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Sérvulo T, Taylor JD, Proietti MC, Rodrigues LDS, Puertas IP, Barutot RA, Lacerda ALDF. Plastisphere composition in a subtropical estuary: Influence of season, incubation time and polymer type on plastic biofouling. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023:121873. [PMID: 37244532 DOI: 10.1016/j.envpol.2023.121873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 05/08/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Plastics are abundant artificial substrates in aquatic systems that host a wide variety of organisms (the plastisphere), including potential pathogens and invasive species. Plastisphere communities have many complex, but not well-understood ecological interactions. It is pivotal to investigate how these communities are influenced by the natural fluctuations in aquatic ecosystems, especially in transitional environments such as estuaries. Further study is needed in sub-tropical regions in the Southern Hemisphere, where plastic pollution is ever increasing. Here we applied DNA-metabarcoding (16S, 18S and ITS-2) as well Scanning Electron Microscopy (SEM) to assess the diversity of the plastisphere in the Patos Lagoon estuary (PLE), South Brazil. Through a one-year in situ colonization experiment, polyethylene (PE) and polypropylene (PP) plates were placed in shallow waters, and sampled after 30 and 90 days within each season. Over 50 taxa including bacteria, fungi and other eukaryotes were found through DNA analysis. Overall, the polymer type did not influence the plastisphere community composition. However, seasonality significantly affected community composition for bacteria, fungi and general eukaryotes. Among the microbiota, we found Acinetobacter sp., Bacillus sp., and Wallemia mellicola that are putative pathogens of aquatic organisms, such as algae, shrimp and fish, including commercial species. In addition, we identified organisms within genera that can potentially degrade hydrocarbons (e.g. Pseudomonas and Cladosporium spp). This study is the first to assess the full diversity and variation of the plastisphere on different polymers within a sub-tropical southern hemisphere estuary, significantly expanding knowledge on plastic pollution and the plastisphere in estuarine regions.
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Affiliation(s)
- Tobias Sérvulo
- Projeto Lixo Marinho - Instituto de Oceanografia, Universidade Federal do Rio Grande - FURG, Rio Grande, Brazil.
| | - Joe D Taylor
- UK Centre for Ecology and Hydrology, Wallingford, UK
| | - Maíra C Proietti
- Projeto Lixo Marinho - Instituto de Oceanografia, Universidade Federal do Rio Grande - FURG, Rio Grande, Brazil
| | - Lucas D S Rodrigues
- Projeto Lixo Marinho - Instituto de Oceanografia, Universidade Federal do Rio Grande - FURG, Rio Grande, Brazil
| | - Igor P Puertas
- Projeto Lixo Marinho - Instituto de Oceanografia, Universidade Federal do Rio Grande - FURG, Rio Grande, Brazil
| | - Roberta A Barutot
- Projeto Lixo Marinho - Instituto de Oceanografia, Universidade Federal do Rio Grande - FURG, Rio Grande, Brazil
| | - Ana L D F Lacerda
- Projeto Lixo Marinho - Instituto de Oceanografia, Universidade Federal do Rio Grande - FURG, Rio Grande, Brazil; University of Salford, Salford, Greater Manchester, United Kingdom
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Bryozoan–cnidarian mutualism triggered a new strategy for greater resource exploitation as early as the Late Silurian. Sci Rep 2022; 12:15556. [PMID: 36114227 PMCID: PMC9481587 DOI: 10.1038/s41598-022-19955-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 09/07/2022] [Indexed: 11/25/2022] Open
Abstract
Bryozoans were common benthic invertebrates in the Silurian seas. The large biodiversity among Silurian benthic organisms prompted diversified interactions, and as a result bryozoans hosted many other organisms as symbionts. Here we analyse the cystoporate bryozoan Fistulipora przhidolensis and unidentified trepostomes intergrown with auloporid tabulate corals and putative hydrozoans. The material comes from the uppermost Přídolí Series (Late Silurian) of the Sõrve Peninsula, Saaremaa, Estonia. Our analysis shows that the interaction was beneficial for both organisms—cnidarians benefited from feeding currents created by the host bryozoan, while the latter benefited from the protection from predators by cnidae, it can thus be classified as mutualism. Such associations are common in modern seas. The analysed organisms are typically encrusting when the symbiosis is absent, when intergrown they display erect, branching morphologies, raised over the substratum, thus exploiting a higher suspension-feeding tier. While similar associations were known from the Devonian, we demonstrate that this novel ecological strategy for greater resource exploitation started as early as the latest Silurian.
