Chemical defenses in Sacoglossan Opisthobranchs: Taxonomic trends and evolutionary implications

Sacoglossan sea slugs (Mollusca: Opisthobranchia) are one of the few groups of specialist herbivores in the marine environment. Sacoglossans feed suctorially on the cell sap of macroalgae, from which they 'steal' chloroplasts (kleptoplasty) and deterrent substances (kleptochemistry), retaining intracellularly both host plastids and chemicals. The ingested chloroplasts continue to photosynthesize for periods ranging from a few hours or days up to 3 months in some species. Shelled, more primitive sacoglossans feed only on the siphonalean green algal genus Caulerpa, and they do not have functional kleptoplasty. The diet of sacoglossans has radiated out from this ancestral food. Among the shell-less Plakobranchidae (=Elysiidae), the more primitive species feed on other siphonales (families Derbesiaceae, Caulerpaceae, Bryopsidaceae and Codiaceae) and fix carbon, while the more 'advanced' species within the Plakobranchidae and Limapontioidae have a more broad dietary range. Most of these 'advanced' species are unable to fix carbon because the chloroplasts of their food algae are mechanically disrupted during ingestion. Mesoherbivores are likely to be eaten if they live on palatable seaweeds, their cryptic coloration and form not always keeping them safe from predators. Sacoglossans prefer to live on and eat chemically defended seaweeds, and they use ingested algal chemicals as deterrents of potential predators. The most ancestral shelled sacoglossans (Oxynoidae) and some Plakobranchidae such as Elysia translucens, Thuridilla hopei and Bosellia mimetica have developed a diet-derived chemical defense mechanism. Oxynoids and Thuridilla hopei are able to biomodify the algal metabolites. However, the Plakobranchidae Elysia timida and E. viridis, together with Limapontioidea species, are characterized by their ability to de novo synthesize polypropionate metabolites. A whole analysis of kleptoplasty and chemical defenses in sacoglossans may offer a better understanding of the ecology and evolution of these specialized opisthobranchs. In this paper we summarize some of the latest findings, related mainly to Mediterranean species, and offer a plausible evolutionary scenario based on the biological and chemical trends we can distinguish in them.

Trichoptera (INSECTA) collected in Mediterranean river basins in the Iberian Peninsula: taxonomic remarks and notes on ecology

As a result of the GUADALMED project, undertaken in Iberian Mediterranean basins, to which were added samples taken by the junior author in the area, we collected numerous caddisfly larvae, pupae and adults. Some larvae were also reared in the lab to obtain adults and allow proper identification. A total of 90 species were identified, which accounts for more than a fourth of the species known in the Iberian Peninsula and Balearic Islands. Here we confirm the presence of doubtful species in the Iberian Peninsula (Glyphotaelius pellucidus) and we expand the distribution range of others (Lype reducta, Micrasema minimum, Limnephilus guadarramicus, Sericostoma pyrenaicum). Moreover, because of the unconformity of morphological larval characteristics with present taxonomical keys (Mesophylax aspersus) or lack of larvae descriptions (Allogamus mortoni, Stenophylax espanioli), here we include some relevant taxonomical aspects that are useful to identify larvae. A brief description of the larva of a possible new species of Hydropsyche (from now on H. gr. instabilis) is also given. Los tricópteros (Insecta) recolectados en las cuencas mediterráneas de la Península Ibérica: notas taxonómicas y requerimientos ecológicos Como resultado de los estudios realizados en el proyecto GUADALMED en las cuencas de los ríos mediterráneos peninsulares y otros muestreos realizados por la primera autora del trabajo se han recolectado numerosas larvas, pupas y adultos de tricópteros. Algunas larvas fueron criadas en el laboratorio para la obtención de adultos y con ello asegurar su identificación. Se han identificado un total de 90 especies que suponen más de una cuarta parte de las especies actualmente conocidas en la Península Ibérica y Baleares. En este trabajo se confirma la presencia, hasta ahora dudosa en la Península Ibérica, de algunas especies (Glyphotaelius pellucidus) y se amplia el área de distribución de otras (Lype reducta, Micrasema minimum, Limnephilus guadarramicus, Sericostoma pyrenaicum). Además, se incluyen algunos aspectos taxonómicos relevantes para la identificación de algunas larvas en futuros estudios, debido a que las claves ya existentes no describen correctamente la larva (Mesophylax aspersus) o porque se trata de larvas sin describir (Allogamus mortoni, Stenophylax espanioli). Se añade también una somera descripción de la larva de una posible nueva especie de Hydropsyche (citada aquí como H. gr. instabilis) y que requiere un estudio más detallado.

