Search results for "class"

Gastrointestinal parasites of two populations of Arctic foxes (Vulpes lagopus) from north-east Greenland

2017

Parasitological examination of 275 faecal samples from Arctic foxes (Vulpes lagopus) collected at Zackenberg Valley and Karupelv Valley in north-east Greenland from 2006 to 2008 was conducted using sieving and microscopy. Overall, 125 (45.5%) samples contained parasite eggs of Taenia crassiceps, Taenia serialis, Toxascaris leonina, Eucoleus boehmi, Physalopteridae and Ancylostomatidae, and Strongyloides-like larvae. As long-term ecological studies are conducted at both sampling locations, the present findings constitute a baseline data set for further parasitological monitoring.

Symbiotic polydnavirus and venom reveal parasitoid to its hyperparasitoids

2018

Symbiotic relationships benefit organisms in utilization of new niches. In parasitoid wasps, symbiotic viruses and venom that are injected together with wasp eggs into the host caterpillar suppress immune responses of the host and enhance parasitoid survival. We found that the virus also has negative effects on offspring survival when placing these interactions in a community context. The virus and venom drive a chain of interactions that includes the herbivore and its food plant and attracts the hyperparasitoid enemies of the parasitoid. Our results shed new light on the importance of symbionts associated with their host in driving ecological interactions and highlight the intricacy of how…

Living in a harsh habitat: epidemiology of the whale louse, Syncyamus aequus (Cyamidae), infecting striped dolphins in the Western Mediterranean

2017

Whale lice (Cyamidae) are ectoparasitic amphipods exclusive to cetaceans. Data on their epidemiology usually come from species infecting baleen whales, which are large, slow-moving hosts. In this study, we provide data on infection parameters, population structure and microhabitat selection in a whale louse exclusive to delphinids, Syncyamus aequus, with the aim of comparing them with those from cyamid species from large whales. A total of 176 striped dolphins Stenella coeruleoalba stranded along the Mediterranean coast of Spain during 1980–2016 were examined. The prevalence of S. aequus was 27.3% (95% CI: 20.9–34.3), and populations were sparse, with a mean number of whale lice per infecte…

Influence of yeast strains on managing wine acidity using Lactobacillus plantarum

2018

Abstract Lactobacillus plantarum has been used for deacidifying wines through malolactic fermentation (MLF), and more recently for acidifying them. The species Oenococcus oeni is mainly responsible for MLF in wines at a pH below 3.5. However, the Lactobacillus and Pediococcus species can carry out this reaction in wines at a higher pH. MLF generally begins once yeasts have completed alcoholic fermentation, but nowadays some winemakers prefer carrying out MLF simultaneously to alcoholic fermentation. The advantages of this strategy are shorter times in which to complete wine vinification and better wine color stabilization. Lactobacillus plantarum is preferred to O. oeni for performing early…

Yeast Mixtures and Saccharomyces Hybrids: Suitable Tools for Performing More Sophisticated Must Fermentations

2017

It can be concluded from the early development of viniculture that the yeast Saccharomyces cerevisiae is one of the oldest domesticated organisms. The wine producing techniques have been further developed empirically over generations. Despite this long time of wine production, our knowledge about the microbiological and biochemical background of the transformation of must into wine is relatively recent. Fundamental investigations about must transformation into wine were carried out at the end of the eighteenth and in the course of the nineteenth century. Today a relatively broad knowledge exists about the diversity of wine-related microorganisms. Nevertheless, sluggish or stuck fermentation…

Impact of Rearing Conditions on the Ambrosia Beetle’s Microbiome

2018

Ambrosia beetles, along with termites and leafcutter ants, are the only fungus-farming lineages within the tree of life. Bacteria harbored by ambrosia beetles may play an essential role in the nutritional symbiotic interactions with their associated fungi

Genomic Differentiation and Demographic Histories of Atlantic and Indo-Pacific Yellowfin Tuna (Thunnus albacares) Populations.

2017

Recent developments in the field of genomics have provided new and powerful insights into population structure and dynamics that are essential for the conservation of biological diversity. As a commercially highly valuable species, the yellowfin tuna (Thunnus albacares) is intensely exploited throughout its distribution in tropical oceans around the world, and is currently classified as near threatened. However, conservation efforts for this species have so far been hampered by limited knowledge of its population structure, due to incongruent results of previous investigations. Here, we use whole-genome sequencing in concert with a draft genome assembly to decipher the global population str…

2016

AbstractPRDM9 is currently the sole speciation gene found in vertebrates causing hybrid sterility probably due to incompatible alleles. Its role in defining the double strand break loci during the meiotic prophase I is crucial for proper chromosome segregation. Therefore, the rapid turnover of the loci determining zinc finger array seems to be causative for incompatibilities. We here investigated the zinc finger domain-containing exon of PRDM9 in 23 tarsiers. Tarsiers, the most basal extant haplorhine primates, exhibit two frameshifting indels at the 5′-end of the array. The first mutation event interrupts the reading frame and function while the second compensates both. The fixation of thi…

Curse of the black spot: spotting negatively correlates with fitness in black grouseLyrurus tetrix

2016

There is growing evidence that achromatic plumage can act as honest indicators of male quality. In some species with areas of white plumage, black melanin spots can be found on parts of the feathers. The functional significance of these spots and the relationship with male quality is yet poorly understood. We investigated the relationship between black melanin spots in an otherwise totally white ornament, the undertail covert, in relation to age, fitness and covariance with past and present expression of sexual traits, in the lekking black grouse Lyrurus tetrix. We found that spots at tips of feathers (tip spots) were negatively related to survival and reproductive success, and covaried neg…

Shoaling with infected conspecifics does not improve resistance to trematode infection

2018

Group‐living animals can gain protection against parasitic infections through social contacts with previously infected conspecifics (social immunization). Recent research suggests that such protective effects can be induced through visual or chemical cues released by infected individuals, resulting in anticipatory immune upregulation among group members. Here, we study cue‐induced social resistance in rainbow trout Oncorhynchus mykiss exposed to a trematode parasite, the eye‐fluke Diplostomum pseudospathaceum. We established groups of naïve individuals (receivers) that were paired with previously infected individuals (donors) at different ratios of donors to receivers and at different time …