Past and recent demographic histories of western Mediterranean demersal chondrichthyans

Chondrichthyans (sharks, rays and chimaeras) play a key role in marine ecosystems, since they are top predators. Because of their life-history traits (slow growth, late maturity and low fecundity), they are especially vulnerable to fishing. In the Mediterranean, which hosts 7% of living chondrichthyans, a notable change in marine ecosystems has occurred due to anthropogenic impacts, with overfishing as one of the most important. For this reason, and because these species can be an important by-catch of fisheries, the International Union for Conservation of Nature (IUCN) considers this region a key hotspot of extinction risk for chondrichthyans. This Thesis contributes to improve the scientific knowledge of chondrichthyans on the circalittoral and bathyal soft bottoms along the western Mediterranean. Methods traditionally used to study population dynamics and biological communities, jointly with molecular tools, were applied to assess the past and present status of these vulnerable species. Data and samples were obtained during the MEDITS bottom trawl research surveys, developed annually in spring-summer since 1994 throughout the four geographic sub-areas (GSAs) established by the General Fisheries Commission for the Mediterranean (GFCM) in the study area: Northern Alboran Sea (GSA01) and Alboran Island (GSA02) considered jointly as GSA01, Balearic Islands (GSA05) and Northern Spain (GSA06). A total of 33 species of demersal chondrichthyans, belonging to 13 families were identified, of which 26, 28, and 19 species were caught in GSA01, GSA05 and GSA06, respectively. Two different assemblages were detected in each GSA, corresponding to the continental shelf and slope. The highest values of diversity, abundance, and biomass were recorded on the continental shelf of GSA05 and the slope of GSA01, while GSA06 showed the lowest values at both depth strata. These results can be explained by differences in trawl fishing exploitation and types of bottom between GSAs. Biological parameters such as optimum depth, length at first maturity, and size structure are provided for the most abundant species: Scyliorhinus canicula, Galeus melastomus, Etmopterus spinax, and Raja clavata. Spatio-temporal trends show fairly stable populations over the last 20 years regarding richness, abundance and biomass, even with an increment in density of species dwelling on the continental shelf and the most abundant on the slope, but decreasing trends in some other deep water species. This can be related to the reduction of trawl fishing effort on the continental shelf over the last decades, because fishing fleet has been reduced and displaced towards deeper waters. Genetic analyses revealed contrasting population patterns in S. canicula and G. melastomus, the two most abundant chondrichthyans on the continental shelf and slope, respectively. The first species showed genetic differences and low connectivity between Alboran Sea (GSA01-GSA02) and Balearic Sea (GSA05-GSA06), while the second one did not show geographic differences. Distinct demographic histories were also detected for both species. While G. melastomus exhibited a recent population expansion, S. canicula showed stability at present, but signs of past bottleneck events. Phylogenetic results revealed a parallel evolutionary history between batoids and the Mediterranean, with two important speciation events: i) during the Eocene-Oligocene transition, when almost all genera were originated; and ii) during the Miocene, when almost all current species appeared. Depth and benthic habitats were shown as the main drivers of speciation in Raja genera, both being of equal importance alongside physical distance and geographical barriers. Molecular analysis showed the presence of 18 batoids in the western Mediterranean and revealed misidentifications based only on morphological characters, including the confirmation of Dasyatis cf. tortonesei as a valid species and the presence of Dipturus nidarosiensis in the MediterraneanHistorias demográficas pasadas y recientes de los condrictios demersales del Mediterráneo Occidental. Los condrictios (tiburones, rayas y quimeras) desempeñan un papel clave en los ecosistemas marinos, dado que son depredadores apicales. Debido a las características de su ciclo vital (crecimiento lento, madurez tardía y baja fecundidad), son especialmente vulnerables a la pesca. El