Reproductive potential of Yellowfin Tuna (Thunnus albacares) in the western Indian Ocean

The reproductive biology of Yellowfin Tuna (Thunnus albacares) in the western Indian Ocean was investigated from samples collected in 2009 and 2010. In our study, 1012 female Yellowfin Tuna were sampled: 320 fish on board a purse seiner and 692 fish at a Seychelles cannery. We assessed the main biological parameters that describe reproductive potential: maturity, spawning seasonality, fish condition, and fecundity. The length at which 50% of the female Yellowfin Tuna population matures (L50) was estimated at 75 cm in fork length (FL) when the maturity threshold was established at the cortical alveolar stage of oocyte development. To enable comparison with previous studies, L50 also was estimated with maturity set at the vitellogenic stage of oocyte development; this assessment resulted in a higher value of L50 at 102 cm FL. The main spawning season, during which asynchrony in reproductive timing among sizes was observed, was November–February and a second peak occurred in June. Smaller females (<100 cm FL) had shorter spawning periods (December to February) than those (November to February and June) of large individuals, and signs of skip-spawning periods were observed among small females. The Yellowfin Tuna followed a “capital-income” breeder strategy during ovarian development, by mobilizing accumulated energy while using incoming energy from feeding. The mean batch fecundity for females 79–147 cm FL was estimated at 3.1 million oocytes, and the mean relative batch fecundity was 74.4 oocytes per gram of gonad-free weight. Our results, obtained with techniques defined more precisely than techniques used in previous studies in this region, provide an improved understanding of the reproductive cycle of Yellowfin Tuna in the western Indian Ocean

Altered glial expression of the cannabinoid 1 receptor in the subiculum of a mouse model of Alzheimer's disease.

The alteration of the endocannabinoid tone usually associates with changes in the expression and/or function of the cannabinoid CB1 receptor. In Alzheimer's disease (AD), amyloid beta (Aβ)-containing aggregates induce a chronic inflammatory response leading to reactivity of both microglia and astrocytes. However, how this glial response impacts on the glial CB1 receptor expression in the subiculum of a mouse model of AD, a brain region particularly affected by large accumulation of plaques and concomitant subcellular changes in microglia and astrocytes, is unknown. The CB1 receptor localization in both glial cells was investigated in the subiculum of male 5xFAD/CB2EGFP/f/f (AD model) and CB2EGFP/f/f mice by immuno-electron microscopy. The findings revealed that glial CB1 receptors suffer remarkable changes in the AD mouse. Thus, CB1 receptor expression increases in reactive microglia in 5xFAD/CB2EGFP/f/f, but remains constant in astrocytes with CB1 receptor labeling rising proportionally to the perimeter of the reactive astrocytes. Not least, the CB1 receptor localization in microglial processes in the subiculum of controls and closely surrounding amyloid plaques and dystrophic neurites of the AD model, supports previous suggestions of the presence of the CB1 receptor in microglia. These findings on the correlation between glial reactivity and the CB1 receptor expression in microglial cells and astrocytes, contribute to the understanding of the role of the endocannabinoid system in the pathophysiology of Alzheimer's disease.post-print4763 K

Biodegradable drifting fish aggregating devices: Current status and future prospects

The structure, materials and designs of drifting Fish Aggregating Devices (dFADs) have generally remained rudimentary and relatively unchanged since they first came into use in the 1980 s. However, more recently, dFADs have been increasing in dimensions and the prevailing use of plastic components. Abandoned, lost or discarded dFADs can therefore contribute to the global marine litter problem. Transitioning to biodegradable and non-toxic materials that have a faster rate of decomposition, and are free of toxins and heavy metals, relative to synthetic materials, has been prescribed as an important part of the solution to reducing marine pollution from industrial tuna fisheries that rely on dFADs. This review of the current state of dFADs considers aspects related to the use of biodegradable materials in their construction, including; regulations related to dFAD materials, trials of biodegradable designs and materials and future alternatives. During the last decade, regulatory measures at tuna Regional Fishery Management Organizations (tRFMOs) have gradually moved towards the clear recommendation to use biodegradable materials in dFAD construction together with other measures limiting the number of active dFADs and the use of netting materials. However, to provide operational guidance, more clarity is needed, starting with a standardised definition of biodegradable dFADs among tRFMOs. Research involving dFAD natural and synthetic materials is required, along with improved data collection for monitoring the transition of dFAD materials against specified standards for biodegradable dFADs. In addition, alternative and complementary actions need to be explored to contribute to minimising adverse effects of dFADs on the environment. Acknowledging the current difficulties for the implementation of fully biodegradable dFADs in tuna fisheries, a stepwise process towards the implementation of commercially viable biodegradable dFADs should be considered.Peer reviewe

