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Olivier Bethoux - One of the best experts on this subject based on the ideXlab platform.
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A 365-Million-Year-Old Freshwater Community Reveals Morphological and Ecological Stasis in Branchiopod Crustaceans
Current Biology, 2016Co-Authors: Pierre Gueriau, Nicolas Rabet, Linda Lagebro, Sebastien Olive, Sylvain Charbonnier, Jean Vannier, Gael Clement, Derek E. G. Briggs, Olivier BethouxAbstract:Summary Branchiopod crustaceans are represented by fairy, tadpole, and clam shrimps (Anostraca, Notostraca, Laevicaudata, Spinicaudata), which typically inhabit temporary freshwater bodies, and water fleas (Cladoceromorpha), which live in all kinds of freshwater and occasionally marine environments [1, 2]. The earliest branchiopods occur in the Cambrian, where they are represented by complete body fossils from Sweden such as Rehbachiella kinnekullensis [3] and isolated mandibles preserved as small carbonaceous fossils [4–6] from Canada. The earliest known continental branchiopods are associated with hot spring environments [7] represented by the Early Devonian Rhynie Chert of Scotland (410 million years ago) and include possible stem-group or crown-group Anostraca, Notostraca, and clam shrimps or Cladoceromorpha [8–10], which differ morphologically from their modern counterparts [1, 2, 11]. Here we report the discovery of an Ephemeral Pool branchiopod community from the 365-million-year-old Strud locality of Belgium. It is characterized by new anostracans and spinicaudatans, closely resembling extant species, and the earliest notostracan, Strudops goldenbergi [12]. These branchiopods released resting eggs into the sediment in a manner similar to their modern representatives [1, 2]. We infer that this reproductive strategy was critical to overcoming environmental constraints such as seasonal desiccation imposed by living on land. The pioneer colonization of Ephemeral freshwater Pools by branchiopods in the Devonian was followed by remarkable ecological and morphological stasis that persists to the present day.
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the Ephemeral Pool crustacean community unchanged since the late devonian
2015Co-Authors: Pierre Gueriau, Nicolas Rabet, Linda Lagebro, Sebastien Olive, Sylvain Charbonnier, Gael Clement, Olivier BethouxAbstract:The Devonian (419-359 million years ago) is the geological period when the terrestrial biota fully established. Early representatives from a terrestrial and continental aquatic biota have previously been reported from the Upper Devonian (Famennian) Strud quarry in Belgium, in the shape of seed-bearing plants and vertebrates (fish and early tetrapods). The palaeoenvironment is interpreted as a floodplain with slow accumulation of sediment in the river channels and adjacent shallow Pools, subject to seasonal flooding and desiccation. This thesis presents the upper Famennian Strud ecosystem with representatives from the largest animal phylum – the Arthropoda. Pancrustaceans are dominating the arthropod assemblage by two eumalacostracans (previously described), three groups of branchiopods, and a putative insect, all collected in fine shales likely deposited in the shallow Pools. The branchiopods from Strud comprise new members from all three extant clades, i.e. notostracans, anostracans, and spinicaudatan diplostracans. The notostracan Strudops goldenbergi is remarkable for its close resemblance with the extant genus Triops by the overall body plan and telson morphology. A phylogenetic analysis including modern and extinct notostracans and anostracans was performed, where Strudops appears as the earliest undisputed notostracan ever found. In addition, new genera of Anostraca (Haltinnaias serrata) and Spinicaudata (Gesvestheria pernegrei) are described herein. The insect Strudiella devonica consists of a single specimen and is interpreted to have been a nymph due to its minute size and wingless appearance. The chelicerates are represented by one or several species of eurypterids. So far unnamed juvenile eurypterid remains have also been found within the Pool strata, and fragments of adult individuals in the coarser river deposits. The branchiopod community displays a unique insight to the ecosystem that these crustaceans inhabited. This is partly because of their co-occurrence, but mainly because they are preserved in close association to draught-resistant encysted eggs, in the same manner as modern day branchiopods do to survive and disperse during periods of drought and freezing. Altogether, the arthropod assemblage offers insight to Late Devonian freshwater ecosystems, and provides further understanding of the evolution of respective groups.
Lien-siang Chou - One of the best experts on this subject based on the ideXlab platform.
