R. D.M. NASH results 23
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Lipid and fatty acid datasets are commonly used to assess the nutritional composition of organisms, trophic ecology, and ecosystem dynamics. Lipids and their fatty acid constituents are essential nutrients to all forms of life because they contribute to biological processes such as energy flow and metabolism. Assessment of total lipids in tissues of organisms provides information on energy allocation and life‐history strategie...
Prolonging survival in good health is a fundamental societal goal. However, the leading determinants of disability-free survival in healthy older people have not been well established. Data from ASPREE, a bi-national placebo-controlled trial of aspirin with 4.7 years median follow-up, was analysed. At enrolment, participants were healthy and without prior cardiovascular events, dementia or persistent physical disability. Disab...
Development, validation and field application of an RNA‐based growth index in juvenile plaice Pleuronectes platessaNARA Subscribed
A general mechanism relating RNA concentration and growth rate is derived from four physiological assumptions and developed into a growth index for juvenile plaice Pleuronectes platessa . The index describing instantaneous growth rates ( G , day −1 ) in the laboratory with the lowest Akaike information criterion with small‐sample bias adjustment was a function of RNA concentration ( R , ), temperature ( T , ° K), body mass ( M...
Is fecundity in plaice ( Pleuronectes platessa L.) down‐regulated in response to reduced food intake during autumn?NARA Subscribed
The effect of controlling food intake during the autumn, which is the time of late vitellogenesis, on fecundity, atresia and follicle and ovary growth was examined for plaice Pleuronectes platessa . Eighteen fish were kept in individual pens and either fed on a high or low ration diet. Fish which increased in whole body condition exhibited an increase in carcass condition which means that when food intake is sufficient to main...
The small‐scale variability in condition and growth of dab Limanda limanda larvae was investigated in relation to a tidal‐mixing front (Manx West Coast front) off the west coast of the Isle of Man, Irish Sea. RNA:DNA ratios and otolith microincrement analysis were used to estimate nutritional status and recent growth rates of larvae captured on 5 May 1999 in mixed, frontal and stratified waters associated with this front. RNA:...
Variations in standard length ( L S ), gape size ( S G ) and jaw length ( L J ) were studied in larval and juvenile gadoids (cod Gadus morhua , haddock Melanogrammus aeglefinus and whiting Merlangius merlangus ) from 4 to 70 mm. The increase in S G and L J was not linear with respect to L S . The relationship was best described by segmented regression lines in all three species, with an inflection point at c . 10·5 mm. The S G...
Temperature development relationships were determined for batches of Irish Sea cod Gadus morhua eggs incubated in flow‐through incubators. Hatching began 16·4 days after fertilization (DAF) at 6° C, 10·3 DAF at 8° C, 9·4 DAF at 10° C and 7·4 DAF at 12° C. Egg mortality increased at the higher temperatures, but survival was >80%. Results were compared with published data at four comparable stage end points: the end of blastula,...
To study the transport of plaice ( Pleuronectes platessa L.) eggs and larvae in the eastern Irish Sea, we constructed a 3D‐baroclinic physical model and coupled it to a particle‐tracking scheme that allowed aspects of larval behaviour to be simulated. Starting positions for eggs were based upon data from a series of ichthyoplankton surveys and final positions were compared with results of settled plaice distributions from two...
The inter‐annual variability in year class strength (1976–2000) of North Sea herring ( Clupea harengus ) was investigated using Paulik diagrams based on survey data and Virtual Population Analysis. The herring life cycle was split into five stages: spawning stock biomass (SSB), egg production, larvae, fish with 0 winter rings on the otolith (0‐wr), 1‐wr and 2‐wr. Surveys were used as indices and Paulik analysis revealed relati...
The life history of the white sea bream Diplodus sargus in the Azores showed a pattern consistent with digynic hermaphroditism achieving sexual maturity during the second year of life, at 16·7 cm L T . Spawning occurred from March to June at temperatures between 15 and 17° C and the onset and duration of spawning season in the sea bream appeared to be influenced by sea water temperatures. As latitude decreased, both in the nor...
The reproduction, age and growth of the spotted rocklingNARA Subscribed
Biology of the Macaronesian endemic rockling Gaidropsarus guttatus was studied in the Azores. The overall sex ratio from the samples was highly in favour of females (1 : 6·33). The growth parameters were L ∞ = 24·23, k = 1·219 and t 0 = −0·059. Fish matured at 15 cm L T and the spawning season was strongly clustered in April.
Predation by sprat and herring on pelagic fish eggs in a plaice spawning area in the Irish SeaNARA Subscribed
Predation on planktonic fish eggs was examined by stomach content analysis of sprat and herring sampled in a plaice spawning area to the east of the Isle of Man in March 1993. Plankton samples were taken to examine prey selection. The clupeids showed a selection for the later developmental stages of plaice eggs. Plaice eggs had a refuge in size from predation by sprat 80 mm total length showed a strong selection for plaice egg...
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