Biomineralized structures in animals can undergo remodeling, altering the original construction o... more Biomineralized structures in animals can undergo remodeling, altering the original construction of the structure. Remodeling such structures could enhance plastic inducible defenses and mitigate some hypothesized limits to adaptive phenotypic plasticity. Predator-induced shell thickening in marine snails, already a model for studies of adaptive plasticity, provides a potentially good system to study the role of hardened structure remodeling for enhancing the adaptive value of phenotypically plastic responses. However, studies on predator-induced shell plasticity tend to examine only recent shell growth, and plastic remodeling of older regions of the shell has been previously unexplored. Therefore, we examined the potential for shell remodeling by the marine snail Nucella lamellosa in response to its major predator, the shell-breaking predatory crab Cancer productus. For snails exposed to chemical cues from C. productus, shell thickness and microstructure in the newest parts of the s...
Synopsis A renaissance in organismal biology has been sparked by recent conceptual, theoretical, ... more Synopsis A renaissance in organismal biology has been sparked by recent conceptual, theoretical, methodological, and computational advances in the life sciences, along with an unprecedented interdisciplinary integration with Mathematics, Engineering, and the physical sciences. Despite a decades-long trend toward reductionist approaches to biological problems, it is increasingly recognized that whole organisms play a central role in organizing and interpreting information from across the biological spectrum. Organisms represent the nexus where sub- and supra-organismal processes meet, and it is the performance of organisms within the environment that provides the material for natural selection. Here, we identify five ‘‘grand challenges’’ for future research in organismal biology. It is intended that these challenges will spark further discussion in the broader community and identify future research priorities, opportunities, and directions, which will ultimately help to guide the all...
Synopsis The amount of knowledge in the biological sciences is growing at an exponential rate. Si... more Synopsis The amount of knowledge in the biological sciences is growing at an exponential rate. Simultaneously, the incorporation of new technologies in gathering scientific information has greatly accelerated our capacity to ask, and answer, new questions. How do we, as organismal biologists, meet these challenges, and develop research strategies that will allow us to address the grand challenge question: how do organisms walk the tightrope between stability and change? Organisms and organismal systems are complex, and multi-scale in both space and time. It is clear that addressing major questions about organismal biology will not come from ‘‘business as usual’ ’ approaches. Rather, we require the collab-oration of a wide range of experts and integration of biological information with more quantitative approaches tradi-tionally found in engineering and applied mathematics. Research programs designed to address grand challenge questions will require deep knowledge and expertise withi...
Bivalves are some of the most important suspension feeders in aquatic systems. Much research has ... more Bivalves are some of the most important suspension feeders in aquatic systems. Much research has been conducted on the feeding mechanisms of adult molluscan suspension feeders, but less is known about the feeding mechanisms of their larval stages. To date, the general consensus is that veligers are restricted to collecting particles 4–20 μm in size and that food selection is indiscriminate within this size range, but this hypothesis remains to be directly tested. Therefore, we experimentally assessed this assumption by quantifying microalgal particle capture rates for the larvae of the Pacific oyster (Crassostrea gigas) when fed five different microalgal species individually and in combination. We then tested whether factors such as cell size affected capture rate and consumption, as well as whether capture rate was affected by the presence of other microalgal species. We found evidence of food preference that was not simply a function of size or relative nutritional quality for C. gigas veligers. Further, we found that food selectivity changed through ontogeny. To our knowledge, the changes in selection that we observed through ontogeny have not been previously reported. Interestingly, there was also a sharp decrease in the variability among replicates in consumption rate as the larvae aged. Whether this is a function of velar structure or larval size remains to be tested. Our results suggest some underlying process resulting in certain species of microalgae being captured and consumed at significantly different rates than others.
Canadian Journal of Fisheries and Aquatic Sciences, 1992
Limnological features of different lakes may limit the density of, or even completely restrict, p... more Limnological features of different lakes may limit the density of, or even completely restrict, populations of the European zebra mussel, Dreissena polymorpha. We developed statistical models to predict the occurrence (presence or absence) and density (number per square metre) of Dreissena in lakes, based on multivariate correlations between the density of Dreissena populations and the limnological characteristics of the lakes they inhabit. We found that both occurrence and average density of Dreissena populations were highly correlated with water chemistry. Dreissena was not found in lakes with average pH values below 7.3 and concentrations of calcium ion below 28.3 mg∙L−1. Above these thresholds, Dreissena density was negatively related to concentration of the algal nutrients PO4 and NO3.
