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Many littoral caprellid species have a very ample distribution, some having been reported from all over the world. The cosmopolitan distribution of many littoral caprellid species might be facilitated by the fact that they are often associated with fouling communities on floating objects, which have a high potential of far-range dispersal. This dispersal potential may also have implications for the distribution of caprellids on local and regional scales. Herein we examined the distribution of littoral caprellid species on two spatial scales, local (tens of kilometers) and regional (hundreds of kilometers) along the Pacific coast of continental Chile. On the local scale, we studied the caprellid fauna in different habitats (intertidal boulders, subtidal algal and seagrass beds, fouling community on buoys and ropes); on the regional scale we focused only on caprellids associated with the fouling community on buoys and ropes. We found a total of six caprellid species, some of which were very abundant both on the local as well as on the regional scale. On the local scale we found a difference between the three studied habitat types with respect to the assemblage of caprellid species, some of which were found in more than one habitat. The highest species richness and abundance of caprellids was found in the fouling community associated with anchored buoys and ropes. On the regional scale we found very high numbers of caprellids in the fouling community of the northern region (n of 30° S), and decreasing abundances and species richness in the central region (30-37° S). No caprellids were found in the southern region of the study area (37-42° S). This pattern coincides with the global distribution of littoral caprellid species, which are most abundant and diverse at low latitudes but occur in low abundances and low diversity at high latitudes. Detached buoys that were found a few km off the coast harbored similar caprellid assemblages (including ovigerous females) as anchored buoys, suggesting that buoys and other floating substrata (litter, macroalgae) may facilitate dispersal of caprellids (and other epibiota) along the Pacific coast of Chile. Since artificial and natural floating substrata are also abundant at high latitudes it is inferred that the low diversity of littoral caprellids at high latitudes is not due to lack of dispersal vectors, but rather of other factors.Key words: Crustacea, Amphipoda, Caprellidea, Chile, biogeography. RESUMENMuchas especies de caprélidos del litoral presentan una amplia distribución, algunas han sido citadas a lo largo de todo el mundo. La distribución cosmopolita de muchas especies de caprélidos podría deberse al hecho de que se asocian frecuentemente a las comunidades "fouling" en objetos flotantes, que presentan una capacidad importante de dispersión a largas distancias. Esta capacidad de dispersión puede tener implicaciones en la distribución de caprélidos a escala local y regional. En este estudio, nosotros examinamos la distribución de las especies de caprélidos litor...

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Dispersal of organisms across the oceans is brought about by dense aggregations of pumice (left), which may appear sporadically after submarine volcanic eruptions, and by ubiquitous accumulations of anthropogenic debris (right). : A. van den Broek, S. Bryan (left); M. Thiel (right) OPEN PEN ACCESS CCESS Photos

Summary Aim To use new collections and taxonomic reviews of the Chilean coastal biota, and studies on biodiversity on a reappraisal of Southeastern Pacific littoral biogeography. Location The temperate coastline of the Southeastern Pacific, extending over 6000 km from northern Peru to the southern tip of Chile. Methods Records of coastal macroinvertebrates were assigned to ten geographic zones along the Chilean coast. The Spearman rank correlation coefficient, ρ, was used to establish the relationship between the total number of species and the number of single records for each zone. Regions and underlying faunal gradient were verified via an unweighted paired group method using arithmetic averages (UPGMA), and ordination non‐metric multidimensional scaling (nMDS) analysis based on a disagreement distance matrix of presence/absence data. Abundance down‐weighting was preferred to rare species down‐weighting, owing to the nature of the records, where a larger number of references for a given taxon did not necessarily indicate a greater abundance or commonness. The dissimilarity matrices between the different zones were used to establish the degree of agreement between the different levels of analysis, using a weighted Spearman rank correlation coefficient ρw. Statistical significance was established using a randomization (permutation) test. Main conclusions Analysis of new macroinvertebrate data and taxonomic reviews of the Chilean coastal fauna indicates a Transitional‐Temperate Region for the Southeastern Pacific littoral, located between 35°S and 48°S where a gradual mixing and replacement of species negates previous hypotheses on the existence of a marked distributional break at 42°S.

The majority of zoogeographic studies along the Chilean Pacific coast have focused on benthic organisms and oceanographic conditions are considered the main factors influencing their distributions. Herein we examined the geographic distribution of pelagic barnacles of the family Lepadidae collected from floating macroalgae at seven sampling areas between 23 and 50° S. Four species were encountered and they are briefly described herein. The most abundant northern species was Lepas anatifera, and it diminished in abundance towards the south (33° S). Moreover, this species was not found in waters with a sea surface temperature (SST) of less than ~18 ºC. Lepas australis, primarily a circumpolar West Wind Drift species, diminished in abundance towards the north (33° S). This species was restricted to waters of < 18 ºC SST. A third species, L. pectinata, was encountered throughout almost the entire study area, but it was most abundant between 29 and 33° S. The fourth species, Dosima fascicularis, was only found at two sampling areas, namely at 27° S and 33° S, and this is the first record of this species from the central coast of Chile. The distributional pattern of the pelagic barnacles found herein corresponds to the three main zoogeographic regions as revealed by the majority of previous studies based on littoral organisms: the northern Peru-Chilean Province, the southern Magellanic Province, and the central Chilean Transition Zone where the two provinces overlap. Even though the present study only considers four species of pelagic barnacles, the results support the hypotheses on the importance of oceanographic conditions (in particular SST) in determining the zoogeographic patterns along the south east Pacific coast of Chile.Key words: zoogeography, Lepas, oceanography, pelagic, Cirripedia. RESUMENLa mayoría de los estudios de zoogeografía a lo largo de la costa chilena del Pacífico sur este se han enfocado en organismos bentónicos y las condiciones oceanográficas se sugieren como factores principales que modulan su distribución. Aquí examinamos la distribución geográfica de especies de cirripedios pelágicos de la familia Lepadidae, asociadas a macroalgas flotando a la deriva, en siete áreas de muestreo entre los 23 y 50º S. Se encontraron cuatro especies de cirripedios lepádidos y cada una se describe brevemente. La especie del norte más abundantes fue Lepas anatifera y disminuye su abundancia hacia el sur (33º S). Además, esta especie no se encontró en temperatura superficial del mar (SST) inferior a ~18 ºC. Lepas australis, que posee una distribución circumpolar, atenúa su abundancia hacia el norte (33º S). Esta especie se restringe a SST < 18 ºC. La tercera especie, L. pectinata se extiende en la mayor parte del área de estudio, pero posee su mayor abundancia relativa en el área central, entre 29 y 33º S. La cuarta especie, Dosima fascicularis, solo se encontró en dos lugares de muestreo, en 27 y 33º S, y es el primer registro para la costa central de Chile. El patrón de distribución de estas especies ...

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Background: Gastric cancer (GC) ranks as one of the major causes of mortality due to cancer worldwide. Materials and Methods: Using whole-genome a group of 14 GC cases. Results