Trends in the decapod crustacean community at the southernmost estuary of the Atlantic coast of Europe

Climate change may enhance the establishment of introduced species, as well as the poleward shift in distribution of numerous species over decades. Long-term research and monitoring of an ecosystem at the southernmost point of the Atlantic coast of Europe should be an important priority in order to detect and understand trends in species composition and the related environmental changes. The Guadalquivir estuary (South West Spain) is more likely to suffer the exacerbated effects of climate change due to its location in the Mediterranean-climate zone. The long-term data set between 1997 and 2006 has allowed us to analyse the variability of the natural and anthropogenic stressors. The mean interannual dissimilarity of the estuarine fauna (Bray-Curtis dissimilarity index) has showed important differences throughout the years, and the species that most contributed to these differences were the exotic species capable of completing their life cycles. This long-term monitoring of the estuarine community has allowed us to anticipate future events and ecological risk assessment in European waters.

A horizon scan exercise for aquatic invasive alien species in Iberian inland waters

As the number of introduced species keeps increasing unabatedly, identifying and prioritising current and potential Invasive Alien Species (IAS) has become essential to manage them. Horizon Scanning (HS), defined as an exploration of potential threats, is considered a fundamental component of IAS management. By combining scientific knowledge on taxa with expert opinion, we identified the most relevant aquatic IAS in the Iberian Peninsula, i.e., those with the greatest geographic extent (or probability of introduction), severe ecological, economic and human health impacts, greatest difficulty and acceptability of management. We highlighted the 126 most relevant IAS already present in Iberian inland waters (i.e., Concern list) and 89 with a high probability of being introduced in the near future (i.e., Alert list), of which 24 and 10 IAS, respectively, were considered as a management priority after receiving the highest scores in the expert assessment (i.e., top-ranked IAS). In both lists, aquatic IAS belonging to the four thematic groups (plants, freshwater invertebrates, estuarine invertebrates, and vertebrates) were identified as having been introduced through various pathways from different regions of the world and classified according to their main functional feeding groups. Also, the latest update of the list of IAS of Union concern pursuant to Regulation (EU) No 1143/2014 includes only 12 top-ranked IAS identified for the Iberian Peninsula, while the national lists incorporate the vast majority of them. This fact underlines the great importance of taxa prioritisation exercises at biogeographical scales as a step prior to risk analyses and their inclusion in national lists. This HS provides a robust assessment and a cost-effective strategy for decision-makers and stakeholders to prioritise the use of limited resources for IAS prevention and management. Although applied at a transnational level in a European biodiversity hotspot, this approach is designed for potential application at any geographical or administrative scale, including the continental one.

Two new hermit crab species of Diogenes (Crustacea: Decapoda: Diogenidae) from Atlanto‐Mediterranean coasts of Iberian Peninsula: Poleward migrants or merely overlooked indigenous species?

A new hermit crab species of the genus Diogenes with reddish‐orange cheliped, Diogenes erythromanus sp. nov., is described and illustrated based on specimens from the Mediterranean coasts of the Iberian Peninsula, southern Spain. In addition, a second morphotype originating from Mauritanian waters and morphologically very close to D. erythromanus sp. nov. is described as a different species, D. arguinensis sp. nov. The new species are here compared to morphologically similar congeners, especially to those inhabiting the same geographical range. Diogenes erythromanus sp. nov. is distinguishable from other Diogenes primarily by the shape and armature of the left cheliped, with a palm slightly higher than long, with a ridge of spines running along the proximal lower margin that continues with a series of spinose rows forming a central band parallel to the upper margin of the palm. The palm in D. arguinensis sp. nov. is longer than high and shows similar proximal ridge, but without central spinose ridge. The shape of the cheliped is also different in D. arguinensis sp. nov., with long dactylus, which is also flattened and twisted. Sequences from two mitochondrial and one nuclear genes, and comparative analyses with other available sequences for the genus, are also included. Molecular phylogenetic analyses support the morphological delimitation, with D. erythromanus sp. nov. and D. arguinensis sp. nov. forming a separate group, more related to other tropical species, which raises different possible explanations for its presence in the Iberian Peninsula.

