Polymorphism and shell reshaping in Pinna nobilis L., 1758: the reliability of shell dimensions for ontogenetic age and population growth rate estimates.

Polymorphism and shell reshaping in Pinna nobilis L., 1758: the reliability of shell dimensions for ontogenetic age and population growth rate estimates

Aportaciones al conocimiento de la biología de Pinna Nobilis Linneo, 1758 (Mollusca bivalvia) en el litoral mediterráneo ibérico.

RESUMEN El molusco bivalvo Pinna nobilis, perteneciente al orden Pterioida, es una especie endémica del Mar Mediterráneo, que suele habitar en las praderas de fanerógamas marinas, donde vive semienterrado, anclado mediante los filamentos del biso. Se trata del molusco más grande del Mediterráneo, ya que puede superar los 80 cm de longitud. El deterioro generalizado de las zonas costeras ha afectado también a esta especie, que ha sido incluida en el Anexo II de la directiva de hábitats, el Anexo IV del Convenio de Barcelona y el Anexo II del Catálogo Nacional de Especies Amenazadas. El presente proyecto de Tesis supone una nueva aportación sobre las características de las poblaciones de esta especie en su medio natural desde un enfoque dinámico, abordando el cambio en el tiempo de una densa población localizada en la ensenada de Moraira (Alicante). Además, se ha profundizado en el estudio de aspectos de su biología y fisiología como el sistema de fijación al sustrato, que ha sido descrito en profundidad, así como la actividad de las valvas y el estudio de la abertura ponderada de las mismas. Por último, se ha estudiado la morfometría dinámica de las valvas, un aspecto muy característico de esta especie, capaz de reconstruir la concha de una forma original, después de grandes procesos de erosión anterior, sin que su característica forma triangular se pierda en el proceso. Los resultados han destacado la gran importancia del hidrodinamismo en la estructura de la población y la existencia de importantes diferencias en la densidad de individuos y la media de tamaños, que aumentan con el incremento de la profundidad. Asimismo, se han observado diferencias muy importantes en las tasas de mortalidad y crecimiento, según la cota de profundidad donde habitan los individuos. El gran número de filamentos que unen al animal al fondo, más de 20.000 y las diversas estrategias de fijación, que se caracterizan por ser muy elaboradas, han hecho suponer que la fijación al sustrato es fundamental para la supervivencia de los individuos, en respuesta a estrés hidrodinámico. El estudio de la actividad de las valvas ha puesto en evidencia que esta especie realiza ciclos circadianos y circalunares, siguiendo estrechamente la posición del Sol y la Luna, de forma que en términos generales, Pinna nobilis cierra las valvas por la noche, excepto cuando la luna está presente en el cielo con el disco iluminado por encima del 50%. Finalmente, el estudio de la morfometría dinámica de la concha ha permitido detectar una serie de registros internos que sirven para estudiar la edad y el crecimiento de los individuos. Además, el descubrimiento de un proceso continuo de neoformación de la concha, mediado por procesos de erosión y reconstrucción anterior, supone una explicación a las causas del polimorfismo de esta especie. A este respecto, se aporta por primera vez una explicación soportada por numerosas pruebas, a la forma papyracea de la concha descrita por Czihak y Dierl (1961). _________________________________________________________________________________________________

Real-Time PCR based test for the early diagnosis of Haplosporidium pinnae affecting fan mussel Pinna nobilis

All sequence files are available from the Genbank database (accession numbers MK142774-MK142779). The protocol is available from protocols.io (DOI: dx.doi.org/10. 17504/protocols.io.xmyfk7w).Noble pen shell or fan mussel, Pinna nobilis Linnaeus (1758), protected since 1992, was incorporated into the Spanish Catalogue of Threatened Species (Category: Vulnerable, Royal Decree 139/2011). The status is presently in the process of being catalogued as critically endangered, pending approval by Spanish Government (https://www.mapama.gob.es/ es/biodiversidad/participacion-publica/Borrador_OM_situacion_critica.aspx). The International Union for the Conservation of Nature (IUCN) alerted the countries of the Mediterranean basin to the “emergent situation” due to serious mortality events suffered by the fan mussel, putting it in serious risk of extinction. Thus, emergency actions have been implemented by Spanish authorities in which several research institutes from all over the country are involved. The parasite, Haplosporidium pinnae, was recently characterized by histology, TEM, SEM and molecular biology techniques and it was considered responsible for the mass mortality of P. nobilis in the Mediterranean Sea. In this context, the aim of this study has been to develop species-specific quantitative PCR (qPCR) protocol carrying out a fast, specific and effective molecular diagnose of H. pinnae. In this sense, the detection limit for qPCR was equal to 30 copies of SSU rDNA / ng of DNA using plasmid alone and when 100ng DNA of non-infected oyster were added. The qPCR assay revealed that 94% of the 32 analysed mantle tissues of fan mussel were infected by H. pinnae, showing a high sensitivity and specificity for its detection (100% if we don’t consider negative and too much degraded samples). This technique will allow us to make quicker follow-ups of the disease, allowing us to get a better understanding of its evolution in order to help in the rescue of P. nobilis populationsProject MAPAMA ref. 28-5310LIFE IPE INTERMARES(LIFE15 IPE ES 012)IFAPA-UCV 014/2018 and co-funded by PHENOFISH ProjectState Plan for Scientific and Technical Research and Innovation 2013-2016, MINECO, ref. PTA2015-14709-IMinisterio de Economía, Industria y Competitividad, Gobierno de España, INIA CCAA (DOC INIA 8-2013)Project BF/HEM 15-1662Ciencias del Ma

