The Experts below are selected from a list of 6642 Experts worldwide ranked by ideXlab platform
Peter Lawton - One of the best experts on this subject based on the ideXlab platform.
-
patterns of seasonal and tidal feeding activity in the dendrochirote sea cucumber cucumaria frondosa echinodermata holothuroidea in the bay of fundy canada
Marine Ecology Progress Series, 1999Co-Authors: Rabindra Singh, Bruce A Macdonald, Martin L.h. Thomas, Peter LawtonAbstract:In situ field observations of the suspension-feeding North Atlantic sea cucumber Cucumaria frondosa from the Bay of Fundy, Canada, conducted over a 3 yr period, revealed a seasonal feeding rhythm. Sea cucumbers extended their tentacles and began feeding in March/April and ceased feeding in September/October. There were significant relationships between this feeding activity daylength and the quality of the Seston, but not its concentration. Together daylength and chloropigment concentration explained 49% of the variability in the percentage of feeding sea cucumbers. Feeding activity was not significantly correlated with the distinct temperature cycle observed in the study area. Feeding activity was influenced by the state of the tide, water temperature and by daylight during some periods of the feeding season. However, for most of the year these factors appeared not to be important. Sea cucumbers increased their rate of tentacle insertion into the mouth as the quality of the Seston increased. The rate of tentacle insertions increased with increasing Seston chloropigment concentration but decreased with increasing current speed. These 2 environmental variables explained about 28% of the variability in tentacle insertion rates. Seston quality is likely the major environmental variable influencing seasonal feeding behaviour and feeding rate in this species.
-
Feeding response of the dendrochirote sea cucumber Cucumaria frondosa (Echinodermata: Holothuroidea) to changing food concentrations in the laboratory
Canadian Journal of Zoology, 1998Co-Authors: Rabindra Singh, Bruce A Macdonald, Peter Lawton, Martin L.h. ThomasAbstract:Sea cucumbers (Cucumaria frondosa) (Echinodermata: Holothuroidea) held in flow-through tanks were exposed to different chloropigment concentrations by manipulating the Seston concentration via the use of water filters in the inflow lines and the addition of cultured algae or natural plankton to tanks. The percentage of sea cucumbers open and feeding increased asymptotically as the Seston chloropigment concentration increased. Below 50 µg·L-1 the percentage of sea cucumbers with tentacles extended and feeding decreased. The rate at which sea cucumbers inserted their tentacles into their mouths (0.96 ± 0.34 insertion/min (mean ± SD)) increased with increasing Seston quality. Cucumaria frondosa fed at faster rates at the higher concentrations. There was a significant positive relationship between the stomach content (amount of chloropigment) of sea cucumbers and the Seston chloropigment concentration to which they were exposed (r2 = 0.200, p < 0.001).
Rabindra Singh - One of the best experts on this subject based on the ideXlab platform.
-
patterns of seasonal and tidal feeding activity in the dendrochirote sea cucumber cucumaria frondosa echinodermata holothuroidea in the bay of fundy canada
Marine Ecology Progress Series, 1999Co-Authors: Rabindra Singh, Bruce A Macdonald, Martin L.h. Thomas, Peter LawtonAbstract:In situ field observations of the suspension-feeding North Atlantic sea cucumber Cucumaria frondosa from the Bay of Fundy, Canada, conducted over a 3 yr period, revealed a seasonal feeding rhythm. Sea cucumbers extended their tentacles and began feeding in March/April and ceased feeding in September/October. There were significant relationships between this feeding activity daylength and the quality of the Seston, but not its concentration. Together daylength and chloropigment concentration explained 49% of the variability in the percentage of feeding sea cucumbers. Feeding activity was not significantly correlated with the distinct temperature cycle observed in the study area. Feeding activity was influenced by the state of the tide, water temperature and by daylight during some periods of the feeding season. However, for most of the year these factors appeared not to be important. Sea cucumbers increased their rate of tentacle insertion into the mouth as the quality of the Seston increased. The rate of tentacle insertions increased with increasing Seston chloropigment concentration but decreased with increasing current speed. These 2 environmental variables explained about 28% of the variability in tentacle insertion rates. Seston quality is likely the major environmental variable influencing seasonal feeding behaviour and feeding rate in this species.
