Pilar Díaz

• PhD
• Assistant Professor at University of Santiago de Compostela

Cryptic diversity is common in the red algae and is often discovered when comparing specimens from distant locations or different morphotypes of species with high phenotypic plasticity. The genus Lophurella includes seven species from the cold-temperate coasts of the southern hemisphere. L. periclados is the only species reported from Australia whe...

Red algae are frequently dominant components of the non-native biotas in coastal areas. They often remain undetected because of morphological similarity between native and introduced species and cryptic diversity. Routine use of DNA barcodes can aid in setting baseline tabulations of native species and for detecting introduced species. We performed...

Our knowledge of seaweed diversity and biogeography still largely relies on information derived from morphological identifications, but the use of molecular tools is revealing that cryptic diversity is common among algae. Polysiphonia scopulorum is a turf-forming red alga widely reported in tropical and temperate coasts worldwide. The only study ba...

Algal turfs are ecosystem engineers receiving steadily growing attention in recent years in relation to their expansion on temperate reefs due to global change. However, their species diversity and taxonomy are still poorly understood, mostly based solely on morphological information. Algal turfs are the dominant type of assemblage in Macaronesia,...

Molecular analyses, in combination with morphological studies, provide invaluable tools for delineating red algal taxa. However, molecular datasets are incomplete and taxonomic revisions are often required once additional species or populations are sequenced. The small red alga Conferva parasitica was described from the British Isles in 1762 and th...

Assessing the taxonomic status of closely related taxa is crucial in plant systematics and can have important implications for conservation and human plant use. Erica andevalensis Cabezudo & Rivera is a metallophyte endemic species from highly metal-polluted soils of SW Iberian Peninsula, an area with a mining history going back more than 5,000 yea...

Kelp forests are critical marine ecosystems that provide habitat and ecological services, as well as economic benefits. However, kelp forests worldwide are facing multiple pressures, including climate change and human activities. In this study, we investigated whether recruitment success, an infrequently recorded variable in kelp monitoring studies...

The 2007 flora “Green Seaweeds of Britain and Ireland” did not present the molecular data underpinning the Ulvaceae treatment, mostly ITS sequences. Subsequently, names have changed as type material of Ulva species is sequenced and intensive sampling with DNA barcoding adds new European species. To update the Ulvaceae, we systematically sampled fro...

Effective monitoring of non-indigenous seaweeds and combatting their effects relies on a solid confirmation of the non-indigenous status of the respective species. We critically analysed the status of presumed non-indigenous seaweed species reported from the Mediterranean Sea, the Northeast Atlantic Ocean and Macaronesia, resulting in a list of 140...

Species identification in red algae poses significant challenges when relying solely on morphological characteristics. Consequently, the absence of molecular information often conceals misidentifications, cryptic diversity and introduced cryptic species. Within the genus Lophocladia, species have traditionally been delineated based on subtle morpho...

Cryptic diversity is common among marine macroalgae, with molecular tools leading to the discovery of many new species. To assign names to these morphologically similar species, the type and synonyms have to be examined , and if appropriate, new species must be described. The turf-forming red alga Polysiphonia scopulorum was originally described fr...

Background and Aims Kelps are the primary foundation species in temperate subtidal rocky shores worldwide. However, global change is causing their decline with consequences for the organisms that rely on them. An accurate assessment of these consequences may depend on which attributes of the associated community are considered. This study shows tha...

Parasitic red algae are an interesting system for investigating the genetic changes that occur in parasites. These parasites have evolved independently multiple times within the red algae. The functional loss of plastid genomes can be investigated in these multiple independent examples, and fine-scale patterns may be discerned. The only plastid gen...

The analysis of biological and ecological traits has a long history in evolutionary and ecological research. However, trait data are often scattered and standardised terminology that transcends taxonomic and biogeographical context are generally missing. As part of the development of a global trait database of marine species, we collated trait info...

Effective monitoring and combatting the effect of non-indigenous seaweeds relies on a solid confirmation of the non-indigenous status of the species. We critically analysed the status of presumed non-indigenous seaweed species reported from the Mediterranean Sea, the Northeast Atlantic Ocean and Macaronesia, resulting in a list of 140 species whose...

