Residential movements of top predators in Chile’s most isolated marine protected area: Implications for the conservation of the Galapagos shark,Carcharhinus galapagensis,and the yellowtail amberjack,Seriola lalandi

1. Marine protected areas (MPAs) are becoming a widely used tool for the conservation of biodiversity and for fishery management; however, most of these areas are designed without prior knowledge of the basic ecological aspects of the species that they are trying to protect.
2. This study investigated the movement of two top predators: the Galapagos shark, Carcharhinus galapagensis, and the yellowtail amberjack, Seriola lalandi, in and around the Motu Motiro Hiva Marine Park (MMHMP) using MiniPAT satellite tags to determine the effectiveness of this MPA for the protection of these species.
3. The Galapagos sharks (n = 4) spent most of their tag deployment periods inside the MMHMP. However, high intraspecific variability was observed in their movement dynamics. Daily individual maximum movements ranged from 17 to 58 km and the maximum distance from Salas y Gómez Island, the only emergent island within the MMHMP, ranged from 31 to 139 km.
4. The maximum linear distance travelled for a female juvenile Galapagos shark (152 cm total length) was 236 km, which is greater than the maximum distance previously documented for juveniles of this species (<50 km).
5. For the yellowtail amberjack (n = 1), 91% of the satellite geolocations were within the MMHMP, with a maximum daily distance travelled of 6 km. The maximum distance travelled between points was 111 km and the maximum distance from Salas y Gómez Island was 62 km.
6. All archival tagged fish spent most of their time at depths of <50 m and never left the epipelagic zone. Daytime versus night-time differences were pronounced in all individuals but showed high interindividual variability.
7. This study provides a baseline on the movement of these two top predators in the MMHMP and provides valuable insights for the creation of MPAs in the region and elsewhere.

     

The effect of timing of extended photoperiod on growth and maturity of brook trout (Salvelinus fontinalis)

The influence of timing of extended photoperiods on growth and maturity of brook trout was investigated in a 112‐day experiment. The fish with mean initial weight of ~192 g were reared under four light regimes: one control group with natural ambient photoperiod and three groups exposed to an 18L:6D regime initiated at days 1, 23 or 46 of the growth trial. Light‐emitting diodes, with intensity of 250–1000 lux, depending on the distance from the light source, were used for extending light periods. There was a positive effect of prolonged day length on fish growth (p < 0.05), and a delay in gonad development and sexual maturity. Significantly higher numbers of sexually mature fish were found among controls groups, regardless of sex. Survival rate was not affected by light regime. This study demonstrated that the short‐term expansion of the photo period delayed maturation and increased the growth rate of brook trout.     

Trawl fishing impacts on the status of seabed fauna in diverse regions of the globe

Bottom trawl fishing is a controversial activity. It yields about a quarter of the world's wild seafood, but also has impacts on the marine environment. Recent advances have quantified and improved understanding of large‐scale impacts of trawling on the seabed. However, such information needs to be coupled with distributions of benthic invertebrates (benthos) to assess whether these populations are being sustained under current trawling regimes. This study collated data from 13 diverse regions of the globe spanning four continents. Within each region, we combined trawl intensity distributions and predicted abundance distributions of benthos groups with impact and recovery parameters for taxonomic classes in a risk assessment model to estimate benthos status. The exposure of 220 predicted benthos‐group distributions to trawling intensity (as swept area ratio) ranged between 0% and 210% (mean = 37%) of abundance. However, benthos status, an indicator of the depleted abundance under chronic trawling pressure as a proportion of untrawled state, ranged between 0.86 and 1 (mean = 0.99), with 78% of benthos groups > 0.95. Mean benthos status was lowest in regions of Europe and Africa, and for taxonomic classes Bivalvia and Gastropoda. Our results demonstrate that while spatial overlap studies can help infer general patterns of potential risk, actual risks cannot be evaluated without using an assessment model that incorporates trawl impact and recovery metrics. These quantitative outputs are essential for sustainability assessments, and together with reference points and thresholds, can help managers ensure use of the marine environment is sustainable under the ecosystem approach to management.     