-
Feeding response of the dendrochirote sea cucumber Cucumaria frondosa (Echinodermata: Holothuroidea) to changing food concentrations in the laboratory
Canadian Journal of Zoology, 1998Co-Authors: Rabindra Singh, Bruce A Macdonald, Peter Lawton, Martin L.h. ThomasAbstract:Sea cucumbers (Cucumaria frondosa) (Echinodermata: Holothuroidea) held in flow-through tanks were exposed to different chloropigment concentrations by manipulating the Seston concentration via the use of water filters in the inflow lines and the addition of cultured algae or natural plankton to tanks. The percentage of sea cucumbers open and feeding increased asymptotically as the Seston chloropigment concentration increased. Below 50 µg·L-1 the percentage of sea cucumbers with tentacles extended and feeding decreased. The rate at which sea cucumbers inserted their tentacles into their mouths (0.96 ± 0.34 insertion/min (mean ± SD)) increased with increasing Seston quality. Cucumaria frondosa fed at faster rates at the higher concentrations. There was a significant positive relationship between the stomach content (amount of chloropigment) of sea cucumbers and the Seston chloropigment concentration to which they were exposed (r2 = 0.200, p < 0.001).
Martin L.h. Thomas - One of the best experts on this subject based on the ideXlab platform.
-
patterns of seasonal and tidal feeding activity in the dendrochirote sea cucumber cucumaria frondosa echinodermata holothuroidea in the bay of fundy canada
Marine Ecology Progress Series, 1999Co-Authors: Rabindra Singh, Bruce A Macdonald, Martin L.h. Thomas, Peter LawtonAbstract:In situ field observations of the suspension-feeding North Atlantic sea cucumber Cucumaria frondosa from the Bay of Fundy, Canada, conducted over a 3 yr period, revealed a seasonal feeding rhythm. Sea cucumbers extended their tentacles and began feeding in March/April and ceased feeding in September/October. There were significant relationships between this feeding activity daylength and the quality of the Seston, but not its concentration. Together daylength and chloropigment concentration explained 49% of the variability in the percentage of feeding sea cucumbers. Feeding activity was not significantly correlated with the distinct temperature cycle observed in the study area. Feeding activity was influenced by the state of the tide, water temperature and by daylight during some periods of the feeding season. However, for most of the year these factors appeared not to be important. Sea cucumbers increased their rate of tentacle insertion into the mouth as the quality of the Seston increased. The rate of tentacle insertions increased with increasing Seston chloropigment concentration but decreased with increasing current speed. These 2 environmental variables explained about 28% of the variability in tentacle insertion rates. Seston quality is likely the major environmental variable influencing seasonal feeding behaviour and feeding rate in this species.
-
Feeding response of the dendrochirote sea cucumber Cucumaria frondosa (Echinodermata: Holothuroidea) to changing food concentrations in the laboratory
Canadian Journal of Zoology, 1998Co-Authors: Rabindra Singh, Bruce A Macdonald, Peter Lawton, Martin L.h. ThomasAbstract:Sea cucumbers (Cucumaria frondosa) (Echinodermata: Holothuroidea) held in flow-through tanks were exposed to different chloropigment concentrations by manipulating the Seston concentration via the use of water filters in the inflow lines and the addition of cultured algae or natural plankton to tanks. The percentage of sea cucumbers open and feeding increased asymptotically as the Seston chloropigment concentration increased. Below 50 µg·L-1 the percentage of sea cucumbers with tentacles extended and feeding decreased. The rate at which sea cucumbers inserted their tentacles into their mouths (0.96 ± 0.34 insertion/min (mean ± SD)) increased with increasing Seston quality. Cucumaria frondosa fed at faster rates at the higher concentrations. There was a significant positive relationship between the stomach content (amount of chloropigment) of sea cucumbers and the Seston chloropigment concentration to which they were exposed (r2 = 0.200, p < 0.001).
Bruce A Macdonald - One of the best experts on this subject based on the ideXlab platform.
