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Megalopas of 15 brachyuran crab species collected in the open sea plankton, and unknown until now, were identified using DNA barcodes (COI and 16S rRNA). Specimens belonging to the families Portunidae, Pseudorhombilidae and Xanthidae (Crustacea, Decapoda, Brachyura), and corresponding to the species Achelous floridanus, Arenaeus mexicanus, Callinectes amnicola, C. arcuatus, C. ornatus, C. toxones, Charybdis (Charybdis) hellerii, Portunus hastatus, Thalamita admete, Scopolius nuttingi, Etisus odhneri, Liomera cinctimanus, Neoliomera cerasinus, Pseudoliomera variolosa, and Williamstimpsonia stimpsoni, are described and illustrated, and compared with other congeneric species previously described. We also provide a new geographical record for N. cerasinus and the most remarkable features for each species., The Ministry of Economy and Competitiveness of Spain (MINECO) and the European Fund for Economic and Regional Development (FEDER) through the MALASPINA 2010 Expedition (Consolider-Ingenio 2010, CSD2008-00077) and MAF Research Project (National Research Program, CTM2012-39587-C04-02) funded this study. We thank the captains and crews of RV Hespérides in 2010-11 and 2015 for the support during the cruises, and Carlos Sánchez (ICMAN-CSIC) by laboratory work.

14 pages, 9 figures, 5 tables, Surface waters are an attractive foraging ground for small fish in the open ocean. This study aims to determine the importance of vertically migrating species in the neuston of oceanic waters across the Atlantic, Indian and Pacific Oceans and to ascertain the influence of environmental variables on their distribution patterns. Neustonic fish assemblages were primarily controlled by light. They were dominated by late-larvae and juveniles of Exocoetidae, Hemiramphidae and Scomberesocidae during the day. At night, the vertical migration of mesopelagic species changed the dominance pattern in favour of Myctophidae and Scomberesocidae. The neustonic families’ distribution was primarily related to sea surface temperatures, whereas environmental variables at deeper layers were related to mesopelagic migrating families. Canonical correspondence analysis showed a low but statistically significant contribution of several environmental variables to myctophid species composition (10%), with minimum oxygen concentrations ranking first in variance explanation followed by maximum fluorescence, sea surface temperature and 400-m temperature. Spatial autocorrelation also explained 17% of the variance, indicating the influence of other factors such as historical, demographic and dispersal constraints. The low number of myctophid species in the North Pacific Equatorial Countercurrent appears to be related to the low oxygen concentrations observed in this province, This study was financed by the Spanish Ministry of Economy and Competitiveness (Consolider-Ingenio 2010, CSD2008-00077 and CTM2012–39587-C04–03)

The complete larval development and the morphology of the first juvenile stages of two freshwater-breeding crab species endemic to Jamaica are described and illustrated in detail in the present paper. One of these species, Sesarma windsor, lives in and near caves in the karst regions of central western Jamaica, whereas the second species, Metopaulias depressus, occurs sympatrically but with a wider range in western and central Jamaica in water-filled leaf axils of bromeliads. Even if these species are placed in separate genera, they are extant representatives of the same adaptive radiation that resulted in at least ten Jamaican endemic crab species thriving in different land-locked habitats. Consequently, larval morphologies of the two species are very similar, but conspicuously different from the developmental patterns in their marine relatives. Both species display an abbreviated mode of development, showing morphological reductions in some features and pre-displacement in the expression of sev...

The aim of this study was to assess the effect of temperature on the survival and duration of larval development in the African pea crab Afropinnotheres monodi, as well as to describe its larval stages. We studied larvae reared in the laboratory and also specimens collected from plankton from the Gulf of Cádiz at two different temperatures. According to the results of this study, larval development of A. monodi involves four zoea stages and one megalopa and lasts around 25 days at 25°C, and longer than 40 days at 19°C. Such a temperature-related duration of this dispersive phase may be causing a higher recruitment to parental populations during the summer, but a higher dispersal to new locations during the rest of the year, a seasonal pattern of dispersion which could favour the successful expansion of this non-native species into European waters. The identification of both larval phases from plankton samples and adult specimens was carried out using morphological characters and molecular techniques. Both the 16S mtDNA sequences of this species, now available in GenBank, and the larval descriptions provided by this study could help to establish an early alert for the detection of this African species in its northward expansion., The research was carried out within the framework of the projects MEGALOPADN [CGL2009-11225], ‘Transporte y reclutamiento larvario de crustáceos bentónicos litorales: importancia de los agentes forzadores costeros y regimen mareal’ [CTM2005-00024/MAR] and AFROBIV [CGL2014-53557-P], co-financed by the ‘Ministerio de Economía y Competividad (MINECO)’ Spanish Plan R+D+I and ERDF, European Union. Elena Marco-Herrero acknowledges a pre-doctoral FPI Fellowship supported by MINECO [BES-2010-033297].

The morphology of the megalopa stage of the panopeid Rhithropanopeus harrisii is redescribed and illustrated in detail from plankton specimens identified by DNA barcode (16S mtDNA) as previous descriptions do not meet the current standard of brachyuran larval description. Several morphological characters vary widely from those of other panopeid species which could cast some doubt on the species' placement in the same family. Besides, some anomalous megalopae of R. harrisii were found among specimens reared at the laboratory from zoeae collected in the plankton. These anomalous morphological features are discussed in terms of problems associated with laboratory rearing conditions. © 2014 Springer-Verlag Berlin Heidelberg and AWI., The research was carried out within the framework of the projects MEGALOPADN (CGL2009-11225) and “Transporte y reclutamiento larvario de crustáceos bentónicos litorales: importancia de los agentes forzadores costeros y regimen mareal” (CTM2005-00024/MAR), both co-financed by the “Ministerio de Economía y Competividad (MINECO)” Spanish Plan R + D + I and European Union FEDER funds. Elena Marco-Herrero acknowledges the pre-doctoral FPI Fellowship supported by MINECO (BES-2010-033297).

Copyright: © 2015 Cózar et al. Concentrations of floating plastic were measured throughout the Mediterranean Sea to assess whether this basin can be regarded as a great accumulation region of plastic debris. We found that the average density of plastic (1 item per 4 m2), as well as its frequency of occurrence (100% of the sites sampled), are comparable to the accumulation zones described for the five subtropical ocean gyres. Plastic debris in the Mediterranean surface waters was dominated by millimeter-sized fragments, but showed a higher proportion of large plastic objects than that present in oceanic gyres, reflecting the closer connection with pollution sources. The accumulation of floating plastic in the Mediterranean Sea (between 1,000 and 3,000 tons) is likely related to the high human pressure together with the hydrodynamics of this semi-enclosed basin, with outflow mainly occurring through a deep water layer. Given the biological richness and concentration of economic activities in the Mediterranean Sea, the affects of plastic pollution on marine and human life are expected to be particularly frequent in this plastic accumulation region., The present study was funded by the EU's Framework Programme 7 and the Spanish Ministry of Economy and Competitiveness through projects MedSeA (EU contract number FP7-2010-265103), ESTRESX (ref. CTM2012-32603) and MEGAN (ref. CTM2013-49048-C2-1-R). Andrés Cózar is grateful for the funding of a >Salvador de Madariaga> stay to continue the study of the plastic pollution in the Mediterranean Sea (Spanish Ministry of Education, Culture and Sport, ref. PRX14/00743)