Laura Núñez-Pons | Universitat de Barcelona (original) (raw)

Papers by Laura Núñez-Pons

Journal of Marine Science and Engineering

During scientific expeditions in Indonesia and Vietnam, several sponge specimens belonging to the... more During scientific expeditions in Indonesia and Vietnam, several sponge specimens belonging to the genus Cladocroce were collected. The integration of morphological and molecular analyses, incorporating species delimitation models (ABGD, ASAP, and bPTP) and phylogenetic approaches using three molecular markers (COI, 28S, and 18S–ITS1–5.8S–ITS2–28S), allowed us to discriminate three congeneric species. Two of these species (C. burapha and C. pansinii sp. nov.) were supported by morphological and molecular data, whereas a third species (C. lamellata sp. nov.) was delimited by morphological data only. We formally describe two new species, C. pansinii sp. nov. and C. lamellata sp. nov. C. aculeata is a newly recorded species for Indonesia and the first documented finding after the original description. The re-examination of the type material of C. burapha, and indirectly the molecular approach, allowed us to confirm that C. burapha lives in sympatry with C. pansinii sp. nov. in Vietnam a...

Background Historically, Hawai’i has had few massive coral bleaching events, until two consecutiv... more Background Historically, Hawai’i has had few massive coral bleaching events, until two consecutive heatwaves elevated seawater temperatures in 2014 and 2015. Consequent mortality and thermal stress were observed in the reef systems of Kane’ohe Bay (O’ahu). Two of the dominant species exhibited a phenotypic dichotomy of either bleaching resistance or susceptibility (Montipora capitata and Porites compressa), while a third species (Pocillopora acuta) was broadly susceptible to bleaching. In order to survey temporal shifts in the coral microbiomes during bleaching and recovery in all three of these coral species, 50 colonies were tagged and periodically monitored. Metabarcoding of three genetic markers (16S rRNA gene ITS1 and ITS2) followed by compositional approaches for community structure analysis, differential abundance and correlations for longitudinal data were used to temporally track and compare Bacteria/Archaea, Fungi and Symbiodiniaceae dynamics of the tagged colonies. Result...

Continental Shelf Research, 2018

Deception Island is an active volcano located at the southern end of the South Shetland Archipela... more Deception Island is an active volcano located at the southern end of the South Shetland Archipelago, in the Antarctic Ocean. After the last eruption in 1970, benthic recolonization took place within the bay, with echinoderms being the dominant epifauna (e.g., the ophiuroid Ophionotus victoriae, the echinoid Sterechinus neumayeri and the sea star Odontaster validus), together with dense infaunal communities (mostly composed by oligochaetes, polychaetes, and bivalves). Here, we aim to describe the actual status of the marine benthic ecosystems inhabiting the shallow subtidal areas of this volcanic island. Benthic species were qualitatively scored as presence versus absence, considering the different sampling effort between localities done over the years. A total of 139 species of macroorganisms, belonging to 16 phyla were found, including fauna and flora, increasing the species richness values previously reported in all sites surveyed within the volcano caldera. Moreover, a dramatic increase in biodiversity was found towards the entrance of the bay. We suggest, however, that recolonization from external waters may not be the only reason for this pattern. In fact, sediment flux rates and substrate instability are common disturbances within the bay, probably being among the major factors determining benthic community assemblages. These processes probably favour deposit feeding communities at the innermost locations of the bay. This study provides a remarkably increased and updated species inventory from previous reports, altogether with a description of the main communities inhabiting the bay and the abiotic factors regulating this, mainly the bottom type.

Marine Ecology Progress Series, 2014

El Instituto Español de Oceanografía (IEO) participa, con la Universidad de Barcelona (UB) y otro... more El Instituto Español de Oceanografía (IEO) participa, con la Universidad de Barcelona (UB) y otros centros de investigación, en el proyecto ACTIQUIM, cuya finalidad principal es determinar la actividad ecológica de productos naturales marinos obtenidos de organismos antárticos mediante experimentos de ecología química realizados in situ.Instituto Español de OceanografíaVersión del edito

International Journal of Molecular Sciences, 2020

The Gram-negative Pantoea eucrina D2 was isolated from the marine sponge Chondrosia reniformis. S... more The Gram-negative Pantoea eucrina D2 was isolated from the marine sponge Chondrosia reniformis. Sponges were collected in a shallow volcanic vents system in Ischia island (South Italy), influenced by CO2 emissions and lowered pH. The chemical diversity of the secondary metabolites produced by this strain, under different culture conditions, was explored by a combined approach including molecular networking, pure compound isolation and NMR spectroscopy. The metabolome of Pantoea cf. eucrina D2 yielded a very complex molecular network, allowing the annotation of several metabolites, among them two biosurfactant clusters: lipoamino acids and surfactins. The production of each class of metabolites was highly dependent on the culture conditions, in particular, the production of unusual surfactins derivatives was reported for the first time from this genus; interestingly the production of these metabolites only arises by utilizing inorganic nitrogen as a sole nitrogen source. Major compon...