Spread of a SARS-CoV-2 variant through Europe in the summer of 2020

[EN] Following its emergence in late 2019, the spread of SARS-CoV-21,2 has been tracked by phylogenetic analysis of viral genome sequences in unprecedented detail3,4,5. Although the virus spread globally in early 2020 before borders closed, intercontinental travel has since been greatly reduced. However, travel within Europe resumed in the summer of 2020. Here we report on a SARS-CoV-2 variant, 20E (EU1), that was identified in Spain in early summer 2020 and subsequently spread across Europe. We find no evidence that this variant has increased transmissibility, but instead demonstrate how rising incidence in Spain, resumption of travel, and lack of effective screening and containment may explain the variant’s success. Despite travel restrictions, we estimate that 20E (EU1) was introduced hundreds of times to European countries by summertime travellers, which is likely to have undermined local efforts to minimize infection with SARS-CoV-2. Our results illustrate how a variant can rapidly become dominant even in the absence of a substantial transmission advantage in favourable epidemiological settings. Genomic surveillance is critical for understanding how travel can affect transmission of SARS-CoV-2, and thus for informing future containment strategies as travel resumes.S

The first wave of the COVID-19 epidemic in Spain was associated with early introductions and fast spread of a dominating genetic variant

SeqCOVID-Spain consortium: Álvaro Chiner-Oms, Irving Cancino-Muñoz, Mariana G. López, Manuela Torres-Puente, Inmaculada Gómez-Navarro, Santiago Jiménez-Serrano, Jordi Pérez-Tur, Darío García de Viedma, Laura Pérez-Lago, Marta Herranz, Jon Sicilia, Pilar Catalán-Alonso, Julia Suárez González, Patricia Muñoz, Mireia Coscolla, Paula Ruiz-Rodríguez, Fernando González-Candelas, Iñaki Comas, Lidia Ruiz-Roldán, María Alma Bracho, Neris García-González, Llúcia Martínez Priego, Inmaculada Galán-Vendrell, Paula Ruiz-Hueso, Griselda De Marco, María Loreto Ferrús-Abad, Sandra Carbó-Ramírez, Giuseppe D’Auria, Galo Adrian Goig, Juan Alberola, Jose Miguel Nogueira, Juan José Camarena, David Navarro, Eliseo Albert, Ignacio Torres, Maitane Aranzamendi Zaldumbide, Óscar Martínez Expósito, Nerea Antona Urieta, María de Toro, María Pilar Bea-Escudero, Jose Antonio Boga, Cristian Castelló-Abietar, Susana Rojo-Alba, Marta Elena Álvarez-Argüelles, Santiago Melón, Elisa Martró, Antoni E. Bordoy, Anna Not, Adrián Antuori, Anabel Fernández-Navarro, Andrés Canut-Blasco, Silvia Hernáez Crespo, Maria Luz Cordón Rodríguez, Maria Concepción Lecaroz Agara, Carmen Gómez-González, Amaia Aguirre-Quiñonero, José Israel López-Mirones, Marina Fernández-Torres, Maria Rosario Almela-Ferrer, Ana Carvajal, Juan Miguel Fregeneda-Grandes, Héctor Argüello, Gustavo Cilla Eguiluz, Milagrosa Montes Ros, Luis Piñeiro Vázquez, Ane Sorarrain, José María Marimón, José J. Costa-Alcalde, Rocío Trastoy, Gema Barbeito Castiñeiras, Amparo Coira, María Luisa Pérez del Molino, Antonio Aguilera, Begoña Palop-Borrás, Inmaculada de Toro Peinado, Maria Concepción Mediavilla Gradolph, Mercedes Pérez-Ruiz, Mirian Fernández-Alonso, Jose Luis del Pozo, Oscar González-Recio, Mónica Gutiérrez-Rivas, Jovita Fernández-Pinero, Miguel Ángel Jiménez Clavero, Begoña Fuster Escrivá, Concepción Gimeno Cardona, María Dolores Ocete Mochón, Rafael Medina-Gonzalez, José Antonio Lepe, Verónica González Galán, Ángel Rodríguez-Villodres, Nieves Gonzalo Jiménez, Jordi Reina, Carla López-Causapé, Maria Dolores Gómez-Ruiz, Eva M. Gonzalez-Barbera, José Luis López-Hontangas, Vicente Martín, Antonio J. Molina, Tania Fernandez-Villa, Ana Milagro Beamonte, Nieves Felisa Martínez-Cameo, Yolanda Gracia-Grataloup, Rosario Moreno-Muñoz, Maria Dolores Tirado Balaguer, José María Navarro-Marí, Irene Pedrosa-Corral, Sara Sanbonmatsu-Gámez, Antonio Oliver, Mónica Parra Grande, Bárbara Gómez Alonso, Francisco José Arjona Zaragozí, Maria Carmen Pérez González, Francisco Javier Chamizo López, Ana Bordes-Benítez, Núria Rabella, Ferran Navarro, Elisenda Miró, Antonio Rezusta, Alexander Tristancho, Encarnación Simarro Córdoba, Julia Lozano-Serra, Lorena Robles Fonseca, Álex Soriano, Francisco Javier Roig Sena, Hermelinda Vanaclocha Luna, Isabel Sanmartín, Daniel García-Souto, Ana Pequeño-Valtierra, Jose M. C. Tubio, Javier Temes, Jorge Rodríguez-Castro, Martín Santamarina García, Manuel Rodríguez-Iglesias, Fátima Galán-Sanchez, Salud Rodríguez-Pallares, José Manuel Azcona-Gutiérrez, Miriam Blasco-Alberdi, Alfredo Mayor, Alberto L. García-Basteiro, Gemma Moncunill, Carlota Dobaño, Pau Cisteró, Oriol Mitjà, Camila González-Beiras, Martí Vall-Mayans, Marc Corbacho-Monné, Andrea Alemany, Cristina Muñoz-Cuevas, Guadalupe Rodríguez-Rodríguez, Rafael Benito, Sonia