Leve diferenciación genética entre los límites occidental y oriental de distribución de Astroides calycularis (Pallas, 1776) (Anthozoa, Scleractinia, Dendrophylliidae), inferida a partir de secuencias de COI e ITS

Understanding population genetic structure and differentiation among populations is useful for the elaboration of management and conservation plans of threatened species. In this study, we use nuclear and mitochondrial markers (internal transcribed spacers -ITS and cytochrome oxidase subunit one -COI) for phylogenetics and nested clade analyses (NCA), thus providing the first assessment of the genetic structure of the threatened Mediterranean coral Astroides calycularis (Pallas, 1766), based on samples from 12 localities along its geographic distribution range. Overall, we found no population differentiation in the westernmost region of the Mediterranean; however, a slight differentiation was observed when comparing this region with the Tyrrhenian and Algerian basins.El estudio de la estructura de las poblaciones y su diferenciación a nivel genético es de gran utilidad para la elaboración de planes de manejo y conservación de especies amenazadas. En este estudio, utilizamos marcadores nucleares y mitocondriales (espaciadores internos de genes ribosomales -ITS y citocromo oxidasa, subunidad I -COI) y métodos de análisis filogenéticos y de clados anidados (NCA), para realizar la primera valoración de la estructura genética del coral naranja Astroides calycularis (Pallas, 1766), una especie amenazada del Mediterráneo, a partir de muestras de 12 localidades a lo largo de su área de distribución. En las localidades situadas en la región más occidental del Mediterráneo se encontró cierta homogeneidad genética, mientras que al comparar estas localidades con las de las cuencas argelina y del mar Tirreno se observó una ligera diferenciación

Environmental drivers of distribution and reef development of the Mediterranean coral Cladocora caespitosa

Cladocora caespitosa is the only Mediterranean scleractinian similar to tropical reef-building corals. While this species is part of the recent fossil history of the Mediterranean Sea, it is currently considered endangered due to its decline during the last decades. Environmental factors affecting the distribution and persistence of extensive bank reefs of this endemic species across its whole geographic range are poorly understood. In this study, we examined the environmental response of C. caespitosa and its main types of assemblages using ecological niche modeling and ordination analysis. We also predicted other suitable areas for the occurrence of the species and assessed the conservation effectiveness of Mediterranean marine protected areas (MPAs) for this coral. We found that phosphate concentration and wave height were factors affecting both the occurrence of this versatile species and the distribution of its extensive bioconstructions in the Mediterranean Sea. A set of factors (diffuse attenuation coefficient, calcite and nitrate concentrations, mean wave height, sea surface temperature, and shape of the coast) likely act as environmental barriers preventing the species from expansion to the Atlantic Ocean and the Black Sea. Uncertainties in our large-scale statistical results and departures from previous physiological and ecological studies are also discussed under an integrative perspective. This study reveals that Mediterranean MPAs encompass eight of the ten banks and 16 of the 21 beds of C. caespitosa. Preservation of water clarity by avoiding phosphate discharges may improve the protection of this emblematic species.Spanish Ministry of Economy and Competitiveness [CTM2014-57949-R]info:eu-repo/semantics/publishedVersio

Overview of the conservation status of Mediterranean anthozoans

The IUCN Red List of Threatened SpeciesTM – Regional AssessmentThis report presents the conservation status of the anthozoans occurring in the Mediterranean Sea, based on the assessment of 136 species using the IUCN Red List methodology. It identifies those species that are threatened with extinction at the regional level to guide appropriate conservation actions in order to improve their statusVersión del edito

Drivers of population structure of the bottlenose dolphin (Tursiops truncatus) in the Eastern Mediterranean Sea

