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Understanding the legacy of stress and whether organisms can adapt or acclimate is an incredibly important question in our rapidly changing world. Organisms can adapt through genetic changes that are passed slowly from generation to generation and/or they can acclimate to a stress within a generation using plasticity (within-generational plasticity, WGP). Intermediate between the two responses is transgenerational plasticity (TGP), which occurs when a change in offspring phenotype or reaction norm is cued by an environmental signal in the parent (or previous generations) without involving a genetic change. Genetic adaptation, WGP, and TGP can all act and interact to create phenotypes in response to a given environmental regime. However, while comparisons among disparate studies and modeling approaches provide us with some predictions as to what forms of plasticity should be adaptive and the conditions under which these occur, there are few empirical data testing these predictions. My dissertation sought to empirically test the relative importance of TGP and other forms of plasticity among populations and species that vary in key traits and environmental characteristics. Marine invertebrates offer unique opportunities for progress because of their diversity of life history strategies, yet they are currently underrepresented in this growing body of literature. Overall, my approach was to run fully factorial experiments manipulating prior exposure either within a generation and/or across generations and measuring the relevant phenotypic responses. The first two chapters of my dissertation focused on linking predictive theory with empirical examples by examining how environmental variance and population history affect the use of plasticity across populations within a generation (Chapter 1) and across generations (Chapter 2). The third chapter took a more applied approach and attempted to understand the stress legacy effects within and across generations in order to opti

Transgenerational plasticity (TGP)-when a parent or previous generation's environmental experience affects offspring phenotype without involving a genetic change-can be an important mechanism allowing for rapid adaptation. However, despite increasing numbers of empirical examples of TGP, there appears to be considerable variation in its strength and direction, yet limited understanding of what causes this variation. We compared patterns of TGP in response to stress across two populations with high versus low historical levels of stress exposure. Specifically, we expected that exposure to acute stress in the population experiencing historically high levels of stress would result in adaptive TGP or alternatively fixed tolerance (no parental effect), whereas the population with low levels of historical exposure would result in negative parental carryover effects. Using a common sessile marine invertebrate, Bugula neritina, and a split brood design, we exposed parents from both populations to copper or control treatments in the laboratory and then had them brood copper-naïve larvae. We then exposed half of each larval brood to copper and half to control conditions before allowing them to grow to maturity in the field. Maternal copper exposure had a strong negative carryover effect on adult offspring growth and survival in the population without historical exposure, especially when larvae themselves were exposed to copper. We found little to no maternal or offspring treatment effect on adult growth and survival in the population with a history of copper exposure. However, parents from this population produced larger larvae on average and were able to increase the size of their larvae in response to copper exposure, providing a potential mechanism for maintaining fitness and suggesting TGP through maternal provisioning. These results indicate that the ability to adjust offspring phenotype via TGP may be a locally adapted trait and potentially influenced by past patterns o

Bugula neritina, met de Nederlandse naam paars vogelkopmosdiertje, is een mosdiertjessoort uit de familie van de Bugulidae. Deze soort vormt kolonies van paarse of bruine bosjes, meestal niet hoger dan acht centimeter. De takjes bestaan uit twee rijen met individuele mosdiertjes, de zoïden. Deze zijn 0,2-0,3 mm breed en 0,6-1,1 mm lang. Iedere zoïde heeft een beschermend omhulsel, waarin zich een complex diertje bevindt met een tentakelkrans met rond de mond 23 of 24 tentakeltjes. Deze tentakelkrans kan naar buiten worden gebracht en weer worden ingetrokken. De tentakelkrans brengt het voedsel naar de mond

The bryozoan Bugula neritina is a cosmopolitan marine fouling species that causes major fouling problems in sub-tropical waters. Settlement of B. neritina larvae can be triggered without an obvious external cue. Here, the negative regulatory role of nitric oxide (NO) during larval settlement of B. neritina was demonstrated to be mediated by cyclic guanosine monophosphate (cGMP). Although the regulatory role of the NO-p38 MAPK signaling axis in larval settlement was not evident, inhibition of nitric oxide synthase (NOS) led to the deactivation of p38 MAPK. Exclusive localization of NO and NO signaling components in sensory-related organs of the larvae is consistent with its signal transduction function in metamorphosis. Overall, this study provides new insights into the regulatory roles of the NO-p38MAPK/cGMP pathway in B. neritina settlement.

The bryozoan Bugula neritina is a cosmopolitan marine fouling species that causes major fouling problems in sub-tropical waters. Settlement of B. neritina larvae can be triggered without an obvious external cue. Here, the negative regulatory role of nitric oxide (NO) during larval settlement of B. neritina was demonstrated to be mediated by cyclic guanosine monophosphate (cGMP). Although the regulatory role of the NO-p38 MAPK signaling axis in larval settlement was not evident, inhibition of nitric oxide synthase (NOS) led to the deactivation of p38 MAPK. Exclusive localization of NO and NO signaling components in sensory-related organs of the larvae is consistent with its signal transduction function in metamorphosis. Overall, this study provides new insights into the regulatory roles of the NO-p38MAPK/cGMP pathway in B. neritina settlement.

The bryozoan Bugula neritina is a cosmopolitan marine fouling species that causes major fouling problems in sub-tropical waters. Settlement of B. neritina larvae can be triggered without an obvious external cue. Here, the negative regulatory role of nitric oxide (NO) during larval settlement of B. neritina was demonstrated to be mediated by cyclic guanosine monophosphate (cGMP). Although the regulatory role of the NO-p38 MAPK signaling axis in larval settlement was not evident, inhibition of nitric oxide synthase (NOS) led to the deactivation of p38 MAPK. Exclusive localization of NO and NO signaling components in sensory-related organs of the larvae is consistent with its signal transduction function in metamorphosis. Overall, this study provides new insights into the regulatory roles of the NO-p38MAPK/cGMP pathway in B. neritina settlement.

In this study, we analyzed the metamorphosis of the marine bryozoan Bugula neritina. We observed the morphogenesis of the ancestrula. We defined three distinct pre-ancestrula stages based on the anatomy of the developing polypide and the overall morphology of pre-ancestrula. We then used an annotation based enrichment analysis tool to analyze the B. neritina transcriptome and identified over-representation of genes related to Wnt signaling pathways, suggesting its involvement in metamorphosis. Finally, we studied the temporal-spatial gene expression studies of several Wnt pathway genes. We found that one of the Wnt ligand, BnWnt10, was expressed spatially opposite to the Wnt antagonist BnsFRP within the blastemas, which is the presumptive polypide. Down-stream components of the canonical Wnt signaling pathway were exclusively expressed in the blastemas. Bn?catenin and BnFz5/8 were exclusively expressed in the blastemas throughout the metamorphosis. Based on the genes expression patterns, we propose that BnWnt10 and BnsFRP may relate to the patterning of the polypide, in which the two genes served as positional signals and contributed to the polarization of the blastemas. Another Wnt ligand, BnWnt6, was expressed in the apical part of the pre-ancestrula epidermis. Overall, our findings suggest that the Wnt signaling pathway may be important to the pattern formation of polypide and the development of epidermis. © 2012 Wong et al.

Butenolide [5-octylfuran-2(5H)-one] is a very promising antifouling compound. Here, the effects of butenolide on larval behavior and histology are compared in two major fouling organisms, viz. cypris larvae of Balanus amphitrite and swimming larvae of Bugula neritina. Butenolide diminished the positive phototactic behavior of B. amphitrite (EC(50) = 0.82 mu g ml(-1)) and B. neritina (EC(50) = 3 mu g ml(-1)). Its effect on the attachment of cyprids of B. amphitrite was influenced by temperature, and butenolide increased attachment of larvae of B. neritina to the bottom of the experimental wells. At concentrations of 4 mu g ml(-1) and 10 mu g ml(-1), butenolide decreased attachment of B. amphitrite and B. neritina, respectively, but the effects were reversible within a certain treatment time. Morphologically, butenolide inhibited the swelling of secretory granules and altered the rough endoplasmic reticulum (RER) in the cement gland of B. amphitrite cyprids. In B. neritina swimming larvae, butenolide reduced the number of secretory granules in the pyriform-glandular complex.

