The gills and skin microbiota of five pelagic fish species from the Atlantic Ocean.

The gills and skin microbiota and microbiome of wild fish remain far more under-investigated compared to that of farmed fish species, despite that these animal-microbe interactions hold the same ecophysiological roles in both cases. In this study, the gills and skin bacterial microbiota profiles and their presumptive bacterial metabolisms were investigated in five open-sea fishes: bullet tuna (Auxis sp.), common dolphinfish (Coryphaena hippurus), Atlantic little tunny (Euthynnus alletteratus), Atlantic bonito (Sarda sarda) and Atlantic white marlin (Kajikia albida). Gills and skin tissues were collected from two to three individuals per species, from specimens caught by recreational trolling during summer of 2019, and their bacterial 16S rRNA gene diversity was analysed by high-throughput sequencing. The gills bacterial communities among the five species were clearly different but not the skin bacterial microbiota. The dominant operational taxonomic units belonged to the Moraxellaceae, Pseudomonadaceae, Rhodobacteraceae, Staphylococcaceae and Vibrionaceae families. Despite the differences in taxonomic composition, the presumptive bacterial metabolisms between the gills and skin of the five fishes investigated here were ≥ 94% similar and were dominated by basic metabolism, most likely reflecting the continuous exposure of these tissues in the surrounding seawater.

Chemical signatures in fin spine edge of Atlantic bluefin tuna (Thunnus thynnus) can serve as habitat markers of geographically distinct marine environments.

Chemical fingerprints in otoliths are commonly used as natural habitat markers in fishes. Alternatively, the first dorsal fin spine can provide valuable chemical information and may be more suitable for studying (i) endangered fish species that cannot be sacrificed for their otoliths or (ii) fishes for which otoliths might not be available because of management or commercial reasons. Here, we studied multi-element chemistry of fin spine edges collected from Atlantic bluefin tuna (ABFT; Thunnus thynnus) (Linnaeus, 1758) to investigate the utility of the fin spine edge as a natural habitat marker. We determined stable isotopic δ18O and δ13C ratios, as well as concentrations of the tracer elements Mg, Mn, Li, Ba, and Sr, at the edge of ABFT fin spines, and then we used these measures to discriminate ABFT individuals among capture regions (i.e., the eastern Atlantic Ocean or Mediterranean Sea). Isotope ratios and tracer element concentrations, and especially a combined multi-element approach, were able to effectively discriminate individuals by capture region. The Mg, Mn, Li, and δ18O concentrations were the strongest variables driving this discrimination. Overall, our results demonstrate that chemical signatures are consistently retained in the ABFT fin spine edge and support the use of fin spine edges for discerning habitat use. The fin spine chemistry as a minimally invasive sampling method, combined with otolith chemistry, genetic markers, and tagging efforts can help us to reconstruct fish movements, providing a deeper understanding of the spatial population dynamics of this iconic fish species.

An autofluorescence-based survey of late follicular atresia in ovaries of a teleost fish (Thunnus thynnus).

In this study, the authors examined late atretic follicles in the ovaries of Atlantic bluefin tuna, Thunnus thynnus (Linnaeus 1758), at different times of the year using transmitted light and epifluorescence microscopy. Atresia (degeneration and resorption of developing ovarian follicles) is a natural process involved in fecundity downregulation in teleosts and is substantially enhanced in stressful conditions. Early (α and ß) atretic stages of yolked oocytes have a relatively short duration in seasonally reproducing species, whereas later (γ and δ) atretic follicles (LAF) persist for longer time in the ovary, serving as a sign of previous vitellogenic activity. LAF can thus be used as reliable markers of maturity during non-reproductive periods. Lipofuscin granules accumulate in the cytoplasm of LAF cells as a result of lysosomal digestion of oocyte components. Taking advantage of the well-known autofluorescent properties of lipofuscins, LAF may be identified in unstained histological sections under fluorescence microscopy using appropriate excitation and emission wavelengths. The authors explore in this study the applicability of fluorescence microscopy to provide a fast and effective method to assess late atresia in fishes. This method may be particularly useful to determine sexual maturity in individuals sampled long after the spawning season, where LAF are difficult to detect in standard histological sections. Furthermore, LAF autofluorescence provides a rapid way to quantify late atresia in fishes using image analysis.

Seasonal feeding patterns of Atlantic bluefin tuna (Thunnus thynnus) in the Strait of Gibraltar.

The Strait of Gibraltar (SoG) houses a large diversity of marine species including large pelagic animals that use this area as permanent or temporary habitat. In particular, the SoG is home to a population of adult and sub-adult Atlantic bluefin tuna (Thunnus thynnus) that occurs there for most of the year. To gain further insight into the life history of this ABFT population, seasonal feeding patterns were investigated combining stomach content analysis (SCA) and stable isotopes analysis (SIA) of muscle and liver tissues. Our results reveal seasonal variations in feeding patterns, which are evidenced by a significant shift in the diet composition and the highest food consumption rates that take place in spring, prior to the spawning season. These changes in feeding habits are consistent with the varying energetic needs along the species' annual biological cycle. The present observations confirm the SoG as an important foraging ground for ABFT resident populations and may have further implications for the management of the resource.

Methylmercury in tissues of Atlantic sturgeon (Acipenser oxyrhynchus) from the Saint John River, New Brunswick, Canada.

Environmental contamination by mercury is a concern in marine food webs, and especially for large fish. We examined methylmercury (MeHg) levels in blood, muscle and liver of 35 individual Atlantic sturgeon (Acipenser oxyrhynchus), a commercially harvested, anadromous fish eastern Canada. Females had higher blood and liver MeHg levels than males, and in some tissues there was a suggestion of higher mercury in longer fish. Collectively, sturgeon MeHg levels were far below Canadian and international guidelines for safe consumption of fish meat.

