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Christian Laforsch - One of the best experts on this subject based on the ideXlab platform.
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Shell resource partitioning as a mechanism of coexistence in two co-occurring terrestrial Hermit Crab species
BMC Ecology, 2020Co-Authors: Sebastian Steibl, Christian LaforschAbstract:Background Coexistence is enabled by ecological differentiation of the co-occurring species. One possible mechanism thereby is resource partitioning, where each species utilizes a distinct subset of the most limited resource. This resource partitioning is difficult to investigate using empirical research in nature, as only few species are primarily limited by solely one resource, rather than a combination of multiple factors. One exception are the shell-dwelling Hermit Crabs, which are known to be limited under natural conditions and in suitable habitats primarily by the availability of gastropod shells. In the present study, we used two co-occurring terrestrial Hermit Crab species, Coenobita rugosus and C. perlatus , to investigate how resource partitioning is realized in nature and whether it could be a driver of coexistence. Results Field sampling of eleven separated Hermit Crab populations showed that the two co-occurring Hermit Crab species inhabit the same beach habitat but utilize a distinct subset of the shell resource. Preference experiments and principal component analysis of the shell morphometric data thereby revealed that the observed utilization patterns arise out of different intrinsic preferences towards two distinct shell shapes. While C. rugosus displayed a preference towards a short and globose shell morphology, C. perlatus showed preferences towards an elongated shell morphology with narrow aperture. Conclusion The two terrestrial Hermit Crab species occur in the same habitat but have evolved different preferences towards distinct subsets of the limiting shell resource. Resource partitioning might therefore be the main driver of their ecological differentiation, which ultimately allowed these co-occurring species to coexist in their environment. As the preferred shell morphology of C. rugosus maximizes reproductive output at the expense of protection, while the preferred shell morphology of C. perlatus maximizes protection against predation at the expense of reproductive output, shell resource partitioning might reflect different strategies to respond to the same set of selective pressures occurring in beach habitats. This work offers empirical support for the competitive exclusion principle-hypothesis and demonstrates that Hermit Crabs are an ideal model organism to investigate resource partitioning in natural populations.
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shell resource partitioning as a mechanism of coexistence in two co occurring terrestrial Hermit Crab species
BMC Ecology, 2020Co-Authors: Sebastian Steibl, Christian LaforschAbstract:Coexistence is enabled by ecological differentiation of the co-occurring species. One possible mechanism thereby is resource partitioning, where each species utilizes a distinct subset of the most limited resource. This resource partitioning is difficult to investigate using empirical research in nature, as only few species are primarily limited by solely one resource, rather than a combination of multiple factors. One exception are the shell-dwelling Hermit Crabs, which are known to be limited under natural conditions and in suitable habitats primarily by the availability of gastropod shells. In the present study, we used two co-occurring terrestrial Hermit Crab species, Coenobita rugosus and C. perlatus, to investigate how resource partitioning is realized in nature and whether it could be a driver of coexistence. Field sampling of eleven separated Hermit Crab populations showed that the two co-occurring Hermit Crab species inhabit the same beach habitat but utilize a distinct subset of the shell resource. Preference experiments and principal component analysis of the shell morphometric data thereby revealed that the observed utilization patterns arise out of different intrinsic preferences towards two distinct shell shapes. While C. rugosus displayed a preference towards a short and globose shell morphology, C. perlatus showed preferences towards an elongated shell morphology with narrow aperture. The two terrestrial Hermit Crab species occur in the same habitat but have evolved different preferences towards distinct subsets of the limiting shell resource. Resource partitioning might therefore be the main driver of their ecological differentiation, which ultimately allowed these co-occurring species to coexist in their environment. As the preferred shell morphology of C. rugosus maximizes reproductive output at the expense of protection, while the preferred shell morphology of C. perlatus maximizes protection against predation at the expense of reproductive output, shell resource partitioning might reflect different strategies to respond to the same set of selective pressures occurring in beach habitats. This work offers empirical support for the competitive exclusion principle-hypothesis and demonstrates that Hermit Crabs are an ideal model organism to investigate resource partitioning in natural populations.
Fernando L Mantelatto - One of the best experts on this subject based on the ideXlab platform.
