Quantitative species-level ecology of reef fish larvae via metabarcoding.

The larval pool of coral reef fish has a crucial role in the dynamics of adult fish populations. However, large-scale species-level monitoring of species-rich larval pools has been technically impractical. Here, we use high-throughput metabarcoding to study larval ecology in the Gulf of Aqaba, a region that is inhabited by >500 reef fish species. We analysed 9,933 larvae from 383 samples that were stratified over sites, depth and time. Metagenomic DNA extracted from pooled larvae was matched to a mitochondrial cytochrome c oxidase subunit I barcode database compiled for 77% of known fish species within this region. This yielded species-level reconstruction of the larval community, allowing robust estimation of larval spatio-temporal distributions. We found significant correlations between species abundance in the larval pool and in local adult assemblages, suggesting a major role for larval supply in determining local adult densities. We documented larval flux of species whose adults were never documented in the region, suggesting environmental filtering as the reason for the absence of these species. Larvae of several deep-sea fishes were found in shallow waters, supporting their dispersal over shallow bathymetries, potentially allowing Lessepsian migration into the Mediterranean Sea. Our method is applicable to any larval community and could assist coral reef conservation and fishery management efforts.

Positive psychological impact of bariatric surgery.

BACKGROUND: Psychological impact of bariatric surgery has been described mostly in terms of reduction of psychopathology. This exploratory study examines the impact of bariatric surgery in terms of positive psychological growth and development. METHODS: 57 patients who underwent LAGB were recruited to this study; 31 patients (54.4%) completed a questionnaire battery 1 year or more following surgery. Positive impact was assessed using the posttraumatic growth questionnaire. Mental and physical health were assessed using the SF-36. Family support was assessed using the perceived family support questionnaire and weight loss measure was assessed using measured weight differences prior to and 1 year after surgery. RESULTS: Positive impact was apparent in all dimensions including greater appreciation of life, increased sense of personal strength and improvement in relating to others. Positive impact appears to be independent of physical and mental health as well as of family social support. CONCLUSION: Positive impact of bariatric surgery is a substantial outcome and should be examined further. Positive impact of bariatric surgery should be taken into account as a therapeutic tool in positive oriented psychological interventions following bariatric surgery.