Algarate, Jessica Bueno, Andrea Vergara-Gómez, Miguel J. Martínez, Jordi Vila, Elisa Rubio, Aida Peiró-Mestres, Jessica Navero-Castillejos, David Posada, Diana Valverde, Nuria Estévez, Iria Fernández-Silva, Loretta de Chiara, Pilar Gallego-García, Nair Varela, Ulises Gómez-Pinedo, Mónica Gozalo-Margüello, Maria Eliecer Cano García, José Manuel Méndez-Legaza, Jesus Rodríguez-Lozano, María Siller, Daniel Pablo-Marcos, Maria Montserrat Ruiz-García, Antonio Galiana, Judith Sánchez-Almendro, Maria Isabel Gascón Ros, Cristina Juana Torregrosa-Hetland, Eva María Pastor Boix, Paloma Cascales Ramos, Pedro Luis Garcinuño Enríquez, Salvador Raga Borja, Julia González Cantó, Olalla Martínez Macias, Adolfo de Salazar, Laura Viñuela González, Natalia Chueca, Federico García, Cristina Gómez-Camarasa, Amparo Farga Martí, Rocío Falcón, Victoria Domínguez-Márquez, Anna M. Planas, Israel Fernández-Cádenas, Maria Ángeles Marcos, Carmen Ezpeleta, Ana Navascués, Ana Miqueleiz Zapatero, Manuel Segovia, Antonio Moreno-Docón, Esther Viedma, Raúl Recio Martínez, Irene Muñoz-Gallego, Sara Gonzalez-Bodi, Maria Dolores Folgueira, Jesús Mingorance, Elias Dahdouh, Fernando Lázaro-Perona, María Rodríguez-Tejedor, María Pilar Romero-Gómez, Julio García-Rodríguez, Juan Carlos Galán, Mario Rodríguez-Dominguez, Laura Martínez-García, Melanie Abreu Di Berardino, Manuel Ponce-Alonso, Jose Maria González-Alba, Ivan Sanz-Muñoz, Diana Pérez San José, Maria Gil Fortuño, Juan B. Bellido-Blasco, Alberto Yagüe Muñoz, Noelia Hernández Pérez, Helena Buj Jordá, Óscar Pérez Olaso, Alejandro González Praetorius, Nora Mariela Martínez Ramírez, Aida Ramírez Marinero, Eduardo Padilla León, Alba Vilas Basil, Mireia Canal Aranda, Albert Bernet Sánchez, Alba Bellés Bellés, Eric López González, Iván Prats Sánchez, Mercè García-González, Miguel José Martínez-Lirola, Manuel Ángel Rodríguez Maresca, Maria Teresa Cabezas Fernández, María Eugenia Carrillo Gil, Maria Paz Ventero Martín, Carmen Molina Pardines, Nieves Orta Mira, María Navarro Cots, Inmaculada Vidal Catalá, Isabel García Nava, Soledad Illescas Fernández-Bermejo, José Martínez-Alarcón, Marta Torres-Narbona, Cristina Colmenarejo, Lidia García-Agudo, Jorge A. Pérez García, Martín Yago López, María Ángeles Goberna Bravo, Victoria Simón García, Gonzalo Llop Furquet, Agustín Iranzo Tatay, Sandra Moreno-Marro, Noelia Lozano Rodríguez, Amparo Broseta Tamarit, Juan José Badiola Díez, Amparo Martínez-Ramírez, Ana Dopazo, Sergio Callejas, Alberto Benguría, Begoña Aguado, Antonio Alcamí, Marta Bermejo Bermejo, Ricardo Ramos-Ruíz, Víctor Manuel Fernández Soria, Fernando Simón Soria & Mercedes Roig CardellsThe coronavirus disease 2019 (COVID-19) pandemic has affected the world radically since 2020. Spain was one of the European countries with the highest incidence during the first wave. As a part of a consortium to monitor and study the evolution of the epidemic, we sequenced 2,170 samples, diagnosed mostly before lockdown measures. Here, we identified at least 500 introductions from multiple international sources and documented the early rise of two dominant Spanish epidemic clades (SECs), probably amplified by superspreading events. Both SECs were related closely to the initial Asian variants of SARS-CoV-2 and spread widely across Spain. We inferred a substantial reduction in the effective reproductive number of both SECs due to public-health interventions (Re < 1), also reflected in the replacement of SECs by a new variant over the summer of 2020. In summary, we reveal a notable difference in the initial genetic makeup of SARS-CoV-2 in Spain compared with other European countries and show evidence to support the effectiveness of lockdown measures in controlling virus spread, even for the most successful genetic variants.This work was mainly funded by the Instituto de Salud Carlos III project COV20/00140, with additional funding by Spanish National Research Council project CSIC-COV19-021, Ministerio de Ciencia project PID2019-104477RB-100, ERC StG 638553 and ERC CoG 101001038 to I.C., and BFU2017-89594R to F.G.C. M.C. is supported by Ramón y Cajal program from Ministerio de Ciencia and grants RTI2018-094399-A-I00 and Generalitat Valenciana (Regional Government) project SEJI/2019/011. We gratefully acknowledge Hospital Universitari Vall d’Hebron, Instituto de Salud Carlos III, IrsiCaixa AIDS Research Lab and all the international researchers and institutions that submitted sequenced SARS-CoV-2 genomes to the GISAID’s EpiCov Database (Supplementary Table 1), as an important part of our analyses has been made possible by the sharing of their work. We also thank Unidad de Bioinformática y Estadística, Centro de Investigación Príncipe Felipe, for allowing us to use the Computer Cluster to perform some of the bioinformatic analysis.Peer reviewe