The marine invertebrate Bugula neritina has a biphasic life cycle that consists of a swimming larval stage and a sessile juvenile and adult stage. The attachment of larvae to the substratum and their subsequent metamorphosis have crucial ecological consequences. Despite many studies on this species, little is known about the molecular mechanism of these processes. Here, we report a comparative study of swimming larvae and metamorphosing individuals at 4 and 24 h postattachment using label-free quantitative proteomics. We identified more than 1100 proteins at each stage, 61 of which were differentially expressed. Specifically, proteins involved in energy metabolism and structural molecules were generally down-regulated, whereas proteins involved in transcription and translation, the extracellular matrix, and calcification were strongly up-regulated during metamorphosis. Many tightly regulated novel proteins were also identified. Subsequent analysis of the temporal and spatial expressions of some of the proteins and an assay of their functions indicated that they may have key roles in metamorphosis of B. neritina. These findings not only provide molecular evidence with which to elucidate the substantial changes in morphology and physiology that occur during larval attachment and metamorphosis but also identify potential targets for antifouling treatment. © 2011 American Chemical Society.

Butenolide [5-octylfuran-2(5H)-one] is a very promising antifouling compound. Here, the effects of butenolide on larval behavior and histology are compared in two major fouling organisms, viz. cypris larvae of Balanus amphitrite and swimming larvae of Bugula neritina. Butenolide diminished the positive phototactic behavior of B. amphitrite (EC(50) = 0.82 mu g ml(-1)) and B. neritina (EC(50) = 3 mu g ml(-1)). Its effect on the attachment of cyprids of B. amphitrite was influenced by temperature, and butenolide increased attachment of larvae of B. neritina to the bottom of the experimental wells. At concentrations of 4 mu g ml(-1) and 10 mu g ml(-1), butenolide decreased attachment of B. amphitrite and B. neritina, respectively, but the effects were reversible within a certain treatment time. Morphologically, butenolide inhibited the swelling of secretory granules and altered the rough endoplasmic reticulum (RER) in the cement gland of B. amphitrite cyprids. In B. neritina swimming larvae, butenolide reduced the number of secretory granules in the pyriform-glandular complex.

The marine invertebrate Bugula neritina has a biphasic life cycle that consists of a swimming larval stage and a sessile juvenile and adult stage. The attachment of larvae to the substratum and their subsequent metamorphosis have crucial ecological consequences. Despite many studies on this species, little is known about the molecular mechanism of these processes. Here, we report a comparative study of swimming larvae and metamorphosing individuals at 4 and 24 h postattachment using label-free quantitative proteomics. We identified more than 1100 proteins at each stage, 61 of which were differentially expressed. Specifically, proteins involved in energy metabolism and structural molecules were generally down-regulated, whereas proteins involved in transcription and translation, the extracellular matrix, and calcification were strongly up-regulated during metamorphosis. Many tightly regulated novel proteins were also identified. Subsequent analysis of the temporal and spatial expressions of some of the proteins and an assay of their functions indicated that they may have key roles in metamorphosis of B. neritina. These findings not only provide molecular evidence with which to elucidate the substantial changes in morphology and physiology that occur during larval attachment and metamorphosis but also identify potential targets for antifouling treatment. © 2011 American Chemical Society.

The marine invertebrate Bugula neritina has a biphasic life cycle that consists of a swimming larval stage and a sessile juvenile and adult stage. The attachment of larvae to the substratum and their subsequent metamorphosis have crucial ecological consequences. Despite many studies on this species, little is known about the molecular mechanism of these processes. Here, we report a comparative study of swimming larvae and metamorphosing individuals at 4 and 24 h postattachment using label-free quantitative proteomics. We identified more than 1100 proteins at each stage, 61 of which were differentially expressed. Specifically, proteins involved in energy metabolism and structural molecules were generally down-regulated, whereas proteins involved in transcription and translation, the extracellular matrix, and calcification were strongly up-regulated during metamorphosis. Many tightly regulated novel proteins were also identified. Subsequent analysis of the temporal and spatial expressions of some of the proteins and an assay of their functions indicated that they may have key roles in metamorphosis of B. neritina. These findings not only provide molecular evidence with which to elucidate the substantial changes in morphology and physiology that occur during larval attachment and metamorphosis but also identify potential targets for antifouling treatment. © 2011 American Chemical Society.

Butenolide [5-octylfuran-2(5H)-one] is a very promising antifouling compound. Here, the effects of butenolide on larval behavior and histology are compared in two major fouling organisms, viz. cypris larvae of Balanus amphitrite and swimming larvae of Bugula neritina. Butenolide diminished the positive phototactic behavior of B. amphitrite (EC(50) = 0.82 mu g ml(-1)) and B. neritina (EC(50) = 3 mu g ml(-1)). Its effect on the attachment of cyprids of B. amphitrite was influenced by temperature, and butenolide increased attachment of larvae of B. neritina to the bottom of the experimental wells. At concentrations of 4 mu g ml(-1) and 10 mu g ml(-1), butenolide decreased attachment of B. amphitrite and B. neritina, respectively, but the effects were reversible within a certain treatment time. Morphologically, butenolide inhibited the swelling of secretory granules and altered the rough endoplasmic reticulum (RER) in the cement gland of B. amphitrite cyprids. In B. neritina swimming larvae, butenolide reduced the number of secretory granules in the pyriform-glandular complex.

Larval attachment and metamorphosis, commonly referred to as larval settlement, of marine sessile invertebrates can be triggered or blocked by chemical cues and affected by changes in overall protein expression pattern and phosphorylation dynamics. This study focuses on the effects of butenolide, an effective larval settlement inhibitor, on larval settlement at the proteome level in the bryozoan Bugula neritina. Liquid-phase IEF sample prefractionation combined with 2-DE and MALDI-TOF MS was used to identify the differentially expressed proteins. Substantial changes occurred both in protein abundance and in phosphorylation status during larval settlement and when settling larvae were challenged with butenolide. The proteins that responded to treatment were identified as structural proteins, molecular chaperones, mitochondrial peptidases and calcium-binding proteins. Compared with our earlier results, both genistein and butenolide inhibited larval settlement of B. neritina primarily by changes in protein abundance and the phosphorylation status of proteins but have different protein targets in the same species. Clearly, to design potent antifouling compounds and to understand the mode of action of compounds, more studies on the effects of different compounds on proteome and phosphoproteome of different larval species are required. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

Background: Metamorphosis in the bryozoan Bugula neritina (Linne) includes an initial phase of rapid morphological rearrangement followed by a gradual phase of morphogenesis. We hypothesized that the first phase may be independent of de novo synthesis of proteins and, instead, involves post-translational modifications of existing proteins, providing a simple mechanism to quickly initiate metamorphosis. To test our hypothesis, we challenged B. neritina larvae with transcription and translation inhibitors. Furthermore, we employed 2D gel electrophoresis to characterize changes in the phosphoproteome and proteome during early metamorphosis. Differentially expressed proteins were identified by liquid chromatography tandem mass spectrometry and their gene expression patterns were profiled using semi-quantitative real time PCR.Results: When larvae were incubated with transcription and translation inhibitors, metamorphosis initiated through the first phase but did not complete. We found a significant down-regulation of 60 protein spots and the percentage of phosphoprotein spots decreased from 15% in the larval stage to12% during early metamorphosis. Two proteins--the mitochondrial processing peptidase beta subunit and severin--were abundantly expressed and phosphorylated in the larval stage, but down-regulated during metamorphosis. MPPbeta and severin were also down-regulated on the gene expression level.Conclusions: The initial morphogenetic changes that led to attachment of B. neritina did not depend on de novo protein synthesis, but the subsequent gradual morphogenesis did. This is the first time that the mitochondrial processing peptidase beta subunit or severin have been shown to be down-regulated on both gene and protein expression levels during the metamorphosis of B. neritina. Future studies employing immunohistochemistry to reveal the expression locality of these two proteins during metamorphosis should provide further evidence of the involvement of these two prot