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Dias GM, Dutra FS, Duarte RC. Artificial habitats induce plasticity in colonies of the marine bryozoan Schizoporella errata. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2020; 336:239-249. [PMID: 32291859 DOI: 10.1002/jez.b.22942] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 02/18/2020] [Accepted: 03/19/2020] [Indexed: 01/08/2023]
Abstract
Modular organization provides flexibility for colonial animals to deal with variable and unpredictable environmental conditions since each module has specific tasks within the colony, such as feeding, defending or reproducing. Depending on the selecting pressures, sessile organisms may phenotypically adjust the morphology of each module or modify their density, increasing individual fitness. Here we used the marine bryozoan Schizoporella errata (Cheilostomata, Schizoporellidae) to test how the divergent conditions between two artificial habitats, the location inside a marina (IM) and the external wall of the breakwater (BW), affect colony size and the density of the distinct modules. The density of avicularia and ovicells, modules related to defense and reproduction, respectively, did not differ between habitats. However, colonies growing in the turbulent waters of BW were, in general, larger and had higher density of feeding autozooids than those at IM. Reciprocal transplants of bryozoan clones indicated that trait variation is genotype-dependent but varies according to the environmental conditions at the assigned location. The occurrence of larger colonies with more zooids in BW is probably linked to the easier feeding opportunity offered by the small diffusive boundary layer around the colony at this location. Since in colonial polymorphic organisms each module (zooid) performs a specific function, the phenotypic response is not uniform across colonies, affecting only those modules that are susceptible to variations in the main selective pressures. Understanding the importance of colony-level plasticity is relevant to predict how modularity will contribute to organisms to deal with human-induced environmental changes in coastal habitats.
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Affiliation(s)
- Gustavo M Dias
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC (UFABC), São Bernardo do Campo, Sao Paulo, Brazil
| | - Felipe S Dutra
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC (UFABC), São Bernardo do Campo, Sao Paulo, Brazil
| | - Rafael C Duarte
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC (UFABC), São Bernardo do Campo, Sao Paulo, Brazil
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Liu F, Skovsted CB, Topper TP, Zhang Z, Shu D. Are hyoliths Palaeozoic lophophorates? Natl Sci Rev 2020; 7:453-469. [PMID: 34692060 PMCID: PMC8289160 DOI: 10.1093/nsr/nwz161] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 10/05/2019] [Accepted: 10/09/2019] [Indexed: 11/22/2022] Open
Abstract
The phylogenetic position of hyoliths has long been unsettled, with recent discoveries of a tentaculate feeding apparatus (‘lophophore’) and fleshy apical extensions from the shell (‘pedicle’) suggesting a lophophorate affinity. Here, we describe the first soft parts associated with the feeding apparatus of an orthothecid hyolith, Triplicatella opimus from the Chengjiang biota of South China. The tuft-like arrangement of the tentacles of T. opimus differs from that of hyolithids, suggesting they collected food directly from the substrate. A reassessment of the feeding organ in hyolithids indicates that it does not represent a lophophore and our analysis of the apical structures associated with some orthothecids show that these represent crushed portions of the shell and are not comparable to the brachiopod pedicle. The new information suggests that hyoliths are more likely to be basal members of the lophotrochozoans rather than lophophorates closely linked with the Phylum Brachiopoda.