Mediterráneo, que alberga alrededor del 7% de los condrictios actuales, ha sufrido cambios importantes en sus ecosistemas marinos, causados por los impactos antropogénicos, entre los cuales la sobrepesca es uno de los más importantes. Por esta razón, y debido a que estas especies son capturadas frecuentemente de forma accidental en las pesquerías, la Unión Internacional para la Conservación de la Naturaleza (UICN) considera esta región como un punto clave de riesgo de extinción para los condrictios. Esta Tesis contribuye a mejorar el conocimiento científico de los condrictios en los fondos circalitorales y batiales del Mediterráneo Occidental. Se han aplicado métodos tradicionales de estudio de dinámica de poblaciones y comunidades biológicas, así como herramientas moleculares, con el propósito de evaluar la situación pasada y presente de estas especies vulnerables. Los datos y muestras se obtuvieron durante las campañas de investigación MEDITS, con arte de arrastre de fondo, realizadas anualmente desde 1994 en primavera-verano, a lo largo de cuatro sub-áreas geográficas (GSAs), establecidas por la Comisión General de Pesca para el Mediterráneo (CGPM) en el área de estudio: Norte del Mar de Alborán (GSA01) e Isla de Alborán (GSA02), considerados conjuntamente como GSA01, Islas Baleares (GSA05) y Norte de España (GSA06). Se han identificado un total de 33 especies de condrictios demersales, pertenecientes a 13 familias, de los cuales 26, 28 y 19 especies fueron capturados en la GSA01, GSA05 y GSA06, respectivamente. Se han detectado dos comunidades diferentes en cada GSA, que corresponden a la plataforma continental y al talud. Los valores más altos de diversidad, abundancia y biomasa se han obtenido en la plataforma continental de la GSA05 y en el talud de la GSA01, mientras que la GSA06 ha mostrado los valores más bajos en ambos estratos batimétricos. Estos resultados se pueden explicar por las diferencias en el esfuerzo de la pesca de arrastre y los tipos de fondo entre estas GSAs. Se han estimado parámetros biológicos (profundidad optima, talla de primera madurez y frecuencia de tallas) de las especies más abundantes: Scyliorhinus canicula, Galeus melastomus, Etmopterus spinax y Raja clavata. Las tendencias espacio-temporales muestran poblaciones bastante estables durante los últimos 20 años con respecto a la riqueza de especies, abundancia y biomasa, incluso con un aumento de la densidad de especies que habitan la plataforma continental y en la especie más abundante en el talud, pero con tendencias decrecientes en algunas otras especies de gran profundidad. Esto se puede relacionar con la reducción del esfuerzo de la pesca de arrastre en la plataforma continental durante las últimas décadas, a causa de la disminución de la flota y de su desplazamiento hacia aguas más profundas. Los análisis genéticos han mostrado que S. canicula y G. melastomus, las dos especies de condrictios más abundantes de la plataforma continental y el talud, respectivamente, tienen patrones poblacionales distintos. La primera ha presentado diferencias genéticas y baja conectividad entre el Mar de Alborán (GSA01-GSA02) y el Mar Balear (GSA05-GSA06), pero la segunda especie no ha mostrado estas diferencias geográficas. También se ha detectado una historia demográfica distinta entre ambas especies. Mientras que G. melastomus ha tenido una expansión poblacional reciente, S. canicula muestra mayor estabilidad, pero con evidencias de haber sufrido eventos de cuello de botella en el pasado. Los resultados filogenéticos han mostrado una historia evolutiva paralela de los batoideos y el Mediterráneo, con dos importantes eventos de especiación: i) durante la transición Eoceno-Oligoceno, cuando se originaron casi todos los géneros; y ii) durante el Mioceno, cuando aparecieron casi todas las especies actuales. Se ha demostrado que la profundidad y los hábitats bentónicos son los principales factores de especiación en el género Raja, siendo de igual importancia que las barreras geográficas y la distancia física. El análisis molecular ha demostrado la presencia de 18 especies de batoideos en el Mediterráneo Occidental y ha evidenciado identificaciones erróneas basadas sólo en caracteres morfológicos. Se ha confirmado Dasyatis cf. tortonesei como especie válida y la presencia de Dipturus nidarosiensis en el MediterráneoHistòries demogràfiques passades i recents dels condrictis demersals de la Mediterrània Occidental. Els condrictis (taurons, rajades i quimeres) tenen un paper clau en els ecosistemes marins, ja que són depredadors apicals. Per les característiques del seu cicle vital (creixement lent, maduresa tardana i baixa fecunditat), són especialment vulnerables a la pesca. La Mediterrània, on hi ha al voltant del 7% dels condrictis actuals, ha sofert canvis importants en els seus ecosistemes marins, causats pels impactes antropogènics, entre els quals la sobrepesca és un dels més importants. Per aquesta raó, i pel fet que aquestes espècies són capturades freqüentment de forma accidental a les pesqueries, la Unió Internacional per a la Conservació de la Naturalesa (IUCN) considera aquesta regió com un punt clau de risc d'extinció per als condrictis. Aquesta Tesi contribueix a millorar el coneixement científic dels condrictis en els fons circalitorals i batials de la Mediterrània Occidental. S'han aplicat mètodes d'estudi tradicionals de dinàmica de poblacions i comunitats biològiques, així com eines moleculars amb el propòsit d'avaluar la situació passada i present d'aquestes espècies vulnerables. Les dades i mostres s’han obtingut durant les campanyes d'investigació MEDITS, amb art de ròssec de fons, realitzades anualment des del 1994 a la primavera-estiu, al llarg de quatre subàrees geogràfiques (GSAs) establertes per la Comissió General de Pesca per a la Mediterrània (CGPM) en l'àrea d'estudi: Nord de la Mar d'Alborán (GSA01) i Illa d'Alborán (GSA02), considerats conjuntament com GSA01, Illes Balears (GSA05) i Nord d'Espanya (GSA06). S'han identificat un total de 33 espècies de condrictis demersals, que pertanyen a 13 famílies, de les quals 26, 28 i 19 espècies van ser capturades a les GSA01, GSA05 i GSA06, respectivament. A cada GSA s'han detectat dues comunitats diferents, que corresponen a la plataforma continental i al talús. Els valors més alts de diversitat, abundància i biomassa s'han obtingut en la plataforma continental de la GSA05 i en el talús de la GSA01, mentre que la GSA06 ha mostrat els valors més baixos en ambdós estrats batimètrics. Aquests resultats es poden explicar per les diferències en l'esforç de la pesca de ròssec i els tipus de fons entre aquestes GSAs. S'han estimat paràmetres biològics (profunditat òptima, talla de primera maduresa i freqüència de talles) de les espècies més abundants: Scyliorhinus canicula, Galeus melastomus, Etmopterus spinax i Raja clavata. Les tendències espai-temporals mostren poblacions bastant estables durant els últims 20 anys pel que fa a la riquesa d'espècies, abundància i biomassa, fins i tot amb un augment de la densitat d'espècies que habiten la plataforma continental i l'espècie més abundant al talús, però amb tendències decreixents en algunes altres espècies de gran profunditat. Això es pot relacionar amb la reducció de l'esforç de la pesca de ròssec en la plataforma continental durant les últimes dècades, a causa de la disminució de la flota i del seu desplaçament cap a aigües més profundes. Les anàlisis genètiques han mostrat que S. canicula i G. melastomus, les dues espècies de condrictis més abundants en la plataforma continental i el talús, respectivament, tenen patrons poblacionals diferents. La primera ha presentat diferències genètiques i baixa connectivitat entre la Mar d'Alborán (GSA01-GSA02) i la Mar Balear (GSA05-GSA06), però la segona espècie no ha mostrat aquestes diferències geogràfiques. També s'ha detectat una història demogràfica diferent entre ambdues espècies. Mentre que G. melastomus ha tingut una expansió poblacional recent, S. canicula mostra major estabilitat, però amb evidències d'haver sofert esdeveniments de coll de botella en el passat. Els resultats filogenètics han mostrat una història evolutiva paral•lela dels batoïdeus i la Mediterrània, amb dos importants esdeveniments d'especiació: i) durant la transició Eocè-Oligocè, quan es van originar gairebé tots els gèneres; i ii) durant el Miocè, quan van aparèixer la majoria de les espècies actuals. S'ha demostrat que la profunditat i els hàbitats bentònics són els principals factors d'especiació en el gènere Raja, sent d'igual importància que les barreres geogràfiques i la distància física. L'anàlisi molecular ha demostrat la presència de 18 espècies de batoïdeus a la Mediterrània Occidental i ha evidenciat identificacions errònies basades només en caràcters morfològics. S’ha confirmat Dasyatis cf. tortonesei com a espècie vàlida i la presència de Dipturus nidarosiensis a la Mediterràni

