Advantages of dispersal on the scales that are possible in a long pelagic larval period are not a... more Advantages of dispersal on the scales that are possible in a long pelagic larval period are not apparent, even for benthic species. An alternative hypothesis is that wide dispersal may be an incidental byproduct of an ontogenetic migration from and then back to the parental habitat. Under this hypothesis, the water column is a better habitat than the bottom for early development. Because the parental area is often an especially favorable habitat for juveniles and adults, selection may even favor larval retention or larval return rather than dispersal. Where larval capabilities and currents permit, a high percentage of recruits may then be produced from local adults. Expected consequences of a high proportion of local recruitment are stronger links between stock and recruitment, greater vulnerability to recruitment overfishing and local modifications of habitat, greater local benefits from fishery reserves, and possibly more localized adaptation within populations. Export of some larvae is consistent with a high proportion of retained or returning larvae, could stabilize populations linked by larval exchange, and provide connectivity between marine reserves. Even a small amount of larval export could account for the greater gene flow, large ranges, and long evolutionary durations seen in species with long pelagic larval stages.
Abstract.—A symbiotic nemer-tean worm found on spiny lobsters is described and compared with othe... more Abstract.—A symbiotic nemer-tean worm found on spiny lobsters is described and compared with other members of the genus Ca'rcino'nemertes. The new species of Carcino-neiriertes has a relatively large basis, stylet, anterior and posterior proboscis chambers, and a voluminous seminal vesicle. In addition, lateral intes-tinal diverticula project anterior to the level of the middle proboscis chamber. These characters distin-guish this species from others in the genus. The life-history patterns of six species of Carcinonemertes appear re- ...
We built a high-resolution topological food web for the kelp forests of the Santa Barbara Channel... more We built a high-resolution topological food web for the kelp forests of the Santa Barbara Channel, California, USA that includes parasites and significantly improves resolution compared to previous webs. The 1,098 nodes and 21,956 links in the web describe an economically, socially, and ecologically vital system. Nodes are broken into life-stages. There are 549 free-living life-stages (comprising 492 species from 21 Phyla) and 549 parasitic life-stages (comprising 450 species from 10 Phyla). Links represent three kinds of trophic interactions. There are 9,352 predator-prey links, 2,733 parasite-host links and 9,871 predator-parasite links. This food web is unique in that all decisions for including nodes and links are documented, and extensive metadata in the node list allows users to filter the node list to suit their research questions. The kelp-forest food web is more species rich than any other published food web with parasites, and has a larger proportion of parasitic species t...
Abstract A dramatic increase in prevalence of the recently discovered bopyrid isopod parasite, Or... more Abstract A dramatic increase in prevalence of the recently discovered bopyrid isopod parasite, Orthione griffenis, likely introduced in the 1980s from Asia to the Pacific coast of North America, coincided with the 2002 collapse of a population of its burrowing mud shrimp host, Upogebia pugettensis, in Willapa Bay, Washington that had been stable since monitoring began in 1988. An examination of whether O. griffenis infections were sufficient to cause this decline and other recently noted U. pugettensis population collapses in ...
This data set presents food webs for three North American Pacific coast estuaries and a ''Metaweb... more This data set presents food webs for three North American Pacific coast estuaries and a ''Metaweb'' composed of the species/stages compiled from all three estuaries. The webs have four noteworthy attributes: (1) parasites (infectious agents), (2) body-size information, (3) biomass information, and (4) ontogenetic stages of many animals with complex life cycles. The estuaries are Carpinteria Salt Marsh, California (CSM); Estero de Punta
Introduced marine species are a major environmental and economic problem. The rate of these biolo... more Introduced marine species are a major environmental and economic problem. The rate of these biological invasions has substantially increased in recent years due to the globalization of the world's economies. The damage caused by invasive species is often a result of the higher densities and larger sizes they attain compared to where they are native. A prominent hypothesis explaining the success of introduced species is that they are relatively free of the effects of natural enemies. Most notably, they may encounter fewer ...
ductivity includes the stimulatory effect on the remaining prawns of selectively harvesting the l... more ductivity includes the stimulatory effect on the remaining prawns of selectively harvesting the largest blue claw and orange claw prawns and suggests that the inclusion of a small proportion of large "target" blue claw males might stimulate the rapid growth of orange claw males in a population of smaller prawns.