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Affiliation(s)
- Fan Liu
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an 710069, China
| | - Christian B Skovsted
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an 710069, China.,Department of Palaeobiology, Swedish Museum of Natural History, Stockholm SE-104 05, Sweden
| | - Timothy P Topper
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an 710069, China.,Department of Palaeobiology, Swedish Museum of Natural History, Stockholm SE-104 05, Sweden
| | - Zhifei Zhang
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an 710069, China
| | - Degan Shu
- State Key Laboratory of Continental Dynamics, Shaanxi Key Laboratory of Early Life and Environments, Department of Geology, Northwest University, Xi'an 710069, China
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Khrizman A, Ribak G, Churilov D, Kolesnikov I, Genin A. Life in the flow: unique adaptations for feeding on drifting zooplankton in garden eels. ACTA ACUST UNITED AC 2018; 221:jeb.179523. [PMID: 29986872 DOI: 10.1242/jeb.179523] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 06/27/2018] [Indexed: 11/20/2022]
Abstract
A major challenge faced by sessile animals that feed in the flow is to maintain effective feeding postures while enduring hydrodynamic forces. Garden eels exhibit an exceptional lifestyle: feeding on drifting zooplankton while being 'anchored' in a burrow they dig in the sand. Using underwater observations, sampling and three-dimensional video recording, we measured the feeding rates and characterized feeding postures of garden eels under a wide range of current speeds. We show that the eels behaviorally resolve the trade-off between adverse biomechanical forces and beneficial fluxes of food by modulating their body postures according to current speeds. In doing so, the eels substantially reduce drag forces when currents are strong, yet keep their head well above bottom in order to effectively feed under conditions of high prey fluxes. These abilities have allowed garden eels to become one of the rare oceanic fishes that live in sandy, predation-rich habitats and feed on zooplankton while being attached to the bottom.
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Affiliation(s)
- Alexandra Khrizman
- The Interuniversity Institute for Marine Sciences in Eilat, Eilat 88103, Israel .,The Fredy and Nadine Hermann Institute of Earth Sciences, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Gal Ribak
- School of Zoology, Faculty of Life Sciences, Tel Aviv University, Tel Aviv 69978, Israel
| | - Dmitri Churilov
- The Interuniversity Institute for Marine Sciences in Eilat, Eilat 88103, Israel
| | - Irena Kolesnikov
- The Interuniversity Institute for Marine Sciences in Eilat, Eilat 88103, Israel
| | - Amatzia Genin
- The Interuniversity Institute for Marine Sciences in Eilat, Eilat 88103, Israel.,Department of Ecology, Evolution, and Behavior, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem 91904, Israel
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Macleod AK, Stanley MS, Day JG, Cook EJ. Biofouling community composition across a range of environmental conditions and geographical locations suitable for floating marine renewable energy generation. BIOFOULING 2016; 32:261-276. [PMID: 26900732 DOI: 10.1080/08927014.2015.1136822] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Knowledge of biofouling typical of marine structures is essential for engineers to define appropriate loading criteria in addition to informing other stakeholders about the ecological implications of creating novel artificial environments. There is a lack of information regarding biofouling community composition (including weight and density characteristics) on floating structures associated with future marine renewable energy generation technologies. A network of navigation buoys were identified across a range of geographical areas, environmental conditions (tidal flow speed, temperature and salinity), and deployment durations suitable for future developments. Despite the perceived importance of environmental and temporal factors, geographical location explained the greatest proportion of the observed variation in community composition, emphasising the importance of considering geography when assessing the impact of biofouling on device functioning and associated ecology. The principal taxa associated with variation in biofouling community composition were mussels (Mytilus edulis), which were also important when determining loading criteria.
