The Experts below are selected from a list of 26307 Experts worldwide ranked by ideXlab platform
Christopher D Mcquaid - One of the best experts on this subject based on the ideXlab platform.
-
Low temperature trumps high food availability to determine the distribution of intertidal mussels Perna Perna in South Africa
Marine Ecology Progress Series, 2016Co-Authors: Morgana Tagliarolo, Justin A. Lathlean, Valeria Montalto, Gianluca Sarà, Christopher D McquaidAbstract:Explanations of species distributions often assume that the absence of a species is due to its inability to tolerate an environmental variable. Recent modelling techniques based on the dynamic energy budget (DEB) theory offer an effective way of identifying how interacting environmental parameters influence distributions through non-lethal effects on growth and development. The mussel Perna Perna is an abundant ecosystem engineer around the coasts of Africa, South America and the Arabian peninsula, with an unexplained 1500 km lacuna in its distribution on the west coast of South Africa. We used a DEB approach to explain its distribution in southern Africa and test the hypothesis that this lacuna is caused by sublethal effects of low temperatures on its metabolism. We parameterized a standard DEB model for P. Perna using eco-physiological parameters measured in the laboratory, validated by comparison with the body size and reproductive effort of animals from the field throughout South Africa. The model highlighted the importance of reproductive failure under the cold water conditions of the west coast, despite particularly high food availability there, and the surprisingly good performance of P. Perna under the warm, highly oligotrophic conditions of the east coast. The results suggest that P. Perna is well adapted to low food conditions, but is reproductively vulnerable to low temperatures. DEB models accurately described and explained the anomalous biogeography of this intertidal mussel, allowing us to disentangle the interaction of antagonistic stressors and reveal the critical importance of sublethal temperature effects on reproduction to the species' distribution
-
Cheating the Locals: Invasive Mussels Steal and Benefit from the Cooling Effect of Indigenous Mussels.
PLOS ONE, 2016Co-Authors: Justin A. Lathlean, Christopher D Mcquaid, Gerardo I. Zardi, Laurent Seuront, Terence P. T. Ng, Katy R. NicastroAbstract:The indigenous South African mussel Perna Perna gapes during periods of aerial exposure to maintain aerobic respiration. This behaviour has no effect on the body temperatures of isolated individuals, but when surrounded by conspecifics, beneficial cooling effects of gaping emerge. It is uncertain, however, whether the presence of the invasive mussel Mytilus galloprovincialis limits the ability of P. Perna for collective thermoregulation. We investigated whether varying densities of P. Perna and M. galloprovincialis influences the thermal properties of both natural and artificial mussel beds during periods of emersion. Using infrared thermography, body temperatures of P. Perna within mixed artificial beds were shown to increase faster and reach higher temperatures than individuals in conspecific beds, indicating that the presence of M. galloprovincialis limits the group cooling effects of gaping. In contrast, body temperatures of M. galloprovincialis within mixed artificial mussel beds increased slower and exhibited lower temperatures than for individuals in beds comprised entirely of M. galloprovincialis. Interestingly, differences in bed temperatures and heating rates were largely dependent on the size of mussels, with beds comprised of larger individuals experiencing less thermal stress irrespective of species composition. The small-scale patterns of thermal stress detected within manipulated beds were not observed within naturally occurring mixed mussel beds. We propose that small-scale differences in topography, size-structure, mussel bed size and the presence of organisms encrusting the mussel shells mask the effects of gaping behaviour within natural mussel beds. Nevertheless, the results from our manipulative experiment indicate that the invasive species M. galloprovincialis steals thermal properties as well as resources from the indigenous mussel P. Perna. This may have significant implications for predicting how the co-existence of these two species may change as global temperatures continue to rise.
-
Mechanisms of habitat segregation between an invasive (Mytilus galloprovincialis) and an indigenous (Perna Perna) mussel: adult growth and mortality.