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spatial niche differentiation of sympatric branchiopoda in a highly unpredictable Ephemeral Pool
Journal of Crustacean Biology, 2012Co-Authors: Chun-chieh Wang, Shiang-lin Huang, Wan-ping Huang, Lien-siang ChouAbstract:Given the limitations of the short life span and the highly unpredictable environment of branchiopods, a spatial differentiation strategy may become an immediate issue rather than a long-term life history adaptation to potential interspecific competition for a multi-species branchiopod community. We found an Ephemeral Pool in northern Taiwan with three sympatric branchiopods, Branchinella kugenumaensis (Ishikawa, 1895), Eulimnadia braueriana (Ishikawa, 1895), and Lynceus biformis (Ishikawa, 1895), and thus we aim to explore the spatial distribution patterns among these three species. We measured the density distributions of these species during two inundation episodes (2008P1 and 2008P2) that lasted for 6 and 32 days respectively. Significant differences in both horizontal and vertical distribution of these species were observed. Horizontally, each species showed its own spatial hotspots, but the hotspots changed irregularly every day. Vertically, while B. kugenumaensis gathered in the upper strata, L. biformis spread over a wide range of depths, with increasing dominance towards the deeper layers. Eulimnadia braueriana, on the other hand, showed no significant pattern of vertical distribution due to its small population size. We suggest that the significant differences in the spatial distribution of these sympatric branchiopod populations can be an adaptive strategy under the selective stresses of high unpredictability and variability.
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Reproductive Potential of the Fairy Shrimp, Branchinella (Branchinellites) Kugenumaensis, in an Unpredictable Ephemeral Pool
Journal of Crustacean Biology, 2011Co-Authors: Shiang-lin Huang, Chun-chieh Wang, Wan-ping Huang, Lien-siang ChouAbstract:Abstract Maintaining a sustainable egg bank through rapid maturation and the production of large clutches is an important strategy for large branchiopods surviving in Ephemeral habitats, and such egg banks can only be replenished by the recruitment of hatched eggs as a function of fitness (F). The ability to reach a threshold F represents a key adaptation to selection pressures. We investigated daily changes in the population density/size and hatching numbers of fairy shrimp, Branchinella kugenumaensis, and estimated their F values in an Ephemeral Pool, Siangtian Pond, in northern Taiwan during 2005, and four cohorts were observed. The number of hatchings per cohort ranged from to , representing a hatching density between 1.42 and 2.83 , and the number of newly produced eggs per cohort ranged from to , representing a high level of recruitment, ranging from 10,631 to 37,425 in the sediment, which yielded a mean fitness of 2.05 produced eggs per hatching (CI = 1.82 ∼ 2.35). The threshold F for replenishin...
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Indeterminate Growth of the Fairy Shrimp, Branchinella (Branchinellites) kugenumaensis (Branchiopoda: Anostraca) in an Unpredictable Ephemeral Pool
Journal of Crustacean Biology, 2010Co-Authors: Shiang-lin Huang, Chun-chieh Wang, Wan-ping Huang, Lien-siang ChouAbstract:Abstract A major life-history challenge for fairy shrimps (Anostraca) is the unpredictable environment of the Ephemeral Pool. The duration and predictability of Pool inundations affects their life history strategy. The growth and reproduction schedule of a thamnocephalid fairy shrimp, Branchinella (Branchinellites) kugenumaensis, in an unpredictable Ephemeral Pool in northern Taiwan was monitored from 2004 to 2008. A total of 15 inundation episodes, resulting from typhoons or, occasionally, frontal systems, was recorded over the five-year period. Thirteen episodes lasted no more than 2-3 weeks. Two exceptionally long inundation periods were caused by additional rain events before the Pool dried out. We recorded the growth patterns, egg spawning time, and clutch size of each fairy shrimp cohort during each inundation episode. No significant differences were observed in either growth or reproductive pattern from hatching to first spawning between short and long inundation episodes. The fairy shrimps stopped...
Pierre Gueriau - One of the best experts on this subject based on the ideXlab platform.
