Distribución espacial de los anélidos poliquetos de fondos blandos en la ensenada de baiona (Ría de Vigo, Galicia, Noroeste de España)

The spatial distribution of the polychaete fauna in the subtidal soft-bottoms of the Ensenada de Baiona (Galicia, NW Spain) was studied by means of quantitative sampling and multivariate analyses. Several faunistic assemblages were determined, which were closely related to the sediment distribution pattern in the inlet. The coarse-medium sand fauna was mainly dominated by syllids and pisionids. Finer sediments (fine sand to mud) showed a greater abundance of deposit-feeding species, mostly spionids, cirratulids and capitellids. The greatest number of species and diversity were found in mixed sediments with medium and fine sand. Organically enriched muds around Baiona harbour have an impoverished fauna, with a high dominance of Cossura pygodactylata Jones, 1956.La distribución espacial de la fauna de poliquetos de fondos blandos submareales de la ensenada de Baiona (Galicia, NW España) ha sido estudiada mediante técnicas de muestreo cuantitativo. Los análisis multivariantes diferenciaron varias asociaciones faunísticas, que coinciden en gran medida con los patrones de distribución sedimentaria en el área estudiada. La fauna de arenas gruesas y medias está dominada principalmente por sílidos y pisiónidos, mientras que los sedimentos más finos (arenas finas a fangos) muestran una mayor abundancia de organismos depositívoros como espiónidos, cirratúlidos y capitélidos. Se han observado los mayores valores de riqueza específica y diversidad en sedimentos mixtos de arena fina y media. Los fangos orgánicamente enriquecidos del puerto de Baiona muestran una fauna empobrecida con una gran dominancia de Cossura pygodactylata. &nbsp

Composición y distribución de las asociaciones de crustáceos submareales e intermareales en fondos blandos de la Ría de Vigo (NO España)

The intertidal and subtidal soft-bottoms of the inner area of the Ria de Vigo (NW Spain) were sampled in November and December 1999, and spatial distribution of crustacean species was examined. Environmental variables from water and sediment were measured at each sampling site. Amphipods and myocopids were the numerically dominant orders (49.9 and 26.9% dominance), amphipods accounting for more than 54% of identified taxa. The highest crustacean densities occurred with 55-41 species and 5953.6-4346.4 ind. m–2 in external areas, where the diversity index reached the maximum values. Multivariate techniques revealed that distribution of crustaceans in the inlet was highly dependent on depth. Ordination analysis determined three major assemblages: Intertidal bottoms colonized by seagrasses and subjected to strong variations of salinity were dominated by the amphipod Melita palmata, harpacticoids and the isopod Idotea baltica (Group A). The amphipod Corophium cf. runcicorne and the cumacean Iphinoe tenella predominated in the muddy bottoms of central areas (Group B). These species were also present in the deep muddy bottoms of the mouth of the inlet, with high carbonate and gravel contents, and with the myocopids and the amphipod Microdeutopus cf. armatus displaying maximum dominances (Group C).Los fondos blandos intermareales y submareales de la parte interna de la Ría de Vigo (NO España) fueron estudiados en relación a la distribución de los crustáceos y a las variables ambientales asociadas a sus aguas y sedimentos. Los anfípodos y miocópidos fueron los órdenes más abundantes (49.9 y 26.9%), presentando los anfípodos más del 54% de los taxa identificados. Las mayores densidades de crustáceos aparecieron en las áreas externas, con 55-41 especies y 5953.6-4346.4 individuos por m2, alcanzándose aquí los máximos valores de diversidad. Se emplearon técnicas multivariantes para analizar los datos, demostrando que la distribución de los crustáceos en la ensenada dependía principalmente de la profundidad. Se observaron tres principales asociaciones de crustáceos: Los fondos intermareales, colonizados por las fanerógamas marinas Zostera marina y Z. noltii y sometidos a drásticos cambios de salinidad, estuvieron dominados por el anfípodo Melita palmata, los harpacticoideos y el isópodo Idotea baltica (Grupo A). El anfípodo Corophium cf. runcicorne y el cumáceo Iphinoe tenella predominaron en los fondos fangosos de la zona central (Grupo B). Estas especies también estuvieron presentes en los fondos profundos de la boca de la ensenada, donde los miocópidos y el anfípodo Microdeutopus cf. armatus presentaron sus máximas dominancias (Grupo C)

Distribución espacial de la macrofauna bentónica de sedimentos submareales de la Ría de Aldán (Galicia, Noroeste de España)