Marine Biology, 2010Co-Authors: Sarah J. Bownes, Christopher D McquaidAbstract:The invasive mussel Mytilus galloprovincialis and the indigenous mussel Perna Perna coexist intertidally on the south coast of South Africa through partial vertical habitat segregation: M. galloprovincialis dominates the upper shore and P. Perna the lower shore. Recruitment patterns can explain the zonation of P. Perna, but not the invasive species. We examined the role of post-recruitment interactions by measuring spatial and temporal differences in adult growth and mortality rates of the two species. Specifically, we tested the hypothesis that interspecific differences in growth and mortality reflect adult distribution patterns. The two study locations, Plettenberg Bay and Tsitsikamma, are 70 km apart with two sites (separated by 300–400 m) per location, each divided into three vertical zones. Growth was measured seasonally using different marking methods in 2001 and 2003. Cumulative adult mortality was measured through summer in 2003/2004. Both species generally grew more slowly upshore, but they showed different effects of season. For P. Perna, growth was significantly reduced in winter in the low zone, but unaffected by season in the high zone. For M. galloprovincialis, growth was either unaffected by season or increased in winter, even in the high zone. Thus, growth of P. Perna and M. galloprovincialis was reduced under cool winter and warm summer temperatures, respectively; and while growth was more similar between species in summer, M. galloprovincialis grew much faster than P. Perna in winter. Mortality of P. Perna increased upshore. For M. galloprovincialis, mortality was not zone-dependent and was significantly greater than for P. Perna on the low-shore and (generally) across the shore in Tsitsikamma. Both species had higher growth and mortality rates in Plettenberg Bay than in Tsitsikamma. Thus, P. Perna seems able to maintain spatial dominance on the low-shore and at certain sites because of higher mortality of M. galloprovincialis. We conclude that seasonality in growth of the two species reflects their biogeographic affinities and that coexistence is possible through pre-recruitment effects that limit the vertical distribution of P. Perna and post-recruitment effects that limit M. galloprovincialis.
-
fine scale spatial and temporal variation in settlement of the intertidal mussel Perna Perna indicates differential hydrodynamic delivery of larvae to the shore
Journal of Experimental Marine Biology and Ecology, 2008Co-Authors: Francesca Porri, Christopher D Mcquaid, S M Lawrie, S J AntrobusAbstract:Abstract Scales of spatial and temporal variation in the settlement of early and late plantigrades of the mussel Perna Perna to artificial substrata were measured on the south coast of South Africa. One study examined daily settlement over one month at three sites of similar tidal height and aspect. The sites were separated by 100′s of m with 5 replicated artificial settlement substrata approximately 1 m apart within each site. Early (
-
Behavioural response of invasive Mytilus galloprovincialis and indigenous Perna Perna mussels exposed to risk of predation
Marine Ecology Progress Series, 2007Co-Authors: Katy R. Nicastro, Gerardo I. Zardi, Christopher D McquaidAbstract:We compared the behavioural responses of an indigenous South African mussel (Perna Perna) and an invasive mussel (Mytilus galloprovincialis) to the risk of predation. Both species were subjected to the specific risk of predation by the native rock lobster Jasus lalandii and the general risk of predation simulated by the presence of damaged conspecifics. We hypothesised that, because M. galloprovincialis evolved in allopatry from the rock lobster, P. Perna would respond more strongly to J. lalandii, but that there would be less difference between species in their response to damaged con- specifics. The results confirmed our initial hypotheses. M. galloprovincialis crawled farther under both predation treatments and generally aggregated more than P. Perna. P. Perna has a larger foot, and our results therefore do not reflect morphological differences between the species but imply greater sensitivity in M. galloprovincialis to chemical cues. Crawling distance was not enhanced under predation threat relative to the control; therefore, increased clumping due to more rapid ran- dom movement cannot explain our results, indicating that chemical attraction among individuals is important. P. Perna clumping behaviour was significantly greater when exposed to local lobster efflu- ent or damaged conspecifics, whereas M. galloprovincialis clumped more when exposed to a general threat of predation but exhibited naive behaviour to local predator effluent. This lack of responsive- ness to a native predator could be due not only to the recent arrival of the European mussel, but also to the relatively low selective effects of predation in South Africa.