Larval attachment and metamorphosis, commonly referred to as larval settlement, of marine sessile invertebrates can be triggered or blocked by chemical cues and affected by changes in overall protein expression pattern and phosphorylation dynamics. This study focuses on the effects of butenolide, an effective larval settlement inhibitor, on larval settlement at the proteome level in the bryozoan Bugula neritina. Liquid-phase IEF sample prefractionation combined with 2-DE and MALDI-TOF MS was used to identify the differentially expressed proteins. Substantial changes occurred both in protein abundance and in phosphorylation status during larval settlement and when settling larvae were challenged with butenolide. The proteins that responded to treatment were identified as structural proteins, molecular chaperones, mitochondrial peptidases and calcium-binding proteins. Compared with our earlier results, both genistein and butenolide inhibited larval settlement of B. neritina primarily by changes in protein abundance and the phosphorylation status of proteins but have different protein targets in the same species. Clearly, to design potent antifouling compounds and to understand the mode of action of compounds, more studies on the effects of different compounds on proteome and phosphoproteome of different larval species are required. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

Non-model organisms represent the majority of life forms in our planet. However, the lack of genetic information hinders us to understand the unique biological phenomena in non-model organisms at the molecular level. In this study, we applied a tandem transcriptome and proteome profiling on a non-model marine fouling organism, Bugula neritina. Using a 454 pyrosequencing platform with the updated titanium reagents, we generated a total of 48M bp transcriptome data consisting of 131 450 high-quality reads. Of these, 122 650 reads (93\%) were assembled to produce 6392 contigs with an average length of 538 bases and the remaining 8800 reads were singletons. Of the total 15 192 unigenes, 13 863 ORFs were predicated, of which 6917 were functionally annotated based on gene ontology and eukaryotic orthologous groups. Subsequent proteome analysis identified and quantified 882 proteins from B. neritina. These results would provide fundamental and important information for the subsequent studies of molecular mechanism in larval biology, development, antifouling research. Furthermore, we demonstrated, for the first time, the combined use of two high-throughput technologies as a powerful approach for accelerating the studies of non-model but otherwise important species.

Non-model organisms represent the majority of life forms in our planet. However, the lack of genetic information hinders us to understand the unique biological phenomena in non-model organisms at the molecular level. In this study, we applied a tandem transcriptome and proteome profiling on a non-model marine fouling organism, Bugula neritina. Using a 454 pyrosequencing platform with the updated titanium reagents, we generated a total of 48M bp transcriptome data consisting of 131 450 high-quality reads. Of these, 122 650 reads (93\%) were assembled to produce 6392 contigs with an average length of 538 bases and the remaining 8800 reads were singletons. Of the total 15 192 unigenes, 13 863 ORFs were predicated, of which 6917 were functionally annotated based on gene ontology and eukaryotic orthologous groups. Subsequent proteome analysis identified and quantified 882 proteins from B. neritina. These results would provide fundamental and important information for the subsequent studies of molecular mechanism in larval biology, development, antifouling research. Furthermore, we demonstrated, for the first time, the combined use of two high-throughput technologies as a powerful approach for accelerating the studies of non-model but otherwise important species.

Larval attachment and metamorphosis, commonly referred to as larval settlement, of marine sessile invertebrates can be triggered or blocked by chemical cues and affected by changes in overall protein expression pattern and phosphorylation dynamics. This study focuses on the effects of butenolide, an effective larval settlement inhibitor, on larval settlement at the proteome level in the bryozoan Bugula neritina. Liquid-phase IEF sample prefractionation combined with 2-DE and MALDI-TOF MS was used to identify the differentially expressed proteins. Substantial changes occurred both in protein abundance and in phosphorylation status during larval settlement and when settling larvae were challenged with butenolide. The proteins that responded to treatment were identified as structural proteins, molecular chaperones, mitochondrial peptidases and calcium-binding proteins. Compared with our earlier results, both genistein and butenolide inhibited larval settlement of B. neritina primarily by changes in protein abundance and the phosphorylation status of proteins but have different protein targets in the same species. Clearly, to design potent antifouling compounds and to understand the mode of action of compounds, more studies on the effects of different compounds on proteome and phosphoproteome of different larval species are required. © 2010 Wiley-VCH Verlag GmbH & Co. KGaA.

Mizolastine, an antihistamine pharmaceutical, was found to significantly inhibit larval settlement of the barnacle Amphibalanus (Balanus) amphitrite, the bryozoan Bugula neritina, and the polychaete Hydroides elegans with EC50 values of 4.2, 11.2, and 4.1 mu g ml(-1), respectively. No toxicity against the larvae of these three species was observed at the concentration range tested during incubations with mizolastine. To determine whether the anti-settlement activity of mizolastine is reversible, recovery bioassays using these three species were conducted. More than 70\% of the larvae that had been exposed for 4 h to mizolastine at concentrations four-fold greater than their respective EC50 values completed normal metamorphosis. The results of the recovery bioassay provide evidence that the anti-settlement effect of mizolastine is reversible in addition to being nontoxic. The anti-settlement activities of several intermediates of the synthesis process of mizolastine were also examined. One of the intermediates, 2-chloro-1-(4-fluorobenzyl)- 1H-benzo[d] imidazole, inhibited larval settlement and metamorphosis with low toxicity. These results may improve the understanding of the key functional group responsible for the anti-settlement activity of mizolastine.

Mizolastine, an antihistamine pharmaceutical, was found to significantly inhibit larval settlement of the barnacle Amphibalanus (Balanus) amphitrite, the bryozoan Bugula neritina, and the polychaete Hydroides elegans with EC50 values of 4.2, 11.2, and 4.1 mu g ml(-1), respectively. No toxicity against the larvae of these three species was observed at the concentration range tested during incubations with mizolastine. To determine whether the anti-settlement activity of mizolastine is reversible, recovery bioassays using these three species were conducted. More than 70\% of the larvae that had been exposed for 4 h to mizolastine at concentrations four-fold greater than their respective EC50 values completed normal metamorphosis. The results of the recovery bioassay provide evidence that the anti-settlement effect of mizolastine is reversible in addition to being nontoxic. The anti-settlement activities of several intermediates of the synthesis process of mizolastine were also examined. One of the intermediates, 2-chloro-1-(4-fluorobenzyl)- 1H-benzo[d] imidazole, inhibited larval settlement and metamorphosis with low toxicity. These results may improve the understanding of the key functional group responsible for the anti-settlement activity of mizolastine.

Mizolastine, an antihistamine pharmaceutical, was found to significantly inhibit larval settlement of the barnacle Amphibalanus (Balanus) amphitrite, the bryozoan Bugula neritina, and the polychaete Hydroides elegans with EC50 values of 4.2, 11.2, and 4.1 mu g ml(-1), respectively. No toxicity against the larvae of these three species was observed at the concentration range tested during incubations with mizolastine. To determine whether the anti-settlement activity of mizolastine is reversible, recovery bioassays using these three species were conducted. More than 70\% of the larvae that had been exposed for 4 h to mizolastine at concentrations four-fold greater than their respective EC50 values completed normal metamorphosis. The results of the recovery bioassay provide evidence that the anti-settlement effect of mizolastine is reversible in addition to being nontoxic. The anti-settlement activities of several intermediates of the synthesis process of mizolastine were also examined. One of the intermediates, 2-chloro-1-(4-fluorobenzyl)- 1H-benzo[d] imidazole, inhibited larval settlement and metamorphosis with low toxicity. These results may improve the understanding of the key functional group responsible for the anti-settlement activity of mizolastine.

In recent years, bryozoans have attracted the attention of applied scientists and marine biotechnologists since bryozoa serve as a source of bioactive substances for biotechnological appliances, e.g. for cosmetic or pharmaceutical industries and for the antifouling industry. The larval production of bryozoa is of interest for both, mariculture and for developmental investigations, e.g. for settlement assays in fouling studies. We optimised maintenance conditions of the bryozoan Bugula neritina accordingly, that larvae could be harvested sustainably within a period of 4 weeks from adult brood stocks which had been kept in bulk in flow-through containers in the laboratory. Preliminary experiments showed that moderate water flow and permanent moderate light conditions without aeration were key-parameters for a maintenance regime that maximizes and prolongs larval harvest for several weeks. (c) 2007 Elsevier B.V All rights reserved.