In the summer of 1997, 27 subtidal stations were quantitatively sampled in the Ría de Aldán. A total of 81770 individuals were collected, comprising 496 species. The distribution and composition of benthic assemblages was correlated to the sedimentary characteristics which, in turn, depend on the hydrodynamic features; those patterns are reflected in a sedimentary gradient present along the ria, which is characterized by an increasing grain size from the inner margins towards the mouth. Several faunal assemblages were determined through multivariate analyses and their composition is compared with that of several communities or facies previously described from similar sediments. The Venus fasciata community was present in clean coarse sediments of the outer ria, the Venus gallina and Tellina fabula-Tellina tenuis communities in the fine-sand bottoms at the centre and margins of the ria, a transition assemblage between the Venus fasciata and the Venus gallina communities in the medium-sand sediments, and a mix of species from the Syndosmya alba and the Amphiura communities in shallower and muddy sediments in the inner areas. In general, subtidal sediments of the Ría de Aldán showed a high benthic diversity which is related to the great sedimentary heterogeneity and the lack of significant anthropogenic alterations.Durante el verano de 1997, se hicieron muestreos en 27 estaciones submareales de modo cuantitativo en la Ría de Aldán. Se recolectaron un total de 81770 individuos, pertenecientes a 496 especies. Los análisis multivariantes permitieron distinguir varias asociaciones faunísticas cuya composición puede ser referida a comunidades o facies previamente descritas de sedimentos similares: la comunidad de “Venus fasciata” está presente en sedimentos limpios de granulometría gruesa de la parte externa de la ría, las comunidades de “Venus gallina” y “Tellina fabula-Tellina tenuis” aparecen principalmente en arena fina en las áreas marginal y central, una fauna de transición entre las comunidades de V. fasciata y V. gallina se encuentra en fondos de arena media, y los fondos someros fangosos de la zona interna están caracterizados por una mezcla de especies propias de las comunidades de “Syndosmya alba” y “Amphiura”. En general, los sedimentos submareales de la Ría de Aldán presentaron una alta diversidad bentónica relacionada con la gran heterogeneidad sedimentaria y la ausencia de perturbaciones humanas significativas

Distribución de los poliquetos de fondos blandos en una ría gallega (NO España)

Macrobenthic polychaete distributions were studied along the soft-bottoms of the Ensenada de San Simón (Galicia, NW Spain). Results suggest that the distribution and abundance of polychaetes in the inlet were highly dependent on depth, sediment characteristics (grain size, organic matter and calcium carbonate content) and bottom water temperature. In the inner area of the inlet, intertidal bottoms colonised by the seagrasses Zostera marina and Z. noltii were dominated by spionids and capitellids, and showed low species number and diversity. Shallow muddy bottoms of central areas were mostly dominated by ampharetids, terebellids and cirratullids. These families along with paraonids, maldanids and syllids were the most abundant families in the deeper subtidal muddy bottoms at the mouth of the inlet. These sediments also showed the highest number of species, diversity and density of individuals.La distribución de los poliquetos macrobentónicos ha sido estudiada en los fondos blandos de la Ensenada de San Simón (Galicia, NO España). La profundidad, las características del sedimento (granulometría, contenido en materia orgánica y carbonatos) y la temperatura del agua del fondo fueron los principales factores que determinaron la distribución y abundancia de los poliquetos en la ensenada. En la zona más interna, los fondos intermareales colonizados por las fanerógamas Zostera marina y Z. noltii estuvieron dominados numéricamente por espiónidos y capitélidos, y mostraron bajos valores de diversidad y número de especies. Los fondos fangosos someros del área central presentaron una fauna de poliquetos dominada principalmente por anfarétidos, terebélidos y cirratúlidos. Asimismo, estas familias estuvieron presentes en los fondos más profundos de la boca de la ensenada, donde paraónidos, maldánidos y sílidos mostraron una dominancia numérica importante. Los máximos valores de diversidad, número de especies y densidad de individuos se registraron en estos fondos submareales fangosos

Patrones de distribución de la familia Syllidae (Annelida: Polychaeta) en praderas de las fanerógamas marinas Zostera marina y Zostera noltei en la ensenada de O Grove (Galicia, NO España)

