multiple sea urchin species in laboratory studies, smaller individuals exhibited significantly shorter righting times than larger individuals. Importantly, sea urchins lacking covering material (shell material, seagrass blades) that were placed on open sand patches took significantly longer to right than those with covering material placed on sand patches. Our field observations indicate the importance of sea urchin size, substrate type, and the presence or absence of covering materials when making righting measurements in the laboratory or the field. Our findings also suggest that higher water velocities facilitate righting, as at higher flows on sand patches, the presence/absence of covering material no longer significantly impacted righting time. These findings are ecologically important as they indicate that, under certain natural conditions (sand substrate, low availability of covering materials and low water velocities), L. variegatus that are displaced onto their aboral side are more vulnerable to predation.
{"title":"In situ measurements of righting behavior in the common sea urchin Lytechinus variegatus: the importance of body size, substrate type, and covering material","authors":"R. Challener, J. McClintock","doi":"10.3354/AB00669","DOIUrl":"https://doi.org/10.3354/AB00669","url":null,"abstract":"Righting behavior has been used extensively in laboratory studies of sea urchins as an indicator of stress under various environmental conditions. In situ measurements of the natural righting response of sea urchins would serve to place such laboratory measurements in an ecological context as well as potentially validate laboratory control conditions. We investigated the righting response of the sea urchin Lytechinus variegatus in seagrass and sand bottom habitats of Saint Joseph’s Bay, Florida. Field-measured righting times (other than the exception mentioned below) in L. variegatus were similar to those measured in laboratory studies. Moreover, as seen in multiple sea urchin species in laboratory studies, smaller individuals exhibited significantly shorter righting times than larger individuals. Importantly, sea urchins lacking covering material (shell material, seagrass blades) that were placed on open sand patches took significantly longer to right than those with covering material placed on sand patches. Our field observations indicate the importance of sea urchin size, substrate type, and the presence or absence of covering materials when making righting measurements in the laboratory or the field. Our findings also suggest that higher water velocities facilitate righting, as at higher flows on sand patches, the presence/absence of covering material no longer significantly impacted righting time. These findings are ecologically important as they indicate that, under certain natural conditions (sand substrate, low availability of covering materials and low water velocities), L. variegatus that are displaced onto their aboral side are more vulnerable to predation.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80683640","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}
Xiangyuan Deng, Xiao-li Hu, Da Li, Ling Wang, Jie Cheng, Kun Gao
MicroRNAs (miRNAs) play important regulatory roles in the growth and development of organisms. The colonial green microalga Botryococcus braunii is an oil-rich algae and little is known about its miRNAs and their target genes. Here we constructed and sequenced a small RNA library for B. braunii using the HiSeq 2000 deep sequencing method. In total, we identified 42 known miRNA families and 14 novel miRNAs from B. braunii via sequence alignment and secondary structure prediction. Quantitative real-time PCR analysis indicated that the majority of miRNAs were effective and credible. Gene ontology analysis showed that most of the targets of miRNAs were classified as being involved in metabolic and cellular processes, gene expression regulation and stress/defense functions. Our findings provide the first large-scale identification and characterization of B. braunii miRNAs and their potential target genes. This study could lead to further identification of B. braunii miRNAs and enhance our understanding of their regulatory mechanisms in diverse biological and metabolic processes.