The introduction of new non-indigenous species (NIS) in Spanish marine waters is addressed under Descriptor 2 of the European Union’s Marine Strategy Framework Directive. National baseline inventories of NIS have been compiled and updated for the three subregions (Western Mediterranean Sea, WMED; Bay of Biscay–Iberian Coast, ABI; Macaronesia, AMA)...

Invasive species have been a focus of concern in recent decades, becoming more problematic due to the cumulative impacts of climate change. Understanding the interactions among stress factors is essential to anticipate ecosystems' responses. Hereby, robust modeling frameworks must be able to identify the environmental drivers of invasion and foreca...

Introduced seaweeds and undescribed species often remain undetected because marine regional floras are as yet poorly understood. DNA sequencing facilitates their detection, but databases are incomplete, so their improvement will continue to lead the discovery of these species. Here we aim to clarify the taxonomy of two turf-forming red algal Austra...

Species of flora and fauna occurring in the west of Ireland and south-west Europe, known as Lusitanian elements, constitute a puzzling case of isolated populations of uncertain origin. Here we studied the population genetic structure of the heather Erica mackayana in Ireland and northern Spain and compared it with its widespread close relative Eric...

The analysis of biological and ecological traits has a long history in evolutionary and ecological research. However, trait data are often scattered and standardised terminology that transcends taxonomic and biogeographical context are generally missing. As part of the development of a global trait database of marine species, we collated trait info...

The number of newly described species has increased since the addition of molecular data to taxonomic studies, revealing that species considered widely distributed by morphological and anatomical studies are often comprised of complexes of several distinct species. This study reports on a new turf-forming species of Digenea from the Greater Caribbe...

Species discovery is facilitated by the application of molecular tools and the exploration of poorly studied habitats. Recent surveys in Bafa Lake, Turkey, which experienced a transition from oligo- to mesohaline conditions during the last 40 years, led to the finding of two species of the genera Lophosiphonia and Polysiphonia. Our molecular and mo...

Alexandrium minutum blooms generally occur in semi-enclosed sites such as estuaries, harbours and lagoons, where enhanced stratification, restricted circulation and accumulation of resting cysts in the sediment set suitable habitat conditions for the proliferation of this paralytic shellfish poisoning toxigenic species. In the Galician Rías Baixas...

The present study adds 19 species (15 Rhodophyta, one Chlorophyta and three Ochrophyta) to the Azorean marine macroalgal flora, increasing the current total of species recorded in this region to 521 (349 Rhodophyta, 76 Chlorophyta and 96 Ochrophyta), and showing that this isolated island group supports a relatively rich marine macroalgal flora. Som...

Algal turfs are ecosystem engineers receiving growing attention in relation to their expansion on temperate reefs as a consequence of global change. However, their species diversity and taxonomy are still poorly understood. Turfs are composed of densely entangled small seaweeds, in which the red algal order Ceramiales is commonly a major component....

The use of molecular tools in red algal diversity surveys often reveals the existence of undescribed species. Here, we report a new Macaronesian turf-forming red alga in the otherwise mostly Pacific genus Melanothamnus Bornet & Falkenberg. This new taxon, Melanothamnus macaronesicus Rodríguez-Buján & Díaz-Tapia, sp. nov. is described based on morph...

The decline of kelps and algal canopies and the expansion of algal turfs because of global change is a recurrent pattern reported in temperate coasts worldwide. This pattern has also been identified in recent years in the northwestern Iberian Peninsula where Fucus serratus, a cold-water species that used to form extensive canopies in the intertidal...

Background: Syngnathid fishes (Actinopterygii, Syngnathidae) are flagship species strongly associated with seaweed and seagrass habitats. Seahorses and pipefishes are highly vulnerable to anthropogenic and environmental disturbances, but most species are currently Data Deficient according to the IUCN (2019), requiring more biological and ecological...