Katy R. Nicastro - One of the best experts on this subject based on the ideXlab platform.
-
Cheating the Locals: Invasive Mussels Steal and Benefit from the Cooling Effect of Indigenous Mussels.
PLOS ONE, 2016Co-Authors: Justin A. Lathlean, Christopher D Mcquaid, Gerardo I. Zardi, Laurent Seuront, Terence P. T. Ng, Katy R. NicastroAbstract:The indigenous South African mussel Perna Perna gapes during periods of aerial exposure to maintain aerobic respiration. This behaviour has no effect on the body temperatures of isolated individuals, but when surrounded by conspecifics, beneficial cooling effects of gaping emerge. It is uncertain, however, whether the presence of the invasive mussel Mytilus galloprovincialis limits the ability of P. Perna for collective thermoregulation. We investigated whether varying densities of P. Perna and M. galloprovincialis influences the thermal properties of both natural and artificial mussel beds during periods of emersion. Using infrared thermography, body temperatures of P. Perna within mixed artificial beds were shown to increase faster and reach higher temperatures than individuals in conspecific beds, indicating that the presence of M. galloprovincialis limits the group cooling effects of gaping. In contrast, body temperatures of M. galloprovincialis within mixed artificial mussel beds increased slower and exhibited lower temperatures than for individuals in beds comprised entirely of M. galloprovincialis. Interestingly, differences in bed temperatures and heating rates were largely dependent on the size of mussels, with beds comprised of larger individuals experiencing less thermal stress irrespective of species composition. The small-scale patterns of thermal stress detected within manipulated beds were not observed within naturally occurring mixed mussel beds. We propose that small-scale differences in topography, size-structure, mussel bed size and the presence of organisms encrusting the mussel shells mask the effects of gaping behaviour within natural mussel beds. Nevertheless, the results from our manipulative experiment indicate that the invasive species M. galloprovincialis steals thermal properties as well as resources from the indigenous mussel P. Perna. This may have significant implications for predicting how the co-existence of these two species may change as global temperatures continue to rise.
-
Characterization of ten highly polymorphic microsatellite loci for the intertidal mussel Perna Perna, and cross species amplification within the genus
BMC research notes, 2012Co-Authors: Nelson C. Coelho, Gerardo I. Zardi, Gareth A. Pearson, Ester A. Serrão, Katy R. NicastroAbstract:Background The brown mussel Perna Perna (Linnaeus, 1758) is a dominant constituent of intertidal communities and a strong invader with multiple non-native populations distributed around the world. In a previous study, two polymorphic microsatellite loci were developed and used to determine population-level genetic diversity in invasive and native P. Perna populations. However, higher number of microsatellite markers are required for reliable population genetic studies. In this context, in order to understand P. Perna origins and history of invasion and to compare population genetic structure in native versus invaded areas, we developed 10 polymorphic microsatellite markers.