{"title":"Identification and analysis of microRNAs in Botryococcus braunii using high-throughput sequencing","authors":"Xiangyuan Deng, Xiao-li Hu, Da Li, Ling Wang, Jie Cheng, Kun Gao","doi":"10.3354/AB00672","DOIUrl":"https://doi.org/10.3354/AB00672","url":null,"abstract":"MicroRNAs (miRNAs) play important regulatory roles in the growth and development of organisms. The colonial green microalga Botryococcus braunii is an oil-rich algae and little is known about its miRNAs and their target genes. Here we constructed and sequenced a small RNA library for B. braunii using the HiSeq 2000 deep sequencing method. In total, we identified 42 known miRNA families and 14 novel miRNAs from B. braunii via sequence alignment and secondary structure prediction. Quantitative real-time PCR analysis indicated that the majority of miRNAs were effective and credible. Gene ontology analysis showed that most of the targets of miRNAs were classified as being involved in metabolic and cellular processes, gene expression regulation and stress/defense functions. Our findings provide the first large-scale identification and characterization of B. braunii miRNAs and their potential target genes. This study could lead to further identification of B. braunii miRNAs and enhance our understanding of their regulatory mechanisms in diverse biological and metabolic processes.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76581099","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. Felline, E. Mollo, A. Cutignano, L. Grauso, F. Andaloro, L. Castriota, P. Consoli, M. Falautano, M. Sinopoli, A. Terlizzi
Recent studies have shown that the Mediterranean white sea bream Diplodus sargus includes the invasive green alga Caulerpa cylindracea in its diet, with consequent metabolic and enzymatic alterations. As a result of this novel alimentary habit, the bioactive algal red pigment caulerpin has been detected in its tissues. However, this may not be an isolated case: other fish species have also been reported to feed on C. cylindracea, although the possible accumulation of caulerpin in their tissues has not yet been investigated. In this report, we analysed stomach contents and caulerpin levels in the native sparid species Spondyliosoma cantharus, Sarpa salpa, and Diplodus vulgaris, and in the scarid Sparisoma cretense, along with the Lessepsian siganid Siganus luridus. C. cylindracea was found in the stomachs of all but one fish species, the exception being S. cretense, in which prey items could not be determined due to the high degree of digestion. Chemical analysis of fish tissues revealed that only S. cantharus and S. salpa accumulated caulerpin, while no traces of the compound were detected in the other species. Despite intense research efforts on natural products obtained from C. cylindracea, a complete picture of the impacts caused by fish including this alga in their diet has not been elucidated. The identification of caulerpin in other Mediterranean native fish suggests a need for further research in order to assess the possible transfer of such molecules to humans through seafood consumption.
{"title":"Preliminary observations of caulerpin accumulation from the invasive Caulerpa cylindracea in native Mediterranean fish species","authors":"S. Felline, E. Mollo, A. Cutignano, L. Grauso, F. Andaloro, L. Castriota, P. Consoli, M. Falautano, M. Sinopoli, A. Terlizzi","doi":"10.3354/AB00671","DOIUrl":"https://doi.org/10.3354/AB00671","url":null,"abstract":"Recent studies have shown that the Mediterranean white sea bream Diplodus sargus includes the invasive green alga Caulerpa cylindracea in its diet, with consequent metabolic and enzymatic alterations. As a result of this novel alimentary habit, the bioactive algal red pigment caulerpin has been detected in its tissues. However, this may not be an isolated case: other fish species have also been reported to feed on C. cylindracea, although the possible accumulation of caulerpin in their tissues has not yet been investigated. In this report, we analysed stomach contents and caulerpin levels in the native sparid species Spondyliosoma cantharus, Sarpa salpa, and Diplodus vulgaris, and in the scarid Sparisoma cretense, along with the Lessepsian siganid Siganus luridus. C. cylindracea was found in the stomachs of all but one fish species, the exception being S. cretense, in which prey items could not be determined due to the high degree of digestion. Chemical analysis of fish tissues revealed that only S. cantharus and S. salpa accumulated caulerpin, while no traces of the compound were detected in the other species. Despite intense research efforts on natural products obtained from C. cylindracea, a complete picture of the impacts caused by fish including this alga in their diet has not been elucidated. The identification of caulerpin in other Mediterranean native fish suggests a need for further research in order to assess the possible transfer of such molecules to humans through seafood consumption.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90259783","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}
L. Fan, Chang‐Po Chen, Mingqiu Yang, Guanglong Qiu, Yong-Yan Liao, H. Hsieh