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A 365-Million-Year-Old Freshwater Community Reveals Morphological and Ecological Stasis in Branchiopod Crustaceans
Current Biology, 2016Co-Authors: Pierre Gueriau, Nicolas Rabet, Linda Lagebro, Sebastien Olive, Sylvain Charbonnier, Jean Vannier, Gael Clement, Derek E. G. Briggs, Olivier BethouxAbstract:Summary Branchiopod crustaceans are represented by fairy, tadpole, and clam shrimps (Anostraca, Notostraca, Laevicaudata, Spinicaudata), which typically inhabit temporary freshwater bodies, and water fleas (Cladoceromorpha), which live in all kinds of freshwater and occasionally marine environments [1, 2]. The earliest branchiopods occur in the Cambrian, where they are represented by complete body fossils from Sweden such as Rehbachiella kinnekullensis [3] and isolated mandibles preserved as small carbonaceous fossils [4–6] from Canada. The earliest known continental branchiopods are associated with hot spring environments [7] represented by the Early Devonian Rhynie Chert of Scotland (410 million years ago) and include possible stem-group or crown-group Anostraca, Notostraca, and clam shrimps or Cladoceromorpha [8–10], which differ morphologically from their modern counterparts [1, 2, 11]. Here we report the discovery of an Ephemeral Pool branchiopod community from the 365-million-year-old Strud locality of Belgium. It is characterized by new anostracans and spinicaudatans, closely resembling extant species, and the earliest notostracan, Strudops goldenbergi [12]. These branchiopods released resting eggs into the sediment in a manner similar to their modern representatives [1, 2]. We infer that this reproductive strategy was critical to overcoming environmental constraints such as seasonal desiccation imposed by living on land. The pioneer colonization of Ephemeral freshwater Pools by branchiopods in the Devonian was followed by remarkable ecological and morphological stasis that persists to the present day.
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the Ephemeral Pool crustacean community unchanged since the late devonian
2015Co-Authors: Pierre Gueriau, Nicolas Rabet, Linda Lagebro, Sebastien Olive, Sylvain Charbonnier, Gael Clement, Olivier BethouxAbstract:The Devonian (419-359 million years ago) is the geological period when the terrestrial biota fully established. Early representatives from a terrestrial and continental aquatic biota have previously been reported from the Upper Devonian (Famennian) Strud quarry in Belgium, in the shape of seed-bearing plants and vertebrates (fish and early tetrapods). The palaeoenvironment is interpreted as a floodplain with slow accumulation of sediment in the river channels and adjacent shallow Pools, subject to seasonal flooding and desiccation. This thesis presents the upper Famennian Strud ecosystem with representatives from the largest animal phylum – the Arthropoda. Pancrustaceans are dominating the arthropod assemblage by two eumalacostracans (previously described), three groups of branchiopods, and a putative insect, all collected in fine shales likely deposited in the shallow Pools. The branchiopods from Strud comprise new members from all three extant clades, i.e. notostracans, anostracans, and spinicaudatan diplostracans. The notostracan Strudops goldenbergi is remarkable for its close resemblance with the extant genus Triops by the overall body plan and telson morphology. A phylogenetic analysis including modern and extinct notostracans and anostracans was performed, where Strudops appears as the earliest undisputed notostracan ever found. In addition, new genera of Anostraca (Haltinnaias serrata) and Spinicaudata (Gesvestheria pernegrei) are described herein. The insect Strudiella devonica consists of a single specimen and is interpreted to have been a nymph due to its minute size and wingless appearance. The chelicerates are represented by one or several species of eurypterids. So far unnamed juvenile eurypterid remains have also been found within the Pool strata, and fragments of adult individuals in the coarser river deposits. The branchiopod community displays a unique insight to the ecosystem that these crustaceans inhabited. This is partly because of their co-occurrence, but mainly because they are preserved in close association to draught-resistant encysted eggs, in the same manner as modern day branchiopods do to survive and disperse during periods of drought and freezing. Altogether, the arthropod assemblage offers insight to Late Devonian freshwater ecosystems, and provides further understanding of the evolution of respective groups.
Shiang-lin Huang - One of the best experts on this subject based on the ideXlab platform.
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spatial niche differentiation of sympatric branchiopoda in a highly unpredictable Ephemeral Pool
Journal of Crustacean Biology, 2012Co-Authors: Chun-chieh Wang, Shiang-lin Huang, Wan-ping Huang, Lien-siang ChouAbstract:Given the limitations of the short life span and the highly unpredictable environment of branchiopods, a spatial differentiation strategy may become an immediate issue rather than a long-term life history adaptation to potential interspecific competition for a multi-species branchiopod community. We found an Ephemeral Pool in northern Taiwan with three sympatric branchiopods, Branchinella kugenumaensis (Ishikawa, 1895), Eulimnadia braueriana (Ishikawa, 1895), and Lynceus biformis (Ishikawa, 1895), and thus we aim to explore the spatial distribution patterns among these three species. We measured the density distributions of these species during two inundation episodes (2008P1 and 2008P2) that lasted for 6 and 32 days respectively. Significant differences in both horizontal and vertical distribution of these species were observed. Horizontally, each species showed its own spatial hotspots, but the hotspots changed irregularly every day. Vertically, while B. kugenumaensis gathered in the upper strata, L. biformis spread over a wide range of depths, with increasing dominance towards the deeper layers. Eulimnadia braueriana, on the other hand, showed no significant pattern of vertical distribution due to its small population size. We suggest that the significant differences in the spatial distribution of these sympatric branchiopod populations can be an adaptive strategy under the selective stresses of high unpredictability and variability.