This paper describes the distribution and composition of the syllid fauna inhabiting seagrass meadows in the Ensenada de O Grove (NW Spain). Samples were collected on muddy sediments colonized by either Zostera marina L., Zostera noltei Hornemann or by a mixed meadow with both species. Syllids were dominant (13340 individuals; 37% of total polychaete abundance), including 22 species (12 genera). The mixed meadows housed the highest number of species and the Z. noltei meadow had practically no syllids. The dominant species were Exogone naidina, Parapionosyllis elegans, Parexogone hebes and Prosphaerosyllis campoyi ( > 80% of total abundance). Carnivores (mainly species of Parapionosyllis, Amblyosyllis, and Streptosyllis) were dominant, especially in muddy sand with either Z. marina or Z. noltei and sandy mud with a mixed meadow. The most important abiotic variables for explaining the composition and distribution of the syllid fauna were bottom water salinity, sorting coefficient and carbonate content. The highest number of species was recorded at sites with a high salinity and carbonate content and the lowest at sites with a high sorting coefficient.El presente trabajo describe la distribución y composición de los sílidos encontrados en las praderas de fanerógamas de la Ensenada de O Grove (NO España). Los fondos fangosos estudiados están colonizados por Zostera marina L., Zostera noltei Hornemann o por ambas especies de fanerógamas. Los sílidos fueron la familia de poliquetos dominante numéricamente (13340 individuos, 37% total de la abundancia total de poliquetos) representados por 22 especies (12 géneros). Los fangos arenosos con pradera mixta albergaron el mayor número de especies de sílidos mientras que en los fondos de fango con Z. noltei estuvieron prácticamente ausentes. Las especies más abundantes fueron Exogone naidina, Parapionosyllis elegans, Parexogone hebes y Prosphaerosyllis campoyi ( > 80% abundancia total). Los carnívoros (principalmente especies de Parapionosyllis, Amblyosyllis y Streptosyllis) fueron dominantes especialmente en arenas fangosas con Z. marina o Z. noltei y en fangos arenosos con una pradera mixta. Las variables abióticas más importantes a la hora de explicar la composición y distribución de los sílidos fueron la salinidad del agua de fondo, el coeficiente de selección y el contenido en carbonatos; así, se ha encontrado un elevado número de especies en estaciones con salinidad y contenido en carbonatos más elevados, en comparación con estaciones con un mayor coeficiente de selección

On the Presence of Prionospio Pulchra (Polychaeta: Spionidae) in the Atlantic Ocean

[Abstract] The presence of the Japanese spionid polychaete Prionospio pulchra in the Atlantic Ocean is confirmed by specimens found in the north-west coast of Spain (Iberian Peninsula). This species is characterized by its eight to ten pairs of long and apinnate branchiae, the longest extending over six to eight segments, and by the presence of five prostomial marginal peaks. Notes on variability of some anatomical aspects and ecological preferences of this species in the Atlantic coast of Spain are also given to complement the original description.X[Résumé] Présence de Prionospio pulchra (Polychaeta: Spionidae) dans l’Océan Atlantique. La présence du Polychète Spionidae japonais Prionospio pulchra dans l’Océan Atlantique est confirmée par la récolte de spécimens au nord-ouest de l’Espagne (Péninsule Ibérique). L’espèce est caractérisée par la présence de huit à dix paires de branchies longues et simples, les plus longues s’étendant sur six à huit segments, et par la présence de cinq pointes marginales au prostomium. Des notes sur la variabilité de quelques particularités anatomiques et sur les préférences écologiques de cette espèce sur les côtes atlantiques espagnoles complètent la description originale.Xunta de Galicia; XUGA30114A96Xunta de Galicia; XUGA30101A98Xunta de Galicia; XUGA10305B9

Ecological features of Terebellida fauna (Annelida, Polychaeta) from Ensenada de San Simón (NW Spain)

Ecological features of Terebellida (Annelida, Polychaeta) inhabiting the intertidal and subtidal soft-bottoms of Ensenada de San Simon (NW Spain) were analysed by means of quantitative sampling. A total of 4,814 specimens belonging to five families (Ampharetidae, Pectinariidae, Terebellidae, Trichobranchidae and Sabellariidae) and ten species were collected in a variety of substrata and depths. Ampharetidae was the numerically dominant family mostly due to the abundance of Ampharete finmarchica and Melinna palmata; these species accounted for up to 94% of the total Terebellida abundance. Intertidal areas colonised by the seagrasses Zostera marina L. and Z. noltii Hornern. One thousand eight hundred and thirty-two harboured low densities of Terebellida, whereas the deeper subtidal muddy bottoms showed high abundances of ampharetids. Multivariate analyses suggested that Terebellida assemblages are highly correlated with sediment compositio

Burying behaviour in the bobtail squid Sepiola atlantica (Cephalopoda: Sepiolidae)