Model of a training program in robotic surgery and its initial results. / Modelo de programa de treinamento em cirurgia robótica e resultados iniciais.

OBJECTIVE:: to describe the implementation of a training program in robotic surgery and to point the General Surgery procedures that can be performed with advantages using the robotic platform. METHODS:: we conducted a retrospective analysis of data collected prospectively from the robotic surgery group in General and Colo-Retal Surgery at the Samaritan Hospital (Rio de Janeiro, Brazil), from October 2012 to December 2015. We describe the training stages and particularities. RESULTS:: two hundred and ninety three robotic operations were performed in general surgery: 108 procedures for morbid obesity, 59 colorectal surgeries, 55 procedures in the esophago-gastric transition area, 16 cholecystectomies, 27 abdominal wall hernioplasties, 13 inguinal hernioplasties, two gastrectomies with D2 lymphadenectomy, one vagotomy, two diaphragmatic hernioplasties, four liver surgeries, two adrenalectomies, two splenectomies, one pancreatectomy and one bilio-digestive anastomosis. The complication rate was 2.4%, with no major complications. CONCLUSION:: the robotic surgery program of the Samaritan Hospital was safely implemented and with initial results better than the ones described in the current literature. There seems to be benefits in using the robotic platform in super-obese patients, re-operations of obesity surgery and hiatus hernias, giant and paraesophageal hiatus hernias, ventral hernias with multiple defects and rectal resections.

Modelo de programa de treinamento em cirurgia robótica e resultados iniciais / Model of a training program in robotic surgery and its initial results

RESUMO Objetivo: descrever a implantação de um programa de treinamento em cirurgia robótica e apontar as operações em Cirurgia Geral que podem ser feitas com vantagens utilizando a plataforma robótica. Métodos: estudo prospectivo do Grupo de Cirurgia Robótica em Cirurgia Geral e Colorretal do Hospital Samaritano (Rio de Janeiro, Brasil), de outubro de 2012 a dezembro 2015. São descritas as etapas do treinamento e particularidades. Resultados: no período do estudo foram realizadas 293 operações robóticas em Cirurgia Geral: 108 cirurgias para obesidade mórbida, 59 colorretais, 55 cirurgias na área da transição esôfago-gástrica, 16 colecistectomias, 27 hérnias da parede abdominal, 13 hernioplastias inguinais, duas gastrectomias com linfadenectomia à D2, uma vagotomia, duas hernioplastias diafragmáticas, quatro cirurgias hepáticas, duas adrenalectomias, duas esplenectomias, uma pancreatectomia, uma anastomose biliodigestiva. O índice de complicações foi de 2,4% sem complicações maiores. Conclusão: o Programa de Cirurgia Robótica do Hospital Samaritano foi implementado de forma segura e com resultados iniciais acima da literatura. Parece haver benefício em se utilizar a plataforma robótica nos super obesos, nas reoperações de cirurgia de obesidade e de hérnias de hiato, hérnias de hiato gigantes e para-esofágicas, hérnias ventrais com múltiplos defeitos e ressecções baixas de reto.

ABSTRACT Objective: to describe the implementation of a training program in robotic surgery and to point the General Surgery procedures that can be performed with advantages using the robotic platform. Methods: we conducted a retrospective analysis of data collected prospectively from the robotic surgery group in General and Colo-Retal Surgery at the Samaritan Hospital (Rio de Janeiro, Brazil), from October 2012 to December 2015. We describe the training stages and particularities. Results: two hundred and ninety three robotic operations were performed in general surgery: 108 procedures for morbid obesity, 59 colorectal surgeries, 55 procedures in the esophago-gastric transition area, 16 cholecystectomies, 27 abdominal wall hernioplasties, 13 inguinal hernioplasties, two gastrectomies with D2 lymphadenectomy, one vagotomy, two diaphragmatic hernioplasties, four liver surgeries, two adrenalectomies, two splenectomies, one pancreatectomy and one bilio-digestive anastomosis. The complication rate was 2.4%, with no major complications. Conclusion: the robotic surgery program of the Samaritan Hospital was safely implemented and with initial results better than the ones described in the current literature. There seems to be benefits in using the robotic platform in super-obese patients, re-operations of obesity surgery and hiatus hernias, giant and paraesophageal hiatus hernias, ventral hernias with multiple defects and rectal resections.

Spawning behaviour and post-spawning migration patterns of atlantic bluefin tuna (Thunnus thynnus) ascertained from satellite archival tags.

Spawning behaviour of Atlantic bluefin tuna (Thunnus thynnus) was investigated using electronic satellite tags deployed in the western Mediterranean spawning ground, around the Balearic Islands (years 2009-2011). All the fish were tagged underwater and released within schools. In general, the fish tagged in the same year/school displayed common migratory trends. Following extended residency around the Balearic Islands, most tagged tuna crossed the Strait of Gibraltar heading for the North Atlantic. Discrepancies between the migratory tracks reconstructed from this and previous electronic tagging studies suggest that the bluefin tuna Mediterranean population may comprise distinct units exhibiting differing migratory behaviours. The diving behaviour varied between oceanic regions throughout the migratory pathways, the shallowest distribution taking place in the spawning ground and the deepest at the Strait of Gibraltar. A unique diving pattern was found on the majority of nights while the fish stayed at the spawning ground; it consisted of frequent and brief oscillatory movements up and down through the mixed layer, resulting in thermal profiles characterized by oscillations about the thermocline. Such a pattern is believed to reflect recent courtship and spawning activity. Reproductive parameters inferred from the analysis of vertical profiles are consistent with those estimated in previous studies based on biological samples.