Acoustic telemetry versus monitored longline fishing for studying the vertical distribution of pelagic fish: bigeye tuna (Thunnus obesus) in French Polynesia

This study compares detailed, nearly continuous, observations on bigeye tuna, Thunnus obesus equipped with electronic tags, with discrete observations on a larger number of individuals from fishing experiments in order to validate the use of instrumented longlines to study the vertical distribution of fish. We show that the depth distributions obtained from the two different observation techniques regarding different environmental variables (temperature, dissolved oxygen (DO), prey distribution) are similar. Bigeye tuna do not seem to be attracted by baits in the vertical dimension (no modification of their vertical distribution by the fishing gear), which allows the use of instrumented longlines to study the vertical behaviour of pelagic species. This technique, when used with appropriate deployment strategy, could therefore represent an alternative to electronic tags (acoustic or archival tags) when there is a need to determine the vertical distribution of fish species by size or sex, in different environments for the study of fishery interactions.     

Development of an accurate model to predict the phenology of Atlantic salmon smolt spring migration

1. Changes in migration timing, resulting from the alteration in river continuity or the effect of climate change, can have major consequences on the population dynamics of diadromous fish. Forecasting the phenology of fish migration is thus critically important to implement management actions aimed at protecting fish during their migration.
2. In this study, an 11‐year monitoring survey of Atlantic salmon smolts (Salmo salar) from the Ourthe River, Belgium, was analysed within a European Special Area of Conservation to improve the understanding of environment‐induced spring migration. A logistic model was fitted to forecast smolt migration and to calculate phenological indicators for management, i.e. the onset, end, and duration of migration, while accounting for the influence of photoperiod, water temperature, and hydrological conditions.
3. The results indicated that the photo‐thermal units accumulated by smolts above a 7°C temperature threshold was a relevant proxy to reflect the synergistic effect between temperature and photoperiod on smolt migration. After integrating the effect of river flow pulses, the model accurately explained the inter‐annual changes in migration timing (R² = 0.95). The model predictions provide decisive management information to identify sensitive periods during which mitigation measures (e.g. hydropower turbine shutdown, river discharge management) should be conducted to promote smolt survival.
4. The model was used to predict phenological characteristics under future scenarios of climate change. The results suggest a joint effect of hydrological alterations and water warming. Temperature increases of 1–4°C were associated with earlier initiation of migration, 6–51 days earlier, and spring flood events greatly influenced the duration of the migration period. Accordingly, the combined effects of human‐induced modifications of the hydrological regimes and increasing temperatures could result in a mismatch between the smolt and favourable survival conditions in the marine environment.

     

Evaluation of methanotroph (Methylococcus capsulatus,Bath) bacteria meal as an alternative protein source for growth performance,digestive enzymes,and health status of Pacific white shrimp (Litopenaeus vannamei)

Aquaculture International - The increasing cost of fishmeal (FM) with limited supply and the continuous development of aquaculture necessitate more economical FM substitutes. This study aimed to...     

Sequence analysis of 43-year old samples of Plantago lanceolata show that Plantain virus X is synonymous with Actinidia virus X and is widely distributed

Plantain virus X was first recognized by the ICTV as a species in the genus Potexvirus in 1982. However, because no sequence was available for plantain virus X (PlVX), abolishing the species was proposed to the Flexiviridae working group of the ICTV in 2015. This initiated efforts to sequence the original isolates from Plantago lanceolata samples. Here we report the full-genome sequencing of two original isolates of PlVX, which demonstrate that the virus is synonymous to Actinidia virus X, a species previously reported from kiwifruit (Actinidia sp.) and blackcurrant (Ribes nigrum). PlVX was previously noted to be widespread in the UK in P. lanceolata. This report additionally presents novel data on the distribution and diversity of PlVX, collected at the same site as the original UK isolates, and from three independent surveys, two in the Netherlands and one in Belgium. This study also includes two new host records for PlVX, Browallia americana and Capsicum annuum (sweet pepper), indicating the virus is more widespread and infects a broader range of hosts than previously reported. This stresses the importance of surveys of noncultivated species to gain insight into viral distribution and host range. This study also demonstrates the value of generating sequence data for isolates retained in virus collections. Additionally, it demonstrates the potential value in prepublication data sharing for giving context to virus detections such as the four independent studies here which, when combined, give greater clarity to the identity, diversity, distribution, and host range of plantain virus X.     

Monitoring the fate of a 30-year-old truffle orchard in Burgundy: from Tuber melanosporum to Tuber aestivum

Truffles, i.e. tree root-associated fungal fruiting bodies, clearly range among the world’s most exclusive delicacies. Despite the quite restricted natural geographic occurrence of one of the most renowned fungal species, namely Tuber melanosporum, the development of inoculation procedures in the late 1960s made it possible to enlarge its production area in different countries. This was achieved by planting orchards with host tree seedlings colonized by the fungus. In the present work, we investigate the behavior of one of the earliest T. melanosporum orchards planted in Burgundy (France) over a long-term scale (more than 30 years). A picture of the orchard evolution was obtained by recording truffle yields and fungal morphotypes over the seasons and relating them to host-tree development and climate data. The most relevant results include the time-delayed, but rather fast replacement of inoculated T. melanosporum by naturally occurring T. aestivum and the key role of climate in the inter-annual variability of truffle production.     