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reproductive features of the deep water Hermit Crab sympagurus dimorphus anomura parapaguridae inhabiting pseudoshells in the sw atlantic ocean
Journal of Natural History, 2017Co-Authors: Laura Schejter, M A Scelzo, Fernando L MantelattoAbstract:We herein provide information on reproductive aspects (the gonopore morphology of both sexes, the size of embryonic eggs and the fecundity) of the Hermit Crab Sympagurus dimorphus from deep waters ...
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reproductive system of the male Hermit Crab clibanarius sclopetarius gonopore spermatophore and spermatozoal morphologies
Aquatic Biology, 2011Co-Authors: Nathalia M Santos, Fernando L MantelattoAbstract:In the present study, the morphology and biometry of the spermatophores of the west- ern Atlantic Hermit Crab Clibanarius sclopetarius (Herbst, 1796) are described, and the results are placed in the context of the Paguroidea, in particular the Diogenidae. Individuals of C. sclopetarius were sampled from a human-impacted mangrove area of southern Brazil. The male reproductive sys- tem was removed, measured and analyzed using stereoscopic, light, transmission-electron and scan- ning-electron microscopy. This system is composed of lobular testes connected to the vas deferens, and gonopores with membranous coverage. The mature spermatophore consists of a spherical pack that stores sperm. These cells consist of a spherical acrosomal vesicle, an amorphous cytoplasm and a distal nucleus. The results revealed that the gonopores, testis and vas deferens have the expected characteristics of the family Diogenidae, while the non-tripartite morphology of the spermatophores and the sperm follow the patterns found only in the genus Clibanarius, and the presence of the dense perforatorial ring is, to date, unique in the species of the genus, being a possible apomorphic charac- teristic.
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shelter association between the Hermit Crab sympagurus dimorphus and the zoanthid epizoanthus paguricola in the southwestern atlantic ocean
Acta Zoologica, 2011Co-Authors: Laura Schejter, Fernando L MantelattoAbstract:Schejter, L. and Mantelatto, F.L. 2011. Shelter association between the Hermit Crab Sympagurus dimorphus and the zoanthid Epizoanthus paguricola in the southwestern Atlantic Ocean. —Acta Zoologica (Stockholm) 92: 141–149. The available literature on zoanthid–Hermit Crab associations deals only with records of this phenomenon, providing no detailed information. We describe, for the first time, the shell-like colonies of Epizoanthus paguricola associated with the Hermit Crab Sympagurus dimorphus from benthic samples taken in the Argentine Sea, between 85 and 131 m depth, and provide information about morphometric relationships between the Hermits and the zoanthids. In total, 260 specimens (137 males and 123 females) of S. dimorphus were collected, 240 (92.3%) of which were living in symbiosis with E. paguricola. The remaining 20 (7.7%) were living inside gastropod shells. As the initial structure of the pseudoshell, 12 different gastropod species were found (all were almost totally covered with colonies of E. paguricola). The Hermit Crab lives in the spiral cavity inside the soft colony, which seemed to be slightly different depending on the initial gastropod. Aperture pseudoshell morphology did not seem to be related to the sex of the Hermit Crab host, although males showed larger apertures for a given colony size. This fact is probably related to a larger size of male’s cheliped (sexual dimorphic character) used like a gastropod operculum and that may serve as a template for the growing of the aperture pseudoshell edge. The number of epizoanthid polyps per colony increased in relation to the weight of the colony and to the size of the Hermit Crab. A process of selection of the initial shell was evident, because species of Naticidae were not the most common gastropods in this benthic community, but were those most used by Hermit Crabs (>60%). The puzzling association between Hermit Crab, shell and zoanthid presumably occurs during the Hermit juvenile phase, when the Crab occupies a small shell, and a zoanthid larva settles on it. Given the close relationship between S. dimorphus and E. paguricola found in this region, we support the idea that due to the low availability of adequate gastropod shells for Hermit life cycle, this association allows the establishment and the continuity of the Hermit Crab population in the studied area.
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a comparative study of population traits between two south american populations of the striped legged Hermit Crab clibanarius vittatus
Acta Oecologica-international Journal of Ecology, 2010Co-Authors: Fernando L Mantelatto, Lissandra Correa Fernandesgoes, Marina Zilio Fantucci, Renata Biagi, Luis Miguel Pardo, Joao Marcos De GoesAbstract:The striped-legged Hermit Crab Clibanarius vittatus, with a geographical distribution covering a wide range of latitudes in the western Atlantic, was selected for a comparative study on population features between two different areas of the Brazilian coast that are separated by approximately 3000 km. The two populations were sampled concurrently for nine months. The populations in northern and southeastern Brazil showed different profiles in terms of size of specimens, sex ratio, and shell occupation. The observed plasticity of these life-cycle traits of C. vittatus in relation to local environmental conditions is discussed.