The drivers of population differentiation in oceanic high dispersal organisms, have been crucial for research in evolutionary biology. Adaptation to different environments is commonly invoked as a driver of differentiation in the oceans, in alternative to geographic isolation. In this study, we investigate the population structure and phylogeography of the bottlenose dolphin (Tursiops truncatus) in the Mediterranean Sea, using microsatellite loci and the entire mtDNA control region. By further comparing the Mediterranean populations with the well described Atlantic populations, we addressed the following hypotheses: (1) bottlenose dolphins show population structure within the environmentally complex Eastern Mediterranean Sea; (2) population structure was gained locally or otherwise results from chance distribution of preexisting genetic structure; (3) strong demographic variations within the Mediterranean basin have affected genetic variation sufficiently to bias detected patterns of population structure. Our results suggest that bottlenose dolphin exhibits population structures that correspond well to the main Mediterranean oceanographic basins. Furthermore, we found evidence for fine scale population division within the Adriatic and the Levantine seas. We further describe for the first time, a distinction between populations inhabiting pelagic and coastal regions within the Mediterranean. Phylogeographic analysis suggests that current genetic structure, results mostly from stochastic distribution of Atlantic genetic variation, during a recent postglacial expansion. Comparison with Atlantic mtDNA haplotypes, further suggest the existence of a metapopulation across North Atlantic/Mediterranean, with pelagic regions acting as source for coastal environments

Genetic assessment of population structure and connectivity in two endemic Mediterranean corals: Astroides calycularis (Pallas, 1766) and Cladocora caespitosa (Linnaeus, 1767)