Redescription of the hermit crab Diogenes pugilator (Decapoda: Anomura) reveals the existence of a species complex in the Atlanto-Mediterranean transition zone, resulting in the resurrection of D. curvimanus and the description of a new species

Examination of material from the coasts of the Iberian Peninsula and nearby areas has revealed that more than one species is mixed under the name for the common diogenid hermit crab, Diogenes pugilator. In this study, three species are recognized, primarily on the basis of a combination of morphological characters and live colour patterns. Diogenes pugilator is redescribed on the basis of a neotype selected from near the supposed type locality, as well as specimens from other localities. Diogenes curvimanus is resurrected and the name attributed to a second species, whereas a third morphotype is described as a new species, Diogenes armatus sp. nov.. The last two species are also fully described and differentiating characters among the three species are discussed. Newly generated sequences from two mitochondrial genes and one nuclear gene, and comparative analyses with other available DNA sequences for the genus, are also included. The corresponding molecular phylogenies support the recognition of the three species and suggest the presence of additional unknown species in the D. pugilator species complex. All previous records of D. pugilator should be revised in the light of these new findings. Finally, a comprehensive identification key to the eastern Atlantic and western Mediterranean species of Diogenes is also provided.

Annotated and updated checklist of marine crabs (Decapoda: Brachyura) of Mozambique supported by morphological and molecular data from shelf and slope species of the MOZAMBIQUE surveys

An updated checklist of Mozambican marine brachyuran crabs is generated based on an exhaustive revision of the existing literature, together with the additional records provided by the specimens collected throughout the three MOZAMBIQUE surveys carried out in Mozambican waters during three consecutive years (20072009) by the Instituto Espaol de Oceanografa, (Spanish Institute of Oceanography, IEO). A total of 269 species, grouped in 15 superfamilies, 26 families and 172 genera are reported in the checklist, and a detailed inventory is produced with the list and remarks about the brachyuran species collected. Thirty-nine crab species belonging to 19 families were identified based on morphological characteristics and/or genetic tools. DNA barcode sequences (16S rRNA and/or COI) were obtained for 37 species, including 16S and COI sequences that are new for 26 and 14 species, respectively. Colour photographs of fresh specimens illustrate the comments about most species, being the first time that the original colour pattern is described for some of them. New records in Mozambican waters are reported for the species Paromolopsis boasi, Mursia aspera, Carcinoplax ischurodous, Tanaoa pustulosus, Euclosiana exquisita, Oxypleurodon difficilis, Naxioides robillardi, Samadinia galathea, Cyrtomaia gaillardi, Paramaja gibba, Pleistacantha ori, Parathranites granosus, Parathranites orientalis, Ovalipes iridescens and Charybdis smithii, and second records for Moloha alcocki, Samadinia pulchra and Charybdis africana. In addition, Raninoides crosnieri, S. galathea and P. ori were collected for the first time after their descriptions. The female of Samadinia galathea is described for the first time, and a potential new species of Mursia is reported. Some records expand the known bathymetric range of certain species and/or their general distribution. New molecular and morphological data suggest the necessity of the revision of P. boasi, R. crosnieri, C. africana and the genera Platymaia and Carcinoplax. The variability and taxonomic validity of some morphological characters in brachyuran systematic is discussed.

Ecological quality assessement of marinas: An integrative approach combining biological and environmental data

The importance of marinas as infrastructures for recreational boating is increasing substantially. However, information on their soft-bottom benthic communities, a key tool for managing programmes, is still scarce. We combined environment features with macro- and meiofaunal soft-bottom community information for assessing the ecological status of marinas with an integrative approach. To address this issue, we focused on eight marinas of the Southern Iberian Peninsula. Macro- and meiofauna data revealed high benthic heterogeneity at a spatial scale. The environmental variables which correlated best with macrofauna were mainly phosphorus, granulometry, and total organic carbon, and secondarily important variables were faecal coliforms, the biocide Irgarol, and heavy metals; total hydrocarbon concentration was also significant for meiofauna. Annelida was the dominant phylum in terms of number of species (37%) and abundance (66%) and were better descriptors of the environmental conditions than Arthropoda and Mollusca. Although identification to the species level is desirable and mandatory for assessing biological pollution, significant differences among marinas and correlations between fauna and abiotic variables were already detected at the level of family and order. This implies that biota assessment at higher levels may still be useful in monitoring programmes limited by time and budget constraints. The major novelty of this study lies in the development of an integrative assessment method based on the following selected ecological indicators: Marinas Environmental Pollution Index (MEPI), Biocontamination Index (BCI), macrofaunal biotic indices (AMBI, M-AMBI, BENTIX, MEDOCC and BENFES), macrofaunal taxa richness and Shannon-Wiener's diversity, and nematode:copepod index. This approach was able to discriminate marinas of the Southern Iberian Peninsula based on their ecological status, which ranged from poor to good. The method can be useful to design standards for assigning "sustainable quality seals" to those marinas with better values of ecological indicators.