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taxonomic re examination of the Hermit Crab species pagurus forceps and pagurus comptus decapoda paguridae by molecular analysis
Zootaxa, 2009Co-Authors: Fernando L Mantelatto, Luis Miguel Pardo, Leonardo G Pileggi, Darryl L FelderAbstract:The current taxonomy of two poorly known Hermit Crab species Pagurus forceps H. Milne Edwards, 1836 and Pagurus comptus White, 1847 from temperate Pacific and Atlantic coastlines of South America is based only on adult morphology. Past studies have questioned the separation of these two very similar species, which occur sympatrically. We included specimens morphologically assignable to P. forceps and P. comptus in a phylogenetic analysis, along with other selected anomuran decapods, based on 16S ribosomal gene sequences. Differences between samples putatively assigned to either P. forceps and P. comptus were moderate, with sequence similarity ranging from 98.2 to 99.4% for the fragments analyzed. Our comparison of mitochondrial DNA sequences (16S rRNA) revealed diagnostic differences between the two putative species, suggesting that P. forceps and P. comptus are indeed phylogenetically close but different species, with no genetic justification to support their synonymization. The polyphyly of Pagurus is not corroborated here among the represented Atlantic species, despite obviously complex relationships among the members of the genus.
Sebastian Steibl - One of the best experts on this subject based on the ideXlab platform.
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Shell resource partitioning as a mechanism of coexistence in two co-occurring terrestrial Hermit Crab species
BMC Ecology, 2020Co-Authors: Sebastian Steibl, Christian LaforschAbstract:Background Coexistence is enabled by ecological differentiation of the co-occurring species. One possible mechanism thereby is resource partitioning, where each species utilizes a distinct subset of the most limited resource. This resource partitioning is difficult to investigate using empirical research in nature, as only few species are primarily limited by solely one resource, rather than a combination of multiple factors. One exception are the shell-dwelling Hermit Crabs, which are known to be limited under natural conditions and in suitable habitats primarily by the availability of gastropod shells. In the present study, we used two co-occurring terrestrial Hermit Crab species, Coenobita rugosus and C. perlatus , to investigate how resource partitioning is realized in nature and whether it could be a driver of coexistence. Results Field sampling of eleven separated Hermit Crab populations showed that the two co-occurring Hermit Crab species inhabit the same beach habitat but utilize a distinct subset of the shell resource. Preference experiments and principal component analysis of the shell morphometric data thereby revealed that the observed utilization patterns arise out of different intrinsic preferences towards two distinct shell shapes. While C. rugosus displayed a preference towards a short and globose shell morphology, C. perlatus showed preferences towards an elongated shell morphology with narrow aperture. Conclusion The two terrestrial Hermit Crab species occur in the same habitat but have evolved different preferences towards distinct subsets of the limiting shell resource. Resource partitioning might therefore be the main driver of their ecological differentiation, which ultimately allowed these co-occurring species to coexist in their environment. As the preferred shell morphology of C. rugosus maximizes reproductive output at the expense of protection, while the preferred shell morphology of C. perlatus maximizes protection against predation at the expense of reproductive output, shell resource partitioning might reflect different strategies to respond to the same set of selective pressures occurring in beach habitats. This work offers empirical support for the competitive exclusion principle-hypothesis and demonstrates that Hermit Crabs are an ideal model organism to investigate resource partitioning in natural populations.