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Affiliation(s)
- Adrian K Macleod
- a The Scottish Association for Marine Science (SAMS) , Ecology Department , Oban , UK
| | - Michele S Stanley
- b The Scottish Association for Marine Science (SAMS) , Microbial and Molecular Biology Department , Oban , UK
| | - John G Day
- b The Scottish Association for Marine Science (SAMS) , Microbial and Molecular Biology Department , Oban , UK
| | - Elizabeth J Cook
- a The Scottish Association for Marine Science (SAMS) , Ecology Department , Oban , UK
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A new species of the cheilostome bryozoan Chiastosella in the Southern Ocean, past and present. Polar Biol 2014. [DOI: 10.1007/s00300-014-1478-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Prada C, Schizas NV, Yoshioka PM. Phenotypic plasticity or speciation? A case from a clonal marine organism. BMC Evol Biol 2008; 8:47. [PMID: 18271961 PMCID: PMC2275222 DOI: 10.1186/1471-2148-8-47] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2007] [Accepted: 02/13/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Clonal marine organisms exhibit high levels of morphological variation. Morphological differences may be a response to environmental factors but also they can be attributed to accumulated genetic differences due to disruption of gene flow among populations. In this study, we examined the extensive morphological variation (of 14 characters) in natural populations observed in the gorgonian Eunicea flexuosa, a widely distributed Caribbean octocoral. Eco-phenotypic and genetic effects were evaluated by reciprocal transplants of colonies inhabiting opposite ends of the depth gradient and analysis of population genetics of mitochondrial and nuclear genes, respectively. RESULTS Significant differences (P < 0.001) in 14 morphological traits were found among colonies inhabiting 12 locations distributed in seven reefs in southwest Puerto Rico. Results from principal component analysis indicated the presence of two groups based on depth distribution, suggesting the presence of two discrete morphotypes (i.e. shallow type < 5 m and deep type > 17 m). A discriminant function analysis based on a priori univariate and multivariate analyses (which separated the colonies in morphotypes) correctly classified 93% of the colonies for each environment. Light, water motion and sediment transport might influence the distribution of the two morphotypes. Reaction norms of morphological characters of colonies reciprocally transplanted showed gradual significant changes through the 15 months of transplantation. Sclerites of shallow water colonies became larger when transplanted to deeper environments and vice versa, but neither of the two transplanted groups overlapped with the residents' morphology. Genetic analysis of mitochondrial and nuclear genes suggested that such discrete morphology and non-overlapping phenotypic plasticity is correlated with the presence of two independent evolutionary lineages. The distribution of the lineages is non-random and may be related to adaptational responses of each lineage to the environmental demands of each habitat. CONCLUSION The extensive distribution and ample morphological variation of Eunicea flexuosa corresponds to two distinct genetic lineages with narrower distributions and more rigid phenotypic plasticity than the original description. The accepted description sensu Bayer (1961) of E. flexuosa is a complex of at least two distinct genetic lineages, adapted to different habitats and do not exchange genetic material despite living in sympatry. The present study highlights the importance of correctly defining species, because the unknowingly use of species complexes can overestimate geographical distribution, population abundance, and physiological tolerance.
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Affiliation(s)
- Carlos Prada
- Department of Marine Sciences, University of Puerto Rico-Mayagüez, Isla Magueyes Laboratories, P.O. Box 908, Lajas, PR 00667, USA
| | - Nikolaos V Schizas
- Department of Marine Sciences, University of Puerto Rico-Mayagüez, Isla Magueyes Laboratories, P.O. Box 908, Lajas, PR 00667, USA
| | - Paul M Yoshioka
- Department of Marine Sciences, University of Puerto Rico-Mayagüez, Isla Magueyes Laboratories, P.O. Box 908, Lajas, PR 00667, USA
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von Dassow M. Function-dependent development in a colonial animal. THE BIOLOGICAL BULLETIN 2006; 211:76-82. [PMID: 16946244 DOI: 10.2307/4134580] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
How does the way an organism functions affect its subsequent development? Bryozoans are colonial animals that capture suspended food particles from water currents they generate using crowns of ciliated tentacles (lophophores). In many encrusting bryozoans the water passes through and then under the lophophores until it exits the colony at "chimneys" where the lophophores spread apart to form an opening. To determine whether these water currents can induce the formation of new chimneys, I augmented the excurrent flow by injecting seawater into the colony. New chimneys began to develop near the site of seawater injection within as little as one to two days. New chimneys rarely began to develop within this time interval at control sites where I did not inject seawater. This shows that fluid flow controls development in an external fluid transport system lacking pipe-like conduits, as has been found in the vertebrate circulatory system, an internal fluid transport system with pipe-like conduits. These fluid transport systems show feedback between the way they function and their own development. This kind of "function-dependent development" should be differentiated from phenotypic plasticity, since the developing system, not the environment, produces the signals that induce morphological change.
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Affiliation(s)
- Michelangelo von Dassow
- Integrative Biology Department, University of California, Berkeley, 3060 Valley Life Sciences Building #3140, Berkeley, California 94720-3140, USA.