[ES] El objetivo general de la presente tesis es determinar la estructura genética y el alcance de la conectividad de las poblaciones de dos corales escleractinios del Mediterráneo, Astroides calycularis (Pallas, 1766) y Cladocora caespitosa (Linnaeus, 1767). Estos procesos están generalmente ligados a diferentes características biológicas de las especies, tales como la densidad y distribución de las poblaciones, la fecundidad, el éxito reproductor, el tipo de desarrollo larvario, la capacidad de dispersión en cualquier etapa de su existencia, las variaciones demográficas y su interacción con otros factores bióticos y abióticos. Estos estudios son de gran utilidad a la hora de prever la respuesta de las poblaciones ante perturbaciones externas o frente al cambio global. Estas técnicas han sido principalmente aplicadas en el campo de las pesquerías, pero en la actualidad es creciente el número de trabajos que se centran también en el estudio genético de especies de invertebrados clave en determinados ecosistemas marinos. Los dos corales objeto de estudio en esta tesis son organismos modulares, bioconstructores, que albergan a su vez una gran diversidad de organismos asociados, tanto en los entresijos de su esqueleto de carbonato cálcico (e.g. pequeños poliquetos, crustáceos, moluscos, algas, organismos perforadores, esponjas, etc.) como en el interior de sus tejidos (e.g. zooxantelas en el caso de C. caespitosa, arqueas, bacterias, etc.), formando por tanto pequeños ecosistemas en sí mismos (de ahí que los corales se hayan denominado como “holobiontes”). Para alcanzar este objetivo, se llevaron a cabo muestreos en distintas áreas del Mediterráneo occidental. En concreto para A. calycularis en el mar de Alborán, donde la especie presenta mayor concentración, con comparaciones en la cuenca argelina y mar Tirreno; y para C. caespitosa el trabajo se ha centró en poblaciones del mar balear y cuenca argelina. Se utilizaron marcadores moleculares universales, y se diseñaron marcadores microsatélite como herramienta fundamental para el presente estudio, dada la escasa variabilidad obtenida con los primeros marcadores mencionados. Asimismo, se ha ahondado en el conocimiento de la biología reproductora de A. calycularis, aspecto básico para la interpretación de los resultados genéticos obtenidos. A partir del conocimiento obtenido con el uso de los marcadores microsatélite se han pretendido dilucidar el grado de variabilidad y el flujo génico de poblaciones de estas especies y la incidencia de posibles barreras oceanográficas (i.e. corrientes, remolinos, frentes). Los resultados de la presente tesis sugieren claramente que el grado de diferenciación genética y la conectividad entre las poblaciones de ambos corales depende principalmente del potencial de dispersión de sus plánulas, el cual viene principalmente determinado por el modo de reproducción sexual (fecundación interna-incubación- vs fecundación externa). A. calycularis y C. caespitosa son especies representativas de estos dos modos de reproducción. En tres poblaciones de A. calycularis geográficamente distantes, las plánulas se han descrito como “reptantes” y con flotabilidad negativa, mostrando escasa capacidad de dispersión. Ello concuerda con los resultados genéticos obtenidos de las poblaciones de la especie, que sugieren un modelo de conectividad y flujo génico predominante de aislamiento por distancia tipo “paso a paso” (“stepping-stone”), con eventos esporádicos de dispersión a de dispersión a mayores distancias a través de corrientes y procesos de “rafting”.Por otro lado, la fecundación en C. caespitosa se produce en la columna de agua. A pesar del escaso conocimiento acerca de la biología de las plánulas de este coral, su modo reproductor y el alto grado de conectividad encontrado entre sus poblaciones sugiere que éstas pueden dispersarse a grandes distancias, probablemente arrastradas por las corrientes superficiales dominantes. En lo que se refiere a la interacción de la fase larvaria de estos corales con barreras oceanográficas que puedan influir al flujo génico, se ha comprobado que el frente Almería-Orán parece actuar como una barrera en el caso de A. calycularis, en sinergia con su escasa capacidad de dispersión. Por otro lado, el frente balear y el canal de Ibiza no actúan como fuerte impedimento al flujo génico, aunque, en general, se ha observado un intercambio ligeramente superior de individuos en relación norte-sur y este-oeste. Para el diseño de las áreas marinas protegidas (AMPs) y en el marco del debate actual sobre el diseño de una red de AMPs (pocas y grandes o muchas pequeñas), debe tenerse en cuenta la escala espacial de dispersión y conectividad de al menos las especies clave de los ecosistemas marinos, como son estos corales. En el caso de A. calycularis, se recomendaría la creación de micro-reservas, por lo tanto, favoreciendo su auto-reclutamiento y permitiendo la dispersión a áreas no protegidas. En el caso de C. caespitosa, se recomienda tener en consideración la escasa presencia de arrecifes monosespecíficos de esta especie de cara a su conservación y el AMP idónea sería aquella que tuviera un tamaño suficiente como para proteger las localidades más ricas. Los dos corales estudiados han sufrido una notable regresión durante el Pleistoceno y Holoceno, debido posiblemente a causas climáticas, agravada en la época actual por la acción humana, bien sea directa o indirectamente. A. calycularis ya cuenta con diferentes figuras de protección en diversas legislaciones nacionales e internacionales, lo que está permitiendo un mayor acercamiento de gestores y entidades interesadas en la conservación a la especie, además de un incremento en el número de estudios acerca de su biología básica y autoecología, así como a respuestas de este coral frente a ambientes cambiantes, los cuales son de gran utilidad a la hora de elaborar los planes adecuados de gestión activa de la especie para su conservación. Sin embargo, C. caespitosa no posee ninguna figura legal de protección, pese a estar incluida en la lista roja de especies de la UICN, y se cree que existen suficientes motivos para la elaboración de las propuestas convenientes a los correspondientes estamentos, y su categorización como especie amenazada. Estudios como los llevados a cabo en la presente tesis son primordiales a la hora de establecer planes de manejo y conservación, no ya sólo de las especies estudiadas, sino de otras especies con características biológicas y ciclos de vida similares, aportando estos resultados un modelo de aproximación a la conectividad de especies cuyas larvas tienen diferente potencial de dispersión.