Canadian Journal of Fisheries and Aquatic Sciences, 2000
Lake Mendota, which is plagued by periodic cyanobacterial blooms, is typical of many lakes in the... more Lake Mendota, which is plagued by periodic cyanobacterial blooms, is typical of many lakes in the Laurentian Great Lakes region that are vulnerable to zebra mussels (Dreissena polymorpha) but have yet to be invaded. We coupled removal estimates with chlorophyll production estimates in a dynamic model to predict the likely impact of mussel-mediated removal of phytoplankton on water clarity across a range of hypothetical zebra mussel densities. Models were fit to chlorophyll and temperature data collected biweekly from Lake Mendota during 1977-1993. When we assumed daily epilimnetic circulation, the percentage of days when the chlorophyll concentration exceeded 50 µg·L-1 was decreased threefold at mussel densities as low as 1000 mussels·m-2. When we assumed less frequent epilimnetic circulation, the density of mussels required to substantially improve water clarity increased dramatically. We predict that zebra mussel invasion would lead to increased water clarity in Lake Mendota. Cyan...
Synopsis Many of the most interesting questions in organismal biology, especially those involving... more Synopsis Many of the most interesting questions in organismal biology, especially those involving the functional and adaptive significance of organismal characteristics, intrinsically transcend levels of biological organization. These organ-ismal functions typically involve multiple interacting biological mechanisms. We suggest that subdisciplinary advances have led both to the opportunity and to the necessity to reintegrate knowledge into a new understanding of the whole organism. We present a conceptual framework for a modeling approach that addresses the functioning of organisms in an integrative way, incorporating elements from environments, populations, individuals, and intra-organismal dynamics such as physiology and behavior. To give substance to our conceptual framework, we provide a preliminary focal case study using phenotypic plasticity in the tooth morphology of snails in the genus Lacuna. We use this case study to illustrate ways in which questions about the evolution a...
Canadian Journal of Fisheries and Aquatic Sciences, 1992
The European zebra mussel, Dreissena polymorpha (Pallas), has recently been introduced to North A... more The European zebra mussel, Dreissena polymorpha (Pallas), has recently been introduced to North American freshwaters. Dreissena exhibits a wide range of population dynamics among different European lakes. In some lakes, long-term population size is fairly constant, while populations in other lakes can fluctuate greatly from year to year. Assessments of the potential ecological and economic effects of Dreissena in North America will be affected if populations show large interannual fluctuations in abundance. We develop a multivariate model for predicting population dynamics of Dreissena in novel lake systems. Our model uses the limnological differences between lakes with constant populations of Dreissena and those with variable populations to identify variables that may determine population dynamics. We find that lakes with more constant populations tend to have larger surface areas, lower levels of calcium, and higher levels of phosphate (PO4) compared with lakes with more variable ...
A wide range of taxa have been shown to display inducible, phenotypically plastic responses to kn... more A wide range of taxa have been shown to display inducible, phenotypically plastic responses to known predators. Most studies of inducible defenses include only known predators but not non-predatory species in experimental designs, precluding tests of specificity for these responses. We tested the specificity of predator-induced defenses in the marine snail Nucella lamellosa, when exposed to chemical cues from potential crab predators as well as more distantly related non-predatory crabs that co-occur with this snail. Surprisingly, all crabs tested, even those that are not predators, triggered the common induced response of a reduction of soft-tissue mass relative to control animals, likely reflecting a reduction in snail feeding activity. In contrast, only N. lamellosa’s major predator, Cancer productus, triggered the production of a thicker apertural lip. Increased thickening of the apertural lip may be an adaptive response specific to C. productus, which uses shell-breaking at the apertural lip (i.e., shell-peeling) as their main form of attack. Apertural lip thickening appeared to be due to reallocation of shell material (i.e., a change in shell shape) rather than an increase in shell deposition. Our findings demonstrate the importance of determining the specificity of cues triggering inducible responses in prey, and the mechanisms that underlie these plastic responses, as the responses to general versus specific cues may limit the adaptive value of an inducible defense.
1. Invasive species threaten marine biodiversity on a global scale. 2. To test whether marine res... more 1. Invasive species threaten marine biodiversity on a global scale. 2. To test whether marine reserves provide resistance to invading species, the abundance of two conspicuous invaders, a seaweed and an oyster, were measured inside marine reserves and in comparable areas outside reserves in north-western Washington State. 3. Densities of both invaders were significantly higher in marine reserves than in comparable unprotected areas outside reserves. Although the causal mechanisms have not yet been identified, differential rates of human harvest do not appear to be responsible for the patterns observed. 4. It is provisionally suggested that physical or biological aspects of the reserves themselves may directly or indirectly facilitate biological invasion.