In recent years, bryozoans have attracted the attention of applied scientists and marine biotechnologists since bryozoa serve as a source of bioactive substances for biotechnological appliances, e.g. for cosmetic or pharmaceutical industries and for the antifouling industry. The larval production of bryozoa is of interest for both, mariculture and for developmental investigations, e.g. for settlement assays in fouling studies. We optimised maintenance conditions of the bryozoan Bugula neritina accordingly, that larvae could be harvested sustainably within a period of 4 weeks from adult brood stocks which had been kept in bulk in flow-through containers in the laboratory. Preliminary experiments showed that moderate water flow and permanent moderate light conditions without aeration were key-parameters for a maintenance regime that maximizes and prolongs larval harvest for several weeks. (c) 2007 Elsevier B.V All rights reserved.

In recent years, bryozoans have attracted the attention of applied scientists and marine biotechnologists since bryozoa serve as a source of bioactive substances for biotechnological appliances, e.g. for cosmetic or pharmaceutical industries and for the antifouling industry. The larval production of bryozoa is of interest for both, mariculture and for developmental investigations, e.g. for settlement assays in fouling studies. We optimised maintenance conditions of the bryozoan Bugula neritina accordingly, that larvae could be harvested sustainably within a period of 4 weeks from adult brood stocks which had been kept in bulk in flow-through containers in the laboratory. Preliminary experiments showed that moderate water flow and permanent moderate light conditions without aeration were key-parameters for a maintenance regime that maximizes and prolongs larval harvest for several weeks. (c) 2007 Elsevier B.V All rights reserved.

In this study, we investigated the effect of mono-species and multi-species biofilms on larval attachment of the bryozoan Bugula neritina. The effect of biofilms was examined through a double-dish choice bioassay in which larvae were given the choice of attaching either to a clean surface of a container or to surfaces covered with biofilms. Larvae attached in response to mono-species biofilms of 5 out of 7 bacterial isolates from a subtidal region, but they avoided surfaces covered by biofilms of 7 out of 8 isolates obtained from an intertidal region. In the follow-up choice experiments with multi-species biofilms developed for 2days, 7days, 14days, 28days and 30days, larvae preferentially attached to filmed surfaces over the unfilmed surfaces. When biofilms from 2 different tidal regions (intertidal and subtidal) were offered as choices in the double-dish bioassay, larvae in all cases attached on the subtidal biofilms. Two-day-old subtidal biofilms with low densities of bacteria induced significantly higher (p < 0.05) attachment than did 30- day-old intertidal biofilms, which had high bacterial density. Terminal Restriction Fragment Polymorphism (T-RFLP) analysis revealed that the bacterial communities were substantially different in the subtidal and intertidal regions during all periods of the experiment. Attachment of B. neritina on subtidal biofilms did not depend on the bacterial density but rather was negatively correlated with diatom density, thickness of the exopolysaccharide layer and biofilm age. Our results suggest that the larvae of B. neritina can discriminate between biofilmed and clean surfaces and between biofilms developed under different tidal zones. (c) 2006 Elsevier B.V All rights reserved.

In this study, we investigated the effect of mono-species and multi-species biofilms on larval attachment of the bryozoan Bugula neritina. The effect of biofilms was examined through a double-dish choice bioassay in which larvae were given the choice of attaching either to a clean surface of a container or to surfaces covered with biofilms. Larvae attached in response to mono-species biofilms of 5 out of 7 bacterial isolates from a subtidal region, but they avoided surfaces covered by biofilms of 7 out of 8 isolates obtained from an intertidal region. In the follow-up choice experiments with multi-species biofilms developed for 2days, 7days, 14days, 28days and 30days, larvae preferentially attached to filmed surfaces over the unfilmed surfaces. When biofilms from 2 different tidal regions (intertidal and subtidal) were offered as choices in the double-dish bioassay, larvae in all cases attached on the subtidal biofilms. Two-day-old subtidal biofilms with low densities of bacteria induced significantly higher (p < 0.05) attachment than did 30- day-old intertidal biofilms, which had high bacterial density. Terminal Restriction Fragment Polymorphism (T-RFLP) analysis revealed that the bacterial communities were substantially different in the subtidal and intertidal regions during all periods of the experiment. Attachment of B. neritina on subtidal biofilms did not depend on the bacterial density but rather was negatively correlated with diatom density, thickness of the exopolysaccharide layer and biofilm age. Our results suggest that the larvae of B. neritina can discriminate between biofilmed and clean surfaces and between biofilms developed under different tidal zones. (c) 2006 Elsevier B.V All rights reserved.

In this study, we investigated the effect of mono-species and multi-species biofilms on larval attachment of the bryozoan Bugula neritina. The effect of biofilms was examined through a double-dish choice bioassay in which larvae were given the choice of attaching either to a clean surface of a container or to surfaces covered with biofilms. Larvae attached in response to mono-species biofilms of 5 out of 7 bacterial isolates from a subtidal region, but they avoided surfaces covered by biofilms of 7 out of 8 isolates obtained from an intertidal region. In the follow-up choice experiments with multi-species biofilms developed for 2days, 7days, 14days, 28days and 30days, larvae preferentially attached to filmed surfaces over the unfilmed surfaces. When biofilms from 2 different tidal regions (intertidal and subtidal) were offered as choices in the double-dish bioassay, larvae in all cases attached on the subtidal biofilms. Two-day-old subtidal biofilms with low densities of bacteria induced significantly higher (p < 0.05) attachment than did 30- day-old intertidal biofilms, which had high bacterial density. Terminal Restriction Fragment Polymorphism (T-RFLP) analysis revealed that the bacterial communities were substantially different in the subtidal and intertidal regions during all periods of the experiment. Attachment of B. neritina on subtidal biofilms did not depend on the bacterial density but rather was negatively correlated with diatom density, thickness of the exopolysaccharide layer and biofilm age. Our results suggest that the larvae of B. neritina can discriminate between biofilmed and clean surfaces and between biofilms developed under different tidal zones. (c) 2006 Elsevier B.V All rights reserved.

Biofilms of marine bacteria and diatoms and their combinations were examined in laboratory choice assays to determine their effects on the attachment and successful metamorphosis of the larvae of the bryozoan Bugula neritina (Linneus). The larval settlement in response to unfilmed surfaces, a natural biofilm (NBF) and adsorbed cells of three strains of bacteria, five strains of pennate diatoms and combinations of the two at different densities. Bacterial and diatom strains showed different effects on the larval settlement of B. neritina. Bacterial monospecific strains of an unidentified alpha-Proteobacterium and Vibrio sp. mediated the same percentage of settlement as a filtered seawater control. Biofilms of Pseudoalteromonas sp. caused significantly lower larval settlement. Larval settlement of B. neritina was negatively correlated with increasing densities of Pseudoalteromonas sp. The highest percentages of settlement were mediated by the biofilms of the diatom species Achnanthes sp., Amphora cofeaeformis, Amphora tenerrima, Nitzschia constricta and a 5-day-old natural biofilm, while the lowest settlement was found on a N. frustulum film. A three-way analysis of valiance demonstrated that the density of bacteria and the presence of particular species of diatoms and bacteria in combined biofilms, significantly affected the settlement of B. neritina larvae. High settlement of larvae (50-90\%) at all treatments indicated that B. neritina larvae are much more indiscriminate settlers than previously expected. Hence, using this species as a monitoring organism to trace ecologically relevant subtle changes of settlement cues in the natural environment should be carefully re-examined. (C) 2004 Elsevier B.V. All rights reserved.

Biofilms of marine bacteria and diatoms and their combinations were examined in laboratory choice assays to determine their effects on the attachment and successful metamorphosis of the larvae of the bryozoan Bugula neritina (Linneus). The larval settlement in response to unfilmed surfaces, a natural biofilm (NBF) and adsorbed cells of three strains of bacteria, five strains of pennate diatoms and combinations of the two at different densities. Bacterial and diatom strains showed different effects on the larval settlement of B. neritina. Bacterial monospecific strains of an unidentified alpha-Proteobacterium and Vibrio sp. mediated the same percentage of settlement as a filtered seawater control. Biofilms of Pseudoalteromonas sp. caused significantly lower larval settlement. Larval settlement of B. neritina was negatively correlated with increasing densities of Pseudoalteromonas sp. The highest percentages of settlement were mediated by the biofilms of the diatom species Achnanthes sp., Amphora cofeaeformis, Amphora tenerrima, Nitzschia constricta and a 5-day-old natural biofilm, while the lowest settlement was found on a N. frustulum film. A three-way analysis of valiance demonstrated that the density of bacteria and the presence of particular species of diatoms and bacteria in combined biofilms, significantly affected the settlement of B. neritina larvae. High settlement of larvae (50-90\%) at all treatments indicated that B. neritina larvae are much more indiscriminate settlers than previously expected. Hence, using this species as a monitoring organism to trace ecologically relevant subtle changes of settlement cues in the natural environment should be carefully re-examined. (C) 2004 Elsevier B.V. All rights reserved.