[EN] The main objective of this thesis is to provide knowledge about the genetic structure and extent of population connectivity in two endemic Mediterranean scleractinian corals, Astroides calycularis (Pallas, 1766) and Cladocora caespitosa (Linnaeus, 1767). These processes are generally linked to different biological characteristics, such as density and population distribution, fertility, reproductive success, the type of larval development, dispersal ability at various life stages, demographic changes and its interactions with other biotic and abiotic factors. These studies are useful for predicting the response of populations that face external disturbances or global changes. Previously, these assessments were mainly restricted to the field of fisheries biology, but recently the number of studies focusing on the genetics of keystone invertebrate species in certain marine ecosystems has grown. The two corals studied here are considered modular organisms and bioconstructor species. They provide a habitat for a diversity of associated micro- and macrofauna, not only in the intricacies of their skeletons (e.g. small polychaetes, crustaceans, molluscs, algae, dwelling organisms, sponges, etc.), but also in their tissues (e.g. zooxantellae, archeas, bacteria, etc.), thereby forming small ecosystems themselves (thus, corals are also known as “holobionts”). To achieve the main objective, different areas of the western Mediterranean Sea were sampled. Sampling for A. calycularis was primarily performed in the Alboran Sea, where the concentration of species is higher, with comparisons of samples from the Algerian Basin and Tyrrhenian Sea; C. caespitosa genetic studies focused on populations in the Balearic Sea and Algerian Basin. For genetic analyses, universal molecular markers were first used, but given the low variability obtained with these markers, microsatellite markers were designed as a basic tool for this study. The findings presented in this thesis also expand the knowledge of the sexual reproductive cycle of A. calycularis, which is important for the interpretation of the genetic analyses.The data based on the analysis of microsatellite markers attempts to clarify the degree of variability and gene flow of populations of these species and the potential impact of oceanographic barriers (i.e. currents, eddy fronts). The results suggest that the degree of genetic differentiation and connectivity among populations of both corals depend mainly on the potential dispersal of their planulae, which is primarily determined by the species sexual reproductive pattern (internal fertilization/incubation vs. external fertilization). A. calycularis and C. caespitosa are representative species of these two different reproductive patterns. In three geographically distant populations of A. calycularis, the planulae were observed to be “crawling larvae” and as and acquiring negative buoyancy at the time of release, showing low dispersal abilities. This description is consistent with the genetic results obtained from the coral populations, which suggest a “stepping-stone” pattern of connectivity and gene flow, with sporadic dispersal events at greater distances by currents and “rafting” processes. In contrast, the fertilization of C. caespitosa occurs in the water column (i.e. a broadcast spawner). Despite the lack of knowledge of the biology of C. caespitosa planulae, its reproductive mode and the high degree of connectivity found among populations suggest that its planulae are able to disperse over long distances, probably via the prevailing surface currents. In terms of the interaction between the planulae of these corals and oceanographic barriers that influence gene flow, it was found that the Almería-Orán front appears to act as a barrier to dispersal in the case of A. calycularis, in synergy with its limited dispersal abilities. In contrast, the Ibiza Channel and Balearic Front do not act as strong impediments to gene flow; although in general, a slightly higher exchange of individuals from north to south and from east to west was observed. The spatial scale of dispersal and connectivity of a keystone species, such as the corals studied in this thesis, should be taken into consideration for the design of marine protected areas (MPAs) and in the current debate of few large or many small (SLOSS). In the case of A. calycularis, the creation of micro-reserves is recommended, thus promoting self-recruitment and allowing the spread into non-protected areas. In the case of C. caespitosa, for their conservation, the scarcity of monospecific reefs should be considered; a suitable MPA would be one that is of sufficient size to protect the wealthiest localities. These two corals have suffered significant regression processes during the Pleistocene and Holocene, possibly due to climatic causes, further aggravated by anthropogenic impacts. A. calycularis is currently catalogued under different national and international legislations, which allows managers and stakeholders interested in conservation to better understand this coral. Thus, the number of studies about its biology and auto-ecology and responses of the coral to changing environments have increased, which is useful for the active management and conservation of the species. Although included in the IUCN red list, C. caespitosa currently has no legal category of protection. However, there are sufficient reasons to consider it a threatened species. Thus, the development of appropriate proposals for the categorization of this species as threatened is recommended. Studies such as those carried out in this thesis are paramount for establishing management and conservation plans, not only for the species studied, but also for other species with similar biological characteristics and life cycles. The results from this thesis provide a model approach for studying anthozoans species with different potential dispersals.Casado-Amezúa P, Gasparini G, Goffredo G. Phenological and morphological variations in the Mediterranean orange coral Astroides calycularis between two distant localities. Zoology 116: 159-167 (2013). http://hdl.handle.net/10261/134950Merino-Serrais, Paula; Casado-Amezúa, P. ; Ocaña, Ó; Templado, José ; Marchordom, Annie. Slight genetic differentiation between western and eastern limits of Astroides calycularis (Pallas, 1776) (Anthozoa, Scleractinia, Dendrophylliidae) distribution inferred from COI and ITS sequences. Graellsia 68(1): 207-218 (2012). http://hdl.handle.net/10261/123341Development of microsatellite markers for the orange coral Astroides calycularis (Scleractinia, Dendrophylliidae). Permanent genetic resources added to Molecular Ecology Resources Database 1 August 2009-30 September 2009. Molecular Ecology Resources 10(1): 232-236 (2010). https://digital.csic.es/handle/10261/43663Casado-Amezúa P, Goffredo S, Templado J, Machordom A. Genetic assessment of population structure and connectivity in the threatened Mediterranean coral Astroides calycularis (Scleractinia, Dendrophylliidae) at different spatia scales. Molecular Ecology 21(15): 3671-3685 (2012). http://hdl.handle.net/10261/123284Casado-Amezúa P, García-Jiménez R, Kersting DK, Templado J, Coffroth MA, Merino P, Acevedo I, Machordom A. Development of microsatellite markers as a molecular tool for conservation studies of the Mediterranean reef builder coral Cladocora caespitosa (Anthozoa, Scleractinia). Journal of Heredity, 102, 622-626 (2011). http://hdl.handle.net/10261/123390Peer reviewe