-
patterns of seasonal and tidal feeding activity in the dendrochirote sea cucumber cucumaria frondosa echinodermata holothuroidea in the bay of fundy canada
Marine Ecology Progress Series, 1999Co-Authors: Rabindra Singh, Bruce A Macdonald, Martin L.h. Thomas, Peter LawtonAbstract:In situ field observations of the suspension-feeding North Atlantic sea cucumber Cucumaria frondosa from the Bay of Fundy, Canada, conducted over a 3 yr period, revealed a seasonal feeding rhythm. Sea cucumbers extended their tentacles and began feeding in March/April and ceased feeding in September/October. There were significant relationships between this feeding activity daylength and the quality of the Seston, but not its concentration. Together daylength and chloropigment concentration explained 49% of the variability in the percentage of feeding sea cucumbers. Feeding activity was not significantly correlated with the distinct temperature cycle observed in the study area. Feeding activity was influenced by the state of the tide, water temperature and by daylight during some periods of the feeding season. However, for most of the year these factors appeared not to be important. Sea cucumbers increased their rate of tentacle insertion into the mouth as the quality of the Seston increased. The rate of tentacle insertions increased with increasing Seston chloropigment concentration but decreased with increasing current speed. These 2 environmental variables explained about 28% of the variability in tentacle insertion rates. Seston quality is likely the major environmental variable influencing seasonal feeding behaviour and feeding rate in this species.
-
Feeding response of the dendrochirote sea cucumber Cucumaria frondosa (Echinodermata: Holothuroidea) to changing food concentrations in the laboratory
Canadian Journal of Zoology, 1998Co-Authors: Rabindra Singh, Bruce A Macdonald, Peter Lawton, Martin L.h. ThomasAbstract:Sea cucumbers (Cucumaria frondosa) (Echinodermata: Holothuroidea) held in flow-through tanks were exposed to different chloropigment concentrations by manipulating the Seston concentration via the use of water filters in the inflow lines and the addition of cultured algae or natural plankton to tanks. The percentage of sea cucumbers open and feeding increased asymptotically as the Seston chloropigment concentration increased. Below 50 µg·L-1 the percentage of sea cucumbers with tentacles extended and feeding decreased. The rate at which sea cucumbers inserted their tentacles into their mouths (0.96 ± 0.34 insertion/min (mean ± SD)) increased with increasing Seston quality. Cucumaria frondosa fed at faster rates at the higher concentrations. There was a significant positive relationship between the stomach content (amount of chloropigment) of sea cucumbers and the Seston chloropigment concentration to which they were exposed (r2 = 0.200, p < 0.001).
-
physiological responses of infaunal mya arenaria and epifaunal placopecten magellanicus bivalves to variations in the concentration and quality of suspended particles ii absorption efficiency and scope for growth
Journal of Experimental Marine Biology and Ecology, 1998Co-Authors: Bruce A Macdonald, Gregory S Bacon, Evan J WardAbstract:Abstract Placopecten magellanicus , an epibenthic scallop, and Mya arenaria, an infaunal clam were studied to compare their physiological responses to variations in the quantity and quality of suspended food. The two bivalve species were exposed, simultaneously, to four concentrations of Seston (1, 3, 7 and 14 mg l −1 ) at each of three levels of organic quality (25, 50 and 80%) for several days. Experimental diets consisted of mixtures of microalgae and silica at concentrations typical of those observed in their natural habitats. Absorption efficiency ( A E ) was not significantly different between scallops and clams. In both species, A E was independent of concentration, and increased as the organic fraction of the Seston increased. Oxygen consumption and ammonia excretion were also similar for both scallops and clams, and there was no consistent effect of concentration or food quality on these metabolic processes for either species. Scope for growth (SFG) in both species increased at a decreasing rate with elevated particle concentrations and organic content of the Seston until an asymptote was reached. SFG in scallops was equal or exceeded SFG in clams at low concentration, but the opposite was true at high concentrations. Mya arenaria appeared to be better suited than Placopecten magellanicus to cope with higher concentrations of Seston, especially if it consisted of relatively poor quality particles.