Revalidación de Arnoglossus blachei, con la nueva descripción de Arnoglossus imperialis del Atlántico nororiental y el Mediterráneo (Teleostei: Bothidae)

   Blache’s flounder, Arnoglossus blachei Stauch, 1965, is redescribed from the eastern Atlantic (Morocco south to Namibia, including the Canary Islands, larvae reaching South Africa) and distinguished from the imperial flounder A. imperialis (Rafinesque, 1810) by having a live colouration of the lower side of males which is bright red (whitish in A. imperialis), the caudal fin with lateral-line scales 52-57 (vs. 58-63), and the dorsal-fin filaments in male light grey, with black margins, distally yellowish (vs. plain white). A lectotype is selected for Arnoglossus blachei. The species is compared with similar species. The externally similar species Arnoglossus imperialis is also redescribed; its distibution range is restricted to the Mediterranean and northeastern Atlantic, including Madeira and the Azores. Neotypes are selected to stabilize the usage of the names Bothus imperialis Rafinesque, 1810, Bothus punctatus Rafinesque, 1814, Rhombus cristatus Lowe, 1839 and Charybdia rhomdoidichthys Facciolà, 1885. Molecular analyses based on two mitochondrial fragments (12s rRNA and COI) clearly support the validity of A. blachei. Moreover, though A. blachei is morphologically close to A. imperialis, the two species show the highest genetic distances among all Arnoglossus species compared (including A. capensis, A. imperialis, A. laterna, A. rueppelii and A. thori). A key to the eastern Atlantic and Mediterranean species of Arnoglossus is presented.   Se vuelve a describir el pez plano de Blache’s Arnoglossus blachei Stauch, 1965 del Atlántico oriental (desde el sur de Marruecos a Namibia incluido las Islas Canarias, pudiendo sus larvas llegar a Sudáfrica), y se distingue del pez plano imperial A. imperialis (Rafinesque, 1810) por tener, en fresco, una coloración rojo brillante en la parte inferior de los machos (blanquecina en A. imperialis), la aleta caudal con escamas en la línea lateral 52-57 (vs. 58-63), y en los machos, los filamentos de la aleta dorsal son de color gris claro, con márgenes negros y en su parte distal amarillenta (vs. blanco liso). La especie se compara con especies similares. Asimismo, la especie externamente similar Arnoglossus imperialis, se vuelve a describir, cuya área de distribución está restringida al Mediterráneo y Atlántico nororiental, incluidas Madeira y Azores. Además, se seleccionan neotipos para estabilizar el uso de los nombres Bothus imperialis Rafinesque, 1810, Bothus punctatus Rafinesque, 1814, Rhombus cristatus Lowe, 1839 y Charybdia rhomdoidichthys Facciolà, 1885. Los análisis moleculares basados en dos fragmentos mitocondriales (12s rRNA y COI) respaldan claramente la validez de A. blachei. Por otra parte, a pesar de que A. blachei es morfológicamente más cercano a A. imperialis, ambas especies muestran las distancias genéticas más largas entre todas las especies de Arnoglossus comparadas (A. capensis, A. imperialis, A. laterna, A. rueppelii y A. thori). Se presenta una clave para las especies de Arnoglossus del Atlántico oriental y Mediterráneo