-
First record of the brown mussel ( Perna Perna ) from the European Atlantic coast
Marine Biodiversity Records, 2012Co-Authors: Carla R. Lourenço, Katy R. Nicastro, Ester A. Serrão, Gerardo I. ZardiAbstract:The occurrence of the brown mussel Perna Perna is reported for the first time from the European Atlantic coast, on the southern Portuguese coast. Several specimens of this mytilidae species were identified in exposed rocky intertidal habitats in Vilamoura (37804019.7000N 8807019.7100W) and Ilha do Farol (36858029.3800N 7851042.5100W). It is suggested that, under warming climate conditions, this subtropical/tropical species might have extended its geographical distribution from North Africa
-
Behavioural response of invasive Mytilus galloprovincialis and indigenous Perna Perna mussels exposed to risk of predation
Marine Ecology Progress Series, 2007Co-Authors: Katy R. Nicastro, Gerardo I. Zardi, Christopher D McquaidAbstract:We compared the behavioural responses of an indigenous South African mussel (Perna Perna) and an invasive mussel (Mytilus galloprovincialis) to the risk of predation. Both species were subjected to the specific risk of predation by the native rock lobster Jasus lalandii and the general risk of predation simulated by the presence of damaged conspecifics. We hypothesised that, because M. galloprovincialis evolved in allopatry from the rock lobster, P. Perna would respond more strongly to J. lalandii, but that there would be less difference between species in their response to damaged con- specifics. The results confirmed our initial hypotheses. M. galloprovincialis crawled farther under both predation treatments and generally aggregated more than P. Perna. P. Perna has a larger foot, and our results therefore do not reflect morphological differences between the species but imply greater sensitivity in M. galloprovincialis to chemical cues. Crawling distance was not enhanced under predation threat relative to the control; therefore, increased clumping due to more rapid ran- dom movement cannot explain our results, indicating that chemical attraction among individuals is important. P. Perna clumping behaviour was significantly greater when exposed to local lobster efflu- ent or damaged conspecifics, whereas M. galloprovincialis clumped more when exposed to a general threat of predation but exhibited naive behaviour to local predator effluent. This lack of responsive- ness to a native predator could be due not only to the recent arrival of the European mussel, but also to the relatively low selective effects of predation in South Africa.
-
balancing survival and reproduction seasonality of wave action attachment strength and reproductive output in indigenous Perna Perna and invasive mytilus galloprovincialis mussels
Marine Ecology Progress Series, 2007Co-Authors: Gerardo I. Zardi, Christopher D Mcquaid, Katy R. NicastroAbstract:The indigenous mussel Perna Perna and the invasive mussel Mytilus galloprovincialis coexist on the low shore of the South African south coast, with partial habitat partitioning. P. Perna dominates the lower mussel zone, where hydrodynamic stress is higher than in the high mussel zone, where M. galloprovincialis dominates. Attachment strength and gonad maturation are highly demanding processes in terms of energy, the former allowing mussels to withstand wave forces, while the latter contributes to recruitment rates. During an 18 mo study, both biological parameters fluctuated seasonally. The invasive and the indigenous species spawned in different periods; gamete maturation was positively correlated with sea surface temperature only for P. Perna. For both species, attachment strength was negatively correlated with sea surface temperature, but increased in response to wave action through the production of more and thicker threads. Peaks in attachment strength coincided with periods of relatively low gamete production for both species, suggesting that mussels cannot afford to invest simultaneously in both processes. P. Perna attachment strength was always significantly higher than that of M. galloprovincialis , while the latter had a greater reproductive output. We suggest that, although high gamete production improves the ability of M. galloprovincialis to colonise free space, it may energetically limit its capacity to invade wave exposed shores.
Gerardo I. Zardi - One of the best experts on this subject based on the ideXlab platform.
-
Cheating the Locals: Invasive Mussels Steal and Benefit from the Cooling Effect of Indigenous Mussels.
PLOS ONE, 2016Co-Authors: Justin A. Lathlean, Christopher D Mcquaid, Gerardo I. Zardi, Laurent Seuront, Terence P. T. Ng, Katy R. NicastroAbstract:The indigenous South African mussel Perna Perna gapes during periods of aerial exposure to maintain aerobic respiration. This behaviour has no effect on the body temperatures of isolated individuals, but when surrounded by conspecifics, beneficial cooling effects of gaping emerge. It is uncertain, however, whether the presence of the invasive mussel Mytilus galloprovincialis limits the ability of P. Perna for collective thermoregulation. We investigated whether varying densities of P. Perna and M. galloprovincialis influences the thermal properties of both natural and artificial mussel beds during periods of emersion. Using infrared thermography, body temperatures of P. Perna within mixed artificial beds were shown to increase faster and reach higher temperatures than individuals in conspecific beds, indicating that the presence of M. galloprovincialis limits the group cooling effects of gaping. In contrast, body temperatures of M. galloprovincialis within mixed artificial mussel beds increased slower and exhibited lower temperatures than for individuals in beds comprised entirely of M. galloprovincialis. Interestingly, differences in bed temperatures and heating rates were largely dependent on the size of mussels, with beds comprised of larger individuals experiencing less thermal stress irrespective of species composition. The small-scale patterns of thermal stress detected within manipulated beds were not observed within naturally occurring mixed mussel beds. We propose that small-scale differences in topography, size-structure, mussel bed size and the presence of organisms encrusting the mussel shells mask the effects of gaping behaviour within natural mussel beds. Nevertheless, the results from our manipulative experiment indicate that the invasive species M. galloprovincialis steals thermal properties as well as resources from the indigenous mussel P. Perna. This may have significant implications for predicting how the co-existence of these two species may change as global temperatures continue to rise.