Isotopic niche provides an insight into the ecology of a symbiont during its geographic expansion

The study of the recent colonization of a symbiont and its interaction with host communities in new locations is an opportunity to understand how they interact. The use of isotopic ratios in trophic ecology can provide measurements of a species’ isotopic niche, as well as knowledge about how the isotopic niches between symbiont and host species overlap. Stable isotope measurements were used to assess the sources of carbon assimilated by the host species (the bivalves Mytilus galloprovincialis and Scrobicularia plana) and their associated symbiont pea crab Afropinnotheres monodi, which occurs within these bivalves’ mantle cavities. The mixing model estimates suggest that all of them assimilate carbon from similar sources, particularly from pseudofaeces and particulate organic matter in this symbiotic system based on filter feeding. The symbiotic species occupy comparable trophic levels and its association seems to be commensal or parasitic depending on the duration of such association. The pea crab A. monodi reflects a sex-specific diet, where males are more generalist than the soft females because the latter’s habitat is restricted to the host bivalve. The high isotopic overlap between soft females and M. galloprovincialis may reflect a good commensal relationship with the host.

Morphology of planktonic zoeal stages of Palicus caronii (Decapoda, Brachyura), identified by DNA barcoding, provides novelties to Palicoidea larval systematics

The zoeal development of the brachyuran crab, Palicus caronii, comprises two zoeal stages and the morphology is described and illustrated in detail. The zoeae were collected in plankton samples from the Southern Ligurian Sea (Western Mediterranean). Although the morphology of the larval stages of this species was unknown, a combination of characters allowed the zoeae to initially be assigned to the Palicidae, based on the previous unique known first zoeal description of one species of this family. Later, the identification of the larvae as Palicus caronii was confirmed through molecular analysis. The morphological features of the zoeae that characterize the Palicidae and separate them from the Crossotonotidae are confirmed. Also, the larval development comprising only two zoeal stages observed in Palicus caronii, the peculiar and uncommon carapace surface setation, and the presence of anterodorsal and posterodorsal sensory dorsal organs suggest that these characters could be common to the Palicoidea.

Large scale and information effects on cooperation in public good games

The problem of public good provision is central in economics and touches upon many challenging societal issues, ranging from climate change mitigation to vaccination schemes. However, results which are supposed to be applied to a societal scale have only been obtained with small groups of people, with a maximum group size of 100 being reported in the literature. This work takes this research to a new level by carrying out and analysing experiments on public good games with up to 1000 simultaneous players. The experiments are carried out via an online protocol involving daily decisions for extended periods. Our results show that within those limits, participants' behaviour and collective outcomes in very large groups are qualitatively like those in smaller ones. On the other hand, large groups imply the difficulty of conveying information on others' choices to the participants. We thus consider different information conditions and show that they have a drastic effect on subjects' contributions. We also classify the individual decisions and find that they can be described by a moderate number of types. Our findings allow to extend the conclusions of smaller experiments to larger settings and are therefore a relevant step forward towards the understanding of human behaviour and the organisation of our society.

Adaptive multiscapes: an up-to-date metaphor to visualize molecular adaptation

Background

Wright’s metaphor of the fitness landscape has shaped and conditioned our view of the adaptation of populations for almost a century. Since its inception, and including criticism raised by Wright himself, the concept has been surrounded by controversy. Among others, the debate stems from the intrinsic difficulty to capture important features of the space of genotypes, such as its high dimensionality or the existence of abundant ridges, in a visually appealing two-dimensional picture. Two additional currently widespread observations come to further constrain the applicability of the original metaphor: the very skewed distribution of phenotype sizes (which may actively prevent, due to entropic effects, the achievement of fitness maxima), and functional promiscuity (i.e. the existence of secondary functions which entail partial adaptation to environments never encountered before by the population).