Canadian Journal of Fisheries and Aquatic Sciences, 1990
Carcinonemertes epialti had a minimal impact on the egg mortality of a lightly infested populatio... more Carcinonemertes epialti had a minimal impact on the egg mortality of a lightly infested population of a commercially important crab host, Cancer anthonyi. The nemertean had a high prevalence (> 97%) but was found at low intensities (mean intensity = 86.5 worms/pleopod, mean density = 0.3 worms/1000 eggs). Egg mortality varied from 0.0–30.5%, and was highly correlated with both worm intensity, and the timing of crab embryogenesis (mean mortality = 5.7%). Separate sites within the pleopod experienced different causal mechanisms of mortality. Mortality at the base of the pleopod was correlated with the presence, abundance, and immigration of C. epialti. Mortality at the tip of the pleopod was less correlated with worm abundance and was most likely a result of abrasion to the eggs or egg mass. Infestations of C. epialti varied between seasons and between host species. The worm was more abundant on host species that bred year-round (Cancer anthonyi and Hemigrapsus oregonensis); hence,...
Predation can have a great impact on populations and communities. A previous study showed that Pa... more Predation can have a great impact on populations and communities. A previous study showed that Pachygrapsus crassipes preferred to consume larger Cerithidea californica, California horn snails, as its size increased and concluded that C. californica was consumed at such a low rate that their populations were unlikely to be impacted by predation. The early developmental stage, egg mass, of C. californica was not included in the predation study therefore the impacts of egg mass predation on the C. californica population needs further ...
We apply a Dynamic Energy Budget model to the common liver fluke (Fasciola hepatica), as well as ... more We apply a Dynamic Energy Budget model to the common liver fluke (Fasciola hepatica), as well as its intermediate and final hosts. First, an introduction to the DEB theory is given. We divide the fluke's seven-stage life cycle into three phases and construct an independent model for each. We link DEB variables to measurable quantities like weight, glycogen content, and oxygen consumption, then find model parameters that match predictions to data from existing studies. We compare the present model to existing ...
The biogeography of host–parasite interactions, Sep 1, 2010
This volume demonstrates that there can be strong geographic patterns for some parasite communiti... more This volume demonstrates that there can be strong geographic patterns for some parasite communities. For instance, one general prediction is that the similarity of parasite communities should decrease as a function of distance (Soininen et al. 2007; see also Chapter 9 of this volume). Species invasions are fundamental biogeographical processes that have occurred through geological time via long distance dispersal and through historical biotic exchange (Vermeij 2005). Now, the globalization of the world's economies ...
Most plant and animal species are most diverse at low latitudes. Differences in species richness ... more Most plant and animal species are most diverse at low latitudes. Differences in species richness between latitudes are often truly amazing. Thus, there are about 150 species of marine fish in the North Sea, but there are thousands in tropical seas of much smaller areas. But even at a particular latitude, differences exist along longitude. For example, the south-east Asian waters are particularly rich in faunal diversity, whereas the eastern Pacific is much poorer. Little is known about species numbers in the deep sea, but the few studies ...
Proceedings of the international symposium on king and tanner crabs. Univ. Alaska sea grant report, 1990
Analyses of egg masses from 772 red king crabs (Paralithodes camtschatica! collected at 28 Alaska... more Analyses of egg masses from 772 red king crabs (Paralithodes camtschatica! collected at 28 Alaskan localities from 1983 to 1985 demonstrated the widespread presence of several species of symbiotic nemertean egg predators. Nemertean intensity was correlated with significant egg mortality. At some localities nearly all crab eggs were consumed. Carcinonemertes regicides was the most abundant of the nemertean egg predators. Its abundance was markedly seasonal.