Spatial α-diversity patterns of diverse insect taxa in Northern China: Lessons for biodiversity conservation

Current approaches in terrestrial biodiversity conservation focus predominantly on plants and vertebrates. While these groups account for less than 4% of the estimated global species richness, it is commonly argued that especially the species richness in higher plants is a suitable indicator of overall biodiversity. We tested this assumption, investigating species richness and equitability patterns in three highly species-rich insect families and their links with the vegetation and other environmental factors. Vegetation surveys were combined with pitfall and light trapping to establish the α-diversity of ground beetles, geometrid moths and arctiid moths on 48 plots at varying altitudes between Beijing and the Inner Mongolian Plateau. Soil pH and nutrient status were also recorded. The α-diversity patterns in the three insect families were non-congruent, and links with phytodiversity were weak. The spatial α-diversity patterns in each of the three insect families were significantly correlated with the species density of individual plant families. These links varied between the three insect taxa and were mostly negative in moths. Furthermore, geometrid moth diversity decreased with increasing elevation and decreasing soil pH. Strongly diverging α-diversity patterns across different insect taxa illustrate that it is impossible to find a simple surrogate representing cross-taxon diversity for these highly diverse groups. Furthermore, phytodiversity and vegetation composition appear to play a limited role in governing insect diversity patterns. These results underline the significant risk that current plant-focused approaches in terrestrial biodiversity conservation are inadequate in addressing the conservation needs of the vast majority of species on earth.     

Otolith elemental characteristics of whitefish (Coregonus lavaretus) from brackish waters of the Gulf of Bothnia,Baltic Sea

To investigate whether European whitefish (Coregonus lavaretus) groups in the brackish (≤7%) Gulf of Bothnia (Baltic Sea) express specific otolith elemental characteristics, concentrations of elements (Ca, Ba, Sr, Zn, Mn, Fe) in whole otoliths were studied by inductively coupled plasma‐optical emission spectrometry. Whitefish (N = 67) were sampled from six different latitudinal sites; four in the sea and two in rivers along the west coast of Finland, and from a fresh water lake for comparison. The concentration of several elements showed significant differences among sampling sites. Otolith Ba concentrations were higher at the northern sampling sites compared to the southern ones, thereby showing negative association to capture‐habitat salinity. In contrast, otolith Sr and Zn concentrations were lower at the northern sampling sites, thereby associating positively to capture‐habitat salinity. Otolith Mn concentrations did not associate with latitude or salinity but markedly varied between sampling sites. Elevated Fe concentrations occurred in fish otoliths from the two northernmost sites. Ca concentrations were at the same levels in otoliths from all whitefish samples. Otoliths of whitefish from the lake had very high Ba and low Sr concentrations compared to concentrations in otoliths from whitefish in the sea and rivers. Our results show that otolith elemental characteristics of whitefish vary considerably at various geographic scales showing high potential for population identification using elemental fingerprints. Analysis of otolith elemental characteristics may therefore provide an efficient tool for the identification of main areas of residence, spawning locations, and migration routes, thus contributing towards the sustainable management of whitefish stocks.     

Changes in the nutritional parameters of muscles of the common carp (Cyprinus carpio) and the silver carp (Hypophthalmichthys molitrix) following environmental exposure to cyanobacterial water bloom

The present study evaluated the effect of naturally developing cyanobacteria on the composition of muscles of two commercially important freshwater fish species. Fish were exposed to cyanobacterial biomass including Microcystis aeruginosa and Microcystis ichthyoblabe for 4 weeks. Then, they were transferred to dechlorinated potable water without any cyanobacteria for another 4-week period, thus modelling their preparation for consumers. Samples of muscles were collected every week during exposure and subsequent stay in dechlorinated potable water. The cyanobacterial water bloom of 3.9–6 × 10⁵ cells mL⁻¹ (133–383 μg g⁻¹ of total MC DW) induced statistically significant effects only in the content of fatty acids ( P <0.05; P <0.01) in the common carp ( Cyprinus carpio ), while all studied parameters including the content of dry matter and fat ( P <0.01), proteins ( P <0.05), fatty acid composition ( P <0.05; P <0.01) and some amino acids ( P <0.05) were affected in the silver carp ( Hypophthalmichthys molitrix ). This study has shown that cyanobacteria in the environment of commercially produced fish may decrease the dietetic value of fish muscles.     