Biofilms of marine bacteria and diatoms and their combinations were examined in laboratory choice assays to determine their effects on the attachment and successful metamorphosis of the larvae of the bryozoan Bugula neritina (Linneus). The larval settlement in response to unfilmed surfaces, a natural biofilm (NBF) and adsorbed cells of three strains of bacteria, five strains of pennate diatoms and combinations of the two at different densities. Bacterial and diatom strains showed different effects on the larval settlement of B. neritina. Bacterial monospecific strains of an unidentified alpha-Proteobacterium and Vibrio sp. mediated the same percentage of settlement as a filtered seawater control. Biofilms of Pseudoalteromonas sp. caused significantly lower larval settlement. Larval settlement of B. neritina was negatively correlated with increasing densities of Pseudoalteromonas sp. The highest percentages of settlement were mediated by the biofilms of the diatom species Achnanthes sp., Amphora cofeaeformis, Amphora tenerrima, Nitzschia constricta and a 5-day-old natural biofilm, while the lowest settlement was found on a N. frustulum film. A three-way analysis of valiance demonstrated that the density of bacteria and the presence of particular species of diatoms and bacteria in combined biofilms, significantly affected the settlement of B. neritina larvae. High settlement of larvae (50-90\%) at all treatments indicated that B. neritina larvae are much more indiscriminate settlers than previously expected. Hence, using this species as a monitoring organism to trace ecologically relevant subtle changes of settlement cues in the natural environment should be carefully re-examined. (C) 2004 Elsevier B.V. All rights reserved.

In the search for new medicines, no realm of the globe holds more intrigue than that of the sea. Many of the more complex, novel and interestingc ompounds discovered in the last decade have been extracted from marine organisms—typically soft corals and sponges, marine algae, even bacteria.

In the search for new medicines, no realm of the globe holds more intrigue than that of the sea. Many of the more complex, novel and interestingc ompounds discovered in the last decade have been extracted from marine organisms—typically soft corals and sponges, marine algae, even bacteria.

The distribution and abundance of peracaridean fauna associated with the bryozoan Bugula neritina have been analysed according to their possible relationships with environmental stress on the coastline of Algeciras Bay. The spatial environmental variability along this bay has been established based on the analysis of five abiotic variables (hydrodynamism, siltation, suspended solids, and organic matter content) at six stations over a 12-month period. The temporal variability of these abiotic variables was not taken into account due to the method used in collecting the samples. The abundance and beta diversity of the peracarid fauna were also calculated monthly. Hydrodynamism was the only abiotic variable significantly correlated with beta diversity, with a linear regression model between the two variables (r = 0.81). The distributional pattern of the peracarids (based on the abundance matrix) was correlated with the environmental variables by matching samples' similarities using the Spearman rank correlation. This analysis showed that the combination of variables that best explains the patterns of distribution is hydrodynamism and siltation (rs = 0.665). Of the species considered the amphipods Ischyrocerus inexpectatus, Jassa marmorata and Podocerus variegatus were negatively correlated with hydrodynamism and positively with temperature. The caprellidea Phtisica marina was also negatively correlated with hydrodynamism. On the other hand, the amphipods Cressa mediterranea and Stenothoe dollfusi preferred environments with high hydrological forces and low sedimentation rate. Due to the particular environmental conditions where they live and their requirements, Gammaropsis maculata, Corophium acutum, J. marmorata, I. inexpectatus, and P. variegatus were categorised as good indicator species in port environments. Others such as Aora spinicornis, Microjassa cumbrensis, and C. mediterranea were categorised as species well adapted to high hydrological forces., Se han estudiado las relaciones entre la distribución y abundancia de la fauna de peracáridos asociados al briozoo Bugula neritina con el estrés medioambiental producido en la costa de la Bahía de Algeciras. La variabilidad espacial del estrés medioambiental a lo largo de la Bahía de Algeciras se ha establecido en base a cinco variables abióticas (hidrodinamismo, sedimentación, materia orgánica disuelta en el agua, sólidos en suspensión y la materia orgánica de dichos sólidos en suspensión) a lo largo de seis estaciones de muestreo durante 12 meses de estudio. La temporalidad de las variables medioambientales no se ha estudiado debido al método de muestreo utilizado para éstas. Sin embargo, se calcularon mensualmente tanto la abundancia como la diversidad beta de la fauna de peracáridos en cada una de las estaciones. El hidrodinamismo fue la única variable abiótica correlacionada significativamente con la diversidad beta, existiendo una relación lineal entre ambas variables (r = 0.81). El patrón de distribución de los peracáridos (basado en la matriz de abundancia) se relacionó con las variables abióticas usando el coeficiente de correlación de Spearman. Este análisis determinó que las variables que mejor explican los patrones de distribución de los peracáridos son el hidrodinamismo y la sedimentación (rs = 0.665). Entre las especies consideradas, los anfípodos Ischyrocerus inexpectatus, Jassa marmorata y Podocerus variegatus se correlacionaron negativamente con el hidrodinamismo y positivamente con la temperatura. El caprélido Phtisica marina también estuvo relacionado negativamente con el hidrodinamismo. Por el contrario, los anfípodos Cressa mediterranea y Stenothoe dollfusi prefirieron hábitats con un fuerte hidrodinamismo y baja sedimentación. Debido a las condiciones ambientales particulares en las que estas especies viven y en base a sus necesidades alimentarias, Gammaropsis maculata, Corophium acutum, J. marmorata, I. inexpectatus, y P. variegatus han sido c

The distribution and abundance of peracaridean fauna associated with the bryozoan Bugula neritina have been analysed according to their possible relationships with environmental stress on the coastline of Algeciras Bay. The spatial environmental variability along this bay has been established based on the analysis of five abiotic variables (hydrodynamism, siltation, suspended solids, and organic matter content) at six stations over a 12-month period. The temporal variability of these abiotic variables was not taken into account due to the method used in collecting the samples. The abundance and beta diversity of the peracarid fauna were also calculated monthly. Hydrodynamism was the only abiotic variable significantly correlated with beta diversity, with a linear regression model between the two variables (r = 0.81). The distributional pattern of the peracarids (based on the abundance matrix) was correlated with the environmental variables by matching samples' similarities using the Spearman rank correlation. This analysis showed that the combination of variables that best explains the patterns of distribution is hydrodynamism and siltation (rs = 0.665). Of the species considered the amphipods Ischyrocerus inexpectatus, Jassa marmorata and Podocerus variegatus were negatively correlated with hydrodynamism and positively with temperature. The caprellidea Phtisica marina was also negatively correlated with hydrodynamism. On the other hand, the amphipods Cressa mediterranea and Stenothoe dollfusi preferred environments with high hydrological forces and low sedimentation rate. Due to the particular environmental conditions where they live and their requirements, Gammaropsis maculata, Corophium acutum, J. marmorata, I. inexpectatus, and P. variegatus were categorised as good indicator species in port environments. Others such as Aora spinicornis, Microjassa cumbrensis, and C. mediterranea were categorised as species well adapted to high hydrological forces., Se han estudiado las relaciones entre la distribución y abundancia de la fauna de peracáridos asociados al briozoo Bugula neritina con el estrés medioambiental producido en la costa de la Bahía de Algeciras. La variabilidad espacial del estrés medioambiental a lo largo de la Bahía de Algeciras se ha establecido en base a cinco variables abióticas (hidrodinamismo, sedimentación, materia orgánica disuelta en el agua, sólidos en suspensión y la materia orgánica de dichos sólidos en suspensión) a lo largo de seis estaciones de muestreo durante 12 meses de estudio. La temporalidad de las variables medioambientales no se ha estudiado debido al método de muestreo utilizado para éstas. Sin embargo, se calcularon mensualmente tanto la abundancia como la diversidad beta de la fauna de peracáridos en cada una de las estaciones. El hidrodinamismo fue la única variable abiótica correlacionada significativamente con la diversidad beta, existiendo una relación lineal entre ambas variables (r = 0.81). El patrón de distribución de los peracáridos (basado en la matriz de abundancia) se relacionó con las variables abióticas usando el coeficiente de correlación de Spearman. Este análisis determinó que las variables que mejor explican los patrones de distribución de los peracáridos son el hidrodinamismo y la sedimentación (rs = 0.665). Entre las especies consideradas, los anfípodos Ischyrocerus inexpectatus, Jassa marmorata y Podocerus variegatus se correlacionaron negativamente con el hidrodinamismo y positivamente con la temperatura. El caprélido Phtisica marina también estuvo relacionado negativamente con el hidrodinamismo. Por el contrario, los anfípodos Cressa mediterranea y Stenothoe dollfusi prefirieron hábitats con un fuerte hidrodinamismo y baja sedimentación. Debido a las condiciones ambientales particulares en las que estas especies viven y en base a sus necesidades alimentarias, Gammaropsis maculata, Corophium acutum, J. marmorata, I. inexpectatus, y P. variegatus han sido c