-
physiological responses of infaunal mya arenaria and epifaunal placopecten magellanicus bivalves to variations in the concentration and quality of suspended particles
Journal of Experimental Marine Biology and Ecology, 1998Co-Authors: Gregory S Bacon, Bruce A Macdonald, Evan J WardAbstract:Placopecten magellanicus, an epibenthic scallop species, and Mya arenaria, an infaunal clam species were studied simultaneously to compare their feeding activity and particle selection in response to variations in the quantity and quality of suspended food. These two bivalve species were exposed to four concentrations of Seston (1, 3, 7, and 14 mg l−1) at each of three levels of organic quality (25, 50 and 80% POM). Experimental diets consisted of mixtures of microalgae and silica at concentrations typical of those observed in their natural habitats. Clearance rates for both species decreased as the concentration and organic content of the Seston increased. Both species have the ability to reject poorer quality inorganic particles, through the production of pseudofaeces, and significantly improve the quality of the particles ingested. The ability to select organic particles over inorganic ones was independent of Seston concentration but diminished as the organic content of the Seston decreased. When exposed to increasing Seston concentrations, scallops reduce clearance rates and increase pseudofaeces production resulting in maximum ingestion rates at approximately 7 mg l−1. Clams also reduce clearance rates as concentration increased but maintain low pseudofaeces rejection rates thus enabling ingestion to continue to increase to at least 14 mg l−1. M. arenaria appears to be better suited than P. magellanicus to ingest organic material at higher concentrations of low quality Seston.
Pedro Caraballo - One of the best experts on this subject based on the ideXlab platform.
-
Crescimento populacional e análise isotópica de Diaphanosoma spinolosum e Ceriodaphnia cornuta (Crustacea: Cladocera), alimentadas com diferentes frações de Seston natural
Acta Scientiarum. Biological Sciences, 2011Co-Authors: Pedro Caraballo, Andrés Felipe Sanchez-caraballo, Bruce R. Forsberg, Rosseval Galdino LeiteAbstract:Population growth and stable isotope analyses of Diaphanosoma spinolosum and Ceriodaphnia cornuta (Crustacea: Cladocera) fed with different Seston size fractions. In order to define the effect of Seston size fraction as a food source for Ceriodaphnia cornuta and Diaphanosoma spinolosum, in situ experiments using natural abundance of δ 13 C and δ 15 N were carried out during the rising water period in Catalao Lake. Both species were fed with three different fractions of Seston from the lake (< 10, < 30 and < 60 μm) and maintained in submerged 1.1 L plastic bottles for nine days. Ten individuals were put in each flask, maintaining three flasks for each fraction, for a total of 27 flasks per species. Every three days we collected three flasks and fixed the individuals for subsequent counting and observation of demographic population parameters. The organisms in the last three flasks of each fraction were fixed for stable isotope analysis of δ 13 C and δ 15 N. Both species grew in all of the food fractions, with the best the performance coming in the < 30 μm fraction. D. spinolosum and C. cornuta showed enrichment in δ 13 C and δ 15 N, which was highest in the < 10 μm fraction for both species. These results show that the Seston size fractions tested produce different population growth rates and isotopic signatures in cladocerans.
-
Crescimento populacional e análise isotópica de Diaphanosoma spinolosum e Ceriodaphnia cornuta (Crustacea: Cladocera), alimentadas com diferentes frações de Seston natural = Population growth and stable isotope analyses of Diaphanosoma spinolosum and
Eduem - Editora da Universidade Estadual de Maringá, 2011Co-Authors: Pedro Caraballo, Andrés Felipe Sanchez-caraballo, Bruce Forsberg, Rosseval LeiteAbstract:Para definir o efeito do Seston como fonte de alimento para Ceriodaphnia cornuta e Diaphanosoma spinolosum durante a enchente no lago Catalao (Amazonia Central) foram desenvolvidos experimentos gin situh, utilizando a variacao natural de ƒÂ13C e ƒÂ15N comotracadores de alimento. As duas especies tiveram acesso a tres diferentes fracoes de Seston (< 10, < 30 e < 60 ƒÊm) sendo mantidas em garrafas plasticas de 1,1 L submersas, durante nove dias. As atividades foram iniciadas com uma populacao de dez individuos em cada frasco, com tres frascos por cada fracao e quatro intervalos de tempo, para um total de 27 frascos por especie. A cada tres dias, foram coletados tres frascos e os organismos foram