-
Characterization of ten highly polymorphic microsatellite loci for the intertidal mussel Perna Perna, and cross species amplification within the genus
BMC research notes, 2012Co-Authors: Nelson C. Coelho, Gerardo I. Zardi, Gareth A. Pearson, Ester A. Serrão, Katy R. NicastroAbstract:Background The brown mussel Perna Perna (Linnaeus, 1758) is a dominant constituent of intertidal communities and a strong invader with multiple non-native populations distributed around the world. In a previous study, two polymorphic microsatellite loci were developed and used to determine population-level genetic diversity in invasive and native P. Perna populations. However, higher number of microsatellite markers are required for reliable population genetic studies. In this context, in order to understand P. Perna origins and history of invasion and to compare population genetic structure in native versus invaded areas, we developed 10 polymorphic microsatellite markers.
-
First record of the brown mussel ( Perna Perna ) from the European Atlantic coast
Marine Biodiversity Records, 2012Co-Authors: Carla R. Lourenço, Katy R. Nicastro, Ester A. Serrão, Gerardo I. ZardiAbstract:The occurrence of the brown mussel Perna Perna is reported for the first time from the European Atlantic coast, on the southern Portuguese coast. Several specimens of this mytilidae species were identified in exposed rocky intertidal habitats in Vilamoura (37804019.7000N 8807019.7100W) and Ilha do Farol (36858029.3800N 7851042.5100W). It is suggested that, under warming climate conditions, this subtropical/tropical species might have extended its geographical distribution from North Africa
-
Behavioural response of invasive Mytilus galloprovincialis and indigenous Perna Perna mussels exposed to risk of predation
Marine Ecology Progress Series, 2007Co-Authors: Katy R. Nicastro, Gerardo I. Zardi, Christopher D McquaidAbstract:We compared the behavioural responses of an indigenous South African mussel (Perna Perna) and an invasive mussel (Mytilus galloprovincialis) to the risk of predation. Both species were subjected to the specific risk of predation by the native rock lobster Jasus lalandii and the general risk of predation simulated by the presence of damaged conspecifics. We hypothesised that, because M. galloprovincialis evolved in allopatry from the rock lobster, P. Perna would respond more strongly to J. lalandii, but that there would be less difference between species in their response to damaged con- specifics. The results confirmed our initial hypotheses. M. galloprovincialis crawled farther under both predation treatments and generally aggregated more than P. Perna. P. Perna has a larger foot, and our results therefore do not reflect morphological differences between the species but imply greater sensitivity in M. galloprovincialis to chemical cues. Crawling distance was not enhanced under predation threat relative to the control; therefore, increased clumping due to more rapid ran- dom movement cannot explain our results, indicating that chemical attraction among individuals is important. P. Perna clumping behaviour was significantly greater when exposed to local lobster efflu- ent or damaged conspecifics, whereas M. galloprovincialis clumped more when exposed to a general threat of predation but exhibited naive behaviour to local predator effluent. This lack of responsive- ness to a native predator could be due not only to the recent arrival of the European mussel, but also to the relatively low selective effects of predation in South Africa.