Understanding which food sources are nutritionally important at nursery grounds is critical in the conservation of the dwindling populations of horseshoe crabs in Asia. We used δ13C and δ15N values to define life-stage changes in dietary carbon sources and trophic position of 2 co-occurring horseshoe crab species, Tachypleus tridentatus and Carci no scorpius rotundicauda, in a mangroveand seagrass-vegetated estuary, Pearl Bay, in Guangxi, China. δ13C signatures in tissues of T. tridentatus and C. rotundicauda varied between species and among life stages within species, with the greatest differences occurring among earlier life stages (instars 5−7; 20−30 mm prosomal width). Life-stage specific diets were consistent with known habitat use by the 2 horseshoe crab species, with T. tridentatus reflecting slightly enriched seagrass carbon sources and C. ro tun di cauda reflecting influences of lighter sediment particulate organic matter (POM; −15.1 vs. ~ −15.8‰). Overall, seagrass contributed most to dietary carbon of both species (~60%), followed by sediment POM (35%). δ15N signatures were similar between species (~11.6‰), with C. rotundicauda adults exhibiting a slightly more enriched signal than juveniles (12.7 vs. 11.6‰), and all horseshoe crabs occupied secondary consumer trophic levels. The δ15N signatures in horseshoe crabs at Pearl Bay were lighter than those from more urbanized waters, likely due to lower anthropogenic nitrogen loading. Our data and those of previous studies suggest that effective international and national strategies for conserving threatened Asian horseshoe crabs would benefit from incorporating efforts to protect seagrass and mangrove habitats. Newly molted juvenile horseshoe crab (left) and its old shell (right) on a tidal flat adjacent to mangroves in the Pearl Bay estuary (Guangxi, China). Photo: Chang-Po Chen
{"title":"Ontogenetic changes in dietary carbon sources and trophic position of two co-occurring horseshoe crab species in southwestern China","authors":"L. Fan, Chang‐Po Chen, Mingqiu Yang, Guanglong Qiu, Yong-Yan Liao, H. Hsieh","doi":"10.3354/AB00670","DOIUrl":"https://doi.org/10.3354/AB00670","url":null,"abstract":"Understanding which food sources are nutritionally important at nursery grounds is critical in the conservation of the dwindling populations of horseshoe crabs in Asia. We used δ13C and δ15N values to define life-stage changes in dietary carbon sources and trophic position of 2 co-occurring horseshoe crab species, Tachypleus tridentatus and Carci no scorpius rotundicauda, in a mangroveand seagrass-vegetated estuary, Pearl Bay, in Guangxi, China. δ13C signatures in tissues of T. tridentatus and C. rotundicauda varied between species and among life stages within species, with the greatest differences occurring among earlier life stages (instars 5−7; 20−30 mm prosomal width). Life-stage specific diets were consistent with known habitat use by the 2 horseshoe crab species, with T. tridentatus reflecting slightly enriched seagrass carbon sources and C. ro tun di cauda reflecting influences of lighter sediment particulate organic matter (POM; −15.1 vs. ~ −15.8‰). Overall, seagrass contributed most to dietary carbon of both species (~60%), followed by sediment POM (35%). δ15N signatures were similar between species (~11.6‰), with C. rotundicauda adults exhibiting a slightly more enriched signal than juveniles (12.7 vs. 11.6‰), and all horseshoe crabs occupied secondary consumer trophic levels. The δ15N signatures in horseshoe crabs at Pearl Bay were lighter than those from more urbanized waters, likely due to lower anthropogenic nitrogen loading. Our data and those of previous studies suggest that effective international and national strategies for conserving threatened Asian horseshoe crabs would benefit from incorporating efforts to protect seagrass and mangrove habitats. Newly molted juvenile horseshoe crab (left) and its old shell (right) on a tidal flat adjacent to mangroves in the Pearl Bay estuary (Guangxi, China). Photo: Chang-Po Chen","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85096195","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}
Scorpionfishes (family Scorpaenidae) occupy a wide range of thermal environments, yet little is known about the group’s thermal ecology. Recent invasions by red lionfish Pterois volitans and devil firefish P. miles into the Atlantic Ocean and Mediterranean Sea have stimulated interest in the ability of these species to withstand thermal extremes, but current temperature data are limited to cold tolerance estimates, or employ nonstandard techniques, making it difficult to compare values across studies. Using standardized methodologies, we quantified metabolic, physiological, and behavioral thermal responses of red lionfish from the Banda Sea, Sulawesi, Indonesia, and interpret the data in light of the group’s diversity and range of thermal habitats. Red lionfish acclimated at temperatures between 13 and 32°C exhibit a thermal scope of nearly 25°C. The resulting thermal niche is moderately large, allowing lionfish to exploit a wide range of thermal habitats, from mid-Atlantic coastal waters to hyperthermal tropical mangroves and tidepools. Although lionfish prefer temperatures of ~23°C, they acclimate to the high temperature of a cycling thermoperiod. This feature, along with their comparatively low temperature sensitivity (metabolic temperature quotient <2), likely permits lionfish to limit energetic costs during forays into warmer waters. Although lionfishes are considered to be a tropical group, they exhibit a number of thermal tolerance characteristics that allow them to persist in some surprisingly cool environments. Modeling thermal strategies used by red lionfish may provide new insights to the range and variability of thermal adaptations of scorpaenid fishes in general.