Accumulation and mobilization of lipids in relation to reproduction of yellowfin tuna (Thunnus albacares) in the Western Indian Ocean

Total lipid content and lipid class composition were analyzed in gonads, liver and white muscle of yellowfin tuna (Thunnus albacares) throughout ovary development to understand its reproductive allocation strategy and to assess the relation between female condition and reproduction. A total of 112 females were collected onboard purse-seiner in the Western Indian Ocean from January to March 2009, from June to July 2009, and from April to May 2010. Gonads were characterized by highly variable total lipid contents ranging from 5 to 27 μg mg−1 of wet weight (ww) with a predominance of neutral lipids, mainly triacylglycerols (TAG) and sterol- and wax-esters. The different lipid classes in gonads described an accumulative pattern through the maturity process from immature to hydration phase. Total lipid content in liver varied from 10 to 21 μg mg−1 ww, and serves as fuel for yellowfin tuna reproduction. TAG and phospholipid deposits became depleted as the ovary developed, suggesting a transfer of lipids directly from liver to the oocytes during vitellogenesis. In contrast, muscle total lipid content was low and constant throughout ovarian development (2.5–6 μg mg−1 ww). Hence, yellowfin tuna can be defined as an income-capital breeder species for which the cost of reproduction depends mainly on concurrent energy income from feeding and only little on stored lipids. Besides, no significant relationship between gonad lipid composition and fecundity was found in females able to spawn. Finally, the influence of yellowfin tuna aggregation behaviour on reproductive female condition has been investigated: gonad total lipid contents were higher in females caught in free-swimming schools than in females caught under fish aggregating devices (FADs). However, these results did not clarify whether the influence of FADs on associated yellowfin tuna affects their reproductive capacity

