Assessment of the microbial communities associated with white syndrome and brown jelly syndrome in aquarium corals

Bacterial and ciliate assemblages associated with aquarium corals displaying white syndrome (WS) and brown jelly syndrome (BJS) were investigated. Healthy (n = 10) and diseased corals (WS n = 18; BJS n = 3) were analysed for 16S rRNA gene bacterial diversity, total bacterial abundance and vibrio-specific 16S rRNA gene abundance. This was conducted alongside analysis of 18S rRNA gene sequenc-ing targeting ciliates, a group of organisms largely overlooked for their potential as causal agents of coral disease. Despite significant differences between healthy and diseased corals in their 16S rRNA gene bacterial diversity, total bacterial abundance and vibrio-specific rRNA gene abundance, no domi-nant bacterial ribotypes were found consistently within the diseased samples. In contrast, one ciliate morphotype, named Morph 3 in this study (GenBank Accession Numbers JF831358 for the ciliate isolated from WS and JF831359 for the ciliate isolated from BJS) was observed to burrow into and underneath the coral tissues at the disease lesion in both disease types and contained algal endosym-bionts indicative of coral tissue ingestion. This ciliate was observed in larger numbers in BJS compared to WS, giving rise to the characteristic jelly like substance in BJS. Morph 3 varied by only 1 bp over 549 bp from the recently described Morph 1 ciliate (GenBank Accession No. JN626268), which has been shown to be present in field samples of WS and Brown Band Disease (BrB) in the Indo-Pacific. This result indicates a close relationship between these aquarium diseases and those observed in the wild

Factors controlling the microbial community associated with reef building corals

Several studies have shown that corals are associated with diverse, host speciesspecific bacterial communities and these have been proposed to be of primary importance for their health. Various factors have been suggested to influence the structure of these communities, including production of antimicrobial chemicals, the supply of microorganisms from the surrounding environment (e.g. sediments and water column), mucus composition and production rates by the coral. However, few studies have investigated the factors that control the development and maintenance of these communities. Describing the microbial communities of healthy corals and how they interact with their surrounding environment is imperative to understanding how environmental stress and health problems in corals are related. This study utilised a culture-independent 16S rRNA gene approach to investigate the structure of the bacterial community on corals, the factors that might control the development of these microbial communities and their organisation within the coral host. In addition, the study identified the role of cytophagous ciliates as a potential cause of White Syndrome in the GBR. Study of the bacterial (16S rRNA gene) community of the surrounding water column (the potential supply to the surface mucus layer of corals) revealed that changes in productivity and/or vertical diurnal migrations of plankton might have greater effects than large scale water movements effected by tidal flows. Results also showed that waterborne bacterial communities and their underlying benthos were not strongly linked, suggesting either that there is little benthic-pelagic coupling or that large-scale (island wide) water column mixing is rapid and highly efficient, resulting in homogeneous bacterial communities in the water column, independent of the underlying benthos. The bacterial communities forming on artificial surfaces and those associated with the mucus layer of corals were different from the water column as well as each other, with a variety of ribotypes of - proteobacteria favouring both the biofilms and those of the surface mucus layer, compared to a high dominance of -proteobacetria within the water column. This suggests that the coral actively controls the microbial community on its surface, rather than it being a result of passive settlement from the water column. Results also show that bacterial communities within the coral are highly compartmentalized with distinct assemblages inhabiting the mucus layer, tissue and skeleton, which indicates high levels of complexity in the coral-microbial associations. The use of a broad spectrum antibiotic treatment further allowed investigation of turnover rates of the microbiota associated with healthy corals. Re-establishment of the corals’ normal microflora was slower than anticipated, taking over 96 h to return to that of its original bacterial community once disturbed, however the fact that the community returned towards its original state indicates a high degree of resilience and strong controls on the microbial community structure Despite the undisputed importance the bacteria associated with corals have on the overall coral holobiont, other microorganisms such as ciliates were also important for coral health, particularly during thermal stress. Results indicated that coral White Syndromes, previously attributed to pathogenic bacteria such as Vibrio spp., may have different etiologies, with cytophagous ciliates playing an important role. These findings further complicate correct disease identification in the field and appropriate treatment and/or prevention methods for diseased corals.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Coral diseases in aquaria and in nature

Many reef coral diseases have been described affecting corals in the wild, several of which have been associated with causal agents based on experimental inoculation and testing of Koch’s postulates. In the aquarium industry, many coral diseases and pathologies are known from the grey literature but as yet these have not been systematically described and the relationship to known diseases in the wild is difficult to determine. There is therefore scope to aid the maintenance and husbandry of corals in aquaria by informing the field of the scientifically described wild diseases, if these can be reliably related. Conversely, since the main driver to identifying coral diseases in aquaria is to select an effective treatment, the lessons learnt by aquarists on which treatments work with particular syndromes provides invaluable evidence for determining the causal agents. Such treatments are not commonly sought by scientists working in the natural environment due the cost and potential environmental impacts of the treatments. Here we review both wild and aquarium diseases and attempt to relate the two. Many important aquarium diseases could not be reconciled to those in the wild. In one case, however, namely that of the ciliate Helicostoma sp. as a causal agent of brown jelly syndrome in aquarium corals, there may be similarities with pathogenic agents of the wild coral diseases, such as white syndrome and brown band syndrome. We propose that Helicostoma is actually a misnomer, but improved understanding of this pathogen and others could benefit both fields. Improved practices in aquarium maintenance and husbandry would also benefit natural environments by reducing the scale of wild harvest and improving the potential for coral culture, both for the aquarium industry and for rehabilitation programmes

Rediscovery of the critically endangered ‘scarce yellow sally stonefly’ Isogenus nubecula in United Kingdom after a 22 year period of absence.