5 páginas, 1 figura, 1 tablaThe burying behavioural pattern of the small Atlantic bobtail squid (Sepiola atlantica) in natural substrate is described, quantitatively differentiating the movements in different phases and the chromatic changes associated with this behaviour. All specimens showed the same two-part sequence of burying, which triggered a display of colour changes peculiar to this species. Our results suggested that this was a consistent behaviour during burial. The mean latency time in the alert posture was 9.55 ± 5.49 s. The mean duration of the first phase was 12.2 ± 4.37 s. The mean duration of the second phase was 10.2 ± 2.95 s. The average time spent completing the behavioural pattern was 21.9 ± 4.93 s. Burying time was not related to size. Differences observed between individuals were associated with the number of movements in each phase. However, these movements were not significantly related to the size of the animals. A comparison of the burying pattern of this species with other members of the family Sepiolidae is madePeer reviewe

Comparing species detection success between molecular markers in DNA metabarcoding of coastal macroinvertebrates

DNA metabarcoding has great potential to improve marine biomonitoring programs by providing a rapid and accurate assessment of species composition in zoobenthic communities. However, some methodological improvements are still required, especially regarding failed detections, primers efficiency and incompleteness of databases. Here we assessed the efficiency of two different marker loci (COI and 18S) and three primer pairs in marine species detection through DNA metabarcoding of the macrozoobenthic communities colonizing three types of artificial substrates (slate, PVC and granite), sampled between 3 and 15 months of deployment. To accurately compare detection success between markers, we also compared the representativeness of the detected species in public databases and revised the reliability of the taxonomic assignments. Globally, we recorded extensive complementarity in the species detected by each marker, with 69% of the species exclusively detected by either 18S or COI. Individually, each of the three primer pairs recovered, at most, 52% of all species detected on the samples, showing also different abilities to amplify specific taxonomic groups. Most of the detected species have reliable reference sequences in their respective databases (82% for COI and 72% for 18S), meaning that when a species was detected by one marker and not by the other, it was most likely due to faulty amplification, and not by lack of matching sequences in the database. Overall, results showed the impact of marker and primer applied on species detection ability and indicated that, currently, if only a single marker or primer pair is employed in marine zoobenthos metabarcoding, a fair portion of the diversity may be overlooked.project ATLANTIDA – Platform for the monitoring of the North Atlantic Ocean and tools for the sustainable exploitation of the marine resources, with the reference NORTE-01-0145-FEDER-000040, co-financed by the European Regional Development Fund (ERDF), through Programa Operacional Regional do Norte (NORTE 2020). BRL benefitted from an FCT fellowship PD/BD/127994/2016. The authors would like to thank Sofia Duarte (University of Minho) for the availability and support during practical stages of the research

Uso de diseños jerárquicos en la detección de escalas de heterogeneidad en la especie invasora Sargassum muticum

Invasion of alien species poses serious threats to many ecosystems. Despite the potential of Sargassum muticum to spread and invade new areas, no attention has been given to the study of variability of structural or morphological features across different spatial scales. We employed a hierarchical sampling design to examine patterns of spatial variability of fertility and morphological variables of S. muticum over different spatial scales (quadrats, sites, locations, rias) ranging from metres to tens of kilometres We repeated the sampling in March, April and July to test for the consistency of patterns through time. There was no variability between rias (tens of kilometres apart), but substantial differences occurred at the other scales examined. Fertility and percent cover varied between locations (1.5-3 km apart), whereas morphological variables varied between sites (tens of metres apart) and quadrats (metres apart). Furthermore, patterns of variation were not consistent over time. The study demonstrated the importance of a multi-scale sampling programme for monitoring seaweed invasion.Las especies invasoras representan una seria amenaza para muchos ecosistemas. A pesar del potencial de Sargassum muticum para extenderse e invadir nuevas áreas, no se ha dedicado ninguna atención al estudio de la variabilidad de las características estructurales o morfológicas a diferentes escalas espaciales. Hemos usado un diseño de muestreo jerárquico para examinar patrones de variabilidad espacial de las variables fenológicas y morfológicas de S. muticum a diferentes escalas espaciales (cuadrantes, sitios, localidades, rías) que van desde unos pocos metros a decenas de kilómetros. Repetimos el muestreo en marzo, abril y julio para comprobar la consistencia de los patrones a lo largo del tiempo. No hubo variabilidad entre rías (decenas de kilómetros de separación), pero se encontraron diferencias sustanciales a otras escalas. La fertilidad y el porcentaje de cobertura variaron entre localidades (1.5-3 km) y tiempo, mientras que las variables morfológicas variaron entre sitios (decenas de metros) y cuadrantes (metros). Asimismo, los patrones de variabilidad no fueron consistentes en el tiempo. El estudio demostró la importancia de los programas de muestreo utilizando múltiples escalas espaciales para el seguimiento de algas invasoras