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von Dassow M. Flow and conduit formation in the external fluid-transport system of a suspension feeder. ACTA ACUST UNITED AC 2006; 208:2931-8. [PMID: 16043598 DOI: 10.1242/jeb.01738] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To what extent is the development of a fluid-transport system related to flow within the system? Colonies of the bryozoan Membranipora membranacea have a simple external fluid-transport system with three components: the canopy of lophophores (crowns of ciliated tentacles), the edge of the canopy, and chimneys (raised openings in the canopy). The lophophores pump seawater into the colony and capture food particles from the seawater. The chimneys and canopy edge let the water back out of the colony. New chimneys form at the canopy edge as the colony grows. I tested whether there was a correlation between chimney formation and excurrent flow speed at the canopy edge by measuring excurrent flow speeds prior to chimney formation. Excurrent flow speeds were higher in regions that produced chimneys than in regions that did not form chimneys. Observations of changes in chimney shape after anesthetization with MgCl2 suggest that both growth and behavior determine chimney shape. Together, the results suggest that there is a strong correlation between growth and flow in this external fluid-transport system, with new chimneys forming at sites of high flow.
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Affiliation(s)
- Michelangelo von Dassow
- Department of Integrative Biology, University of California, Berkeley, 3060 VLSB #3140, CA 94720-3140, USA.
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Aquaculture of “Non-Food Organisms” for Natural Substance Production. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2005. [DOI: 10.1007/b135821] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register]
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von Dassow M. Effects of ambient flow and injury on the morphology of a fluid transport system in a bryozoan. THE BIOLOGICAL BULLETIN 2005; 208:47-59. [PMID: 15713812 DOI: 10.2307/3593100] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Many organisms use fluid transport systems that are open to the external environment for suspension feeding or gas exchange. How do factors related to the environment, such as injuries and ambient currents, affect remodeling of these systems? In the bryozoan Membranipora membranacea, the lophophores (crowns of ciliated tentacles) form a canopy over the colony. The lophophores pump seawater from above the colony through themselves to capture food particles. The seawater then flows under the canopy to exit the colony at chimneys (openings in the canopy) or at the canopy edge. To test whether either ambient flow speed or injury affects remodeling of this system, I measured changes in chimney size and spacing in colonies grown in flow tanks at different ambient flow speeds, and in colonies in which I killed patches of zooids. There was no effect of either ambient flow speed or injury size on chimney remodeling. Injury did not induce chimney formation. In addition, chimneys formed at the canopy edge, indicating that high pressure under the canopy did not induce chimney formation. These results suggest that ambient flow, injury, and the pressure under the canopy may have little effect on the remodeling of this fluid transport system.
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Pratt MC. Effect of zooid spacing on bryozoan feeding success: is competition or facilitation more important? THE BIOLOGICAL BULLETIN 2004; 207:17-27. [PMID: 15315940 DOI: 10.2307/1543625] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Most Recent bryozoan species are encrusting sheets, and many of these colonies have densely packed feeding zooids. In this study, I tested whether tight packing of feeding zooids affects food capture. Colonies of a bryozoan with an encrusting sheet form (Membranipora membranacea) were dissected to produce individuals whose feeding zooids were (1) closely packed, (2) more widely spaced, or (3) isolated. For each type, rates of particle ingestion were measured in still water and in a freestream velocity of 2.7 cm s(-1). Ingestion rate increased when zooids were closest together, probably because of reduced refiltration and increased feeding current strength farther from the lophophores. The mean incurrent velocity within 0.02 cm above the center of the lophophore was 0.28 cm s(-1) regardless of zooid spacing; however, when the incurrent velocity was measured more than 0.1 cm from the lophophores, zooids that were close together or spaced one zooid's width apart had significantly faster incurrent velocities than single zooids. Flow visualization suggests that isolated zooids and those spaced far apart refilter more water than zooids that are close together. These results along with the observed trend of increased zooid integration over evolutionary time suggest that the benefits of increasing coordination outweigh the consequences of intrazooid competition.
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Affiliation(s)
- Marney C Pratt
- Department of Biology, Duke University, Durham, North Carolina 27708-0338, USA.