Abstract.- Fecundity of the yellow rock crab Cancer antkcmyi was examined seasonally over two yea... more Abstract.- Fecundity of the yellow rock crab Cancer antkcmyi was examined seasonally over two years. Ovigenous crabs varied in she from 59 to 153 mm carapace width. Crabs held in the laboratory brooded more than three cintihes per year without molting or mating. Crab fecundity varied seasonally, with peaks ir tate spring-early summer and late fallsarly winter. Ovigerotis crabs carried an estimated 0.73-3.30 million eggs, depending on crab size, stage of egg development, and season. The log body size-log fecundity relationship changed ...
Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears... more Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected].
Proceedings of the Royal Society B: Biological Sciences, 2021
The abundances of free-living species have changed dramatically in recent decades, but little is ... more The abundances of free-living species have changed dramatically in recent decades, but little is known about change in the abundance of parasitic species. We investigated whether populations of several parasites have shifted over time in two shore crab hosts, Hemigrapsus oregonensis and Hemigrapsus nudus, by comparing the prevalence and abundance of three parasite taxa in a historical dataset (1969–1970) to contemporary parasite abundance (2018–2020) for hosts collected from 11 intertidal sites located from Oregon, USA, to British Columbia, Canada. Our data suggest that the abundance of the parasitic isopod Portunion conformis has varied around a stable mean for the past 50 years. No change over time was observed for larval acanthocephalans. However, larval microphallid trematodes increased in prevalence over time among H. oregonensis hosts, from a mean of 8.4–61.8% between the historical and contemporary time points. The substantial increase in the prevalence of larval microphallid...
The American Journal of Tropical Medicine and Hygiene, 2020
The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was created in 200... more The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was created in 2008 to answer questions of importance to program managers working to reduce the burden of schistosomiasis in Africa. In the past, intermediate host snail monitoring and control was an important part of integrated schistosomiasis control. However, in Africa, efforts to control snails have declined dramatically over the last 30 years. A resurgence of interest in the control of snails has been prompted by the realization, backed by a World Health Assembly resolution (WHA65.21), that mass drug administration alone may be insufficient to achieve schistosomiasis elimination. SCORE has supported work on snail identification and mapping and investigated how xenomonitoring techniques can aid in the identification of infected snails and thereby identify potential transmission areas. Focal mollusciciding with niclosamide was undertaken in Zanzibar and Côte d'Ivoire as a part of elimination studies. Two studies involving biological control of snails were conducted: one explored the association of freshwater riverine prawns and snail hosts in Côte d'Ivoire and the other assessed the current distribution of Procambarus clarkii, the invasive Louisiana red swamp crayfish, in Kenya and its association with snail hosts and schistosomiasis transmission. SCORE also supported modeling studies on the importance of snail control in achieving elimination and a meta-analysis of the impact of molluscicide-based snail control programs on human schistosomiasis prevalence and incidence. SCORE's snail control studies contributed to increased investment in building capacity, and specimens collected during SCORE research deposited in the Schistosomiasis Collections at the Natural History Museum (SCAN) will provide a valuable resource for the years to come.
For trophically transmitted parasites that manipulate the phenotype of their hosts, whether the p... more For trophically transmitted parasites that manipulate the phenotype of their hosts, whether the parasites do or do not experience resource competition depends on such factors as the size of the parasites relative to their hosts, the intensity of infection, the extent to which parasites share the cost of defending against the host's immune system or manipulating their host, and the extent to which parasites share transmission goals. Despite theoretical expectations for situations in which either no, or positive, or negative density-dependence should be observed, most studies document only negative density-dependence for trophically transmitted parasites. However, this trend may be an artifact of most studies having focused on systems in which parasites are large relative to their hosts. Yet, systems are common where parasites are small relative to their hosts, and these trophically transmitted parasites may be less likely to experience resource limitation. We looked for signs of ...