The classification of Cystoclonium obtusangulum has been questioned since the species was first described by Hooker and Harvey as Gracilaria? obtusangula. The objective of this study was to provide the first comprehensive taxonomic analysis of Cystoclonium obtusangulum, based on DNA sequences coupled with morphological observations made on syntype...

Background Syngnathid fishes (Actinopterygii, Syngnathidae) are flagship species strongly associated with seaweed and seagrass habitats. Seahorses and pipefishes are highly vulnerable to anthropogenic and environmental disturbances, but most species are currently Data Deficient according to the IUCN (2019), requiring more biological and ecological...

Background: Syngnathid fishes (Actinopterygii, Syngnathidae) are flagship species strongly associated with seaweed and seagrass habitats. Seahorses and pipefishes are highly vulnerable to anthropogenic and environmental disturbances, but most species are currently Data Deficient according to the IUCN (IUCN, 2019), requiring more biological and ecol...

The use of molecular tools often shows that regional species diversity differs from what we know from assessments based on morphological identifications. The seaweed flora of the British Isles has been well established over a long period from foundational work published during the xviii-xix centuries to more recent revisions based on molecular tool...

Seaweed communities are important coastal ecosystems representing good indicators of environmental variation related to climate change and other long-term changes. Long-term variation in the distribution of seaweed communities and individual seaweed species has been intensively investigated; however, long-term studies considering the whole seaweed...

Background: Syngnathid fishes (Actinopterygii, Syngnathidae) are flagship species highly associated to seaweed and seagrass habitats of marine ecosystems biodiversity. Seahorses and pipefish are highly vulnerable to anthropogenic and environmental disturbances, but most species are currently Data Defficient by IUCN (IUCN, 2019), requiring more biol...

Background: Syngnathid fishes (Actinopterygii, Syngnathidae) are flagship species strongly associated with seaweed and seagrass habitats. Seahorses and pipefishes are highly vulnerable to anthropogenic and environmental disturbances, but most species are currently Data Deficient according to the IUCN (IUCN, 2019), requiring more biological and ecol...

Number of species/taxa recorded 133 78 59 111 CHLOROPHYTA-ULVOPHYCEAE Acetabularia acetabulum + + + + Bryopsis corymbosa + + + Bryopsis cupressina + + Bryopsis duplex + Bryopsis feldmannii + Bryopsis hypnoides + + Bryopsis muscosa + Bryopsis pennata + + Bryopsis plumosa + + + Chaetomorpha ligustica + + Chaetomorpha linum + + + Cladophora coelothrix...

CHLOROPHYTA-ULVOPHYCEAE Acetabularia acetabulum + + + + Bryopsis corymbosa + + + Bryopsis cupressina + + Bryopsis duplex + + Bryopsis hypnoides + + + + + Bryopsis pennata + Bryopsis plumosa + + + + + Chaetomorpha ligustica + + Chaetomorpha linum + + + + Cladophora coelothrix + Cladophora dalmatica + + Cladophora hutchinsiae + +

The known distribution of seaweed species often requires updating after findings of new records outside the known range. The green algal family Halimedaceae is predominantly distributed in tropical and subtropical regions. Flabellia petiolata was considered endemic to the Mediterranean, but has also been recorded in the Canary Islands and Cape Verd...

Continuando con los estudios para la actualización del inventariado de la flora bentónica marina del Atlántico Ibérico.En este trabajo se incluye nueva información de distribución para 18 especies (3 Cyanobacteria, 9 Rhodophyta, 4 Ochrophyta, 2 Chlorophyta) de algas bentónicas marinas, recolectadas en el intermareal y submareal de 46 localidades de...

The exploration of seaweed diversity in poorly studied habitats has often led to the discovery of new species. Sand-covered rocks are an example, as they received less attention than sand-free rocky intertidal habitats during seaweed diversity surveys in Brazil. In sand-covered rocks from Espírito Santo and Rio de Janeiro we found an alga whose mor...

Zostera marina meadows represent an important marine ecosystem in the North temperate region. They are common in the northwestern Spain, but their distribution and biological traits remain poorly studied. Improving the knowledge of eelgrasses and identifying potential impact sources is necessary to implement conservation programs. Distribution, cov...