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Marchinko KB. Dramatic phenotypic plasticity in barnacle legs (Balanus glandula Darwin): magnitude, age dependence, and speed of response. Evolution 2003; 57:1281-90. [PMID: 12894936 DOI: 10.1111/j.0014-3820.2003.tb00336.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The precise dependence of barnacle leg form on flow suggests the wave-swept environment imposes strong selection on suspension feeding limbs. I conducted three experiments to determine the mechanism, age dependence, and response time of cirrus variation in the acorn barnacle Balanus glandula. (1) To test whether cirrus variation arises via genetic or environmental mechanisms, I transplanted juvenile barnacles from one wave-exposed and one protected population into high and low flow conditions. Both populations exhibited similar abilities to modify cirri in response to experimental velocities: transplanted barnacles grew legs up to 84% longer in low flow. A small (up to 24%), but significant difference between source populations suggested slight genetic divergence in leg form. (2) Because flow is heterogeneous over space and time, I tested whether cirrus plasticity was limited to juveniles by transplanting both juveniles and adults from exposed and protected shores into quiet water. Remarkably, both juveniles and adults from the wave-exposed population produced legs over 100% longer than the original population, whereas protected barnacles remained unchanged. (3) A third transplant of adults into quiet water demonstrated that wave-exposed B. glandula modified cirrus form very quickly-within 18 days, or one to two molts. Results from these experiments suggest that variation in cirrus form is largely environmentally induced, but genetic differences may account for some variation observed among field populations; spatial and temporal flow heterogeneity appear to have selected for extreme flexibility of feeding form throughout a barnacle's life; and flow heterogeneity in the wave-swept environment appears to have selected for rapid ecophenotypic responses in the form of feeding structures.
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Affiliation(s)
- Kerry B Marchinko
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada.
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Marchinko KB, Palmer AR. Feeding in flow extremes: dependence of cirrus form on wave-exposure in four barnacle species. ZOOLOGY 2003; 106:127-41. [PMID: 16351898 DOI: 10.1078/0944-2006-00107] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2002] [Accepted: 03/12/2003] [Indexed: 11/18/2022]
Abstract
Wave-exposure influences the form of many organisms. Curiously, the impact of flow extremes on feeding structures has received little attention. Barnacles extend feather-like legs to feed, and prior work revealed a highly precise association between leg length and water velocity in one species. To assess the generality of this flow-dependence, we quantified variation in four leg traits (ramus length, ramus diameter, seta length, and intersetal spacing) in four intertidal barnacles (Balanus glandula, Chthamalus dalli, Semibalanus cariosus, Pollicipes polymerus) over a wave-exposure gradient in the North-Eastern Pacific. All species exhibited a negative allometric relation between leg length and body mass. Proportionally longer feeding legs may permit smaller barnacles to avoid lower flow and particle flux associated with boundary layers. Although coefficients of allometry did not vary with wave-exposure, form differences among wave-exposures were substantial. Depending on the species, acorn barnacles of the same size from protected shores had feeding legs that were 37-80% longer and 18-25% thinner, and setae that were 36-50% longer and up to 25% more closely spaced, than those from exposed shores. Differences were less pronounced for the gooseneck barnacle, P. polymerus. Moreover, in situ water velocity explained an impressive percentage of overall leg-length variation: 92% in B. glandula, 67% in C. dalli, 91% in S. cariosus, and 92% in P. polymerus. Clearly, both size and shape of barnacle feeding legs respond to local flow conditions. This response appears widespread--across two orders of thoracican barnacles, Pedunculata and Sessilia, and two superfamilies of acorn barnacles (Balanoidea and Chthamaloidea)--and likely adaptive. Longer rami and setae would yield a larger feeding area in low flow, whereas shorter, stouter rami with shorter setae would be less vulnerable to damage in high flow. Finally, the proportionally most variable species was abundant in the widest range of habitats, suggesting that increased plasticity may permit a wider niche breadth.
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Affiliation(s)
- Kerry B Marchinko
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada.
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Marchinko KB. DRAMATIC PHENOTYPIC PLASTICITY IN BARNACLE LEGS (BALANUS GLANDULA DARWIN): MAGNITUDE, AGE DEPENDENCE, AND SPEED OF RESPONSE. Evolution 2003. [DOI: 10.1554/02-477] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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