Understanding an animal's metabolic rate and thermal history is pivotal for ecological research. Recent studies have proposed the use of stable carbon and oxygen isotopes (δC and δO) in biogenic carbonates as proxies of metabolic rate and experienced temperature, respectively, to overcome the challenges of directly measuring these data in the field. Our study represents the first experimental investigation to develop δC and δO proxies in octopus.
View Article and Find Full Text PDFRationale: Although the proportion of structural carbonates in vertebrate bones is low, the values of isotopes, namely stable oxygen (δ O) and carbon (δ C), in structural carbonates provide environmental and physiological information, which can be beneficial for estimating the palaeontological and ecological parameters of vertebrates. However, a few studies have analysed the isotopes of structural carbonates in modern teleost fishes, and a well-developed protocol for sample preparation is lacking.
Methods: We examined different pre-treatment methods of preparing bone samples of three marine teleost fishes (Japanese flounder, Pacific bluefin tuna and yellowtail) and investigated the effects of the cleaning methods on the stable isotope values of structural carbonates among vertebrae in the same individual.
This study examined the spatial and monthly variations in reproductive dynamics of Pacific saury collected in the high sea (40°N-49°N, 149°E-168°E) of the northwestern Pacific during the fishing season of the Taiwanese stick-held dip-net fisheries (July-November) from 2018 to 2019. Generalized additive mixed-effects models (GAMMs) were applied to explore the relationship between the probability of maturing and spawning occurrence (P ) and the explanatory variables (month, body length, sea-surface temperature [SST] as fixed effects, and fishing set as a random effect) for the age 0 and age 1 fish, respectively. In addition, the impact of the geographical difference in growth rates of age 0 fish, quantified as the radius of the otolith annual ring, on the P of age 1 fish was explored in the GAMMs.
View Article and Find Full Text PDFPatagonian aquatic environments have been invaded since the end of the last century by different species of salmonids. Knowing the natal origin and homing/straying rate of the salmonids in colonised environments is essential to understanding the dispersal mechanisms and developing management plans. In the last two decades, Chinook salmon Oncorhynchus tshawytscha showed the greatest natural dispersal capacity in Patagonia.
View Article and Find Full Text PDFMassive populations of sardines inhabit both the western and eastern boundaries of the world's subtropical ocean basins, supporting both commercial fisheries and populations of marine predators. Sardine populations in western and eastern boundary current systems have responded oppositely to decadal scale anomalies in ocean temperature, but the mechanism for differing variability has remained unclear. Here, based on otolith microstructure and high-resolution stable isotope analyses, we show that habitat temperature, early life growth rates, energy expenditure, metabolically optimal temperature, and, most importantly, the relationship between growth rate and temperature are remarkably different between the two subpopulations in the western and eastern North Pacific.
View Article and Find Full Text PDFMetabolic rate underpins our understanding of how species survive, reproduce and interact with their environment, but can be difficult to measure in wild fish. Stable carbon isotopes (δC) in ear stones (otoliths) of fish may reflect lifetime metabolic signatures but experimental validation is required to advance our understanding of the relationship. To this end, we reared juvenile Australasian snapper (), an iconic fishery species, at different temperatures and used intermittent-flow respirometry to calculate standard metabolic rate (SMR), maximum metabolic rate (MMR) and absolute aerobic scope (AAS).
View Article and Find Full Text PDFField metabolic rate (FMR) is key to understanding individual and population-level responses to environmental changes, but is challenging to measure in field conditions, particularly in aquatic environments. Here we show that FMR can be estimated directly from the isotopic composition of carbon in fish otoliths (δC). We describe the relationship between δC values and oxygen consumption rate, and report results from laboratory experiments relating individual-level measurements of oxygen consumption rates to δC values in Atlantic cod ().
View Article and Find Full Text PDFPhilos Trans R Soc Lond B Biol Sci
April 2016
The fossil record provides the only direct evidence of temporal trends in biodiversity over evolutionary timescales. Studies of biodiversity using the fossil record are, however, largely limited to discussions of taxonomic and/or morphological diversity. Behavioural and physiological traits that are likely to be under strong selection are largely obscured from the body fossil record.
View Article and Find Full Text PDFThis study aims to evaluate the feasibility of using chemical and isotopic compositions of coffee beans to identify their geographic origins. Twenty-one Coffea arabica beans collected from 14 countries in 3 major coffee-producing regions, Africa, America and Asia, were analysed for multi-element of B, Rb, Sr, Ba, Fe, Mn and Zn, as well as isotopic compositions of B and Sr. Our results demonstrate that the geographic origin of coffee beans could be classified based on concentrations of Rb, Sr and Ba.
View Article and Find Full Text PDFUnlabelled: Connatal tuberculosis is increasing in incidence and the mortality and morbidity of this disease remains high. We report a 27-week-old, 896 g female premature infant who had mild respiratory distress syndrome after birth. She developed signs of infection, progressive pneumonia and atelectasis which did not respond to mechanical ventilation and antibiotics.
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