-
balancing survival and reproduction seasonality of wave action attachment strength and reproductive output in indigenous Perna Perna and invasive mytilus galloprovincialis mussels
Marine Ecology Progress Series, 2007Co-Authors: Gerardo I. Zardi, Christopher D Mcquaid, Katy R. NicastroAbstract:The indigenous mussel Perna Perna and the invasive mussel Mytilus galloprovincialis coexist on the low shore of the South African south coast, with partial habitat partitioning. P. Perna dominates the lower mussel zone, where hydrodynamic stress is higher than in the high mussel zone, where M. galloprovincialis dominates. Attachment strength and gonad maturation are highly demanding processes in terms of energy, the former allowing mussels to withstand wave forces, while the latter contributes to recruitment rates. During an 18 mo study, both biological parameters fluctuated seasonally. The invasive and the indigenous species spawned in different periods; gamete maturation was positively correlated with sea surface temperature only for P. Perna. For both species, attachment strength was negatively correlated with sea surface temperature, but increased in response to wave action through the production of more and thicker threads. Peaks in attachment strength coincided with periods of relatively low gamete production for both species, suggesting that mussels cannot afford to invest simultaneously in both processes. P. Perna attachment strength was always significantly higher than that of M. galloprovincialis , while the latter had a greater reproductive output. We suggest that, although high gamete production improves the ability of M. galloprovincialis to colonise free space, it may energetically limit its capacity to invade wave exposed shores.
César Lodeiros - One of the best experts on this subject based on the ideXlab platform.
-
Tropical mussels Perna Perna and P. viridis (Bivalvia: Mytilidae): Bottom or suspended culture?
Aquaculture, 2019Co-Authors: Vanessa Acosta-balbás, César Lodeiros, Jeremy Mendoza-hill, José Manuel Mazón-suásteguiAbstract:Abstract Growth and survival of size-classes of the green Perna viridis and the brown P. Perna mussels were compared in suspended and bottom culture systems in the Southern Caribbean Sea. The size-classes (juveniles, medium-size and adults) were defined in relation to somatic and reproductive characteristics of both species. Survival of P. viridis in bottom culture was close to 100% in all size groups, while in P. Perna was between 75 and 80% in juveniles and medium-size and 63% in adults. Survival of P. Perna in suspended culture was higher than 85% for juvenile and medium-size individuals and
-
Biochemical components of the tissues of Perna Perna and P. viridis (Lineo, 1758) (Bivalvia: Mytilidae), in relation to the growth under conditions of suspended cultivation
Latin American Journal of Aquatic Research, 2010Co-Authors: Vanessa Acosta, César Lodeiros, Luis Freites, Yolimar Natera, Aleikar VásquezAbstract:In the organisms, the variations of the biochemical composition of reproductive and somatic tissues in the growth permit to infer about its adaptative to environment. In the present study, we evaluate the changes observed in carbohydrates, lipids and proteins of digestive gland, muscle and gonad tissues of Perna Perna and P. viridis , growing in suspended culture at Cariaco Gulf, Venezuela. The reproductive condition of both mussels and environmental factors (temperature, chlorophyll a and of the seston) were determinate. The results show that, in both species, the gonadic lobes showed the highest variations in the biochemical component. The variations in the biochemical components were direct explained by the variations in the gonad development and the food availability, particularly chlorophyll a for P. Perna and total seston for P. viridis . The temperature was a negative factor affecting P. viridis . Along almost the whole experimental period, the contents of the different energy components observed in P. Perna were higher than P. viridis , this indicate species that P. Perna show a major capacity to exploit the resources alimentary present under the conditions of suspended cultivation.
-
Depth effect on growth of the mussels Perna Perna and Perna viridis (Bivalvia: Mytilidae) in suspended culture in the Cariaco Gulf, Sucre state, Venezuela.