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Reproductive Potential of the Fairy Shrimp, Branchinella (Branchinellites) Kugenumaensis, in an Unpredictable Ephemeral Pool
Journal of Crustacean Biology, 2011Co-Authors: Shiang-lin Huang, Chun-chieh Wang, Wan-ping Huang, Lien-siang ChouAbstract:Abstract Maintaining a sustainable egg bank through rapid maturation and the production of large clutches is an important strategy for large branchiopods surviving in Ephemeral habitats, and such egg banks can only be replenished by the recruitment of hatched eggs as a function of fitness (F). The ability to reach a threshold F represents a key adaptation to selection pressures. We investigated daily changes in the population density/size and hatching numbers of fairy shrimp, Branchinella kugenumaensis, and estimated their F values in an Ephemeral Pool, Siangtian Pond, in northern Taiwan during 2005, and four cohorts were observed. The number of hatchings per cohort ranged from to , representing a hatching density between 1.42 and 2.83 , and the number of newly produced eggs per cohort ranged from to , representing a high level of recruitment, ranging from 10,631 to 37,425 in the sediment, which yielded a mean fitness of 2.05 produced eggs per hatching (CI = 1.82 ∼ 2.35). The threshold F for replenishin...
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Indeterminate Growth of the Fairy Shrimp, Branchinella (Branchinellites) kugenumaensis (Branchiopoda: Anostraca) in an Unpredictable Ephemeral Pool
Journal of Crustacean Biology, 2010Co-Authors: Shiang-lin Huang, Chun-chieh Wang, Wan-ping Huang, Lien-siang ChouAbstract:Abstract A major life-history challenge for fairy shrimps (Anostraca) is the unpredictable environment of the Ephemeral Pool. The duration and predictability of Pool inundations affects their life history strategy. The growth and reproduction schedule of a thamnocephalid fairy shrimp, Branchinella (Branchinellites) kugenumaensis, in an unpredictable Ephemeral Pool in northern Taiwan was monitored from 2004 to 2008. A total of 15 inundation episodes, resulting from typhoons or, occasionally, frontal systems, was recorded over the five-year period. Thirteen episodes lasted no more than 2-3 weeks. Two exceptionally long inundation periods were caused by additional rain events before the Pool dried out. We recorded the growth patterns, egg spawning time, and clutch size of each fairy shrimp cohort during each inundation episode. No significant differences were observed in either growth or reproductive pattern from hatching to first spawning between short and long inundation episodes. The fairy shrimps stopped...
Peter L Starkweather - One of the best experts on this subject based on the ideXlab platform.
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susceptibility of Ephemeral Pool hexarthra to predation by the fairy shrimp branchinecta mackini can predation drive local extinction
Hydrobiologia, 2005Co-Authors: Peter L StarkweatherAbstract:Isolated rock Pools in the US desert southwest often develop dense populations of a lithophilic species of the rotifer Hexarthra. I hypothesized that rotifers persist in these isolated ponds due to the absence of either competition with or predation by potentially sympatric crustaceans, especially anostracans. I tested the latter idea with laboratory and field experiments, in each case exposing rotifers to adult fairy shrimp (Branchinecta mackini, the dominant anostracan in this region in winter ponds) in 200 ml microcosms. In most cases individual female fairy shrimp had distinct negative effects on rotifer suspensions due to direct predatory consumption of the smaller animals. Estimated effective water processing rates ranged from ca. 50 to over 300 ml ind−1 h−1 and rotifer consumption rates by female B. mackini were between 280 and >600 Hexarthra consumed per individual predator per hour. Male B. mackini never significantly reduced rotifer numbers in either laboratory or field microcosms. The results indicate that, while perhaps not the sole determinant of rotifer distribution in these Ephemeral Pools, fairy shrimp predation can have a strong negative influence on natural Hexarthra populations.