The distribution and abundance of peracaridean fauna associated with the bryozoan Bugula neritina have been analysed according to their possible relationships with environmental stress on the coastline of Algeciras Bay. The spatial environmental variability along this bay has been established based on the analysis of five abiotic variables (hydrodynamism, siltation, suspended solids, and organic matter content) at six stations over a 12-month period. The temporal variability of these abiotic variables was not taken into account due to the method used in collecting the samples. The abundance and beta diversity of the peracarid fauna were also calculated monthly. Hydrodynamism was the only abiotic variable significantly correlated with beta diversity, with a linear regression model between the two variables (r = 0.81). The distributional pattern of the peracarids (based on the abundance matrix) was correlated with the environmental variables by matching samples' similarities using the Spearman rank correlation. This analysis showed that the combination of variables that best explains the patterns of distribution is hydrodynamism and siltation (rs = 0.665). Of the species considered the amphipods Ischyrocerus inexpectatus, Jassa marmorata and Podocerus variegatus were negatively correlated with hydrodynamism and positively with temperature. The caprellidea Phtisica marina was also negatively correlated with hydrodynamism. On the other hand, the amphipods Cressa mediterranea and Stenothoe dollfusi preferred environments with high hydrological forces and low sedimentation rate. Due to the particular environmental conditions where they live and their requirements, Gammaropsis maculata, Corophium acutum, J. marmorata, I. inexpectatus, and P. variegatus were categorised as good indicator species in port environments. Others such as Aora spinicornis, Microjassa cumbrensis, and C. mediterranea were categorised as species well adapted to high hydrological forces., Se han estudiado las relaciones entre la distribución y abundancia de la fauna de peracáridos asociados al briozoo Bugula neritina con el estrés medioambiental producido en la costa de la Bahía de Algeciras. La variabilidad espacial del estrés medioambiental a lo largo de la Bahía de Algeciras se ha establecido en base a cinco variables abióticas (hidrodinamismo, sedimentación, materia orgánica disuelta en el agua, sólidos en suspensión y la materia orgánica de dichos sólidos en suspensión) a lo largo de seis estaciones de muestreo durante 12 meses de estudio. La temporalidad de las variables medioambientales no se ha estudiado debido al método de muestreo utilizado para éstas. Sin embargo, se calcularon mensualmente tanto la abundancia como la diversidad beta de la fauna de peracáridos en cada una de las estaciones. El hidrodinamismo fue la única variable abiótica correlacionada significativamente con la diversidad beta, existiendo una relación lineal entre ambas variables (r = 0.81). El patrón de distribución de los peracáridos (basado en la matriz de abundancia) se relacionó con las variables abióticas usando el coeficiente de correlación de Spearman. Este análisis determinó que las variables que mejor explican los patrones de distribución de los peracáridos son el hidrodinamismo y la sedimentación (rs = 0.665). Entre las especies consideradas, los anfípodos Ischyrocerus inexpectatus, Jassa marmorata y Podocerus variegatus se correlacionaron negativamente con el hidrodinamismo y positivamente con la temperatura. El caprélido Phtisica marina también estuvo relacionado negativamente con el hidrodinamismo. Por el contrario, los anfípodos Cressa mediterranea y Stenothoe dollfusi prefirieron hábitats con un fuerte hidrodinamismo y baja sedimentación. Debido a las condiciones ambientales particulares en las que estas especies viven y en base a sus necesidades alimentarias, Gammaropsis maculata, Corophium acutum, J. marmorata, I. inexpectatus, y P. variegatus han sido c

The distribution and abundance of peracaridean fauna associated with the bryozoan Bugula neritina have been analysed according to their possible relationships with environmental stress on the coastline of Algeciras Bay. The spatial environmental variability along this bay has been established based on the analysis of five abiotic variables (hydrodynamism, siltation, suspended solids, and organic matter content) at six stations over a 12-month period. The temporal variability of these abiotic variables was not taken into account due to the method used in collecting the samples. The abundance and beta diversity of the peracarid fauna were also calculated monthly. Hydrodynamism was the only abiotic variable significantly correlated with beta diversity, with a linear regression model between the two variables (r = 0.81). The distributional pattern of the peracarids (based on the abundance matrix) was correlated with the environmental variables by matching samples' similarities using the Spearman rank correlation. This analysis showed that the combination of variables that best explains the patterns of distribution is hydrodynamism and siltation (rs = 0.665). Of the species considered the amphipods Ischyrocerus inexpectatus, Jassa marmorata and Podocerus variegatus were negatively correlated with hydrodynamism and positively with temperature. The caprellidea Phtisica marina was also negatively correlated with hydrodynamism. On the other hand, the amphipods Cressa mediterranea and Stenothoe dollfusi preferred environments with high hydrological forces and low sedimentation rate. Due to the particular environmental conditions where they live and their requirements, Gammaropsis maculata, Corophium acutum, J. marmorata, I. inexpectatus, and P. variegatus were categorised as good indicator species in port environments. Others such as Aora spinicornis, Microjassa cumbrensis, and C. mediterranea were categorised as species well adapted to high hydrological forces., Se han estudiado las relaciones entre la distribución y abundancia de la fauna de peracáridos asociados al briozoo Bugula neritina con el estrés medioambiental producido en la costa de la Bahía de Algeciras. La variabilidad espacial del estrés medioambiental a lo largo de la Bahía de Algeciras se ha establecido en base a cinco variables abióticas (hidrodinamismo, sedimentación, materia orgánica disuelta en el agua, sólidos en suspensión y la materia orgánica de dichos sólidos en suspensión) a lo largo de seis estaciones de muestreo durante 12 meses de estudio. La temporalidad de las variables medioambientales no se ha estudiado debido al método de muestreo utilizado para éstas. Sin embargo, se calcularon mensualmente tanto la abundancia como la diversidad beta de la fauna de peracáridos en cada una de las estaciones. El hidrodinamismo fue la única variable abiótica correlacionada significativamente con la diversidad beta, existiendo una relación lineal entre ambas variables (r = 0.81). El patrón de distribución de los peracáridos (basado en la matriz de abundancia) se relacionó con las variables abióticas usando el coeficiente de correlación de Spearman. Este análisis determinó que las variables que mejor explican los patrones de distribución de los peracáridos son el hidrodinamismo y la sedimentación (rs = 0.665). Entre las especies consideradas, los anfípodos Ischyrocerus inexpectatus, Jassa marmorata y Podocerus variegatus se correlacionaron negativamente con el hidrodinamismo y positivamente con la temperatura. El caprélido Phtisica marina también estuvo relacionado negativamente con el hidrodinamismo. Por el contrario, los anfípodos Cressa mediterranea y Stenothoe dollfusi prefirieron hábitats con un fuerte hidrodinamismo y baja sedimentación. Debido a las condiciones ambientales particulares en las que estas especies viven y en base a sus necesidades alimentarias, Gammaropsis maculata, Corophium acutum, J. marmorata, I. inexpectatus, y P. variegatus han sido c