Euphorbia L. subsect. Esula (Boiss. in DC.) Pax in the Iberian Peninsula. Leaf surface, chromosome numbers and taxonomic treatment

Presentem l'estudi taxonòmic dels représentants d'Euphorbia subsect. Esula a la Península Ibèrica. Prèviament, s'inclou un primer capítol dedicai a l'estudi de les epidermis foliars i un segon capítol sobre nombres cromosòmics...

Fruit and seed morphology of Euphorbia aggr. flavicoma. Taxonomic implications

Capsula and seed morphology of W. European species of Euphorbia aggr. flavicoma has been studied. A total of 1500 seeds coming from 13 taxa have been investigated under light microscope, scanning electron microscope and binocular stereoscope. Data were processed by multivariate analysis and the corresponding dendrogram is presented. At de end of the paper, a key is presented allowing to the separation of taxa down to the species level.

Taxonomic study of the isopod crustaceans from the Spanish expedition 'Antartida 1986-11' in the Scotia Sea, South Atlantic

This paper summarizes the results of a taxonomic study of the isopods collected during the 'Antártida 1986-11' expedition. A total of 123 specimens were studied, of which 99 were in the adult or juvenile phases and 24 were in the postmanca phase. The specimens were attributed to 11 species, 9 genera, 5 families and 4 suborders. The most abundant species were Glyptonotus antarcticus and Ceratoserolis trilobitoides. Several records are reported for the first time from the archipelagos of the Scotia Arc.

Sistema de Informació i Gestió Integral de la Producció Pesquera Internacional (SIGIPPI)

Des de la ciència geogràfica combinada amb el coneixement biològic i comercial, aquest projecte pretén crear una eina basada en la biogeografia i les últimes tecnologies de la Informació Geogràfica, que permetrà a l’usuari disposar de informació actualitzada per cada espècie amb interès comercial. El projecte es basa en el desenvolupament d’una aplicació web de consulta, entrada i actualització de dades referents a la producció pesquera internacional. Les eines utilitzades són les bases de dades MySQL i PostgreSQL i programació web amb html, php i javacript. Aquesta aplicació està pensada per ser accessible des de qualsevol ordinador amb connexió a internet i es subdivideix en tres sub-aplicacions. La primera sub-aplicació es basa en l’entrada d’espècies a partir de l’estructura taxonòmica. Partint de l’arbre taxonòmic, l’usuari té la possibilitat d’entrar, eliminar o modificar qualsevol tàxon o espècie. La segona subaplicació és una eina de digitalització cartogràfica on-line on l’usuari podrà marcar, eliminar o modificar sobre un mapa les localitzacions de les espècies que estiguin entrades en la sub-aplicació anterior. Finalment, la tercera sub-aplicació és una eina d’entrada de dades quinzenals referent als comportaments pel que fa tan a les dimensions com a les disponibilitats de pesca per cada espècie i localització.

Landscape context on generalist and specialist aphid natural enemies

Report for the scientific sojourn at the University of Lund, Sweden, between May and September 2007. A landscape-scale research approach has been highlighted by a growing body of literature as essential for understanding important ecosystem services as biological control. Aphids are victims of a diversity of enemies making the aphid-enemy interaction a nice example for the role of enemy diversity for the functioning of biological control. Here it is examined the effects of landscape complexity on cereal aphids and associated natural enemies that varied in the degree of specialization. Parasitoids wasps abundance did not differ between landscape types but was strongly negatively related to the percentage of arable land. In contrast, abundances of generalist predators like Coccinellidae were significantly higher in simple landscapes since can benefit from the high availability of a variety of alternative resources within cropping systems. Consequently coccinellidae-to-aphid ratio was significantly higher in fields in homogenous landscapes as compared to fields included in an heterogeneous landscape, suggesting that enemy pressure on cereal aphids increases with landscape simplification. The landscape effect will depend mainly on the degree of specialization of functionally dominant natural enemies, so that the results imply that conservation actions aiming to optimise abundance for one taxonomic group in the agricultural landscape will not automatically increase abundance of other groups. Given that the strength of natural enemy impact on biocontrol depends on landscape features and the role of functionally dominant natural enemies. So, therefore it is essential to focus the future empirical work in examining the schedule of agricultural landscapes that maintain a diversity of generalist and specialist natural enemies.