Biomineralized structures in animals can undergo remodeling, altering the original construction o... more Biomineralized structures in animals can undergo remodeling, altering the original construction of the structure. Remodeling such structures could enhance plastic inducible defenses and mitigate some hypothesized limits to adaptive phenotypic plasticity. Predator-induced shell thickening in marine snails, already a model for studies of adaptive plasticity, provides a potentially good system to study the role of hardened structure remodeling for enhancing the adaptive value of phenotypically plastic responses. However, studies on predator-induced shell plasticity tend to examine only recent shell growth, and plastic remodeling of older regions of the shell has been previously unexplored. Therefore, we examined the potential for shell remodeling by the marine snail Nucella lamellosa in response to its major predator, the shell-breaking predatory crab Cancer productus. For snails exposed to chemical cues from C. productus, shell thickness and microstructure in the newest parts of the s...
Synopsis A renaissance in organismal biology has been sparked by recent conceptual, theoretical, ... more Synopsis A renaissance in organismal biology has been sparked by recent conceptual, theoretical, methodological, and computational advances in the life sciences, along with an unprecedented interdisciplinary integration with Mathematics, Engineering, and the physical sciences. Despite a decades-long trend toward reductionist approaches to biological problems, it is increasingly recognized that whole organisms play a central role in organizing and interpreting information from across the biological spectrum. Organisms represent the nexus where sub- and supra-organismal processes meet, and it is the performance of organisms within the environment that provides the material for natural selection. Here, we identify five ‘‘grand challenges’’ for future research in organismal biology. It is intended that these challenges will spark further discussion in the broader community and identify future research priorities, opportunities, and directions, which will ultimately help to guide the all...
Synopsis The amount of knowledge in the biological sciences is growing at an exponential rate. Si... more Synopsis The amount of knowledge in the biological sciences is growing at an exponential rate. Simultaneously, the incorporation of new technologies in gathering scientific information has greatly accelerated our capacity to ask, and answer, new questions. How do we, as organismal biologists, meet these challenges, and develop research strategies that will allow us to address the grand challenge question: how do organisms walk the tightrope between stability and change? Organisms and organismal systems are complex, and multi-scale in both space and time. It is clear that addressing major questions about organismal biology will not come from ‘‘business as usual’ ’ approaches. Rather, we require the collab-oration of a wide range of experts and integration of biological information with more quantitative approaches tradi-tionally found in engineering and applied mathematics. Research programs designed to address grand challenge questions will require deep knowledge and expertise withi...
Bivalves are some of the most important suspension feeders in aquatic systems. Much research has ... more Bivalves are some of the most important suspension feeders in aquatic systems. Much research has been conducted on the feeding mechanisms of adult molluscan suspension feeders, but less is known about the feeding mechanisms of their larval stages. To date, the general consensus is that veligers are restricted to collecting particles 4–20 μm in size and that food selection is indiscriminate within this size range, but this hypothesis remains to be directly tested. Therefore, we experimentally assessed this assumption by quantifying microalgal particle capture rates for the larvae of the Pacific oyster (Crassostrea gigas) when fed five different microalgal species individually and in combination. We then tested whether factors such as cell size affected capture rate and consumption, as well as whether capture rate was affected by the presence of other microalgal species. We found evidence of food preference that was not simply a function of size or relative nutritional quality for C. gigas veligers. Further, we found that food selectivity changed through ontogeny. To our knowledge, the changes in selection that we observed through ontogeny have not been previously reported. Interestingly, there was also a sharp decrease in the variability among replicates in consumption rate as the larvae aged. Whether this is a function of velar structure or larval size remains to be tested. Our results suggest some underlying process resulting in certain species of microalgae being captured and consumed at significantly different rates than others.
Canadian Journal of Fisheries and Aquatic Sciences, 1992
Limnological features of different lakes may limit the density of, or even completely restrict, p... more Limnological features of different lakes may limit the density of, or even completely restrict, populations of the European zebra mussel, Dreissena polymorpha. We developed statistical models to predict the occurrence (presence or absence) and density (number per square metre) of Dreissena in lakes, based on multivariate correlations between the density of Dreissena populations and the limnological characteristics of the lakes they inhabit. We found that both occurrence and average density of Dreissena populations were highly correlated with water chemistry. Dreissena was not found in lakes with average pH values below 7.3 and concentrations of calcium ion below 28.3 mg∙L−1. Above these thresholds, Dreissena density was negatively related to concentration of the algal nutrients PO4 and NO3.