A physical map of the 1-gigabase bread wheat chromosome 3B

As the staple food for 35% of the world's population, wheat is one of the most important crop species. To date, sequence-based tools to accelerate wheat improvement are lacking. As part of the international effort to sequence the 17-billion-base-pair hexaploid bread wheat genome (2n = 6x = 42 chromosomes), we constructed a bacterial artificial chromosome (BAC)-based integrated physical map of the largest chromosome, 3B, that alone is 995 megabases. A chromosome-specific BAC library was used to assemble 82% of the chromosome into 1036 contigs that were anchored with 1443 molecular markers, providing a major resource for genetic and genomic studies. This physical map establishes a template for the remaining wheat chromosomes and demonstrates the feasibility of constructing physical maps in large, complex, polyploid genomes with a chromosome-based approach.     

Identification and characterization of a neuron-specific nuclear antigen in Drosophila

An antigen found only in neuronal nuclei of Drosophila melanogaster is revealed by staining with a monoclonal antibody (Mab44C11). This antigen appears early in development, before neurons show any other signs of antigenic or morphologic differentiation, and persists throughout development. This nuclear staining permits reliable detection of neurons in developmental studies of wild-type and mutant flies. Protein immunoblot analyses and immune precipitation experiments show that the neuronal nuclear antigen is a 50-kilodalton polypeptide.     

In vitro and in vivo bioactivity of recombinant canine hepatocyte growth factor

Hepatocyte growth factor (HGF) is crucial for the development and regeneration of the liver and offers a possible new therapeutic strategy for the treatment of canine liver disease. In this study, the in vitro and in vivo bioactivity of recombinant canine HGF (rcHGF) produced with a baculoviral expression system in insect cells was measured. In vitro rcHGF induced mitogenesis, motogenesis, and phosphorylated the HGF receptor c-MET and its downstream mediators PKB and ERK1/2 in two canine epithelial cell lines. After a partial hepatectomy (phx) in dogs, rcHGF increased phosphorylation of c-MET, PKB and ERK1/2. A moderate increase was seen with the cell cycle protein PCNA in rcHGF treated livers, but no HGF-induced increase in liver weight was seen 7 days after phx. Furthermore, rcHGF treated livers showed lower levels of the key mediator of apoptosis, caspase-3, at 7days after phx. It is concluded that rcHGF is a biologically active protein in vitro and in vivo and the baculoviral expression system supplies sufficient amounts of rcHGF for future clinical studies in dogs.     

Ultrasonographic assessment of hemodynamic changes in the portal vein during surgical attenuation of congenital extrahepatic portosystemic shunts in dogs

OBJECTIVE: To determine portal hemodynamic changes associated with surgical shunt ligation and establish ultrasonographic criteria for determining the optimal degree of shunt narrowing and predicting outcome. DESIGN: Case series. ANIMALS: 17 dogs, each with a single congenital extrahepatic portosystemic shunt. PROCEDURE: Pre- and postligation flow velocities and flow directions were determined by Doppler ultrasonography intraoperatively in the shunt and in the portal vein cranial and caudal to the shunt origin. Outcome was evaluated 1 month after surgery by measuring blood ammonia concentration and performing abdominal ultrasonography. RESULTS: Hepatofugal flow was detected in 9 of 17 dogs before shunt attenuation in the portal segment that was between the shunt origin and the entering point of the gastroduodenal vein. If hepatofugal flow became hepatopetal after shunt ligation, hyperammonemia resolved. Hepatofugal portal flow was caused by blood that flowed from the gastroduodenal vein toward the shunt. Shunt attenuation converted hepatofugal flow to hepatopetal in the shunt in 12 of 17 dogs. Chronic portal hypertension developed or perioperative death occurred when the portal congestion index caudal to the shunt origin increased by > 3.6 times. CONCLUSIONS AND CLINICAL RELEVANCE: After hepatopetal flow in the cranial portal vein and the shunt is established, further shunt narrowing is contraindicated. Increase of the portal congestion index caudal to the shunt > 3.5 times should be avoided. Poor outcome because of severe hypoplasia of the portal branches can be expected if the flow direction remains hepatofugal after shunt occlusion cranial to the shunt origin.