The order Ceramiales contains about one third of red algal diversity and it was classically classified into four families according to morphology. The first phylogenies based on one or two molecular markers were poorly supported and failed to resolve these families as monophyletic. Nine families are currently recognized, but relationships within an...

Pleurostichidium falkenbergii is an obligate epiphyte on Xiphophora chondrophylla and is endemic to northern New Zealand. This monotypic genus is characterised by having dorsiventral and laterally compressed thalli with 20 pericentral cells and complete cortication, adventitious trichoblasts, spherical spermatangial branches formed from cortical ce...

The composition, abundance, and distribution of epiphytic macroalgae living in meadows of Zostera marina L. in the northwestern Iberian Peninsula are here analyzed. We identified 63 species: 40 red algae, 16 brown algae, and 7 green algae. Most of them are classified as filamentous or filiform functional forms, while Pneophyllum fragile Kütz. was t...

Calliblepharis occidentalis was originally described from northeastern Brazil and later reduced to synonymy with C. fimbriata from South Africa. It was later reinstated, but phylogenetic relationships with other congeners and several morphological characters remain poorly understood. In the present article, topotype specimens of C. occidentalis wer...

The red algal order Ceramiales was previously arranged on the basis of morphological studies into five families: Ceramiaceae, Dasyaceae, Delesseriaceae, Rhodomelaceae and Sarcomeniaceae. The first phylogenies based on one or two molecular markers failed to produce well-resolved phylogenies or to resolve the first three families as monophyletic. At...

Cryptic diversity has been often detected in the red algae when molecular assisted taxonomy has been applied. It is common in species with alleged wide distributions or high phenotypic plasticity. The red algal genus Lophurella includes seven species from the cold and temperate southern hemisphere. L. caespitosa is endemic to New Zealand. L. pericl...

The widely distributed genus Codium is a major component of the marine macroalgal flora and has its largest species diversity in warm-temperate regions. Along the South coast of Australia, Codium is a diverse group, but the species diversity in the easternmost region of Victoria is not well-documented. In this study, we characterized the species di...

Polysiphonia adamsiae was originally described from Tasmania and simultaneously reported in New Zealand. It has an unusual combination of morphological characters: 10–12 pericentral cells and rhizoids in open connection with the pericentral cells. Rhizoid anatomy is similar to that of the tribe Polysiphonieae. However, P. adamsiae differs from most...

Despite studies suggesting that most seaweeds are poor dispersers, many red algal species are reported to have circumglobal distributions. Such distributions have mostly been based on morphological identifications, but molecular data have revealed a range of issues with morphologically defined species boundaries. Consequently, the real distribution...

Ten sites (2- 20 m depth), along the West coast of Cíes Archipelago (Atlantic Islands National Park, NW Spain), were surveyed twice in spring and summer 2016 to study distribution, habitat, genetic diversity and stable isotope signatures of Syngnathids (seahorses and pipefishes), a Family of vulnerable fish species. Most bottoms were characterized...

In recent years, the use of molecular data in algal systematics has increased as high-throughput sequencing (HTS) has become more accessible, generating very large datasets at a reasonable cost. In this perspectives paper, our goal is to describe how HTS technologies can advance algal systematics. Following an introduction to some common HTS techno...

In 2015 NatureScot commissioned a seabed habitat survey in the Sound of Barra MPA with a focus on the maerl and seagrass bed protected features of the site. This report presents the results of the diving survey work undertaken. Research Report 951 presents results of sediment grab sampling completed in 2015.

During our sampling surveys of the tribes Polysiphonieae and Streblocladieae in Spain and Australia, three previously unrecorded species were collected. Based on molecular and morphological evidence they are proposed as new species. Polysiphonia delicata sp. nov. and Polysiphonia radiata sp. nov. belong to the Polysiphonieae and share the synapomor...

The introduction of molecular tools has revolutionized the study of red algal systematics throughout all taxonomic levels over the last 25 years. Most of the research employed a single or a few molecular markers, with the inherent limitation that it does not provide enough data to resolve many phylogenetic relationships. The recent development of h...