Canadian Journal of Fisheries and Aquatic Sciences, 2000
Lake Mendota, which is plagued by periodic cyanobacterial blooms, is typical of many lakes in the... more Lake Mendota, which is plagued by periodic cyanobacterial blooms, is typical of many lakes in the Laurentian Great Lakes region that are vulnerable to zebra mussels (Dreissena polymorpha) but have yet to be invaded. We coupled removal estimates with chlorophyll production estimates in a dynamic model to predict the likely impact of mussel-mediated removal of phytoplankton on water clarity across a range of hypothetical zebra mussel densities. Models were fit to chlorophyll and temperature data collected biweekly from Lake Mendota during 1977-1993. When we assumed daily epilimnetic circulation, the percentage of days when the chlorophyll concentration exceeded 50 µg·L-1 was decreased threefold at mussel densities as low as 1000 mussels·m-2. When we assumed less frequent epilimnetic circulation, the density of mussels required to substantially improve water clarity increased dramatically. We predict that zebra mussel invasion would lead to increased water clarity in Lake Mendota. Cyan...
Synopsis Many of the most interesting questions in organismal biology, especially those involving... more Synopsis Many of the most interesting questions in organismal biology, especially those involving the functional and adaptive significance of organismal characteristics, intrinsically transcend levels of biological organization. These organ-ismal functions typically involve multiple interacting biological mechanisms. We suggest that subdisciplinary advances have led both to the opportunity and to the necessity to reintegrate knowledge into a new understanding of the whole organism. We present a conceptual framework for a modeling approach that addresses the functioning of organisms in an integrative way, incorporating elements from environments, populations, individuals, and intra-organismal dynamics such as physiology and behavior. To give substance to our conceptual framework, we provide a preliminary focal case study using phenotypic plasticity in the tooth morphology of snails in the genus Lacuna. We use this case study to illustrate ways in which questions about the evolution a...
Canadian Journal of Fisheries and Aquatic Sciences, 1992
The European zebra mussel, Dreissena polymorpha (Pallas), has recently been introduced to North A... more The European zebra mussel, Dreissena polymorpha (Pallas), has recently been introduced to North American freshwaters. Dreissena exhibits a wide range of population dynamics among different European lakes. In some lakes, long-term population size is fairly constant, while populations in other lakes can fluctuate greatly from year to year. Assessments of the potential ecological and economic effects of Dreissena in North America will be affected if populations show large interannual fluctuations in abundance. We develop a multivariate model for predicting population dynamics of Dreissena in novel lake systems. Our model uses the limnological differences between lakes with constant populations of Dreissena and those with variable populations to identify variables that may determine population dynamics. We find that lakes with more constant populations tend to have larger surface areas, lower levels of calcium, and higher levels of phosphate (PO4) compared with lakes with more variable ...
A wide range of taxa have been shown to display inducible, phenotypically plastic responses to kn... more A wide range of taxa have been shown to display inducible, phenotypically plastic responses to known predators. Most studies of inducible defenses include only known predators but not non-predatory species in experimental designs, precluding tests of specificity for these responses. We tested the specificity of predator-induced defenses in the marine snail Nucella lamellosa, when exposed to chemical cues from potential crab predators as well as more distantly related non-predatory crabs that co-occur with this snail. Surprisingly, all crabs tested, even those that are not predators, triggered the common induced response of a reduction of soft-tissue mass relative to control animals, likely reflecting a reduction in snail feeding activity. In contrast, only N. lamellosa’s major predator, Cancer productus, triggered the production of a thicker apertural lip. Increased thickening of the apertural lip may be an adaptive response specific to C. productus, which uses shell-breaking at the apertural lip (i.e., shell-peeling) as their main form of attack. Apertural lip thickening appeared to be due to reallocation of shell material (i.e., a change in shell shape) rather than an increase in shell deposition. Our findings demonstrate the importance of determining the specificity of cues triggering inducible responses in prey, and the mechanisms that underlie these plastic responses, as the responses to general versus specific cues may limit the adaptive value of an inducible defense.
1. Invasive species threaten marine biodiversity on a global scale. 2. To test whether marine res... more 1. Invasive species threaten marine biodiversity on a global scale. 2. To test whether marine reserves provide resistance to invading species, the abundance of two conspicuous invaders, a seaweed and an oyster, were measured inside marine reserves and in comparable areas outside reserves in north-western Washington State. 3. Densities of both invaders were significantly higher in marine reserves than in comparable unprotected areas outside reserves. Although the causal mechanisms have not yet been identified, differential rates of human harvest do not appear to be responsible for the patterns observed. 4. It is provisionally suggested that physical or biological aspects of the reserves themselves may directly or indirectly facilitate biological invasion.
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