Marine Environmental Research, 2017

Bryozoans are among the most abundant and diverse members of the Antarctic benthos, however the r... more Bryozoans are among the most abundant and diverse members of the Antarctic benthos, however the role of bioactive metabolites in ecological interactions has been scarcely studied. To extend our knowledge about the chemical ecology of Antarctic bryozoans, crude ether extracts (EE) and butanol extracts (BE) obtained from two Antarctic common species (Cornucopina pectogemma and Nematoflustra flagellata), were tested for antibacterial and repellent activities. The extracts were screened for quorum quenching and antibacterial activities against four Antarctic bacterial strains (Bacillus aquimaris, Micrococcus sp., Oceanobacillus sp. and Paracoccus sp.). The Antarctic amphipod Cheirimedon femoratus and the sea star Odontaster validus were selected as sympatric predators to perform anti-predatory and substrate preference assays. No quorum quenching activity was detected in any of the extracts, while all EE exhibited growth inhibition towards at least one bacterium strain. Although the species were not repellent against the sea star, they caused repellence to the amphipods in both extracts, suggesting that defence activities against predation derive from both lipophilic and hydrophilic metabolites. In the substrate preference assays, one EE and one BE deriving from different specimens of the species C. pectogemma were active. This study reveals intraspecific variability of chemical defences and supports the fact that chemically mediated interactions are common in Antarctic bryozoans as means of protection against fouling and predation.