Genome-Based Vaccinology Applied to Bovine Anaplasmosis

Bovine anaplasmosis is an infectious non-contagious disease transmitted mainly by ticks or fomites contaminated with Anaplasma marginale. Once cattle have developed the disease it can be treated with antibiotics or chemotherapy, although with partial success. Still, there is no effective and global prophylactic method available, mainly because of variability and diversity showed by different A. marginale strains distributed worldwide. In this regard, several proteins have been proposed as immunogens, MSPs, OMPs, Type IV Secretion System Proteins and some other hypothetical proteins, which have been chosen either by experimental evidence or more recently by genome-based analysis. So far, the results suggest that a single molecule will not be enough to trigger a protective immune response in the host, so it is necessary to identify other proteins or epitopes with adequate immunological properties, a process in which omics tools have potential. In order to develop a vaccine against bovine anaplasmosis, it has been proposed by the use of combinations of molecules, exposure formats and application protocols to provide an effective control of the disease

Environmental DNA: State-of-the-art of its application for fisheries assessment in marine environments

Fisheries management involves a broad and complex set of tasks that are necessary to prevent overfishing and to help the recovery of overfished stock. Monitoring fishing activities based on two main sources, landings data and scientific surveys, is a challenging task. Fisheries collection data is often limited, which compromises the accuracy of the results obtained. Therefore, several emerging applications of molecular methods have the potential to provide unique understanding of ecological processes in marine environments and to build stronger empirical underpinnings for the Ecosystem-Based Fisheries Management. Environmental DNA (eDNA) is a complex mixture of genetic material shed by those organisms that inhabit a given environment, whereby DNA is extracted from an environmental sample without accessing the target organism. eDNA studies can be categorized into two main approaches, i) eDNA metabarcoding or semi-targeted (community) approaches and ii) species-specific or targeted approaches (single). Although both categories are often discussed, they differ drastically in their methodology, interpretations and accuracy. Both approaches involve a series of steps that include eDNA capture, preservation, extraction and amplification. This detection will depend on the affinity to the targeted taxa sequences and completeness and accuracy of DNA reference collection databases. The eDNA method applied in marine environments are probably the most challenging aquatic environments for applying this technique. This is because of the extreme relationship between water-volume to biomass, dynamics and the physical and chemical properties of seawater that affect dispersion, dilution and preservation. Here, we review the present application of this novel method in fishery assessment in marine environments. To date, many studies suggest that this method offers the potential to revolutionize fisheries monitoring, which will contribute to improving the range of tasks involved in fisheries management. The compelling conclusion is that the methodological steps including in eDNA surveys should be standardized and that research efforts should focus on developing appropriately validated tests to address environmental and sampling factors that may affect eDNA detection in marine environments in order to draw reliable conclusions. This bioassessment tool can assist fisheries professionals in achieve their research, management, and conservation objectives, but not as a replacement for time-proven assessment methods

The Amygdala and Anxiety

The amygdala has a central role in anxiety responses to stressful and arousing situations. Pharmacological and lesion studies of the basolateral, central, and medial subdivisions of the amygdala have shown that their activation induces anxiogenic effects, while their inactivation produces anxiolytic effects. Many neurotransmitters and stress mediators acting at these amygdalar nuclei can modulate the behavioral expression of anxiety. These mediators may be released from different brain regions in response to different types of stressors. The amygdala is in close relationship with several brain regions within the brain circuitry that orchestrates the expression of anxiety. Recent developments in optogenetics have begun to unveil details on how these areas interact

Morphological abnormalities in the Chilean Eagle ray Myliobatis chilensis (Myliobatiformes: Myliobatidae) off the Peruvian coast, Southeast Pacific