The critically endangered ‘scarce yellow sally stonefly’ Isogenus nubecula (Newman, 1833) (Plecoptera: Perlodidae) was rediscovered in the United Kingdom (UK) in 2017. This rediscovery comes after a 22-year period of absence despite numerous surveys since its last record in 1995. This species is one of the rarest stoneflies in the UK and Europe and its rediscovery is of international significance, being the westernmost point in Europe where the species is found, with the next nearest populations occurring in Austria and western Hungary, Slovakia, and central Sweden. The species is classed as pRDB2 (vulnerable), however is not listed in the British Red Data Book despite only being present (as far as records detail) in one river, the River Dee in North Wales, UK. Only fourteen individuals were caught and the need for conservation of this rare stonefly is therefore of paramount importance. We have made recommendations for the need to increase survey effort using environmental DNA (eDNA) techniques in order to fully understand the species range in this river and those in the surrounding area. The DNA sequence of I. nubecula has been uploaded on GenBank for further genetic studies. Captive rearing could also be explored with possible reintroductions to sites within its former UK range

First detection of a highly invasive freshwater amphipod (Crangonyx floridanus) in the United Kingdom

The freshwater gammarid, Crangonyx floridanus, originates from North America but has invaded and subsequently spread rapidly throughout Japan. We provide here the first genetic and microscopic evidence that C. floridanus has now also reached the United Kingdom. We found this species in two locations separated by more than 200 km (Lake Windermere in the North of the UK and Smestow Brook, West Midlands). The current distribution of C. floridanus is currently unknown, however, both sites are well connected to other river and canal systems. Therefore, the chance of further spread is high. Genetic analyses of C. floridanus indicate that British inland waters are colonised by the same lineage, which invaded Japan. We recommend further work to assess the distribution of this species and its impact on the local fauna and flora

Cardiovascular fitness associated with cognitive performance in heart failure patients enrolled in cardiac rehabilitation

Abstract Background Reduced cognitive function is common in persons with heart failure (HF). Cardiovascular fitness is a known contributor to cognitive function in many patient populations, but has only been linked to cognition based on estimates of fitness in HF. The current study examined the relationship between fitness as measured by metabolic equivalents (METs) from a standardized stress test and cognition in persons with HF, as well as the validity of office-based predictors of fitness in this population. Methods Forty-one HF patients enrolled in cardiac rehabilitation completed a standardized exercise stress test protocol, a brief neuropsychological battery, the 2-minute step test (2MST), and a series of medical history and self-report questionnaires. Results Maximum METs from stress testing demonstrated incremental predictive validity for attention (β = .41,p = .03), executive function (β = .37,p = .04), and memory domains (β = .46,p = .04). Partial correlations accounting for key medical and demographic characteristics revealed greater METs was associated with the 2MST (r(32) = .41,p = .02) but not with the Duke Activity Status Index (DASI) (r(32) = .24,p = .17). Conclusion The current findings indicate that better fitness levels measured by METs is independently associated with better cognitive function in older adults with HF. Results also showed that METs was closely associated with one office-based measure of fitness (2MST), but not another (DASI). Prospective studies are needed to clarify the mechanisms linking fitness and cognitive function in HF

Deep-sea sponge derived environmental DNA analysis reveals demersal fish biodiversity of a remote Arctic ecosystem

The deep-sea is vast, remote, and largely underexplored. However, methodological advances in environmental DNA (eDNA) surveys could aid in the exploration efforts, such as using sponges as natural eDNA filters for studying fish biodiversity. In this study, we analyzed the eDNA from 116 sponge tissue samples and compared these to 18 water eDNA samples and visual surveys obtained on an Arctic seamount. Across survey methods, we revealed approximately 30% of the species presumed to inhabit this area and 11 fish species were detected via sponge derived eDNA alone. These included commercially important fish such as the Greenland halibut and Atlantic mackerel. Fish eDNA detection was highly variable across sponge samples. Highest detection rates were found in sponges with low microbial activity such as those from the class Hexactinellida. The different survey methods also detected alternate fish communities, highlighted by only one species overlap between the visual surveys and the sponge eDNA samples. Therefore, we conclude that sponge eDNA can be a useful tool for surveying deep-sea demersal fish communities and it synergises with visual surveys improving overall biodiversity assessments. Datasets such as this can form comprehensive baselines on fish biodiversity across seamounts, which in turn can inform marine management and conservation practices in the regions where such surveys are undertaken.publishedVersio