Results

Here we revise some of the shortcomings of the fitness landscape metaphor and propose a new “scape” formed by interconnected layers, each layer containing the phenotypes viable in a given environment. Different phenotypes within a layer are accessible through mutations with selective value, while neutral mutations cause displacements of populations within a phenotype. A different environment is represented as a separated layer, where phenotypes may have new fitness values, other phenotypes may be viable, and the same genotype may yield a different phenotype, representing genotypic promiscuity. This scenario explicitly includes the many-to-many structure of the genotype-to-phenotype map. A number of empirical observations regarding the adaptation of populations in the light of adaptive multiscapes are reviewed.

Conclusions

Several shortcomings of Wright’s visualization of fitness landscapes can be overcome through adaptive multiscapes. Relevant aspects of population adaptation, such as neutral drift, functional promiscuity or environment-dependent fitness, as well as entropic trapping and the concomitant impossibility to reach fitness peaks are visualized at once. Adaptive multiscapes should aid in the qualitative understanding of the multiple pathways involved in evolutionary dynamics.

Reviewers

This article was reviewed by Eugene Koonin and Ricard Solé.

A salt bath will keep you going? Euryhalinity tests and genetic structure of caridean shrimps from Iberian rivers

We assessed the role of euryhalinity and life-history traits on the population genetic structure of the four main caridean shrimp species from the Iberian Peninsula (Atyaephyra desmarestii, Dugastella valentina, Palaemon varians and Palaemon zariquieyi) able to complete their life cycle in freshwater/oligohaline habitats. Seawater exposure experiments indicated that A. desmarestii, D. valentina and P. zariquieyi are more sensitive to high salinity waters than P. varians and confirm the relationship between osmolality regulation and spatial distribution of species. The limited or no survival in seawater could explain the restricted distributions observed in D. valentina and P. zariquieyi, whereas the current A. desmarestii distribution could be due to either past river dynamics and/or human-mediated water transfers. Conversely, the high tolerance of P. varians to a large salinity range (euryhalinity) could explain its capacity to colonize geographically distant estuaries. In agreement with osmoregulation results, the phylogeography patterns of the cytochrome oxidase 1 (Cox 1) gene fragment revealed significant genetic differentiation among river systems whatever the species considered. Atyidae species presented higher nucleotide diversity levels than Palaemonidae species, while isolation-by-distance patterns were only found for the latter. Our results have important implications for the management and conservation of freshwater species, since the inter-catchment connectivity may affect the speciation processes.

Morphological and morphometric comparison of the first zoeal stage of the mangrove crabs of the genus Aratus H. Milne Edwards, 1853 (Decapoda: Sesarmidae)

The mangrove crab Aratus pisonii (H. Mile Edwards, 1837) was considered to have an amphi-American distribution but a recent genetic study revealed that the Eastern Tropical Pacific populations represent a new species, A. pacificus (Thiercelin & Schubart, 2014). These sister species separated by the Central American Isthmus have developed under different environmental conditions that may influence their larval development. A comparison of morphological and morphometric features (length and width of cephalothorax and length of rostral and dorsal spine, antenna, antennule, telson, and furcae) of recently-hatched larvae of A. pacificus (Pacific coast) and A. pisonii (Caribbean coast) from Costa Rica revealed that the setation pattern of the antennules differed between the species and the analyzed morphometric features were larger in A. pisonii larvae. Difference in size may be a response to different environmental conditions, as the lower primary production in coastal Caribbean waters, which may have forced females of A. pisonii to allocate more energy into the offspring, resulting in larger zoeal size. A greater endogenous reserve may allow the larvae to reduce the duration of the planktonic phase and increase the size at metamorphosis, thus enhancing their survival chances during the planktonic phase. These data regarding morphological and morphometric differences in recently-hatched larvae of the Pacific and Caribbean species support the conclusion that specimens of Aratus from both coasts of Costa Rica represent indeed different species.