Phenological and morphological variations in the Mediterranean orange coral Astroides calycularis between two distant localities

[EN] This adaptation text reproduces chapter I of the dissertation “Results”: Estudio genético de la estructura poblacional y conectividad de dos corales endémicos del Mediterráneo: Astroides calycularis (Pallas, 1766) y Cladocora caespitosa (Linnaeus, 1767)= Genetic assessment of population structure and connectivity in two endemic Mediterranean corals: Astroides calycularis (Pallas, 1766) and Cladocora caespitosa (Linnaeus, 1767), of P. Casado-Amezúa (2012). http://hdl.handle.net/10261/134913[ES] Este artículo es una adaptación del capítulo I de “Resultados” de la tesis doctoral: Estudio genético de la estructura poblacional y conectividad de dos corales endémicos del Mediterráneo: Astroides calycularis (Pallas, 1766) y Cladocora caespitosa (Linnaeus, 1767)= Genetic assessment of population structure and connectivity in two endemic Mediterranean corals: Astroides calycularis (Pallas, 1766) and Cladocora caespitosa (Linnaeus, 1767), of P. Casado-Amezúa (2012). http://hdl.handle.net/10261/134913[EN] Studies of intraspecific variation in the presence of different environmental features are essential to improving the knowledge of species population dynamics and structure. Astroides calycularis is an azooxanthellate scleractinian coral commonly found in shallow rocky habitats of the southwestern Mediterranean Sea. This study compares the fertilization period of two coral populations located in dis- tantly separated localities; one in an upwelling area off the southern coast of the Iberian Peninsula, and the other on the southwestern coasts of Italy. Colony morphology varied between localities, the former having massive-shaped morphology with densely crowded polyps, the latter having bush-shaped morphology and separated polyps. These differences are possibly due to the different hydrodynamic conditions of their respective habitats. Gonochorism and planula brooding as sexual patterns and conditions of the coral coincide at both sites, but a delay in the timing of fertilization and planulation of the southern Iberian Peninsula population was observed, probably linked to a shift in the time at which seawater reaches its maximum temperature at each site.[ES] Estudios acerca de la variación intraespecífica en la presencia de diferentes características ambientales son esenciales para mejorar el conocimiento de la dinámica de las poblaciones. La temperatura superficial del agua (SST por sus siglas en inglés) juega un papel fundamental en el período de maduración gonadal de los corales escleractinios. Astroides calycularis es un coral escleractinio azooxanthelados que se encuentran comúnmente en hábitats rocosos poco profundos del suroeste del mar Mediterráneo. Este estudio compara el periodo de maduración gonadal del coral entre dos localidades distantes con diferentes SST, una en la costa sur de la Península Ibérica (promedio de SST 20,4 ± 1,8 º C), y la otra en la costa suroeste de Italia (promedio de SST 21,5 ± 1,9 º C). La colonias presentaban morfologías diferentes entre localidaes, las colonias colectadas en la primera localidad presentaban una morfología “masiva” (i.e. colonias con gran densidad de pólipos), mientras que en la localidad de Italia las colonias mostraban una morfología “ramificada” (i.e. pólipos separados en el interior de las colonias). y los pólipos separados. Estas diferencias se deben posiblemente a las diferentes condiciones hidrodinámicas de sus respectivos hábitats. Gonocorismo e incubación de la plánula como condición y patrón sexual del coral coincidíeron en ambas localidades, pero en relación a los aspectos cuantitativos de la gametogénesis, se observó un retraso en la maduración gonadal y planulación de la población del sur de la Península Ibérica con respecto a la del suroeste del mar Tirreno, ligado al periodo en el que el agua alcanza el máximo de temperatura anual en ambas áreas.P. Casado-Amezua was funded by a grant from the Spanish Research Council (CSIC).S. Goffredo was funded by the European Research Council (CoralWarm, ERC grant agreement n ◦ 249930).This study was supported by grants from Scuba Nitrox Safety International, the Association of Italian Tour Operators, the Ministry of Tourism of Egypt, Project AWARE Foundation and the Spanish Ministry of Science and Innovation (CTM2008-00496/MAR).Peer reviewe