Advantages of dispersal on the scales that are possible in a long pelagic larval period are not a... more Advantages of dispersal on the scales that are possible in a long pelagic larval period are not apparent, even for benthic species. An alternative hypothesis is that wide dispersal may be an incidental byproduct of an ontogenetic migration from and then back to the parental habitat. Under this hypothesis, the water column is a better habitat than the bottom for early development. Because the parental area is often an especially favorable habitat for juveniles and adults, selection may even favor larval retention or larval return rather than dispersal. Where larval capabilities and currents permit, a high percentage of recruits may then be produced from local adults. Expected consequences of a high proportion of local recruitment are stronger links between stock and recruitment, greater vulnerability to recruitment overfishing and local modifications of habitat, greater local benefits from fishery reserves, and possibly more localized adaptation within populations. Export of some larvae is consistent with a high proportion of retained or returning larvae, could stabilize populations linked by larval exchange, and provide connectivity between marine reserves. Even a small amount of larval export could account for the greater gene flow, large ranges, and long evolutionary durations seen in species with long pelagic larval stages.
Abstract.—A symbiotic nemer-tean worm found on spiny lobsters is described and compared with othe... more Abstract.—A symbiotic nemer-tean worm found on spiny lobsters is described and compared with other members of the genus Ca'rcino'nemertes. The new species of Carcino-neiriertes has a relatively large basis, stylet, anterior and posterior proboscis chambers, and a voluminous seminal vesicle. In addition, lateral intes-tinal diverticula project anterior to the level of the middle proboscis chamber. These characters distin-guish this species from others in the genus. The life-history patterns of six species of Carcinonemertes appear re- ...
We built a high-resolution topological food web for the kelp forests of the Santa Barbara Channel... more We built a high-resolution topological food web for the kelp forests of the Santa Barbara Channel, California, USA that includes parasites and significantly improves resolution compared to previous webs. The 1,098 nodes and 21,956 links in the web describe an economically, socially, and ecologically vital system. Nodes are broken into life-stages. There are 549 free-living life-stages (comprising 492 species from 21 Phyla) and 549 parasitic life-stages (comprising 450 species from 10 Phyla). Links represent three kinds of trophic interactions. There are 9,352 predator-prey links, 2,733 parasite-host links and 9,871 predator-parasite links. This food web is unique in that all decisions for including nodes and links are documented, and extensive metadata in the node list allows users to filter the node list to suit their research questions. The kelp-forest food web is more species rich than any other published food web with parasites, and has a larger proportion of parasitic species t...
Abstract A dramatic increase in prevalence of the recently discovered bopyrid isopod parasite, Or... more Abstract A dramatic increase in prevalence of the recently discovered bopyrid isopod parasite, Orthione griffenis, likely introduced in the 1980s from Asia to the Pacific coast of North America, coincided with the 2002 collapse of a population of its burrowing mud shrimp host, Upogebia pugettensis, in Willapa Bay, Washington that had been stable since monitoring began in 1988. An examination of whether O. griffenis infections were sufficient to cause this decline and other recently noted U. pugettensis population collapses in ...
This data set presents food webs for three North American Pacific coast estuaries and a ''Metaweb... more This data set presents food webs for three North American Pacific coast estuaries and a ''Metaweb'' composed of the species/stages compiled from all three estuaries. The webs have four noteworthy attributes: (1) parasites (infectious agents), (2) body-size information, (3) biomass information, and (4) ontogenetic stages of many animals with complex life cycles. The estuaries are Carpinteria Salt Marsh, California (CSM); Estero de Punta
Introduced marine species are a major environmental and economic problem. The rate of these biolo... more Introduced marine species are a major environmental and economic problem. The rate of these biological invasions has substantially increased in recent years due to the globalization of the world's economies. The damage caused by invasive species is often a result of the higher densities and larger sizes they attain compared to where they are native. A prominent hypothesis explaining the success of introduced species is that they are relatively free of the effects of natural enemies. Most notably, they may encounter fewer ...
ductivity includes the stimulatory effect on the remaining prawns of selectively harvesting the l... more ductivity includes the stimulatory effect on the remaining prawns of selectively harvesting the largest blue claw and orange claw prawns and suggests that the inclusion of a small proportion of large "target" blue claw males might stimulate the rapid growth of orange claw males in a population of smaller prawns.