Records about morphological abnormalities in rays of the genus Myliobatis are scarce worldwide. In the present study, three specimens exhibiting different malformations were identified during the monitoring of the reproductive biology of the Chilean eagle ray Myliobatis chilensis, conducted from 2017 to 2018 in the fishing port of Salaverry (northern Peru). The identified specimens included: (i) a female with split pectoral fins, (ii) a male with an unfused-to-the-head pectoral fin, and (iii) a female with a short and thick tail. Here we report and discuss the implications and likely causes of these first three cases of morphological abnormalities in M. chilensis from the western Pacific

First substantiated record of Raja asterias Delaroche, 1809 (Elasmobranchii: Rajiformes: Rajidae) in the Gulf of Cádiz, North-eastern Atlantic

The Mediterranean starry ray, Raja asterias, considered endemic in the Mediterranean, has recently been reported by other authors from Atlantic fisheries in southern Portugal and northern Morocco. There has been, however, no substantiated record of the species outside the Mediterranean. This fact and the easiness of confusion of R. asterias with other species have probably prevented those records from being taken into account in the recent catalogue of North Atlantic elasmobranchs species, in the assessment of the population status of this species, and in recent annotated global checklists of chondrichthyans. In our study, a specimen of R. asterias was collected from the Gulf of Cádiz and its species identity was assessed based on morphological and molecular methods. The presently reported finding constitutes a substantiated record of R. asterias from the Atlantic. Based on this record, previously reported catches of the Mediterranean starry ray in the Atlantic should be confirmed, and if so, these populations should be included in future assessments of this vulnerable species and in the description of its geographic distributionVersión del editor0,54

Double hemispheric Microdialysis study in poor-grade SAH patients

Delayed cerebral ischemia (DCI) is a dreadful complication present in 30% of subarachnoid hemorrhage (SAH) patients. DCI prediction and prevention are burdensome in poor grade SAH patients (WFNS 4-5). Therefore, defining an optimal neuromonitoring strategy might be cumbersome. Cerebral microdialysis (CMD) offers near-real-time regional metabolic data of the surrounding brain. However, unilateral neuromonitoring strategies obviate the diffuse repercussions of SAH. To assess the utility, indications and therapeutic implications of bilateral CMD in poor grade SAH patients. Poor grade SAH patients eligible for multimodal neuromonitoring were prospectively collected. Aneurysm location and blood volume were assessed on initial Angio-CT scans. CMD probes were bilaterally implanted and maintained, at least, for 48 hours (h). Ischemic events were defined as a Lactate/Pyruvate ratio >40 and Glucose concentration <0.7 mmol/L. 16 patients were monitored for 1725 h, observing ischemic events during 260 h (15.1%). Simultaneous bilateral ischemic events were rare (5 h, 1.9%). The established threshold of ≥7 ischemic events displayed a specificity and sensitivity for DCI of 96.2% and 83.3%, respectively. Bilateral CMD is a safe and useful strategy to evaluate areas at risk of suffering DCI in SAH patients. Metabolic crises occur bilaterally but rarely simultaneously. Hence, unilateral neuromonitoring strategies underestimate the risk of infarction and the possibility to offset its consequences

CAPACIDADE PREDITIVA DOS MODELOS DA FAMÍLIA ARCH

Nas últimas décadas, um notável número de modelos, variantes da família Autoregressive Conditional Heteroscedastic, foram desenvolvidos e testados empiricamente, tornando extremamente complexo o processo de escolha de um modelo específico. Esta pesquisa busca comparar a capacidade preditiva, utilizando o Model Confidence Set procedure, de cinco modelos de heterocedasticidade condicional, levando em consideração oito diferentes distribuições de probabilidade estatística. As séries financeiras utilizadas referem-se às séries de log-retorno do Índice Bovespa e do Índice Dow Jones Industrial, no período compreendido entre 27 de outubro de 2008 e 30 de dezembro de 2014. As evidências empíricas demonstraram que, em geral, os modelos concorrentes possuem uma grande homogeneidade para realizar previsões, tanto para um mercado acionário de um país desenvolvido quanto para um mercado acionário de um país em desenvolvimento. Depreende-se um resultado equivalente para as diferentes distribuições de probabilidade estatísticas utilizadas