蝎子鱼(Scorpaenidae科)占据了广泛的热环境，但对该群体的热生态知之甚少。最近，红狮鱼(Pterois volitans)和魔鬼萤火虫(devil firefish P. miles)入侵大西洋和地中海，激发了人们对这些物种抵御极端高温能力的兴趣，但目前的温度数据仅限于耐寒性估计，或采用非标准技术，因此很难对不同研究的值进行比较。使用标准化的方法，我们量化了来自印度尼西亚苏拉威西班达海的红狮鱼的代谢、生理和行为热反应，并根据该群体的多样性和热栖息地的范围来解释数据。在13至32°C的温度下适应的红狮鱼表现出接近25°C的热范围。由此产生的热生态位是中等大小的，允许狮子鱼利用广泛的热栖息地，从大西洋中部沿海水域到高温的热带红树林和潮汐池。虽然狮子鱼更喜欢~23°C的温度，但它们适应了循环热周期的高温。这一特点，加上它们相对较低的温度敏感性(代谢温度商<2)，可能使狮子鱼在进入较温暖的水域时限制了能量消耗。尽管狮子鱼被认为是热带种群，但它们表现出许多耐热性特征，使它们能够在一些令人惊讶的凉爽环境中生存。对红狮鱼的热适应策略进行建模，可以为了解蝎科鱼类的热适应范围和变异性提供新的见解。
{"title":"Thermal ecology of red lionfish Pterois volitans from Southeast Sulawesi, Indonesia, with comparisons to other Scorpaenidae","authors":"Theresa F. Dabruzzi, W. Bennett, N. Fangue","doi":"10.3354/AB00668","DOIUrl":"https://doi.org/10.3354/AB00668","url":null,"abstract":"Scorpionfishes (family Scorpaenidae) occupy a wide range of thermal environments, yet little is known about the group’s thermal ecology. Recent invasions by red lionfish Pterois volitans and devil firefish P. miles into the Atlantic Ocean and Mediterranean Sea have stimulated interest in the ability of these species to withstand thermal extremes, but current temperature data are limited to cold tolerance estimates, or employ nonstandard techniques, making it difficult to compare values across studies. Using standardized methodologies, we quantified metabolic, physiological, and behavioral thermal responses of red lionfish from the Banda Sea, Sulawesi, Indonesia, and interpret the data in light of the group’s diversity and range of thermal habitats. Red lionfish acclimated at temperatures between 13 and 32°C exhibit a thermal scope of nearly 25°C. The resulting thermal niche is moderately large, allowing lionfish to exploit a wide range of thermal habitats, from mid-Atlantic coastal waters to hyperthermal tropical mangroves and tidepools. Although lionfish prefer temperatures of ~23°C, they acclimate to the high temperature of a cycling thermoperiod. This feature, along with their comparatively low temperature sensitivity (metabolic temperature quotient <2), likely permits lionfish to limit energetic costs during forays into warmer waters. Although lionfishes are considered to be a tropical group, they exhibit a number of thermal tolerance characteristics that allow them to persist in some surprisingly cool environments. Modeling thermal strategies used by red lionfish may provide new insights to the range and variability of thermal adaptations of scorpaenid fishes in general.","PeriodicalId":8111,"journal":{"name":"Aquatic Biology","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2017-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80364741","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}
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