La consulta d'aquesta tesi queda condicionada a l'acceptació de les següents condicions d'ús: La ... more La consulta d'aquesta tesi queda condicionada a l'acceptació de les següents condicions d'ús: La difusió d'aquesta tesi per mitjà del servei TDX (www.tdx.cat) ha estat autoritzada pels titulars dels drets de propietat intel•lectual únicament per a usos privats emmarcats en activitats d'investigació i docència. No s'autoritza la seva reproducció amb finalitats de lucre ni la seva difusió i posada a disposició des d'un lloc aliè al servei TDX. No s'autoritza la presentació del seu contingut en una finestra o marc aliè a TDX (framing). Aquesta reserva de drets afecta tant al resum de presentació de la tesi com als seus continguts. En la utilització o cita de parts de la tesi és obligat indicar el nom de la persona autora. ADVERTENCIA. La consulta de esta tesis queda condicionada a la aceptación de las siguientes condiciones de uso: La difusión de esta tesis por medio del servicio TDR (www.tdx.cat) ha sido autorizada por los titulares de los derechos de propiedad intelectual únicamente para usos privados enmarcados en actividades de investigación y docencia. No se autoriza su reproducción con finalidades de lucro ni su difusión y puesta a disposición desde un sitio ajeno al servicio TDR. No se autoriza la presentación de su contenido en una ventana o marco ajeno a TDR (framing). Esta reserva de derechos afecta tanto al resumen de presentación de la tesis como a sus contenidos. En la utilización o cita de partes de la tesis es obligado indicar el nombre de la persona autora. WARNING. On having consulted this thesis you're accepting the following use conditions: Spreading this thesis by the TDX (www.tdx.cat) service has been authorized by the titular of the intellectual property rights only for private uses placed in investigation and teaching activities. Reproduction with lucrative aims is not authorized neither its spreading and AGRADECIMIENTOS… y otros relatos..... Una pequeña referencia a la Antártida desde Valencia con amor: "L'Antártida no està lluny…, ni molt lluny…, està a fer la ma!!!... On mengen els pingüins." En un lugar de la Antártida, de cuyo nombre, seguro consigo que acabéis acordándoos… existen unos fondos marinos misteriosos habitados por maravillosos seres… adaptados a condiciones extremas y duras. Es casi como pasar un invierno en Teruel, que sí que existe, y verte a esas abuelillas comiendo sopas de ajo. Igualmente, estos sorprendentes animales polares llegan a ser totalmente desconocidos para muchos, con esponjas que pueden vivir más que Chavela Vargas dopada con antioxidantes. Sin ellos nada de esto hubiera pasado, quizás la tesis hubiera sido mucho más sencilla, pero seguro no tan divertida ni intensa. A estos seres les debo todo lo que me han dejado descubrirles… Puede ser que en algo me engañen… (nunca hay que fiarse, ni con seres sésiles y blanditos como ellos, en esto de la ciencia hay que ser un poco gallego) pero han definitivamente contribuido a enriquecer mi pasión por la biología marina, todo dicho, a veces no me hubiera importado calentarme un poco más estudiando especies caribeñas... Pero en nada me arrepiento vestirme de cazafantasmas con nuestro traje seco DUI y bajar a visitar a estos curiosos organismos. Este lugar del que os aprenderéis el nombre sin quererlo, es el Mar de Weddell y el Archipiélago de las Shetland del Sur, con la Isla Decepción como punto de referencia, experimentación y residencia secundaria… De hecho, si hubiera continuado lo del ladrillo, yo me compraba un iglú adosado con lago, y un leoncito marino de mascota… Y por supuesto me apuntaba al comité de fiestas locales, que no son pocas. Mi padre, al igual que mis animales de estudio, no ha sobrevivido a mi tesis… , la Antártida es dura, y todo ocurre con mucha lentitud… pero cada uno ha tenido sus causas. Ahora, que me registren, no hice ningún extracto con mi padre. Si alguien tuvo la posibilidad de conocerlo físicamente, habría pensado que se pasó media vida buscando a la Pantera Rosa (era igual que Peter Sellers)… No, en realidad arreglaba corazones, pulmones y otras cosas… también rompía unas cuantas pero de esas sin vida conocida. Me hubiera encantado que estuviese aquí, aunque no hubiera aguantado una hora y media de tesis sin fumar… con lo cuál una cosa que se ha ahorrado. Me he dado cuenta que de pequeña detestaba a los enfermos porque me quitaban el tiempo que podía estar con mis padres, que trabajaban como mulas… Mi padre adoraba a los enfermos, pero detestaba a los médicos, me decía que eran todos unos gilipollas, y que nunca se me ocurriera estudiar medicina como él. Sin embargo, cuando le dije a mi padre al acabar el instituto que de estudiar algo, quería estudiar Biología o Filosofía, mi padre echó el grito en el cielo…. ¡te morirás de hambre! decía… Ahora se arrepentía de haberme inculcado ese odio hacia los médicos, a lo que añadía: pues hazte forense, tratarás con policías, detectives y asesinos, y los enfermos no se te quejarán… pero hija mía, biología, filosofía… yo no voy a vivir para mantenerte. A lo que yo respondía, bueno, al menos o estoy con locos o con animales, pero no con enfermos y gilipollas… Ahora, me gustaría que viera que, aunque no está dicho que no me vaya a morir de hambre, al menos he hecho algo dejando mucho esfuerzo y dedicación, y de lo que estoy orgullosa. Lo de librarme de enfermos y gilipollas, casi me lo he ahorrado, lo de locos ya… menos mal que, por si acaso, siempre tenemos a los animales. Una persona paciente y parsimoniosa es lo que debió ver mi Jefa en mí al conocerme… nada más equivocado para casi todo, pero por el camino yo me entretengo, y eso engaña, y en algunos aspectos, estos años de ciencia me han enseñado. Un buen día de cumpleaños, cuando hacía menos años que una esponja de cristal, pero más que un anfípodo, me llamaron (una tal Conxita Avila a la que intentaba venderle mis servicios de buza, bióloga, y potencial doctoranda como fuese), y me hicieron el mejor regalo de cumpleaños que me podían dar… ¡¡PharmaMar me contrataba y me pagaba una campaña a la Antártida!!!... Impresionaaaaaante… considerando que yo me encontraba enterrando un tejón atropellado medio descompuesto por el norte de Cataluña, la noticia hacía tronar mi cabeza y las Campanas de San Juan del centro cerebral del "¡eso hay que celebrarlo!". La noticia me vino tan a gusto, que ya ni me olía el cadáver del mustélido ese, y fue un entierro bastante alegre, con aperitivo de celebración… Así, poco más o menos, empezó el contacto con-tacto con la que se convertiría mi directora de tesis, Conxita. Ella se ha convertido en mi "madre científica", hemos discutido muuucho, reído y nos hemos abrazado, la verdad que la quiero, me sigue sorprendiendo en cierta cosas, y eso me Abstract Many ecosystems are structured by generalist predation, and this constitutes a driving force for the evolution of defensive strategies, such as chemical defense. This, in conjunction with low nutritional quality, helps prey to avoid being consumed. Producing protective metabolites is expensive, and the Optimal Defense Theory (ODT) postulates their administration and distribution to guarantee survival. Antarctic benthos is influenced by opportunistic feeders, mainly asteroids and also abundant mesograzers. Hence, feedingdeterrence experiments were performed with the circumpolar asteroid macropredator Odontaster validus, to determine the presence of apolar unpalatable defenses in extracts from Antarctic benthic invertebrates and macroalgae. Moreover, feeding acceptabilities towards the circum-Antarctic omnivorous amphipod Cheirimedon femoratus, were assessed using the same lipophilic fractions. In this study, we aim to contrast the results obtained in both types of bioassays against two relevant sympatric consumers. A 44.9% of the extracts were unpalatable for both consumers, versus a 10.2% resulting suitable. Furthermore, 38.8% were repellent to the amphipod but edible for the asteroid, and 6.1% of the fractions were rejected only by sea stars. Overall more deterrent activities were reported towards amphipods than against asteroids, principally in fractions coming from algae and sponges, in which amphipods may especially have an effect in defenses distribution. Generalist mesograzers through casual host-prey associations may be significant promoters of defensive chemistry on their living substrata, because of the localized pressure they exert. Only a few of the samples tested did allocate repellents in specific body-regions following the ODT, and several species seem to combine different defensive traits. Key words Antarctic invertebrates • Antarctic algae • chemical ecology • sea star Odontaster validus • amphipod Cheirimedon femoratus • chemical defense

