Co-existence of two mytilids in a heterogeneous environment: mortality, growth and strength of shell and byssus attachment

14 páginas, 1 apéndice, 5 tablas, 7 figurasThe co-existence patterns of 2 mytilid species were studied in order to evaluate the performance of the alien mussel Xenostrobus securis and the indigenous Mytilus galloprovincialis through monospecific and mixed co-habiting experiments in the Ría de Vigo (northwest Spain). Mytilus galloprovincialis was found to be the best performer in all tests. Shell growth was ~4-fold greater for the indigenous mussel when deployed without interspecific competition and regardless of density. Differences in shell growth were found to be similar within mixed populations wherein M. galloprovincialis showed greater ability for upward migratory movements on the mixed beds and distanced itself from the mud influenced layer. The alien X. securis, however, was found to inhabit underneath the M. galloprovincialis layer, which resulted in higher mortality rates. Species-specific features such as byssus filaments and lifestyle may account for such different behaviour. M. galloprovincialis secreted thicker and stronger shells and byssus regardless of their density in both monospecific and mixed experiments. This might indicate that the indigenous mussel performs better when confronted with abiotic stress or biotic pressure. The alien X. securis is currently found to establish high-density patches of individuals at the confluence of main rivers that flow into the estuary (highly heterogeneous scenario). Such behaviour favours its settlement far from the native mussel influence area. X. securis also colonises hard substrates that are not-fully occupied by other invertebrates, but its range was found to be limited by the presence of the indigenous mussel.This study was funded by the project AGL2010-16464 (Ministerio de Ciencia e Innovación, Spanish Government).Peer reviewe

Variability of taurine concentrations in Mytilus galloprovincialis as a function of body size and specific tissue

7 páginas, 5 figurasVariability of taurine (2-aminoethane sulfonic acid) was studied as afunction of size in the mussel Mytilus galloprovincialis and tissue specificity. Isometric and/or allometric relationships were established with regard to total soft mass of the mussels between 20 and 60 mm shell length. Relative amounts of taurine dropped significantly with increasing mass of whole soft tissues with an allometric coefficient value of − 0.15. The inverse relationship between taurine and increasing size of mussels was confirmed for gill epithelium and labial palp (allometric coefficient values of − 0.16 and − 0.10, respectively), tissues that, in turn, represented isometric functions with regard to total soft mass. Although relative amounts of taurine were significantly different in digestive gland, mantle and foot, relationships with increasing size of mussels remained unchanged in these tissues. Gill area of mussels was related to soft mass with an allometric coefficient of 0.70 by 2D Image Analysis, but increased to 0.85 when introducing a third dimension, i.e. gill thickness. Results are discussed according to gill structure analysis and taurine functionality.This study was supported by the contract-project PROINSA, Code CSIC 2004448, Galicia PGDIT03RMA13E. JMFB acknowledges funding by the Program Ramón y Cajal 2003 from Ministry of Education and Science (Spain).Peer reviewe

Importance of phenotypic plastic traits on invasion success: Response of Xenostrobus securis to the predatory dogwhelk Nucella lapillus

14 páginas, 7 figuras, 3 tablasThe ability of the invasive mussel Xenostrobus securis to activate defence mechanisms in response to the novel predatory dogwhelk Nucella lapillus was explored using field- and laboratory-based approaches. The importance of the origin of mussels was investigated in relation to different environmental conditions and levels of predation pressure (high and low). In the field, the responses of mussels were clearly asymmetrical: only individuals caged with dogwhelks at the site of high predation risk underwent phenotypical changes (stronger attachment, thicker shells and heavier adductor muscle). In contrast, shell growth was faster in mussels held in cages without dogwhelks at the high predation-risk site, suggesting trade-off patterns between growth and other energy-demanding actions. Nevertheless, X. securis activated inducible morphological defences without any detrimental effect on soft tissue growth (i.e. condition index). In the laboratory, the role of temperature on phenotypic responses of mussels exposed to dogwhelk was also evaluated. Mussels originally from the site of low predation risk showed a weaker response to the predator N. lapillus, probably because of difficulties in correctly identifying predator cues. At higher temperatures, mussels secreted stronger byssal threads regardless of their origin, while condition was poorer, shells thinner and gametogenesis activated more rapidly, particularly in the presence of dogwhelks. In summary, X. securis appears to be highly capable of activating protective mechanisms in marine environments within its geographical range of expansion through improved fitnessThis study was funded by the Spanish government through the Ministerio de Ciencia e Innovación (project AGL2010-16464) and the Autonomic government Xunta de Galicia-FEDER (project GRC2013-004)Peer reviewe