Canadian Journal of Fisheries and Aquatic Sciences, 1990
Carcinonemertes epialti had a minimal impact on the egg mortality of a lightly infested populatio... more Carcinonemertes epialti had a minimal impact on the egg mortality of a lightly infested population of a commercially important crab host, Cancer anthonyi. The nemertean had a high prevalence (> 97%) but was found at low intensities (mean intensity = 86.5 worms/pleopod, mean density = 0.3 worms/1000 eggs). Egg mortality varied from 0.0–30.5%, and was highly correlated with both worm intensity, and the timing of crab embryogenesis (mean mortality = 5.7%). Separate sites within the pleopod experienced different causal mechanisms of mortality. Mortality at the base of the pleopod was correlated with the presence, abundance, and immigration of C. epialti. Mortality at the tip of the pleopod was less correlated with worm abundance and was most likely a result of abrasion to the eggs or egg mass. Infestations of C. epialti varied between seasons and between host species. The worm was more abundant on host species that bred year-round (Cancer anthonyi and Hemigrapsus oregonensis); hence,...
Predation can have a great impact on populations and communities. A previous study showed that Pa... more Predation can have a great impact on populations and communities. A previous study showed that Pachygrapsus crassipes preferred to consume larger Cerithidea californica, California horn snails, as its size increased and concluded that C. californica was consumed at such a low rate that their populations were unlikely to be impacted by predation. The early developmental stage, egg mass, of C. californica was not included in the predation study therefore the impacts of egg mass predation on the C. californica population needs further ...
We apply a Dynamic Energy Budget model to the common liver fluke (Fasciola hepatica), as well as ... more We apply a Dynamic Energy Budget model to the common liver fluke (Fasciola hepatica), as well as its intermediate and final hosts. First, an introduction to the DEB theory is given. We divide the fluke's seven-stage life cycle into three phases and construct an independent model for each. We link DEB variables to measurable quantities like weight, glycogen content, and oxygen consumption, then find model parameters that match predictions to data from existing studies. We compare the present model to existing ...
The biogeography of host–parasite interactions, Sep 1, 2010
This volume demonstrates that there can be strong geographic patterns for some parasite communiti... more This volume demonstrates that there can be strong geographic patterns for some parasite communities. For instance, one general prediction is that the similarity of parasite communities should decrease as a function of distance (Soininen et al. 2007; see also Chapter 9 of this volume). Species invasions are fundamental biogeographical processes that have occurred through geological time via long distance dispersal and through historical biotic exchange (Vermeij 2005). Now, the globalization of the world's economies ...
Most plant and animal species are most diverse at low latitudes. Differences in species richness ... more Most plant and animal species are most diverse at low latitudes. Differences in species richness between latitudes are often truly amazing. Thus, there are about 150 species of marine fish in the North Sea, but there are thousands in tropical seas of much smaller areas. But even at a particular latitude, differences exist along longitude. For example, the south-east Asian waters are particularly rich in faunal diversity, whereas the eastern Pacific is much poorer. Little is known about species numbers in the deep sea, but the few studies ...
Proceedings of the international symposium on king and tanner crabs. Univ. Alaska sea grant report, 1990
Analyses of egg masses from 772 red king crabs (Paralithodes camtschatica! collected at 28 Alaska... more Analyses of egg masses from 772 red king crabs (Paralithodes camtschatica! collected at 28 Alaskan localities from 1983 to 1985 demonstrated the widespread presence of several species of symbiotic nemertean egg predators. Nemertean intensity was correlated with significant egg mortality. At some localities nearly all crab eggs were consumed. Carcinonemertes regicides was the most abundant of the nemertean egg predators. Its abundance was markedly seasonal.