2009Co-Authors: Vanessa Acosta, César Lodeiros, María Glem, Antulio Prieto, Yolimar NateraAbstract:The effect of depth (4, 8, and 16 m) on the growth of the mussels Perna Perna and Perna viridis was evaluated under culture conditions in the Gulf of Cariaco, Venezuela, during a period of six months. Bimonthly, it was determined the dimension and dry mass of the shell, tissues (somatic and reproductive), and the "fouling" on the shell to both species. At each depth, biweekly registrations of temperature, salinity, dissolved oxygen, and food availability (total, organic seston, and fitoplanktonic biomass) were obtained. At 8 m depth, the highest increments were reached in size, dry mass of the shell, and somatic and reproductive tissues, obtaining P. Perna the highest values. The higher growth at this depth was associated with the values of organic seston (>20 mg/L). In both species the mass of the repeat tended to decrease with the increment of the depth, as well as the biomass of the fouling. The lower growth of P. viridis, jointly with the low survival (70%) during the experimental period demonstrates that it was not affected by the environmental changes that took place in the water column. Among the environmental factors, food availability was the most determining on the difference of growth between the species in the experimental depths.
-
Differential growth of the mussels Perna Perna and Perna viridis (Bivalvia: Mytilidae) in suspended culture in the Golfo de Cariaco, Venezuela.
Journal of the World Aquaculture Society, 2009Co-Authors: Vanessa Acosta, Trinidad Urbano, John H. Himmelman, María Glem, Yolimar Natera, Manuel Rey-méndez, César LodeirosAbstract:We evaluated the growth of mussels Perna Perna and Perna viridis in suspended culture in the Golfo de Cariaco in Venezuela. Juveniles were cultured for up to 13 mo on cultch strings suspended from longline, with monthly sampling for determination of shell length and dry weights of shell and soft tissues. Water temperature, oxygen, salinity, chlorophyll a, seston, and shell fouling were also monitored. In both species, growth during the first 5 mo (the stratification period in the region) was slow. Subsequently, the onset of the coastal upwelling period (November/December) generated lower temperatures and higher plankton levels, correlated with higher growth rates, particularly in P. Perna, which by the end of the experiment had reached a mean length 1.3-fold greater than that of P. viridis (95.3 ± 7.91 vs. 73.3 ± 6.99 mm) together with a 1.9-fold greater somatic tissue. Likewise, reproductive activity differed between the two species, P. Perna showing a higher gonad development and its reproductive activity starting earlier than that of P. viridis. Our results show that P. Perna presents higher growth and survival than P. viridis in suspension culture, a fact related to a greater tolerance to the environmental characteristics of the Golfo de Cariaco.
-
Crecimiento y supervivencia de los mejillones Perna Perna, Perna viridisy de un morfotipo indefinido bajo cultivo suspendido
Ciencias Marinas, 2005Co-Authors: Trinidad Urbano, César Lodeiros, Marcos De Donato, Vanessa Acosta, Dwight Arrieche, Maximiano Núñez, John H. HimmelmanAbstract:We evaluated the growth and influence of environmental factors under suspended culture conditions of the mussels Perna Perna L. and P. viridis L. and of an ...
John W Lawson - One of the best experts on this subject based on the ideXlab platform.
-
immunomodulation of murine collagen induced arthritis by n n dimethylglycine and a preparation of Perna canaliculus
BMC Complementary and Alternative Medicine, 2007Co-Authors: Brian R Lawson, Stanley M Belkowski, John F Whitesides, Paul F Davis, John W LawsonAbstract:Background: Rheumatoid arthritis (RA) and its accepted animal model, murine collagen-induced arthritis (CIA), are classic autoimmune inflammatory diseases which require proinflammatory cytokine production for pathogenesis. We and others have previously used N, N-dimethylglycine (DMG) and extracts from the New Zealand green-lipped mussel Perna canaliculus (Perna) as potent immunomodulators to modify ongoing immune and/or inflammatory responses. Methods: In our initial studies, we treated lipopolysaccahride (LPS) stimulated THP-1 monocytes in vitro with increasing concentrations of Perna extract or DMG. Additionally, we treated rat peripheral blood neutrophils with increasing concentrations of Perna extract and measured superoxide burst. In subsequent in vivo experiments, CIA was induced by administration of type II collagen; rats were prophylactically treated with either Perna or DMG, and then followed for disease severity. Finally, to test whether Perna and/or DMG could block or inhibit an ongoing pathologic disease process, we induced CIA in mice and treated them therapeutically with either of the two immunomodulators. Results: Following LPS stimulation of THP-1 monocytes, we observed dose-dependent reductions in TNF-α and IL-12p40 production in Perna treated cultures. DMG treatment, however, showed significant increases in both of these cytokines in the range of 0.001–1 µM. We also demonstrate that in vitro neutrophil superoxide burst activity is dose-dependently reduced in the presence of Perna. Significant reductions in disease incidence, onset, and severity of CIA in rats were noted following prophylactic treatment with either of the two immunomodulators. More importantly, amelioration of mouse CIA was observed following therapeutic administration of Perna. In contrast, DMG appeared to have little effect in mice and may act in a species-specific manner. Conclusion: These data suggest that Perna, and perhaps DMG, may be useful supplements to the treatment of RA in humans.