Reputation drives cooperative behaviour and network formation in human groups

Cooperativeness is a defining feature of human nature. Theoreticians have suggested several mechanisms to explain this ubiquitous phenomenon, including reciprocity, reputation, and punishment, but the problem is still unsolved. Here we show, through experiments conducted with groups of people playing an iterated Prisoner's Dilemma on a dynamic network, that it is reputation what really fosters cooperation. While this mechanism has already been observed in unstructured populations, we find that it acts equally when interactions are given by a network that players can reconfigure dynamically. Furthermore, our observations reveal that memory also drives the network formation process, and cooperators assort more, with longer link lifetimes, the longer the past actions record. Our analysis demonstrates, for the first time, that reputation can be very well quantified as a weighted mean of the fractions of past cooperative acts and the last action performed. This finding has potential applications in collaborative systems and e-commerce.

Freshwater scarcity effects on the aquatic macrofauna of a European Mediterranean-climate estuary

In the Mediterranean-climate zone, recurrent drought events and increasing water demand generally lead to a decrease in freshwater input to estuaries. This water scarcity may alter the proper function of estuaries as nursery areas for marine species and as permanent habitat for estuarine species. A 12-year data set of the aquatic macrofauna (fish, decapod and mysid crustaceans) in a Mediterranean estuary (Guadalquivir estuary, South Spain) was analysed to test if water scarcity favours the nursery function of regional estuaries to the detriment of permanent estuarine inhabitants. Target species typically displayed a salinity-related distribution and estuarine salinisation in dry years resulted in a general upstream community displacement. However, annual densities of marine species were neither consistently higher in dry years nor estuarine species during wet years. Exceptions included the estuarine mysid Neomysis integer and the marine shrimp Crangon crangon, which were more abundant in wet and dry years, respectively. High and persistent turbidity, a collateral effect of water scarcity, altered both the structural (salinity-related pattern) and functional (key prey species and predator density) community characteristics, chiefly after the second drought period of the analysis. The observed high inter-year environmental variability, as well as species-specific effects of water scarcity, suggests that exhaustive and long-term sampling programmes will be required for rigorously monitoring the estuarine communities of the Mediterranean-climate region.

Taxonomic study of the Pagurus forbesii "complex" (Crustacea: Decapoda: Paguridae). Description of Pagurus pseudosculptimanus sp. nov. from Alborán Sea (Southern Spain, Western Mediterranean Sea)

Study of hermit crabs from Alboran Sea has allowed recognition of two different morphological forms under what had been understood as Pagurus forbesii. Based on morphological observations with various species of Pagurus, and molecular studies, a new species is described as P. pseudosculptimanus. An overview of species of Pagurus from the eastern Atlantic and Mediterranean Sea is provided.

Two cases of pseudohermaphroditism in loggerhead sea turtles Caretta caretta

Two juvenile (curved carapace lengths: 28 and 30 cm) loggerhead sea turtles Caretta caretta with precocious male external characteristics were admitted to the ARCA del Mar rescue area at the Oceanogràfic Aquarium in Valencia, Spain, in 2009 and 2010. Routine internal laparoscopic examination and subsequent histopathology confirmed the presence of apparently healthy internal female gonads in both animals. Extensive tissue biopsy and hormone induction assays were consistent with female sex. To the best of our knowledge, this is the first report of pseudohermaphroditism in loggerhead sea turtles based on sexual external characteristics and internal laparoscopic examination. Our findings suggest that the practice of using external phenotypical characteristics as the basis for gender identification in sea turtles should be reevaluated. Future research should focus on detecting more animals with sexual defects and their possible effects on the sea turtle population.

Nekton response to freshwater inputs in a temperate European estuary with regulated riverine inflow

The aim of this 12-year study was to assess the nekton (fish, decapod crustaceans) response to freshwater inputs (rainfall, dam discharges) in a temperate estuary with regulated riverine inflow. Although interannual variability in river discharges to the Guadalquivir estuary has been extremely high since the construction of a dam in 1930, a significant decreasing trend in the dam's discharges has been observed in the last 80 years. During this study, an alternation of wet, standard and dry years occurred in the estuarine area but no significant long-term trend was observed. River discharge, in turn, showed a considerable interannual variability and a significantly decreasing long-term trend. Freshwater inputs had an immediate effect on estuarine salinity and turbidity, and consequently on prey availability (mysids). Although 124 nektonic species were collected, only 47 of them (adding up to 99.7% of total abundance) were regularly present in the estuary: 32 marine migrants, 13 estuarine species and 2 diadromous species. Well-defined temporal changes in species composition and abundance yielded clear seasonal patterns in the estuarine nektonic community. Considerable intermonth and interannual changes were occasionally observed relating to freshwater inputs, mainly in winter/autumn of wet years. Thus, within each two-month period, some significant interannual differences in the nektonic community were also observed, with marine migrants tending to be more abundant in dry years. However, changes in the studied nektonic community did not show long-term trends. In conclusion, natural and human-controlled freshwater inputs currently play a significant role in determining the physicochemical conditions and the biota of the Guadalquivir estuary. However, although freshwater input seemed to transitorily affect the estuarine nekton, either directly (flushing out) or indirectly (through changes in salinity, turbidity and prey availability), a quick reestablishment of the estuarine nekton (strong resilience) was observed following freshwater inputs together with the recovery of environmental conditions within the estuary.