Síntesi i caracterització de micro- i nanoestructures de compostos fotoactius de perilendiimida

En el present treball de recerca s’ha portat a terme la síntesi i caracterització de fibres a escala micro- i nanomètrica mitjançant l’auto-assemblatge dels compostos 1 i 2. Aquests compostos estan formats per una unitat de perilendiimida (PI) i una unitat d’estilbè i, en base a estudis previs desenvolupats al nostre grup de recerca, haurien de comportar-se com a sistemes acceptor-donador d’electrons fotoinduïts. Per tant, les corresponents estructures obtingudes podrien presentar activitat fotovoltaica. En primer lloc, s’ha abordat la síntesi dels compostos 1 i 2, seguint la metodologia posada a punt prèviament al nostre grup de recerca. A continuació, s’han estudiat les propietats òptiques de 1 i 2 en dissolució, la qual cosa ha permès establir que: (a) tal i com es pretenia, tots dos compostos presenten transferència electrònica fotoinduïda entre la unitat electró-acceptora de PI i la unitat electró-donadora de trans-estilbè; (b) la diferent morfologia de la cadena alquílica lateral del grup de PI a 1 i 2 afecta la seva capacitat d’auto-assemblatge mitjançant interaccions intermoleculars de tipus π-π. A continuació, s’han assajat diferents metodologies per a la fabricació de micro- i nanoestructures auto-assemblades de 1 i 2. Els millors resultats s’han obtingut mitjançant l’ús de motlles d’òxid d’alúmina i per al compost 2 degut al menor impediment estèric de la seva cadena alquílica lateral. La caracterització de les estructures resultants en aquest cas mitjançant tècniques microscòpiques i espectroscòpiques han permès demostrar la formació de nanotubs de 200 nm de diàmetre, d’uns 15 μm de longitud i en què les unitats de PI s’ordenen amb els seus sistemes aromàtics de forma co-facial o gairebé co-facial. La possible activitat fotovoltaica d’aquestes estructures s’estudiarà posteriorment.

Capacity-approaching rate function for layered multiantenna architectures

The simultaneous use of multiple transmit and receive antennas can unleash very large capacity increases in rich multipath environments. Although such capacities can be approached by layered multi-antenna architectures with per-antenna rate control, the need for short-term feedback arises as a potential impediment, in particular as the number of antennas—and thus the number of rates to be controlled—increases. What we show, however, is that the need for short-term feedback in fact vanishes as the number of antennas and/or the diversity order increases. Specifically, the rate supported by each transmit antenna becomes deterministic and a sole function of the signal-to-noise, the ratio of transmit and receive antennas, and the decoding order, all of which are either fixed or slowly varying. More generally, we illustrate -through this specific derivation— the relevance of some established random CDMA results to the single-user multi-antenna problem.

The importance of intraespeciphic variation in the taxonomy of marine nematodes: The case of Terschellingia longispiculata Wieser & Hopper 1967 (Nematoda, Linhomoeidae)

In the presentstudy, the priority of taxonomic characters of cephalic region of Terschellingialongispiculata over those of the tail and reproductive system is discussed.Four morphological varieties of the species are established based on variationsof the tail and reproductive system. The problem of considering only changes inthe posterior region for determination of some species is posed. From this,studies on important populations must be done for the establishment of newspecies based on one of these characters, but taken together with characters inother regions such as the cephalic.

Phenotypic plasticity in the Caribbean sponge Callyspongia vaginalis (Porifera: Haplosclerida)

Sponge morphological plasticity has been a long-standing source of taxonomic difficulty. In the Caribbean, several morphotypes of the sponge Callyspongia vaginalis have been observed. To determine the taxonomic status of three of these morphotypes and their relationship with the congeneric species C. plicifera and C. fallax, we compared the spicule composition, spongin fiber skeleton and sequenced fragments of the mitochondrial genes 16S and COI and nuclear genes 28S and 18S ribosomal RNA. Phylogenetic analyses with ribosomal markers 18S and 28S rRNA confirmed the position of our sequences within the Callyspongiidae. None of the genetic markers provided evidence for consistent differentiation among the three morphotypes of C. vaginalis and C. fallax, and only C. plicifera stood as a distinct species. The 16S mtDNA gene was the most variable molecular marker for this group, presenting a nucleotide variability (π = 0.024) higher than that reported for COI. Unlike recent studies for other sponge genera, our results indicate that species in the genus Callyspongia maintain a high degree of phenotypic plasticity, and that morphological characteristics may not reflect reproductive boundaries in C. vaginalis.