-
In vitro modulation of inflammatory cytokine and IgG levels by extracts of Perna canaliculus
BMC Complementary and Alternative Medicine, 2006Co-Authors: Sachin Mani, John W LawsonAbstract:Background Inflammation is a predominant characteristic of autoimmune diseases which is characterized by the increased expression of pro-inflammatory cytokines. Soon to be published work from our laboratory has shown that ingestion of Perna canaliculus prevents the development of autoimmune diseases such as Systemic Lupus Erythematosus and rheumatoid arthritis in laboratory animals. The current paper attempts to illustrate how Perna can alleviate inflammation by modulating inflammatory cytokines, cyclooxygenase enzymes and Immunoglobulin-G (IgG) levels. Methods In the present study, hydrochloric acid [HCl] and Tween-20 were used to develop extracts of Perna. These extracts were assayed for protein content. Increasing concentrations of these extracts were then tested in cell culture for modulation of inflammatory cytokine, cyclooxygenase enzymes and IgG levels. Parallel tests were run using an available glycogen extract of Perna as a comparison to our in-house laboratory preparations. Results Tween-20 Perna extracts were found to be more stable and less toxic in cell culture than HCl digest of Perna. They also assayed higher in protein content that HCl extracts. Although both extracts inhibited IgG production in V2E9 hybridomas, Tween-20 extracts were more consistent in IgG suppression than HCl extracts. Overall Tween-20 extracts effectively decreased levels of TNF-α, IL-1, IL-2 and IL-6 as observed using cytokine bioassays. Twenty micrograms of Tween-20 Perna extracts induced such significant decreases in inflammatory cytokine production that when tested on sensitive cell lines, they very nearly abolished the decrease in viability induced by these cytokines. Tween-20 extracts effectively inhibited both COX-1 and COX-2 cyclooxygenase activity. As a comparison, the glycogen extract also demonstrated a similar though weaker effect on COX-1 and COX-2 enzymes. The active components of both extracts (Tween-20 and glycogen) were observed to possess molecular weights above 100 kDa. Although the anti-cytokine activity of the Tween-20 extract was destroyed by Proteinase-K treatment, the anti-COX-1 and anti-COX-2 activity of both the extracts were not sensitive to protease treatment. Conclusion We have successfully demonstrated modulation in the levels of inflammatory cytokines, cyclooxygenase enzymes and immunoglobulins by our in-house laboratory preparations of Perna canaliculus , whereby suggesting an immunomodulatory role of Perna canaliculus in regulating inflammation.
-
in vitro modulation of inflammatory cytokine and igg levels by extracts of Perna canaliculus
BMC Complementary and Alternative Medicine, 2006Co-Authors: Sachin Mani, John W LawsonAbstract:Background Inflammation is a predominant characteristic of autoimmune diseases which is characterized by the increased expression of pro-inflammatory cytokines. Soon to be published work from our laboratory has shown that ingestion of Perna canaliculus prevents the development of autoimmune diseases such as Systemic Lupus Erythematosus and rheumatoid arthritis in laboratory animals. The current paper attempts to illustrate how Perna can alleviate inflammation by modulating inflammatory cytokines, cyclooxygenase enzymes and Immunoglobulin-G (IgG) levels.