Phenological and morphological variations in the Mediterranean orange coral Astroides calycularis between two distant localities

Studies of intraspecific variation in the presence of different environmental features are essential to improving the knowledge of species population dynamics and structure. Astroides calycularis is an azooxanthellate scleractinian coral commonly found in shallow rocky habitats of the southwestern Mediterranean Sea. This study compares the fertilization period of two coral populations located in distantly separated localities; one in an upwelling area off the southern coast of the Iberian Peninsula, and the other on the southwestern coasts of Italy. Colony morphology varied between localities, the former having massive-shaped morphology with densely crowded polyps, the latter having bush-shaped morphology and separated polyps. These differences are possibly due to the different hydrodynamic conditions of their respective habitats. Gonochorism and planula brooding as sexual patterns and conditions of the coral coincide at both sites, but a delay in the timing of fertilization and planulation of the southern Iberian Peninsula population was observed, probably linked to a shift in the time at which seawater reaches its maximum temperature at each site

Genetic assessment of population structure and connectivity in the threatened mediterranean coral Astroides calycularis (Scleractinia, Dendrophylliidae) at different spatial scales

[EN] This adaptation text reproduces chapter IV of the dissertation “Results”: Estudio genético de la estructura poblacional y conectividad de dos corales endémicos del Mediterráneo: Astroides calycularis (Pallas, 1766) y Cladocora caespitosa (Linnaeus, 1767)= Genetic assessment of population structure and connectivity in two endemic Mediterranean corals: Astroides calycularis (Pallas, 1766) and Cladocora caespitosa (Linnaeus, 1767), of P. Casado-Amezúa (2012). http://hdl.handle.net/10261/134913[ES] Este artículo es una adaptación del capítulo IV de “Resultados” de la tesis doctoral: Estudio genético de la estructura poblacional y conectividad de dos corales endémicos del Mediterráneo: Astroides calycularis (Pallas, 1766) y Cladocora caespitosa (Linnaeus, 1767)= Genetic assessment of population structure and connectivity in two endemic Mediterranean corals: Astroides calycularis (Pallas, 1766) and Cladocora caespitosa (Linnaeus, 1767), of P. Casado-Amezúa (2012). http://hdl.handle.net/10261/134913Understanding dispersal patterns, population structure and connectivity among populations is helpful in the management and conservation of threatened species. Molecular markers are useful tools as indirect estimators of these characteristics. In this study, we assess the population genetic structure of the orange coral Astroides calycularis in the Alboran Sea at local and regional scale, and at three localities outside of this basin. Bayesian clustering methods, traditional F-statistics and D est statistics were used to determine the patterns of genetic structure. Likelihood and coalescence approaches were used to infer migration patterns and effective population sizes. The results obtained reveal a high level of connectivity among localities separated by as much as 1 km and moderate levels of genetic differentiation among more distant localities, somewhat corresponding with a stepping-stone model of gene flow and connectivity. These data suggest that connectivity among populations of this coral is mainly driven by the biology of the species, with low dispersal abilities; in addition, hydrodynamic processes, oceanographic fronts and the distribution of rocky substrate along the coastline may influence larval dispersal. © 2012 Blackwell Publishing Ltd.P. Casado-Amezúa was funded by a grant from the Spanish Research Council (CSIC). S. Goffredo was funded by the European Research Council (CoralWarm, ERC grant agreement n. 249930). This research was supported by BBVA Foundation and the Spanish Ministry of Science and Innovation (CTM2008-00496 ⁄ MAR).Peer Reviewe