Towards sampling of the circalittoral benthos for monitoring impacts on marine communities: limitations and next steps

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Haplosporidium pinnae Parasite Detection in Seawater Samples

In this study, we investigated the presence of the parasite Haplosporidium pinnae, which is a pathogen for the bivalve Pinna nobilis, in water samples from different environments. Fifteen mantle samples of P. nobilis infected by H. pinnae were used to characterize the ribosomal unit of this parasite. The obtained sequences were employed to develop a method for eDNA detection of H. pinnae. We collected 56 water samples (from aquaria, open sea and sanctuaries) for testing the methodology. In this work, we developed three different PCRs generating amplicons of different lengths to determine the level of degradation of the DNA, since the status of H. pinnae in water and, therefore, its infectious capacity are unknown. The results showed the ability of the method to detect H. pinnae in sea waters from different areas persistent in the environment but with different degrees of DNA fragmentation. This developed method offers a new tool for preventive analysis for monitoring areas and to better understand the life cycle and the spread of this parasite.info:eu-repo/semantics/publishedVersio

Population Structure and Growth of the Threatened Pen Shell, Pinna rudis (Linnaeus, 1758) in a Western Mediterranean Marine Protected Area

Coastal ecosystems are being extensively degraded by human activities. Benthic, slow-growing and long-lived species are highly vulnerable to these impacts. Marine protected areas may avoid biodiversity losses through habitat protection. The pen shell Pinna rudis is a protected species, but scarce data are available on its ecology and biology. The present study is a comprehensive ecological study encompassing several unknown aspects of the growth and inner record in relation to habitat types, density and size distribu¬tion. During the summers of 2011, 2012 and 2013, a total of 418 strip transects were conducted by scuba diving in the Marine Pro¬tected Area of Cabrera National Park (39.14° N, 2.96° E). Samples were conducted across different habitats and depths, exploring 152,146.35 m2 in total. A large range of sizes and ages were recorded within the park with densities ranging from 0 to 6.89 ind./100 m2. Most pen shells were patchily distributed and concentrated mainly in caves. Two hotspots represented the highest densities ever recorded worldwide, showing a potential link to high larval accumulation and settlement. The population size structure showed a unimodal distribution with shell width ranging from 6.2 to 25.0 cm, with an average shell width of 16.0 ± 3.4 cm. The absolute growth was asymptotic, with a maximum age of 28-31 years and length of 45 cm. This study on the biology and ecology of a well-established population of Pinna rudis in the Western Mediterranean could set a baseline for the conservation of this species in other areasVersión del editor0,56

Evaluation of Physiological State of Pen Shell Pinna nobilis (Linnaeus, 1758) by a Non-Invasive Heart Rate Recording under Short-Term Hyposalinity Test

A non-invasive laser fiber-optic method based on infrared sensors for heart rate (Hr) recording was applied to assess the physiological condition of Pinna nobilis. During 2017, the specimens of P. nobilis were sampled at three sites within the Boka Kotorska Bay, Montenegro and used for ex situ experiments with short-term reduction/restoration of ambient salinity to evaluate their physiological adaptive capacity based on heart rate recovery time (Trec). Mean Trec for specimens from Sv. Nedjelja (reference site), Dobrota and Sv. Stasije were 72 ± 3, 91 ± 7 and 117 ± 15 min, while the coefficients of variation (CV) were 0.12, 0.13 and 0.17, respectively. Resting heart rate (Hrrest) and Trec showed statistically significant differences between the groups of mussels from Dobrota and Sv. Stasije in comparison to the reference site. Statistically significant correlations were observed between Trec and shell length/width, which was not the case in comparison between Hrrest and shell length/width. The lower adaptive capacity within the P. nobilis specimens from Dobrota and Sv. Stasije in comparison to the reference site could occur due to stress induced by deterioration of environmental conditions, which could have led to impairment of the physiological state of the mussels evaluated by Hr. All the specimens of P. nobilis survived the experimental treatments; afterwards, they were successfully transplanted at the Dobrota site. The experimental unit with sensor technology applied in this study can provide Hr recording in real time and could have an application in monitoring the physiological/health state of P. nobilis individuals maintained in aquaria