The distribution and abundance of peracaridean fauna associated with the bryozoan Bugula neritina have been analysed according to their possible relationships with environmental stress on the coastline of Algeciras Bay. The spatial environmental variability along this bay has been established based on the analysis of five abiotic variables (hydrodynamism, siltation, suspended solids, and organic matter content) at six stations over a 12-month period. The temporal variability of these abiotic variables was not taken into account due to the method used in collecting the samples. The abundance and beta diversity of the peracarid fauna were also calculated monthly. Hydrodynamism was the only abiotic variable significantly correlated with beta diversity, with a linear regression model between the two variables (r = 0.81). The distributional pattern of the peracarids (based on the abundance matrix) was correlated with the environmental variables by matching samples' similarities using the Spearman rank correlation. This analysis showed that the combination of variables that best explains the patterns of distribution is hydrodynamism and siltation (rs = 0.665). Of the species considered the amphipods Ischyrocerus inexpectatus, Jassa marmorata and Podocerus variegatus were negatively correlated with hydrodynamism and positively with temperature. The caprellidea Phtisica marina was also negatively correlated with hydrodynamism. On the other hand, the amphipods Cressa mediterranea and Stenothoe dollfusi preferred environments with high hydrological forces and low sedimentation rate. Due to the particular environmental conditions where they live and their requirements, Gammaropsis maculata, Corophium acutum, J. marmorata, I. inexpectatus, and P. variegatus were categorised as good indicator species in port environments. Others such as Aora spinicornis, Microjassa cumbrensis, and C. mediterranea were categorised as species well adapted to high hydrological forces., Se han estudiado las relaciones entre la distribución y abundancia de la fauna de peracáridos asociados al briozoo Bugula neritina con el estrés medioambiental producido en la costa de la Bahía de Algeciras. La variabilidad espacial del estrés medioambiental a lo largo de la Bahía de Algeciras se ha establecido en base a cinco variables abióticas (hidrodinamismo, sedimentación, materia orgánica disuelta en el agua, sólidos en suspensión y la materia orgánica de dichos sólidos en suspensión) a lo largo de seis estaciones de muestreo durante 12 meses de estudio. La temporalidad de las variables medioambientales no se ha estudiado debido al método de muestreo utilizado para éstas. Sin embargo, se calcularon mensualmente tanto la abundancia como la diversidad beta de la fauna de peracáridos en cada una de las estaciones. El hidrodinamismo fue la única variable abiótica correlacionada significativamente con la diversidad beta, existiendo una relación lineal entre ambas variables (r = 0.81). El patrón de distribución de los peracáridos (basado en la matriz de abundancia) se relacionó con las variables abióticas usando el coeficiente de correlación de Spearman. Este análisis determinó que las variables que mejor explican los patrones de distribución de los peracáridos son el hidrodinamismo y la sedimentación (rs = 0.665). Entre las especies consideradas, los anfípodos Ischyrocerus inexpectatus, Jassa marmorata y Podocerus variegatus se correlacionaron negativamente con el hidrodinamismo y positivamente con la temperatura. El caprélido Phtisica marina también estuvo relacionado negativamente con el hidrodinamismo. Por el contrario, los anfípodos Cressa mediterranea y Stenothoe dollfusi prefirieron hábitats con un fuerte hidrodinamismo y baja sedimentación. Debido a las condiciones ambientales particulares en las que estas especies viven y en base a sus necesidades alimentarias, Gammaropsis maculata, Corophium acutum, J. marmorata, I. inexpectatus, y P. variegatus han sido c

The distribution and abundance of peracaridean fauna associated with the bryozoan Bugula neritina have been analysed according to their possible relationships with environmental stress on the coastline of Algeciras Bay. The spatial environmental variability along this bay has been established based on the analysis of five abiotic variables (hydrodynamism, siltation, suspended solids, and organic matter content) at six stations over a 12-month period. The temporal variability of these abiotic variables was not taken into account due to the method used in collecting the samples. The abundance and beta diversity of the peracarid fauna were also calculated monthly. Hydrodynamism was the only abiotic variable significantly correlated with beta diversity, with a linear regression model between the two variables (r = 0.81). The distributional pattern of the peracarids (based on the abundance matrix) was correlated with the environmental variables by matching samples' similarities using the Spearman rank correlation. This analysis showed that the combination of variables that best explains the patterns of distribution is hydrodynamism and siltation (rs = 0.665). Of the species considered the amphipods Ischyrocerus inexpectatus, Jassa marmorata and Podocerus variegatus were negatively correlated with hydrodynamism and positively with temperature. The caprellidea Phtisica marina was also negatively correlated with hydrodynamism. On the other hand, the amphipods Cressa mediterranea and Stenothoe dollfusi preferred environments with high hydrological forces and low sedimentation rate. Due to the particular environmental conditions where they live and their requirements, Gammaropsis maculata, Corophium acutum, J. marmorata, I. inexpectatus, and P. variegatus were categorised as good indicator species in port environments. Others such as Aora spinicornis, Microjassa cumbrensis, and C. mediterranea were categorised as species well adapted to high hydrological forces., Se han estudiado las relaciones entre la distribución y abundancia de la fauna de peracáridos asociados al briozoo Bugula neritina con el estrés medioambiental producido en la costa de la Bahía de Algeciras. La variabilidad espacial del estrés medioambiental a lo largo de la Bahía de Algeciras se ha establecido en base a cinco variables abióticas (hidrodinamismo, sedimentación, materia orgánica disuelta en el agua, sólidos en suspensión y la materia orgánica de dichos sólidos en suspensión) a lo largo de seis estaciones de muestreo durante 12 meses de estudio. La temporalidad de las variables medioambientales no se ha estudiado debido al método de muestreo utilizado para éstas. Sin embargo, se calcularon mensualmente tanto la abundancia como la diversidad beta de la fauna de peracáridos en cada una de las estaciones. El hidrodinamismo fue la única variable abiótica correlacionada significativamente con la diversidad beta, existiendo una relación lineal entre ambas variables (r = 0.81). El patrón de distribución de los peracáridos (basado en la matriz de abundancia) se relacionó con las variables abióticas usando el coeficiente de correlación de Spearman. Este análisis determinó que las variables que mejor explican los patrones de distribución de los peracáridos son el hidrodinamismo y la sedimentación (rs = 0.665). Entre las especies consideradas, los anfípodos Ischyrocerus inexpectatus, Jassa marmorata y Podocerus variegatus se correlacionaron negativamente con el hidrodinamismo y positivamente con la temperatura. El caprélido Phtisica marina también estuvo relacionado negativamente con el hidrodinamismo. Por el contrario, los anfípodos Cressa mediterranea y Stenothoe dollfusi prefirieron hábitats con un fuerte hidrodinamismo y baja sedimentación. Debido a las condiciones ambientales particulares en las que estas especies viven y en base a sus necesidades alimentarias, Gammaropsis maculata, Corophium acutum, J. marmorata, I. inexpectatus, y P. variegatus han sido c

The tube building polychaete Hydroides elegans occurs in dense aggregations and often attaches to colonies of the arborescent bryozoan Bugula neritina in Hong Kong waters. Laboratory assays showed that H. elegans larvae require proper chemical cues to settle and metamorphose; the larvae either settled and metamorphosed in response to conspecific cues or extracts/leachate of B. neritina or biofilm. With aid of rigorous bioassay-guided isolation and purification procedures, conspecific cues have been identified to be a group of amino acids. Compounds extracted from the leachate of B. neritina induced very high percentage of H. elegans larvae to settle and appears to be different compounds in nature from conspecific cues. Larval settlement in response to 12 isolated bacterial strains was species-specific. Bacterial films combined with different bacterial strains at different proportions also affected larval settlement. Bioassays with supernatant of the bacterial broth culture revealed that inductive cues were not released into the medium but, presumably, bound to the bacterial cell surfaces. Addition of D-glucose solution into bacterial treatment almost entirely blocked the larval settlement. This confirmed the previous finding that recognition of bacterial cells by H. elegans larvae might involve lectinlike receptors that could be blocked by glucose on the larval surface. Our results suggest that larvae of H. elegans may settle in response to a broad range of chemical cues. Current studies in my laboratory are to identify these chemical cues and to study chemoreceptors and signaling pathways involved in metamorphosis.