Standardized purse seine CPUE of Yellowfin tuna in the Indian Ocean for the European fleet

WPTT.Working Party on Tropical Tuna, [En ligne], 2021/10/25-2021/10/30The time series of EU purse seine fleet catches per unit effort (CPUE) of small (=10kg) yellowfin tuna (YFT) from the Indian Ocean were standardized using an extension of the Delta-lognormal GLMM to three components. These components are: (i) the detection rate of schools per unit of searching time, (ii) the proportion of sets for which the targeted size category is present and (iii) the biomass of the targeted size category in the fish school. The aim was to use the commercial size categories as a proxy to depict the trend in abundance for adult and juvenile YFT observed in free schools (FSC), as well as for juveniles caught under floating objects (FOB)

Ecological data for western Indian Ocean tuna

International audienceTuna are marine apex predators that inhabit the tropical and subtropical waters of the Indian Ocean where they support socially and economically important fisheries. Key component of pela-gic communities, tuna are bioindicator species of anthropogenic and climate-induced changes through modifications of the structure and related energy-flow of food webs and ecosystems. The IndianEcoTuna dataset provides a panel of ecological tracers measured in four soft tissues (white muscle, red muscle, liver, gonads) from 1,364 individuals of four species, i.e., the albacore (ALB, Thunnus alalunga), the bigeye (BET, T. obesus), the skipjack (SKJ, Katsuwomus pelamis), and the yellowfin (YFT, T. albacares), collected throughout the western Indian Ocean from 2009 to 2015. Sampling was carried out during routine monitoring programs, at sea by observers onboard professional vessels or at landing. For each record, the type of fishing gear, the conservation mode, as well as the fishing date and catch location are provided. Individuals were sampled to span a wide range of body sizes: 565 ALB with fork length from 58 to 118 cm, 155 BET from 29.5 to 173 cm, 304 SKJ from 30 to 74 cm, and 340 YFT from 29 to 171.5 cm. The IndianEcoTuna dataset combines: (1) 9,512 records of carbon and nitrogen stable isotopes (percent element weights, d 13 C and d 15 N values) in 1,185 fish, (2) 887 concentrations of total proteins in 242 fish, (3) 8,356 concentrations of total lipids and three lipid classes (triacylglycerols TAG; phospholipids PL; sterols ST) in 695 fish, and (4) 1,150 and 1,033 profiles of neutral and polar fatty acids in 397 and 342 fish, respectively. Information on sex and weights of the whole fish, gonads, liver and stomach is provided. Because of the essential trophic role and wide-ranging of tuna in marine systems, and the large panel of tropho-energetic tracers and derived-key quantitative parameters provided (e.g., niche width, trophic position, condition indices), the IndianEcoTuna dataset should be of high interest for global and regional research on marine trophic ecology and food web analysis, as well as on the impacts of anthropogenic changes on Indian Ocean marine ecosystems. There are no copyright restrictions for research and/or teaching purposes. Usage of the dataset must include citation of this Data Paper

A standard processing framework for the location data of satellite-linked buoys on drifting fish aggregating devices

Satellite-linked buoys used by tropical tuna purse-seine vessels on drifting fish aggregating devices (DFADs) provide a continuous stream of information on both the ocean characteristics and the presence and size of fish aggregations associated with DFADs, enabling the study of pelagic communities. This unprecedented amount of data is characterized by ocean-scale coverage with high spatial and temporal resolutions, but also by different data formats and specifications depending on buoy model and brand, as well as on the type of data exchange agreements into play. Their use for scientific and management purposes is therefore critically dependent on the abilities of algorithms to process heterogeneous data formats and resolutions. This paper proposes a unified set of algorithms for processing the buoys location data used by the two major purse seine fleets operating in the Atlantic and Indian oceans. Three main issues that need to be addressed prior to the exploitation of the data are identified (structural errors, data records on land and on-board vessels) and five specific filtering criteria are proposed to improve the data cleaning process and, hence, quality. Different filtering procedures are also compared, and their advantages and limitations are discussed