Scope for growth and dietary needs of Mediteranean Pinnids maintained in captivity

Abstract Background: The measurement of the energy available for growth (scope of growth, SFG) can be used in bivalves to make a long-term prediction in a short-term experiment of the condition of the individual. In order to tackle the best conditions for captive maintenance of Mediterranean Pinnids, a SFG study was conducted using Pinna rudis as a model species. Three diets were examined to test the viability of live microalgae and commercial products: i) a control diet using 100% of live microalgae based on the species Isochrysis galbana (t-ISO), ii) a 100% of commercial microalgae diet based on the product Shellfish Diet 1800®, and iii) a 50/50% mix diet of I. galbana (t-ISO) and Shellfish Diet 1800®. Results: SFG results showed significant differences among diets in the physiological functions measured and suggested lower acceptability and digestibility of the commercial product. Negative SFG values were obtained for the commercial diet which indicates that it should be rejected for both Pinnid maintenance. The mixed diet showed improved physiological performance compared to the commercial diet, resulting in a higher SFG that had no significant differences with the control diet. However, in the long-term, the lower digestibility of the mixed diet compared to the control diet could lead to a deterioration of individuals’ conditions and should be considered cautiously. Conclusions: This work represents the first case study of SFG in Pinna spp. and provides fundamental data on dietary needs for the critically endangered species, P. nobilis.En prens

Breeding, planktonic and settlement factors shape recruitment patterns of one of the last remaining major population of Pinna nobilis within Spanish waters

The pen shell, Pinna nobilis L., is a critically endangered bivalve threatened by mass mortality events throughout the Mediterranean, but the Alfacs Bay (Ebro Delta) still hosts many healthy individuals. Herein, we study the main factors controlling recruitment patterns in this locality, including gonadal development and abundance of critical life-stages, as well as the effect of environmental factors. Growth records from empty shells suggested a single major peak of recruitment during a period of 11 years, although many juveniles were found in two very shallow sand bars possibly acting as a barrier for water circulation and as a trap for larvae. Collectors deployed outside these sand bar areas showed zero settlers, and the availability of planktonic larvae was very low. Gonadal examination evidenced breeding throughout the summer period with successive hermaphroditism, but 20% of individuals were simultaneous hermaphrodites, a condition that has been associated with environmental stress and that could lead to in-breeding depression and potentially reduced fertility. Yet, given the large size of the population and the wide breeding period observed, planktonic processes causing larval mortality such as freshwater discharges from rice locally important rice agriculture are also proposed as possible impacts accounting for patterns of low larval availability.info:eu-repo/semantics/acceptedVersio

Genetic and oceanographic tools reveal high population connectivity and diversity in the endangered pen shell Pinna nobilis

For marine meta-populations with source-sink dynamics knowledge about genetic connectivity is important to conserve biodiversity and design marine protected areas (MPAs). We evaluate connectivity of a Mediterranean sessile species, Pinna nobilis. To address a large geographical scale, partial sequences of cytochrome oxidase I (COI, 590 bp) were used to evaluate phylogeographical patterns in the Western Mediterranean, and in the whole basin using overlapping sequences from the literature (243 bp). Additionally, we combined (1) larval trajectories based on oceanographic currents and early life-history traits and (2) 10 highly polymorphic microsatellite loci collected in the Western Mediterranean. COI results provided evidence for high diversity and low inter-population differentiation. Microsatellite genotypes showed increasing genetic differentiation with oceanographic transport time (isolation by oceanographic distance (IBD) set by marine currents). Genetic differentiation was detected between Banyuls and Murcia and between Murcia and Mallorca. However, no genetic break was detected between the Balearic populations and the mainland. Migration rates together with numerical Lagrangian simulations showed that (i) the Ebro Delta is a larval source for the Balearic populations (ii) Alicante is a sink population, accumulating allelic diversity from nearby populations. The inferred connectivity can be applied in the development of MPA networks in the Western MediterraneanProject MEDEICG funded by the Spanish Ministry of Economy and Competitiveness (CTM2009-07013)IEH was supported by Ramon y Cajal Fellowship RYC2014-14970Spanish Ministry of Economy, Industry and Competitiveness IFCT Investigator Programme-Career Development (IF/00998/2014)MGW and AHE was supported by FCT fellowships SFRH/BPD/63703/2009 and SFRH/BPD/107878/2015National Science Foundation (OCE-1419450)CCMAR team via excellence research line EXCL/AAG-GLO/0661/2012Ciencias del Ma