With over a thousand species, the Rhodomelaceae is the most species-rich family of red algae. While its genera have been assigned to 14 tribes, the high-level classification of the family has never been evaluated with a molecular phylogeny. Here, we reassess its classification by integrating genome-scale phylogenetic analysis with observations of t...

Este trabajo da a conocer la distribución, extensión, características, biodiversidad y flora asociada de las praderas de Zostera marina en el Parque Nacional Marítimo Terrestre de las Islas Atlánticas de Galicia (PNIAG) y territorios adyacentes. Se han encontrado praderas de Z. marina en los archipiélagos de Sálvora y Cortegada, mientras que la pra...

Polysiphonia is the largest genus of red algae, and several schemes subdividing it into smaller taxa have been proposed since its original description. Most of these proposals were not generally accepted, and currently the tribe Polysiphonieae consists of the large genus Polysiphonia (190 species), the segregate genus Neosiphonia (43 species) and 1...

Available at: http://www.biolveg.uma.es/abm/Volumenes/vol41/vol41.html

Pterosiphonia parasitica is a species of the family Rhodomelaceae that inhabits in the lower intertidal and subtidal of the Atlantic Iberian Peninsula. The first observation of spermatangial branches, procarps and cystocarps in the Iberian Peninsula is reported in this paper.

Zostera marina is the most widely distributed seagrass, which dominates the northern temperate region. In the Atlantic Iberian Peninsula, Zostera marina is common in wave-protected areas, including a few locations in Portugal and the Cantabrian coast. By contrast, it is much more abundant in Galicia where the convoluted shoreline, with numerous ria...

Diversity of macroalgal flora in Zostera marina meadows from the northwestern Iberian Peninsula.

New records and geographical additions to the benthic marine flora of the Atlantic Iberian Peninsula: In this work, we provide new records and geographical distribution data for 22 species (10 Rhodophyta, 9 Ochrophyta and 3 Chlorophyta) of seaweeds inhabiting from the intertidal to the deep subtidal of the Atlantic Iberian. Ulva australis is a new...

This work presents a taxonomic, floristic and chorological account of the most representative turf-forming species from sand-covered rocks along the Atlantic Iberian Peninsula, including in this Part 2 species belonging to six orders of the Rhodophyta and one of the Phaeophyceae. For each species are provided morphological descriptions, distributio...

Lectotypes for the red algae Polysiphonia schousboei (= Leptosiphonia schousboei) and P. simpliciuscula (= Ophidocladus simpliciusculus) were designated here after the examination of original material housed in the Museum national d'Histoire naturelle de Paris (cryptogamy collections, Herbier National).

Sand-covered rocks provide a particular habitat to benthic seaweeds, which must tolerate the stressful conditions imposed by the presence of sediments. Turf assemblages are dominant in this habitat, which is widely distributed along the Atlantic Iberian Peninsula, neverthelss their flora remained poorly known. This work presents a taxonomic, floris...

Calliblepharis hypneoides Díaz-Tapia, Bárbara & Hommersand, sp. nov., is described based on plants collected in sand-covered rocks from southern France to Portugal. Calliblepharis hypneoides is distinguished by a terete thallus, forming an extensive basal system of entangled prostrate axes that bear few irregularly branched upright axes, an inner s...

Morphological and molecular studies were carried out on two Polysiphonia with 6–9 pericentral cells from the Atlantic Iberian Peninsula. A detailed description is provided for P. foetidissima, a poorly known species originally described from the UK that is widespread and abundant in the Iberian Peninsula. Polysiphonia schneideri, originally describ...

Polysiphonia tripinnata, a member of the Rhodomelaceae originally described from the Mediterranean Sea, is newly recorded off the European Atlantic coast. It was collected mostly from sand-covered rocks between the low intertidal zone and the upper subtidal zone of 18 sites from the Iberian Peninsula. Most locations were from the southern Iberian P...

The genus Pterosiphonia is composed of 22 species worldwide and four of these species have been reported in the North-East Asia. In Korea, P. pennata originally described from the Mediterranean Sea has been previously recorded from the southern coast as a widespread species. In order to confirm the same species from Korea and Mediterranean, we obse...