Atomic parity nonconservation, neutron radii, and effective field theories of nuclei

Accurately calibrated effective field theories are used to compute atomic parity nonconserving (APNC) observables. Although accurately calibrated, these effective field theories predict a large spread in the neutron skin of heavy nuclei. Whereas the neutron skin is strongly correlated to numerous physical observables, in this contribution we focus on its impact on new physics through APNC observables. The addition of an isoscalar-isovector coupling constant to the effective Lagrangian generates a wide range of values for the neutron skin of heavy nuclei without compromising the success of the model in reproducing well-constrained nuclear observables. Earlier studies have suggested that the use of isotopic ratios of APNC observables may eliminate their sensitivity to atomic structure. This leaves nuclear structure uncertainties as the main impediment for identifying physics beyond the standard model. We establish that uncertainties in the neutron skin of heavy nuclei are at present too large to measure isotopic ratios to better than the 0.1% accuracy required to test the standard model. However, we argue that such uncertainties will be significantly reduced by the upcoming measurement of the neutron radius in 208^Pb at the Jefferson Laboratory.

Raw sewage harbors diverse viral populations

At this time, about 3,000 different viruses are recognized, but metagenomic studies suggest that these viruses are a small fraction of the viruses that exist in nature. We have explored viral diversity by deep sequencing nucleic acids obtained from virion populations enriched from raw sewage. We identified 234 known viruses, including 17 that infect humans. Plant, insect, and algal viruses as well as bacteriophages were also present. These viruses represented 26 taxonomic families and included viruses with single-stranded DNA (ssDNA), double-stranded DNA (dsDNA), positive-sense ssRNA [ssRNA(¿)], and dsRNA genomes. Novel viruses that could be placed in specific taxa represented 51 different families, making untreated wastewater the most diverse viral metagenome (genetic material recovered directly from environmental samples) examined thus far. However, the vast majority of sequence reads bore little or no sequence relation to known viruses and thus could not be placed into specific taxa. These results show that the vast majority of the viruses on Earth have not yet been characterized. Untreated wastewater provides a rich matrix for identifying novel viruses and for studying virus diversity.

High altitude Chironomidae (Diptera) of Serra da Estrela (Portugal): Additions to the Portuguese and Iberian Peninsula fauna

A Chironomidae (Diptera) fauna list for headwater streams of high altitude areas in Serra da Estrela (Portugal) is presented, doubling the previously established species richness for the region. The findings include 17 new records for Portugal, which represent an increase to 219 species for the Continental Portugal Chironomidae fauna. Two new records were detected for the Iberian Peninsula: one species (Tvetenia duodenaria), and one subgenusPsectrocladius (Mesopsectrocladius); and the presence of the genus Natarsia is confirmed. The last two occurrences correspond to monoespecific taxa of the Palearctic region. However, as taxonomic identification has been based on larval material, instead of pupae, pupal exuviae or imagoes, species level assignment is still uncertain. Key words: Diptera, Chironomidae, high mountain streams, Serra da Estrela, Portugal, Iberian Peninsula. RESUMEN Quironómidos (Diptera, Chironomidae) de alta montaña de la Sierra de Estrela (Portugal) y adiciones a la fauna de Portugal y la Península Ibérica Se presenta una lista de especies de Chironomidae (Diptera) recolectados en los ríos de cabecera de zonas de alta montaña en la Serra da Estrela (Portugal). Con esta aportación se duplica la riqueza de especies regional conocida hasta el momento y se eleva la fauna de quironómidos del Portugal continental a 219 especies. Se incluyen dos nuevas citas para la Península Ibérica, una especie (Tvetenia duodenaria) y un subgéneroPsectrocladius (Mesopsectrocladius), y se confirma la presencia del género Natarsia. En los dos últimos casos se trata de larvas de taxones hasta el momento monoespecíficos en la región paleárctica, pero al no haberse recolectado pupas o adultos no se puede asegurar la identificación específica. Palabras clave: Diptera, Chironomidae, ríos de alta montaña, Serra da Estrela, Portugal,

Taxonomy of the genus Chamaesyce S.F. Gray in the Iberian Peninsula and the Balearic Islands

A taxonomic study is undertaken of the ten taxa (nine of them specific) belonging to the genus Chamaesyce S.F. Gray (Euphorbiaceae) which are present in the Iberian Peninsula and the Balearic Islands and a dichotomic key is provided. The taxonomic chacarcteristics of ecology are given. The presence of Chamaesyce humifusa (Willd.) Prokh. in the Iberian Peninsula is confirmed and Chamaesyce humistrata (Gray) Small is recorded for the first time from Europe.