fixados para contagem e observacao de parametros populacionais. Os organismos nos ultimos tres frascos de cada fracao foram fixados com formalina e usados para analise de isotopos estaveis de carbono e nitrogenio. As duas especies cresceram em todas as fracoes de alimento, sendo melhor seu desempenho populacional na fracao < 30 ƒÊm. D. spinolosum e C. cornuta apresentaram enriquecimento nos valores de ƒÂ13C e ƒÂ15N, sendo maior na fracao < 10 ƒÊm. Estes resultados sugerem que as fracoes do Seston testadas produzem diferentes taxas de crescimento populacional e assinaturas isotopicas nos cladoceros.In order to define the effect of Seston size fraction as a food source for Ceriodaphnia cornuta and Diaphanosoma spinolosum, in situ experiments using natural abundance of ƒÂ13C and ƒÂ15N were carried out during the rising water period in Catalao Lake. Both species werefed with three different fractions of Seston from the lake (< 10, < 30 and < 60 ƒÊm) and maintained in submerged 1.1 L plastic bottles for nine days. Ten individuals were put in each flask, maintaining three flasks for each fraction, for a total of 27 flasks per species. Every three days we collected three flasks and fixed the individuals for subsequent counting and observation of demographic population parameters. The organisms in the last three flasks of each fractionwere fixed for stable isotope analysis of ƒÂ13C and ƒÂ15N. Both species grew in all of the food fractions, with the best the performance coming in the < 30 ƒÊm fraction. D. spinolosum and C. cornuta showed enrichment in ƒÂ13C and ƒÂ15N, which was highest in the < 10 ƒÊm fraction for both species. These results show that the Seston size fractions tested produce different population growth rates and isotopic signatures in cladocerans
-
Crescimento populacional e análise isotópica de Diaphanosoma spinolosum e Ceriodaphnia cornuta (Crustacea: Cladocera), alimentadas com diferentes frações de Seston natural - doi: 10.4025/actascibiolsci.v33i1.7260 Population growth and stable isotope
Eduem - Editora da Universidade Estadual de Maringá, 2011Co-Authors: Bruce Forsberg, Andrés Felipe Sanchez-caraballo, Rosseval Leite, Pedro CaraballoAbstract:Para definir o efeito do Seston como fonte de alimento para Ceriodaphnia cornuta e Diaphanosoma spinolosum durante a enchente no lago Catalão (Amazônia Central) foram desenvolvidos experimentos “in situ”, utilizando a variação natural de δ13C e δ15N como traçadores de alimento. As duas espécies tiveram acesso a três diferentes frações de Seston (< 10, < 30 e < 60 µm) sendo mantidas em garrafas plásticas de 1,1 L submersas, durante nove dias. As atividades foram iniciadas com uma população de dez indivíduos em cada frasco, com três frascos por cada fração e quatro intervalos de tempo, para um total de 27 frascos por espécie. A cada três dias, foram coletados três frascos e os organismos foram fixados para contagem e observação de parâmetros populacionais. Os organismos nos últimos três frascos de cada fração foram fixados com formalina e usados para análise de isótopos estáveis de carbono e nitrogênio. As duas espécies cresceram em todas as frações de alimento, sendo melhor seu desempenho populacional na fração < 30 µm. D. spinolosum e C. cornuta apresentaram enriquecimento nos valores de delta;13C e δ15N, sendo maior na fração < 10 µm. Estes resultados sugerem que as frações do Seston testadas produzem diferentes taxas de crescimento populacional e assinaturas isotópicas nos cladóceros.In order to define the effect of Seston size fraction as a food source for Ceriodaphnia cornuta and Diaphanosoma spinolosumin, situ experiments using natural abundance of delta;13C and δ15N were carried out during the rising water period in Catalão Lake. Both species were fed with three different fractions of Seston from the lake (< 10, < 30 and < 60 µm) and maintained in submerged 1.1 L plastic bottles for nine days. Ten individuals were put in each flask, maintaining three flasks for each fraction, for a total of 27 flasks per species. Every three days we collected three flasks and fixed the individuals for subsequent counting and observation of demographic population parameters. The organisms in the last three flasks of each fraction were fixed for stable isotope analysis of delta;13C and δ15N. Both species grew in all of the food fractions, with the best the performance coming in the < 30 µm fraction. D. spinolosum and C. cornuta showed enrichment in delta;13C and δ15N, which was highest in the < 10 µm fraction for both species. These results show that the Seston size fractions tested produce different population growth rates and isotopic signatures in cladocerans