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shell resource partitioning as a mechanism of coexistence in two co occurring terrestrial Hermit Crab species
BMC Ecology, 2020Co-Authors: Sebastian Steibl, Christian LaforschAbstract:Coexistence is enabled by ecological differentiation of the co-occurring species. One possible mechanism thereby is resource partitioning, where each species utilizes a distinct subset of the most limited resource. This resource partitioning is difficult to investigate using empirical research in nature, as only few species are primarily limited by solely one resource, rather than a combination of multiple factors. One exception are the shell-dwelling Hermit Crabs, which are known to be limited under natural conditions and in suitable habitats primarily by the availability of gastropod shells. In the present study, we used two co-occurring terrestrial Hermit Crab species, Coenobita rugosus and C. perlatus, to investigate how resource partitioning is realized in nature and whether it could be a driver of coexistence. Field sampling of eleven separated Hermit Crab populations showed that the two co-occurring Hermit Crab species inhabit the same beach habitat but utilize a distinct subset of the shell resource. Preference experiments and principal component analysis of the shell morphometric data thereby revealed that the observed utilization patterns arise out of different intrinsic preferences towards two distinct shell shapes. While C. rugosus displayed a preference towards a short and globose shell morphology, C. perlatus showed preferences towards an elongated shell morphology with narrow aperture. The two terrestrial Hermit Crab species occur in the same habitat but have evolved different preferences towards distinct subsets of the limiting shell resource. Resource partitioning might therefore be the main driver of their ecological differentiation, which ultimately allowed these co-occurring species to coexist in their environment. As the preferred shell morphology of C. rugosus maximizes reproductive output at the expense of protection, while the preferred shell morphology of C. perlatus maximizes protection against predation at the expense of reproductive output, shell resource partitioning might reflect different strategies to respond to the same set of selective pressures occurring in beach habitats. This work offers empirical support for the competitive exclusion principle-hypothesis and demonstrates that Hermit Crabs are an ideal model organism to investigate resource partitioning in natural populations.
Bill S Hansson - One of the best experts on this subject based on the ideXlab platform.
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expression of ionotropic receptors in terrestrial Hermit Crab s olfactory sensory neurons
Frontiers in Cellular Neuroscience, 2015Co-Authors: Katrin C Grohlunow, Ewald Grossewilde, Merid Negash Getahun, Bill S HanssonAbstract:Coenobitidae are one out of at least five crustacean lineages which independently succeeded in the transition from water to land. This change in lifestyle required adaptation of the peripheral olfactory organs, the antennules, in order to sense chemical cues in the new terrestrial habitat. Hermit Crab olfactory aesthetascs are arranged in a field on the distal segment of the antennular flagellum. Aesthetascs house approximately 300 dendrites with their cell bodies arranged in spindle-like complexes of ca. 150 cell bodies each. While the aesthetascs of aquatic crustaceans have been shown to be the place of odor uptake and previous studies identified ionotropic receptors (IRs) as the putative chemosensory receptors expressed in decapod antennules, the expression of IRs besides the IR co-receptors IR25a and IR93a in olfactory sensory neurons (OSNs) has not been documented yet. Our goal was to reveal the expression and distribution pattern of non-co-receptor IRs in OSNs of Coenobita clypeatus, a terrestrial Hermit Crab, with RNA in situ hybridization. We expanded our previously published RNAseq dataset, and revealed 22 novel IR candidates in the Coenobita antennules. We then used RNA probes directed against three different IRs to visualize their expression within the OSN cell body complexes. Furthermore we aimed to characterize ligand spectra of single aesthetascs by recording local field potentials and responses from individual dendrites. This also allowed comparison to functional data from insect OSNs expressing antennal IRs. We show that this orphan receptor subgroup with presumably non-olfactory function in insects is likely the basis of olfaction in terrestrial Hermit Crabs.
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the Hermit Crab s nose antennal transcriptomics
Frontiers in Neuroscience, 2014Co-Authors: Katrin C Groh, Heiko Vogel, Marcus C Stensmyr, Ewald Grossewilde, Bill S HanssonAbstract:In the course of evolution, crustaceans adapted to a large variety of habitats. Probably the most extreme habitat shift was the transition from water to land, which occurred independently in at least five crustacean lineages. This substantial change in life style required adaptations in sensory organs, as the medium conveying stimuli changed in both chemical and physical properties. One important sensory organ in crustaceans is the first pair of antennae, housing their sense of smell. Previous studies on the crustacean transition from water to land focused on morphological, behavioral and physiological aspects but did not analyze gene expression. Our goal was to scrutinize the molecular makeup of the crustacean antennulae, comparing the terrestrial Coenobita clypeatus and the marine Pagurus bernhardus. We sequenced and analyzed the antennal transcriptomes of two Hermit Crab species. Comparison to previously published datasets of similar tissues revealed a comparable quality and GO annotation confirmed a highly similar set of expressed genes in both datasets. The chemosensory gene repertoire of both species displayed a similar set of ionotropic receptors (IRs), most of them belonging to the divergent IR subtype. No binding proteins, gustatory receptors (GRs) or insect-like olfactory receptors (ORs) were present. Additionally to their olfactory function, the antennules were equipped with a variety of pathogen defense mechanisms, producing relevant substances on site. The overall similarity of both transcriptomes is high and does not indicate a general shift in genetic makeup connected to the change in habitat. Ionotropic receptors seem to perform the task of olfactory detection in both Hermit Crab species studied.