Español. Se dan a conocer nuevas localizaciones y datos corológicos para 98 especies (61 Rhodophyta, 22 Ochrophyta, 15 Chlorophyta) de algas bentónicas marinas recolectadas en el intermareal y submareal de más de 80 localidades de las costas atlánticas y cantábricas de la Península Ibérica. Polysiphonia devoniensis, P. fibrata y Zonaria tourneforti...

En este trabajo estudiamos la variabilidad temporal de los céspedes de R. floridula, P. scopulorum y O. simpliciusculus, con objeto de detectar cambios a lo largo del año en la granulometría del sedimento atrapado en los céspedes y en la playa. Paralelamente, analizamos la correlación entre la granulometría del sedimento atrapado dentro de los césp...

En este trabajo estudiamos la composición florística y la cobertura de las especies de los céspedes algales de Galicia y su relación con el grado de exposición al oleaje.

We report new records and chorological data for seven French marine algae that make their distribution records more complete. Three species (Erythroglossum lusitanicum, Hildenbrandia occidentalis and Ulva bifrons) are new records for France, two species (Antithamnion hubbsii and Pterocladiella melanoidea) are new records for the French Atlantic coa...

Lampisiphonia iberica gen. et sp. nov. is described on the basis of specimens collected from subtidal rocky bottom habitats on the Atlantic coast of the Iberian Peninsula. The new genus was distinguished by an erect habit, pseudodichotomous branching, and 9-11 pericentral cells. Plants were bright red to brown-red in colour, 3-6 cm high, firm at th...

In this work, we provide new records and geographical distribution data for 98 seaweeds (61 Rhodophyta, 22 Ochrophyta, 15 Chlorophyta) inhabiting more than 80 sites (intertidal and subtidal) of the Atlantic Iberian Peninsula. Polysiphonia devoniensis, P. fibrata y Zonaria tournefortii are new records for Portugal and 5 species (Bonnemaisonia hamife...

The NE Atlantic endemic species Erythroglossum lusitanicum was described by Ardré in the 70s from two Portuguese localities, but only the tetrasporophyte stage was known at the moment. Since 1996 it has been also reported in 30 new sites from Northwestern Spain, Portugal and Morocco. Data about this species are scarce since it is a rare species tha...

Erythroglossum lusitanicum is a foliose, turf-forming member of the Delesseriaceae that colonizes sand-covered intertidal rocks on the Atlantic Iberian Peninsula. We examined (i) the phenology of this alga and (ii) the structure and temporal dynamics of its associated flora at two sites over one year. Species diversity was low in the assemblage, wh...

Sexual structures of Ptilothamnion sphaericum and Pterosiphonia complanata are described for the first time. Spermatangial heads of P. sphaericum are densely clustered in short lateral branchlets, each cell of which bears up to three spermatangial heads. They consist of a stalk cell and 3-4 axial cells bearing a cluster of spermatangial mother cell...

A new red algal species (Polysiphonia iberica) is described from the Atlantic Iberian Peninsula (Basque country, Galicia and South of Portugal), based on morphology and molecular evidence. It is confined to sciaphilic subtidal rocky bottoms and can be distinguished by its erect habit, 5–7 orders of dichotomous branching, axes 350–900 mm in diameter...

Erythroglossum lusitanicum was originally described from sterile and tetrasporophytic material. The apical organization and the sexual structures have considerable relevance for classification of Delesseriaceae, and these are described here for the first time in this species. The range of morphological variability in some species of the genus Eryth...

The northern Portuguese coast is a biogeographic tran- sition zone where many macroalgal species have their distribution limits; it is thus a particularly interesting region for investigating species distribution shifts. An updated and complete list of species for this region is not available in spite of its baseline importance for com- parative st...

Scageliopsis patens, previously known from southern Australia and reported for the North Atlantic at the Azores Islands, is recorded for the first time along the European coast. This new alien species was collected in the subtidal and lower intertidal zones at seven Atlantic locations of the Iberian Peninsula, within the warm Atlantic Iberian area...