Free amino acid composition in juveniles of Mytilus galloprovincialis: spatial variability after Prestige oil spill

10 páginas, 5 figuras, 2 tablasComposition of free amino acids (FAA) in juveniles of Mytilus galloprovincialis was analysed along a large geographical coastline area in Galicia (NW Spain). Individuals were sampled in February 2003, three months after the Prestige oil spill. Pollution values at sampling time were reported as polycyclic aromatic hydrocarbons (PAHs) concentrations in soft tissues of individuals and varied between the highest amount observed in Carrumeiro mussels (502 ng/g dw) and the lowest in Pindo mussels (196 ng/g dw), both locations being close to each other in the centre of the geographical area under study. Pollution values in the other populations varied within the range of 241–347 ng/g dw. Total free amino acids (TFAA) were highest in Aguiño–Pindo–Carrumeiro juveniles at the centre of the Coastline area studied (420–462 μmol/g dw) as compared to the other populations at North and South of Galicia (312–347 μmol/g dw). TFAA results were based on the variability observed in protein free amino acids (PFAA μmol/g dw) among populations (214–249 μmol/g dw for Aguiño–Pindo–Carrumeiro mussels and 98–149 μmol/g dw for the other populations) whereas non-protein free amino acids (NPFAA) taurine and ornithine did not show any significant spatial pattern of variation. Glycine and alanine represented the most abundant PFAA (16–29% and 2.7–11.9% of TPFAA, respectively) and significant correlations between PFAA and both the protein content of soft tissues (r=−0.82) and the condition index of juveniles (r=0.86) were observed. No significant relationships were detected, however, between pollution values in soft tissues as PAHs and FAA profiles with the exception of alanine concentrations as percentage of TFAA (r=0.88; P<0.01). The latter seemed to be an “all or nothing” effect likely due to the influence of other abiotic factors at one of the sampling sites. Such relationship was found not significant when the outlier represented by Carrumeiro mussels was removed from the analysis. The most abundant free amino acid taurine (43.2–68.5%TFAA) followed an inverse variability of that of glycine and by extension of the group PFAA most likely as a compensatory decrease in mussel populations with low protein content (and high condition index). Accordingly, taurine:glycine (t:g) ratio varied between 1 and 2 in most mussel populations but increased up to 3.2–4.2 in Miranda and Bueu mussels at both ends of the geographical interval studied with a corresponding PAHs concentrations of 261 and 304 ng/g dw, respectively. These mussel populations with the highest t:g ratios were characterised by the lowest PFAA contents (below 40%) and condition index values (below 10%). Results of the present study established a significant link between energetic status of growing juveniles and FAA concentrations in environments with different pollution degrees. Variability of the free amino acids profiles in soft tissues were related to endogenous factors of juveniles (protein content, condition index) whereas no relationship with contamination values could be observed. The utility of t:g ratio as general condition factor for M. galloprovincialis is also corroborated for in situ growing juveniles.This study was supported by the contract-project PROINSA, Code CSIC 2004448, Galicia PGDIT03RMA13E. JMFB acknowledges funding by the Program Ramón y Cajal 2003 from Ministry of Education and Sciences (Spain).Peer reviewe

Valorization of Pinus pinaster wood by one-pot treatments in butanol/water biphasic mixtures

Biphasic butanol/water treatments have been proposed for the efficient fractionation of Pinus pinaster wood, with the objective of recovering glucan enriched solid phases, and two liquid streams, one organic and one aqueous, mainly made up of lignin-solubilized products and hemicellulosic compounds, respectively. Under selected operating conditions (190ºC, 40% of butanol, 1% of catalyst, and 10 min), high lignin solubilization (77.82%) and glucan recovery (86.93%) were achieved and an aqueous phase containing 15.8 g/L of oligosaccharides was also obtained. Further processing of the organic phase allowed the recovery of 62.69% of the initial lignin with a high purity (close to 94%). Finally, the enzymatic digestibility of the treated solid was evaluated achieving a saccharification yield of about 95%. Therefore, a promising softwood biorefinery scheme based on the use of a hydrophobic green solvent is proposed.Agencia Estatal de Investigación | Ref. PID2020-116717RB-I00Xunta de Galicia | Ref. GRC-ED431C 2022/0