[Laparoscopic surgery in urology]

At the present time minimally invasive surgery is present in all the standards of quality of a surgical service. Laparoscopic surgery, the basis of this minimally invasive surgery, is revolutionizing the teaching and handling of many surgical pathologies. In the urological sphere, although with a delay of 5 years with respect to neighbouring countries, laparoscopy has become established as a prevalent technique in many processes of the urinary-genital apparatus. At present it is the chosen technique for the surgical treatment of the suprarenal, and it is rapidly becoming established in different pathologies such as renal tumours, prostate tumours, staging in neoplastic diseases of the testicles, benign surgical pathology and in reconstructive surgery. Since 1995, the Urology Service at the Hospital de Navarra has been a pioneer in the employment of this type of technique, and, since 1998, it has been a pioneer of so-called advanced laparoscopic surgery, in which it is a national reference point in some of the procedures, such as laparoscopic adrenalectomy. At present, all of the laparoscopic procedures are incorporated in the service, with a learning curve that has been surpassed. All of this has made it possible to improve patient care, to obtain a reduction in postoperative pain and in length of hospital stay, and a rapid return to labour activity with oncological results that can be equivalent on those of open surgery.

Molecular phylogeny, taxonomy, and evolution of nonmarine lineages within the American grapsoid crabs (Crustacea: brachyura)

Grapsoid crabs are best known from the marine intertidal and supratidal. However, some species also inhabit shallow subtidal and freshwater habitats. In the tropics and subtropics, their distribution even includes mountain streams and tree tops. At present, the Grapsoidea consists of the families Grapsidae, Gecarcinidae, and Mictyridae, the first being subdivided into four subfamilies (Grapsinae, Plagusiinae, Sesarminae, and Varuninae). To help resolve phylogenetic relationships among these highly adaptive crabs, portions of the mitochondrial genome corresponding to the 16S rRNA gene were sequenced for all grapsoid genera occurring in America. The resulting phylogeny confirms most of the present grapsid subfamilies but suggests reclassification of some of the genera and recognition of new taxonomic units. The two American gecarcinid genera might not represent a sister group to the Grapsidae but rather appear to have evolved within the latter. Colonization of inland habitats evolved in several lineages of the grapsoids, resulting in various forms of nonmarine life and different degrees of independence from the sea.

Initial effects of the toxic waste spill (Aznalcóllar mine accident) on the aquatic macrofauna of the Guadalquivir Estuary

The initial effects of the toxic waste spill in April 1998 at the Aznalcóllar mine (SW Spain) on the nektonic community of the Guadalquivir Estuary were examined at three sampling sites using univariate and multivariate techniques. Since studied communities showed a considerable seasonal trend, only seasonally homogenous periods were compared to analyse effects of the spill: May-August 1997 (before spill) and May-August 1998 (after spill). Results of both techniques (two-way nested ANOVA and ANOSIM tests, P > 0.05) indicated that there was no significant difference between the nektonic community of the estuary before and after the spill (monthly number of species, abundance, biomass and similarity among samples). Conversely, an unusually high density was observed at the outer sampling site immediately after the spill for species typical of more stagnant estuarine habitats. This feature seems to indicate that the fauna in the estuarine area through which the untreated water penetrated into the main course may have been disturbed. Results also suggest that this initial sudden input of fresh water to the estuary could have enhanced the effects of an increased river flow (a drop in the salinity). Nevertheless, longer temporal series of data, especially for permanent estuarine inhabitants, are recommended before conclusions can be drawn on the effects of the toxic waste spill on estuarine communities.