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brain architecture in the terrestrial Hermit Crab coenobita clypeatus anomura coenobitidae a crustacean with a good aerial sense of smell
BMC Neuroscience, 2008Co-Authors: Steffen Harzsch, Bill S HanssonAbstract:Background During the evolutionary radiation of Crustacea, several lineages in this taxon convergently succeeded in meeting the physiological challenges connected to establishing a fully terrestrial life style. These physiological adaptations include the need for sensory organs of terrestrial species to function in air rather than in water. Previous behavioral and neuroethological studies have provided solid evidence that the land Hermit Crabs (Coenobitidae, Anomura) are a group of crustaceans that have evolved a good sense of aerial olfaction during the conquest of land. We wanted to study the central olfactory processing areas in the brains of these organisms and to that end analyzed the brain of Coenobita clypeatus (Herbst, 1791; Anomura, Coenobitidae), a fully terrestrial tropical Hermit Crab, by immunohistochemistry against synaptic proteins, serotonin, FMRFamide-related peptides, and glutamine synthetase.
Mark Briffa - One of the best experts on this subject based on the ideXlab platform.
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Hermit Crab shell assessment under noise
2019Co-Authors: Svenja Tidau, Mark BriffaAbstract:Hermit Crab shell assessment under nois
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whole organism performance capacity predicts resource holding potential in the Hermit Crab pagurus bernhardus
Animal Behaviour, 2010Co-Authors: Sophie L Mowles, Peter A Cotton, Mark BriffaAbstract:Animal contests often involve the production of repeated signals, which are assumed to be energetically demanding to perform and advertise the performer’s fighting ability through a demonstration of stamina. Although the costs of repeated signals have been investigated by the postfight analysis of metabolites, single physiological measures may not adequately reflect an individual’s overall stamina. An alternative approach is to investigate whole-organism performance capacities. We examined the relationship between locomotor capacities and the vigour of repeated bouts of shell-rapping signals during fights over gastropod shells in the Hermit Crab Pagurus bernhardus. In these fights only attacking Crabs perform shell rapping while defenders withdraw into their shell. Successful attackers and defenders had higher mean and maximum walking speeds than losers. Furthermore, maximum speed was a better correlate of fighting ability in defenders, whereas mean speed was better in attackers. This study demonstrates that whole-organism performance capacities correlate with success in agonistic encounters, and that different aspects of performance capacity appear to be important depending on the behaviours performed by different roles. Thus, this study supports the assumptions of theoretical models such as the cumulative assessment model and the energetic war of attrition, which predict that repeated signals advertise stamina and fighting ability, by demonstrating that mean rates of performance, a key component of stamina, are related to success in Hermit Crab shell fights.
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monoamines and decision making during contests in the Hermit Crab pagurus bernhardus
Animal Behaviour, 2007Co-Authors: Mark Briffa, Robert W ElwoodAbstract:During fights animals are expected to make a series of strategic decisions that involve interactions between information about the contest and the individual's nervous system that produce a change in behaviour. Biogenic monoamines such as serotonin (‘5-HT’) and dopamine are thought to prime decision-making centres for appropriate responses during aggressive interactions in crustaceans, and circulating levels vary both between individuals and during agonistic encounters. Aminergenic systems operate in diverse animal taxa and in this study we assayed circulating levels of 5-HT and dopamine following shell fights in the common European Hermit Crab, Pagurus bernhardus. The two roles in these fights, attacker and defender, perform different activities but, in both, 5-HT increased and dopamine declined in response to engaging in a fight. In defenders but not attackers, giving up was correlated with low 5-HT and dopamine. In attackers, motivation to initiate a fight was positively correlated with dopamine levels. Circulating monoamines are therefore involved in decision making during these aggressive encounters.