From Broad-Spectrum Biocides to Quorum Sensing Disruptors and Mussel Repellents: Antifouling Profile of Alkyl Triphenylphosphonium Salts

30 páginas, 13 figuras, 4 tablas.-- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited‘Onium’ compounds, including ammonium and phosphonium salts, have been employed as antiseptics and disinfectants. These cationic biocides have been incorporated into multiple materials, principally to avoid bacterial attachment. In this work, we selected 20 alkyl-triphenylphosphonium salts, differing mainly in the length and functionalization of their alkyl chains, in fulfilment of two main objectives: 1) to provide a comprehensive evaluation of the antifouling profile of these molecules with relevant marine fouling organisms; and 2) to shed new light on their potential applications, beyond their classic use as broad-spectrum biocides. In this regard, we demonstrate for the first time that these compounds are also able to act as non-toxic quorum sensing disruptors in two different bacterial models (Chromobacterium violaceum and Vibrio harveyi) as well as repellents in the mussel Mytilus galloprovincialis. In addition, their inhibitory activity on a fouling-relevant enzymatic model (tyrosinase) is characterized. An analysis of the structure-activity relationships of these compounds for antifouling purposes is provided, which may result useful in the design of targeted antifouling solutions with these molecules. Altogether, the findings reported herein provide a different perspective on the biological activities of phosphonium compounds that is particularly focused on, but, as the reader will realize, is not limited to their use as antifouling agentsThis study was supported by the Spanish Ministry of Economy and Competitiveness (http:// www.mineco.gob.es/), SAF2011-28883-C03-01 (JJF), CTQ2011-28417-C02-01/BQU (VSM), AGL2010- 16464 (JMFB), MAT2013-40852-R (FL); Spanish Ministry of Education, Culture and Sport (http://www. mecd.gob.es/portada-mecd/), CEI 10/00018 (MN)Peer reviewe

Influence of environmental factors on the reproductive cycle of the eared ark Anadara notabilis (Röding, 1798) in Northeastern Venezuela

5 figuras, 2 tablasThe reproductive cycle of the eared ark Anadara notabilis and its relationship with environmental factors was evaluated every 15 days between March 2004 and February 2005 at the northern part of the Peninsula de Araya, Venezuela. Environmental factors measured included temperature, salinity, chlorophyll a, and total seston, including the particulate organic matter and particulate inorganic matter fractions. Adult specimens were collected using a net drag and then randomly selected to estimate wet live biomass and dry biomass of soft body tissues. Gonad samples were processed with histological analysis to determine sex ratio, developmental stages, and variations of follicle size. Reproduction in A. notabilis was continuous throughout the year, with spawning peaks occurring in June and October, coinciding with the lowest water temperatures. In March, September, and November 2004, specimens attained the highest dry biomass values, whereas lowest dry biomass occurred in June and October 2004. Stepwise regression analyses demonstrated that temperature and particulate organic matter values are the main modulators of reproductive events. When temperature decreased, dribble spawning was detected in this species, possibly inducing a survival strategy whereby the spawning period is extended to increase reproductive successPeer reviewe

Arduino controlled valvometry equipment for laboratory monitoring

High-Frequency Non-Invasive (HFNI) instruments are currently used in bivalve mollusks in order to use them as bioindicators of the local conditions of the environment. Under the STRAUSS project an Arduino controlled equipment has been developed to log the valve movements activity of clams (Polititapes rhomboides) using Hall-efect sensors. The equipment is able to record at 10Hz the signals of 16 Hall-sensors, to store the records in internal microSD cards and to send the stream of data to a personal computer for storing and plotting them in real-time.Peer Reviewe

Arduino controlled valvometry equipment for mussel raft monitoring

High-Frequency Non-Invasive (HFNI) instruments are currently used in bivalve mollusks in order to use them as bio-indicators of the local conditions of the environment. Under the STRAUSS project an Arduino controlled equipment has been developed to log the valve movements activity of mussels (Mytilus galloprovincialis) using Hall-effect sensors. The equipment is able to record at 10Hz the signals of 27 Hall-sensors, temperature, fluorescence and , to store the records in internal microSD cards and to send the stream of data to in premisses data servers for storing and plotting them.Peer Reviewe