Marine Drugs, 2014

Many bioactive products from benthic invertebrates mediating ecological interactions have proved ... more Many bioactive products from benthic invertebrates mediating ecological interactions have proved to reduce predation, but their mechanisms of action, and their molecular identities, are usually unknown. It was suggested, yet scarcely investigated, that nutritional quality interferes with defensive metabolites. This means that antifeedants would be less effective when combined with energetically rich prey, and that higher amounts of defensive compounds would be needed for predator avoidance. We evaluated the effects of five types of repellents obtained from Antarctic invertebrates, in combination with diets of different energetic values. The compounds came from soft corals, ascidians and hexactinellid sponges; they included wax esters, alkaloids, a meroterpenoid, a steroid, and the recently described organic acid, glassponsine. Feeding repellency was tested through preference assays by preparing diets (alginate pearls) combining different energetic content and inorganic material. Experimental diets contained various concentrations of each repellent product, and were offered along with control compound-free pearls, to the Antarctic omnivore amphipod Cheirimedon femoratus. Meridianin alkaloids were the most active repellents, and wax esters were the least active when combined with foods of distinct energetic content. Our data show that levels of repellency vary for each compound, and that they perform differently when mixed with distinct assay foods. The natural products that interacted the most with energetic content were those occurring in nature at higher concentrations. The bioactivity of the remaining metabolites tested was found to depend on a threshold concentration, enough to elicit feeding repellence, independently from nutritional quality.

Polar Biology, 2010

Predation and competition are important factors structuring Antarctic benthic communities and are... more Predation and competition are important factors structuring Antarctic benthic communities and are expected to promote the production of chemical defenses. Tunicates are subject to little predation, and this is often attributed to chemical compounds, although their defensive activity has been poorly demonstrated against sympatric predators. In fact, these animals, particularly the genus Aplidium, are rich sources of bioactive metabolites. In this study, we report the natural products, distribution and ecological activity of two Aplidium ascidian species from the Weddell Sea (Antarctica). In our investigation, organic extracts obtained from external and internal tissues of specimens of A. falklandicum demonstrated to contain deterrent agents that caused repellency against the Antarctic omnivorous predator, the sea star Odontaster validus. Chemical analysis performed with Antarctic colonial ascidians Aplidium meridianum and Aplidium falklandicum allowed the puriWcation of a group of known bioactive indole alkaloids, meridianins A-G. These isolated compounds proved to be responsible for the deterrent activity.

Marine Drugs, 2012

Ascidians have developed multiple defensive strategies mostly related to physical, nutritional or... more Ascidians have developed multiple defensive strategies mostly related to physical, nutritional or chemical properties of the tunic. One of such is chemical defense based on secondary metabolites. We analyzed a series of colonial Antarctic ascidians from deep-water collections belonging to the genera Aplidium and Synoicum to evaluate the incidence of organic deterrents and their variability. The ether fractions from 15 samples including specimens of the species A. falklandicum, A. fuegiense, A. meridianum, A. millari and S. adareanum were subjected to feeding assays towards two relevant sympatric predators: the starfish Odontaster validus, and the amphipod Cheirimedon femoratus. All samples revealed repellency. Nonetheless, some colonies concentrated defensive chemicals in internal body-regions rather than in the tunic. Four ascidian-derived meroterpenoids, rossinones B and the three derivatives 2,3-epoxy-rossinone B, 3-epi-rossinone B, 5,6-epoxy-rossinone B, and the indole alkaloids meridianins A-G, along with other minoritary meridianin compounds were isolated from several samples. Some purified metabolites were tested in feeding assays exhibiting potent unpalatabilities, thus revealing