The tube building polychaete Hydroides elegans occurs in dense aggregations and often attaches to colonies of the arborescent bryozoan Bugula neritina in Hong Kong waters. Laboratory assays showed that H. elegans larvae require proper chemical cues to settle and metamorphose; the larvae either settled and metamorphosed in response to conspecific cues or extracts/leachate of B. neritina or biofilm. With aid of rigorous bioassay-guided isolation and purification procedures, conspecific cues have been identified to be a group of amino acids. Compounds extracted from the leachate of B. neritina induced very high percentage of H. elegans larvae to settle and appears to be different compounds in nature from conspecific cues. Larval settlement in response to 12 isolated bacterial strains was species-specific. Bacterial films combined with different bacterial strains at different proportions also affected larval settlement. Bioassays with supernatant of the bacterial broth culture revealed that inductive cues were not released into the medium but, presumably, bound to the bacterial cell surfaces. Addition of D-glucose solution into bacterial treatment almost entirely blocked the larval settlement. This confirmed the previous finding that recognition of bacterial cells by H. elegans larvae might involve lectinlike receptors that could be blocked by glucose on the larval surface. Our results suggest that larvae of H. elegans may settle in response to a broad range of chemical cues. Current studies in my laboratory are to identify these chemical cues and to study chemoreceptors and signaling pathways involved in metamorphosis.

The tube building polychaete Hydroides elegans occurs in dense aggregations and often attaches to colonies of the arborescent bryozoan Bugula neritina in Hong Kong waters. Laboratory assays showed that H. elegans larvae require proper chemical cues to settle and metamorphose; the larvae either settled and metamorphosed in response to conspecific cues or extracts/leachate of B. neritina or biofilm. With aid of rigorous bioassay-guided isolation and purification procedures, conspecific cues have been identified to be a group of amino acids. Compounds extracted from the leachate of B. neritina induced very high percentage of H. elegans larvae to settle and appears to be different compounds in nature from conspecific cues. Larval settlement in response to 12 isolated bacterial strains was species-specific. Bacterial films combined with different bacterial strains at different proportions also affected larval settlement. Bioassays with supernatant of the bacterial broth culture revealed that inductive cues were not released into the medium but, presumably, bound to the bacterial cell surfaces. Addition of D-glucose solution into bacterial treatment almost entirely blocked the larval settlement. This confirmed the previous finding that recognition of bacterial cells by H. elegans larvae might involve lectinlike receptors that could be blocked by glucose on the larval surface. Our results suggest that larvae of H. elegans may settle in response to a broad range of chemical cues. Current studies in my laboratory are to identify these chemical cues and to study chemoreceptors and signaling pathways involved in metamorphosis.

This dissertation investigates the identity and function of a bacterial symbiont described in the marine bryozoan Bugula neritina by R.M. Woollacott in 1981. B. neritina is the source of bryostatins, unique cytotoxins suspected to have a bacterial source, and is considered a single species throughout its cosmopolitan temperate range. Bryostatins found from different collections of B. neritina vary, and only certain populations produce bryostatins that possess an octa-2,4-dienoate substituent. In this dissertation the bacterial symbionts of the larvae are identified by small subunit ribosomal rRNA {SSU) gene sequences and named "Candidatus Endobugula sertula." The variable regions of these genes were used to design oligonucleotides specific to the symbiont. These specific oligonucleotides were used for in situ hybridization to the bacteria in the pallial sinus to confirm the origin of the sequence, and for specific amplification of symbiont SSU rRNA genes by PCR. Then the mitochondrial cytochrome c oxidase subunit I gene was used to identify two distinct species of B. neritina each harboring a different symbiont as determined by SSU rRNA sequence. Variation in the bryostatin profiles is associated with this genetic difference. Only one B. neritina/"E. sertula" association can produce bryostatins with an octa-2,4-dienoate substituent (bryostatins 1-3, 12 and 15). In order to elucidate the possible involvement of the symbiont in production of bryostatins, experiments were conducted to eliminate "E. sertula" from R. neritina to determine whether B. neritina can continue to grow normally without the symbiont, and/or continue to produce equivalent levels of bryostatins. Symbiont levels were estimated using a symbiont-specific PCR assay, then bryostatin activity levels were compared between control and treated B. neritina colonies. When symbiont levels were greatly reduced, bryostatin activity declined by approximately 50%. Genetic evidence was discovered that indicates "E

The calcareous tube-building polychaete Hydroides elegans (Haswell) is a major fouling organism in tropical waters around the world. In the marine environment, larvae of H. elegans rapidly settle and metamorphose in response to acceptable surface-bound bio-organic films. In addition to biological inducers, previous investigations by our group have indicated chemical inducers for larval settlement and metamorphosis in H. elegans. Crude samples derived from adult H. elegans and colonies of the bryozoan Bugula neritina induced a high percentage of larval metamorphosis in laboratory assays. Here, we describe a bioassay-guided isolation and purification of larval metamorphic inducers originating from these samples. Biologically active HPLC-purified fractions of both samples were composed of free amino acids. The entire free amino acid composition was determined by quantitation with ortho-phthaldialdehyde (OPA) and was found to be comprised of aspartic acid, glutamic acid, serine, histidine, glycine, arginine, alanine, asparagine, glutamine and taurine in concentrations ranging from 0.2 mu M (histidine) to 5.6 mu M (taurine). In the laboratory assay, the larval metamorphic response to an artificially prepared sample in identical concentrations of these amino acids was very similar to the natural isolates.

The calcareous tube-building polychaete Hydroides elegans (Haswell) is a major fouling organism in tropical waters around the world. In the marine environment, larvae of H. elegans rapidly settle and metamorphose in response to acceptable surface-bound bio-organic films. In addition to biological inducers, previous investigations by our group have indicated chemical inducers for larval settlement and metamorphosis in H. elegans. Crude samples derived from adult H. elegans and colonies of the bryozoan Bugula neritina induced a high percentage of larval metamorphosis in laboratory assays. Here, we describe a bioassay-guided isolation and purification of larval metamorphic inducers originating from these samples. Biologically active HPLC-purified fractions of both samples were composed of free amino acids. The entire free amino acid composition was determined by quantitation with ortho-phthaldialdehyde (OPA) and was found to be comprised of aspartic acid, glutamic acid, serine, histidine, glycine, arginine, alanine, asparagine, glutamine and taurine in concentrations ranging from 0.2 mu M (histidine) to 5.6 mu M (taurine). In the laboratory assay, the larval metamorphic response to an artificially prepared sample in identical concentrations of these amino acids was very similar to the natural isolates.

This dissertation investigates the identity and function of a bacterial symbiont described in the marine bryozoan Bugula neritina by R.M. Woollacott in 1981. B. neritina is the source of bryostatins, unique cytotoxins suspected to have a bacterial source, and is considered a single species throughout its cosmopolitan temperate range. Bryostatins found from different collections of B. neritina vary, and only certain populations produce bryostatins that possess an octa-2,4-dienoate substituent. In this dissertation the bacterial symbionts of the larvae are identified by small subunit ribosomal rRNA {SSU) gene sequences and named "Candidatus Endobugula sertula." The variable regions of these genes were used to design oligonucleotides specific to the symbiont. These specific oligonucleotides were used for in situ hybridization to the bacteria in the pallial sinus to confirm the origin of the sequence, and for specific amplification of symbiont SSU rRNA genes by PCR. Then the mitochondrial cytochrome c oxidase subunit I gene was used to identify two distinct species of B. neritina each harboring a different symbiont as determined by SSU rRNA sequence. Variation in the bryostatin profiles is associated with this genetic difference. Only one B. neritina/"E. sertula" association can produce bryostatins with an octa-2,4-dienoate substituent (bryostatins 1-3, 12 and 15). In order to elucidate the possible involvement of the symbiont in production of bryostatins, experiments were conducted to eliminate "E. sertula" from R. neritina to determine whether B. neritina can continue to grow normally without the symbiont, and/or continue to produce equivalent levels of bryostatins. Symbiont levels were estimated using a symbiont-specific PCR assay, then bryostatin activity levels were compared between control and treated B. neritina colonies. When symbiont levels were greatly reduced, bryostatin activity declined by approximately 50%. Genetic evidence was discovered that indicates "E