Search results for "Fish"
showing 10 items of 3164 documents
Successive Invasion-Mediated Interspecific Hybridizations and Population Structure in the Endangered Cichlid Oreochromis mossambicus.
2013
Hybridization between invasive and native species accounts among the major and pernicious threats to biodiversity. The Mozambique tilapia Oreochromis mossambicus, a widely used freshwater aquaculture species, is especially imperiled by this phenomenon since it is recognized by the IUCN as an endangered taxon due to genetic admixture with O. niloticus an invasive congeneric species. The Lower Limpopo and the intermittent Changane River (Mozambique) drain large wetlands of potentially great importance for conservation of O. mossambicus, but their populations have remained unstudied until today. Therefore we aimed (1) to estimate the autochthonous diversity and population structure among genet…
Effect of a fish stock's demographic structure on offspring survival and sensitivity to climate
2017
Commercial fishing generally removes large and old individuals from fish stocks, reducing mean age and age diversity among spawners. It is feared that these demographic changes lead to lower and more variable recruitment to the stocks. A key proposed pathway is that juvenation and reduced size distribution causes reduced ranges in spawning period, spawning location, and egg buoyancy; this is proposed to lead to reduced spatial distribution of fish eggs and larvae, more homogeneous ambient environmental conditions within each year-class, and reduced buffering against negative environmental influences. However, few, if any, studies have confirmed a causal link from spawning stock demographic …
Ocean acidification affects fish spawning but not paternity at CO2 seeps
2016
Fish exhibit impaired sensory function and altered behaviour at levels of ocean acidification expected to occur owing to anthropogenic carbon dioxide emissions during this century. We provide the first evidence of the effects of ocean acidification on reproductive behaviour of fish in the wild. Satellite and sneaker male ocellated wrasse ( Symphodus ocellatus ) compete to fertilize eggs guarded by dominant nesting males. Key mating behaviours such as dominant male courtship and nest defence did not differ between sites with ambient versus elevated CO 2 concentrations. Dominant males did, however, experience significantly lower rates of pair spawning at elevated CO 2 levels. Despite the hig…
Identifying a key host in an acanthocephalan-amphipod system.
2015
SUMMARYTrophically transmitted parasites may use multiple intermediate hosts, some of which may be ‘key-hosts’, i.e. contributing significantly more to the completion of the parasite life cycle, while others may be ‘sink hosts’ with a poor contribution to parasite transmission. Gammarus fossarum and Gammarus roeseli are sympatric crustaceans used as intermediate hosts by the acanthocephalan Pomphorhynchus laevis. Gammarus roeseli suffers higher field prevalence and is less sensitive to parasite behavioural manipulation and to predation by definitive hosts. However, no data are available on between-host differences in susceptibility to P. laevis infection, making it difficult to untangle the…
Size‐selective harvesting fosters adaptations in mating behaviour and reproductive allocation, affecting sexual selection in fish
2019
The role of sexual selection in the context of harvest-induced evolution is poorly understood. However, elevated and trait-selective harvesting of wild populations may change sexually selected traits, which in turn can affect mate choice and reproduction. We experimentally evaluated the potential for fisheries-induced evolution of mating behaviour and reproductive allocation in fish. We used an experimental system of zebrafish (Danio rerio) lines exposed to large, small or random (i.e. control) size-selective mortality. The large-harvested line represented a treatment simulating the typical case in fisheries where the largest individuals are preferentially harvested. We used a full factoria…
Replacing red meat and processed red meat for white meat, fish, legumes or eggs is associated with lower risk of incidence of metabolic syndrome.
2016
BACKGROUND & AIMS: Few studies have assessed the association between consumption of red meat (RM) and processed red meats (PRM) and the incidence of metabolic syndrome (MetS) and results have been inconsistent. We investigated associations between total consumption of meat and its subtypes and incident MetS and estimated the effect of substituting RM or PRM for alternative protein-rich foods. METHODS: We analyzed 1868 participants (55-80 years-old) recruited into the PREDIMED study who had no MetS at baseline and were followed for a median of 3.2 years. MetS was defined using updated harmonized criteria. Anthropometric variables, dietary habits, and blood biochemistry were determined at bas…
Food neophobia and its association with intake of fish and other selected foods in a Norwegian sample of toddlers: A cross-sectional study
2016
Reluctance to try novel foods (food neophobia) prevents toddlers from accepting healthy foods such as fish and vegetables, which are important for child development and health. Eating habits established between ages 2 and 3 years normally track into adulthood and are therefore highly influential; even so, there are few studies addressing food neophobia in this age group. This cross-sectional study investigated the relationship between the level of food neophobia and the frequency of toddlers' intake of fish, meat, berries, fruit, vegetables, and sweet and salty snacks. Parents of 505 toddlers completed a questionnaire assessing the degree of food neophobia in their toddlers (mean age 28 mon…
A healthy Nordic diet and physical performance in old age : findings from the longitudinal Helsinki Birth Cohort Study
2016
AbstractEpidemiological studies have shown that a number of nutrients are associated with better physical performance. However, little is still known about the role of the whole diet, particularly a healthy Nordic diet, in relation to physical performance. Therefore, we examined whether a healthy Nordic diet was associated with measures of physical performance 10 years later. We studied 1072 participants from the Helsinki Birth Cohort Study. Participants’ diet was assessed using a validated 128-item FFQ at the mean age of 61 years, and a priori-defined Nordic diet score (NDS) was calculated. The score included Nordic fruits and berries, vegetables, cereals, PUFA:SFA and trans-fatty acids ra…
Mediterranean Diet and atherothrombosis biomarkers: a randomized controlled trial
2020
Scope To assess whether following a Mediterranean diet (MedDiet) improves atherothrombosis biomarkers in high cardiovascular risk individuals. Methods and results In 358 random volunteers from the PREvención con DIeta MEDiterránea trial, the 1‐year effects on atherothrombosis markers of an intervention with MedDiet, enriched with virgin olive oil (MedDiet‐VOO; n = 120) or nuts (MedDiet‐Nuts; n = 119) versus a low‐fat control diet (n = 119), and whether large increments in MedDiet adherence (≥3 score points, versus compliance decreases) and intake changes in key food items are associated with 1‐year differences in biomarkers. Differences are observed between 1‐year changes in the MedDiet‐VOO…
Evidence of a significant vitamin D deficiency among 9–13-year-old Polish children: results of a multicentre study
2018
Purpose To evaluate the extent to which the population of Polish preadolescents is vitamin D deficient and to assess seasonal variations in vitamin D status. Participants and methods A total of 720 healthy children aged 9–13 years (409 girls, 311 boys) residing in 6 representative geographical locations in Poland were studied. A parental-assisted questionnaire provided data on nutritional habits, vitamin D supplements and sun exposure. Serum concentration of 25-hydroxyvitamin was determined twice, after the winter in March and after the summer in October. Results In March, vitamin D deficiency (25–50 nmol/L) was found in 64%, and severe deficiency (< 25 nmol/L) in 20.2% of children. In Octo…