Evidence of Bartonella sp. in questing adult and nymphal Ixodes ricinus ticks from France and co-infection with Borrelia burgdorferi sensu lato and Babesia sp

Ticks are known vectors for a wide range of pathogenic microorganisms. Their role in the transmission of some others is so far only suspected. Ticks can transmit multiple pathogens, however, little is known about the co-existence of these pathogens within questing ticks. We looked for the presence of DNA from three micro-organisms, Bartonella sp., Borrelia burgdorferi sensu lato and Babesia sp. which are known or suspected tick-borne pathogens, using a cohort of 92 questing Ixodes ricinus ticks collected from pastures in northern France. DNA was extracted from each individual tick and the presence of the three pathogens was investigated using Polymerase Chain Reaction (PCR) amplification. Nine among 92 samples (9.8%) demonstrated PCR products using Bartonella specific primers, 3 among 92 (3.3%) using Borrelia burgdorferi sensu lato specific primers and 19 among 92 (20.6%) using Babesia specific primers. Seven among 92 samples (7.6%) were PCR positive for at least two of the pathogens and one sample was positive for all three. Adult ticks (12/18; 67%) showed significantly higher infection rates compared to nymphs (11/74; 15%) for all three pathogens (P < 0.001). This study is the demonstration of the simultaneous presence of Bartonella sp., Borrelia burgdorferi sensu lato and Babesia sp. in questing Ixodes ricinus ticks.     

What a few hairs can tell us about the resource use of giant armadillos

Understanding of resource requirements of vulnerable species is key for conservation planning. Here, we used stable carbon (δ¹³C) and nitrogen isotopes (δ¹⁵N) of hair from giant armadillos (Priodontes maximus) to understand individual resource use. We collected hair from 19 giant armadillos analyzing 34 samples from the Brazilian Pantanal and compared the resource use between sexes and age classes. We also assessed the relationship of isotopic values with individuals’ body mass and the habitat type used. We observed a wide variation in resource use by giant armadillos, showing that individuals consume prey that feeds on distinct resources and occupies different habitat types, indicating that there is individual variation in foraging behavior. Most giant armadillos presented a mixed diet (C₃/C₄ resources, forests/open areas), but a quarter of individuals had strictly C₄ diets (open areas). Males are more prone to forage on C₄ resources, presenting an isotopic niche 2.6-times larger than that of females. Subadults presented diets more associated with habitats with high arboreal cover (C₃ resources, forests), while adults foraged more in open areas (C₄ resources). This result is mirrored by the positive relationship between δ¹³C values and body mass, suggesting that larger giant armadillos tend to feed more in open areas. We observed that δ¹³C values decreased as individuals increased the use of habitats with high arboreal cover. We stress the importance of conserving the natural mosaic in the Pantanal landscape for the species persistence, given that giant armadillos require all habitat types to fulfill their dietary, spatial, and developmental needs.     

IMAGING DIAGNOSIS—ULTRASOUND UNCOMMON FEATURES OF AN ABDOMINAL GOSSYPIBOMA IN A DOG

An abdominal mass was incidentally detected in a 12‐year‐old, neutered female, crossed breed dog. Abdominal ultrasonographic examination showed a well‐delineated, irregular, heterogeneous mass that did not generate any distal acoustic shadowing. Transcutaneous US‐guided biopsy of the mass were nonconclusive but raised the possibility of neoplasia. Surgery discovered a mass embedded in the omentum and a large quantity of surgical sponges were identified in cut section. To the authors’ knowledge, this represents the first published case of gossypiboma casting no characteristic distal acoustic shadowing.     

Antioxidants, phenolic compounds, and nutritional quality of different strawberry genotypes

Strawberry contains high levels of micronutrients and phytochemical compounds. These exhibit functional roles in plant growth and metabolism and are also essential for the nutritional and organoleptic qualities of the fruit. The aim of the present work was to better characterize the phytochemical and antioxidant profiles of the fruit of nine different genotypes of strawberry, by measuring the total flavonoid, anthocyanin, vitamin C, and folate contents. Cultivar effects on the total antioxidant capacities of strawberries were also tested. In addition, the individual contribution of the main antioxidant compounds was assessed by HPLC separation coupled to an online postcolumn antioxidant detection system. This study showed the important role played by the genetic background on the chemical and antioxidant profiles of strawberry fruits. Significant differences were found between genotypes for the total antioxidant capacity and for all tested classes of compounds. The HPLC analyses confirmed qualitative and quantitative variability in the antioxidant profiles. These studies show that differences exist among cultivars, applicable in dietary studies in human subjects.