Journal of Sea Research, 2013

Polar marine ecosystems have global ecological and economic importance because of their unique bi... more Polar marine ecosystems have global ecological and economic importance because of their unique biodiversity and their major role in, between others, climate processes and commercial fisheries. Portugal and Spain have been highly active in a wide range of disciplines in marine biology of the Antarctic and the Arctic. The main aim of this paper is to provide a synopsis of some of the results and initiatives undertaken by Portuguese and Spanish polar teams within the field of marine sciences, particularly on the benthic and pelagic biodiversity (species diversity and abundance, including microbial), molecular, physiological and chemical mechanisms in polar organisms, conservation and ecology of top predators (particularly penguins, albatrosses and seals), pollutants and evolution of marine organisms, associated with major issues such as climate change, ocean acidification and UV radiation effects. Both countries have focused their polar research more in the Antarctic than in the Arctic. Portugal and Spain should encourage research groups to continue increasing their collaborations with other countries and develop multidisciplinary research projects, as well as to maintain highly active within major organizations, such as the Scientific Committee for Antarctic Research (SCAR), the International Arctic Science Council (IASC)

Journal of Natural Products, 2009

Chemical investigation of the lipophilic extract of the Antarctic soft coral Alcyonium grandis le... more Chemical investigation of the lipophilic extract of the Antarctic soft coral Alcyonium grandis led us to the finding of nine unreported sesquiterpenoids, 2-10. These molecules are members of the illudalane class and in particular belong to the group of alcyopterosins, illudalanes isolated from marine organisms. The structures of 2-10 were determined by interpretation of spectroscopic data. Repellency experiments conducted using the omnivorous Antarctic sea star Odontaster Validus revealed a strong activity in the lipophilic extract of A. grandis against predation.

Natural Product Communications, 2014

The n-butanol extract of an Antarctic hexactinellid sponge, Anoxycalyx (Scolymastra) joubini, was... more The n-butanol extract of an Antarctic hexactinellid sponge, Anoxycalyx (Scolymastra) joubini, was found to contain a taurine-conjugated anthranilic acid, never reported so far either as a natural product or by synthesis. The compound was inactive against human cancer cells in an in vitro growth inhibitory test, and also showed no antibacterial activity.

Journal of Chemical Ecology, 2013

Alcyonacean soft corals lack physical or skeletal defenses and their nematocyst system is weak, l... more Alcyonacean soft corals lack physical or skeletal defenses and their nematocyst system is weak, leading to the conclusion that soft corals mainly rely on chemistry for protection from predators and microbes. Defensive chemicals of primary and secondary metabolic origin are exuded in the mucus surface layer, explaining the general lack of heavy fouling and predation in corals. In Antarctic ecosystems, where generalist predation is intense and mainly driven by invertebrate consumers, the genus Alcyonium is represented by eight species. Our goal was to investigate the understudied chemical ecology of Antarctic Alcyonium soft corals. We obtained six samples belonging to five species: A. antarcticum, A. grandis, A. haddoni, A. paucilobulatum, and A. roseum, and assessed the lipid-soluble fractions for the presence of defensive agents in these specimens. Ethyl ether extracts were tested in feeding bioassays with the sea star Odontaster validus and the amphipod Cheirimedon femoratus as putative sympatric predators. Repellent activities were observed towards both consumers in all but one of the samples assessed. Moreover, three of the extracts caused inhibition to a sympatric marine bacterium. The ether extracts afforded characteristic illudalane sesquiterpenoids in two of the samples, as well as particular wax esters subfractions in all the colonies analyzed. Both kinds of metabolites displayed significant deterrent activities demonstrating their likely defensive role. These results suggest that lipophilic chemicals are a first line protection strategy in Antarctic Alcyonium soft corals against predation and bacterial fouling.

Amplicon sequencing dataset (Illumina MiSeq) of bacteria (16S ssu rRNA gene) and Fungi (ITS) asso... more Amplicon sequencing dataset (Illumina MiSeq) of bacteria (16S ssu rRNA gene) and Fungi (ITS) associated with healthy and diseased Antarctic sea stars (Odontaster validus)