Abstract.- Fecundity of the yellow rock crab Cancer antkcmyi was examined seasonally over two yea... more Abstract.- Fecundity of the yellow rock crab Cancer antkcmyi was examined seasonally over two years. Ovigenous crabs varied in she from 59 to 153 mm carapace width. Crabs held in the laboratory brooded more than three cintihes per year without molting or mating. Crab fecundity varied seasonally, with peaks ir tate spring-early summer and late fallsarly winter. Ovigerotis crabs carried an estimated 0.73-3.30 million eggs, depending on crab size, stage of egg development, and season. The log body size-log fecundity relationship changed ...
Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears... more Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected].
Proceedings of the Royal Society B: Biological Sciences, 2021
The abundances of free-living species have changed dramatically in recent decades, but little is ... more The abundances of free-living species have changed dramatically in recent decades, but little is known about change in the abundance of parasitic species. We investigated whether populations of several parasites have shifted over time in two shore crab hosts, Hemigrapsus oregonensis and Hemigrapsus nudus, by comparing the prevalence and abundance of three parasite taxa in a historical dataset (1969–1970) to contemporary parasite abundance (2018–2020) for hosts collected from 11 intertidal sites located from Oregon, USA, to British Columbia, Canada. Our data suggest that the abundance of the parasitic isopod Portunion conformis has varied around a stable mean for the past 50 years. No change over time was observed for larval acanthocephalans. However, larval microphallid trematodes increased in prevalence over time among H. oregonensis hosts, from a mean of 8.4–61.8% between the historical and contemporary time points. The substantial increase in the prevalence of larval microphallid...
The American Journal of Tropical Medicine and Hygiene, 2020
The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was created in 200... more The Schistosomiasis Consortium for Operational Research and Evaluation (SCORE) was created in 2008 to answer questions of importance to program managers working to reduce the burden of schistosomiasis in Africa. In the past, intermediate host snail monitoring and control was an important part of integrated schistosomiasis control. However, in Africa, efforts to control snails have declined dramatically over the last 30 years. A resurgence of interest in the control of snails has been prompted by the realization, backed by a World Health Assembly resolution (WHA65.21), that mass drug administration alone may be insufficient to achieve schistosomiasis elimination. SCORE has supported work on snail identification and mapping and investigated how xenomonitoring techniques can aid in the identification of infected snails and thereby identify potential transmission areas. Focal mollusciciding with niclosamide was undertaken in Zanzibar and Côte d'Ivoire as a part of elimination studies. Two studies involving biological control of snails were conducted: one explored the association of freshwater riverine prawns and snail hosts in Côte d'Ivoire and the other assessed the current distribution of Procambarus clarkii, the invasive Louisiana red swamp crayfish, in Kenya and its association with snail hosts and schistosomiasis transmission. SCORE also supported modeling studies on the importance of snail control in achieving elimination and a meta-analysis of the impact of molluscicide-based snail control programs on human schistosomiasis prevalence and incidence. SCORE's snail control studies contributed to increased investment in building capacity, and specimens collected during SCORE research deposited in the Schistosomiasis Collections at the Natural History Museum (SCAN) will provide a valuable resource for the years to come.
For trophically transmitted parasites that manipulate the phenotype of their hosts, whether the p... more For trophically transmitted parasites that manipulate the phenotype of their hosts, whether the parasites do or do not experience resource competition depends on such factors as the size of the parasites relative to their hosts, the intensity of infection, the extent to which parasites share the cost of defending against the host's immune system or manipulating their host, and the extent to which parasites share transmission goals. Despite theoretical expectations for situations in which either no, or positive, or negative density-dependence should be observed, most studies document only negative density-dependence for trophically transmitted parasites. However, this trend may be an artifact of most studies having focused on systems in which parasites are large relative to their hosts. Yet, systems are common where parasites are small relative to their hosts, and these trophically transmitted parasites may be less likely to experience resource limitation. We looked for signs of ...
Uploads
Papers by Armand Kuris