Influence of trophic pathways on daily growth patterns of western Mediterranean anchovy Engraulis encrasicolus larvae

2015 ◽  
Vol 531 ◽  
pp. 263-275 ◽  
Author(s):  
JM Quintanilla ◽  
R Laiz-Carrión ◽  
A Uriarte ◽  
A García
Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 818
Author(s):  
Maria Royo-Navascues ◽  
Edurne Martinez del Castillo ◽  
Roberto Serrano-Notivoli ◽  
Ernesto Tejedor ◽  
Klemen Novak ◽  
...  

Understanding the influence of the current climate on the distribution, composition, and carbon storage capacity of Mediterranean tree species is key to determining future pathways under a warmer and drier climate scenario. Here, we evaluated the influence of biotic and environmental factors on earlywood (EW) and latewood (LW) growth in Aleppo pine (Pinus halepensis Mill.). Our investigation was based on a dense dendrochronological network (71 sites), which covered the entire distribution area of the species in the Iberian Peninsula (around 119.652 km2), and a high-resolution climate dataset of the Western Mediterranean area. We used generalized linear-mixed models to determine the spatial and temporal variations of EW and LW across the species distribution. Our results showed an intense but differentiated climatic influence on both EW and LW growth components. The climatic influence explained significant variations across the environmental gradients in the study area, which suggested an important adaptation through phenotypic plasticity and local adaptation to varying climatic conditions. In addition, we detected a clear spatial trade-off between efficiency and safety strategy in the growth patterns across the species distribution. Additionally, in more productive areas, the trees presented a higher proportion of EW (more efficient to water transport), while, in more xeric conditions, the LW proportion increased (more safety to avoid embolisms), implying an adaptation to more frequent drought episodes and a higher capacity of carbon depletion. We therefore concluded that Mediterranean forests adapted to dryer conditions might be more efficient as carbon reservoirs than forests growing in wetter areas. Finally, we advocated for the need to consider wood density (EW/LW proportion) when modeling current and future forest carbon sequestrations.


2019 ◽  
Vol 40 (2) ◽  
pp. 272-283
Author(s):  
Yiyang Ding ◽  
Pauliina Schiestl-Aalto ◽  
Heljä-Sisko Helmisaari ◽  
Naoki Makita ◽  
Kira Ryhti ◽  
...  

Abstract Scots pine (Pinus sylvestris L.) is one of the most important conifers in Northern Europe. In boreal forests, over one-third of net primary production is allocated to roots. Pioneer roots expand the horizontal and vertical root systems and transport nutrients and water from belowground to aboveground. Fibrous roots, often colonized by mycorrhiza, emerge from the pioneer roots and absorb water and nutrients from the soil. In this study, we installed three flatbed scanners to detect the daily growth of both pioneer and fibrous roots of Scots pine during the growing season of 2018, a year with an unexpected summer drought in Southern Finland. The growth rate of both types of roots had a positive relationship with temperature. However, the relations between root elongation rate and soil moisture differed significantly between scanners and between root types indicating spatial heterogeneity in soil moisture. The pioneer roots were more tolerant to severe environmental conditions than the fibrous roots. The pioneer roots initiated elongation earlier and ceased it later than the fibrous roots. Elongation ended when the temperature dropped below the threshold temperature of 4 °C for pioneer roots and 6 °C for fibrous roots. During the summer drought, the fibrous roots halted root surface area growth at the beginning of the drought, but there was no drought effect on the pioneer roots over the same period. To compare the timing of root production and the aboveground organs’ production, we used the CASSIA model, which estimates the aboveground tree carbon dynamics. In this study, root growth started and ceased later than growth of aboveground organs. Pioneer roots accounted for 87% of total root productivity. We suggest that future carbon allocation models should separate the roots by root types (pioneer and fibrous), as their growth patterns are different and they have different reactions to changes in the soil environment.


2019 ◽  
Vol 31 (3) ◽  
pp. 116-122 ◽  
Author(s):  
Jake R. Wallis ◽  
Jessica E. Melvin ◽  
Robert King ◽  
So Kawaguchi

AbstractGrowth, which is intrinsically linked to environmental conditions including temperature and food availability are highly variable both temporally and spatially. Estimates of growth rates of the Southern Ocean euphausiid Thysanoessa macrura are currently restricted to limited studies which rely upon repeated sampling and length-frequency analysis to quantify growth rates. The instantaneous growth method (IGR) was used to measure the growth rate of T. macrura successfully in the southern Kerulen Plateau region during summer, providing the first IGR parameters for the Southern Ocean euphausiid species. Results of the four-day IGR incubation indicate a period of low somatic growth for adult T. macrura. Males had a longer intermoult period (IMP) (62 days) than females (42 days), but the sexes exhibited similar daily growth rates of 0.011 mm day−1 and 0.012 mm day−1 respectively. Juveniles exhibited the fastest growth, with an IMP of 13 days and daily growth rate of 0.055 mm day−1 indicating a prolonged growth season, similar to the Antarctic krill E. superba. Consequently, we highlight the usability of the IGR method and strongly encourage its use in developing a comprehensive understanding of spatial and seasonal growth patterns of T. macrura.


2009 ◽  
Vol 66 (10) ◽  
pp. 2176-2182 ◽  
Author(s):  
Iratxe Zarraonaindia ◽  
Miguel Angel Pardo ◽  
Mikel Iriondo ◽  
Carmen Manzano ◽  
Andone Estonba

Abstract Zarraonaindia, I., Pardo, M. A., Iriondo, M., Manzano, C., and Estonba, A. 2009. Microsatellite variability in European anchovy (Engraulis encrasicolus) calls for further investigation of its genetic structure and biogeography. – ICES Journal of Marine Science, 66: 2176–2182. Attention to genetic and ecological perspectives can enhance strategies for using fishery resources sustainably. A potentially important application is the use of molecular markers to assess the genetic stock structure of a harvested species. In this study, seven microsatellite markers were analysed in anchovy samples from the Bay of Biscay, the Gulf of Cádiz, and the Gulf of Lions to assess the genetic structure of anchovy (Engraulis encrasicolus) populations in the Bay of Biscay and to infer the biogeographic origin of these populations. All samples showed a deficit of heterozygotes that could be explained by non-random mating, Wahlund's effect, and especially by the presence of null alleles. Global FST and RST values, uncorrected and corrected for null alleles, were significant. There was significant genetic heterogeneity between two populations in the Bay of Biscay, suggesting that anchovy there may not be panmictic. Moreover, the results reinforce the hypothesis of a recent common ancestor shared by Bay of Biscay and western Mediterranean anchovy. These results, together with those of earlier studies, suggest merit in further investigating spatio-temporal genetic variation among anchovy populations in the Northeastern Atlantic.


Author(s):  
Guido Plaza ◽  
Mauricio F. Landaeta ◽  
C. Valeria Espinoza ◽  
F. Patricio Ojeda

Otolith microstructure analysis was used to reveal daily growth patterns of young-of-the year (YOY) of six species of perciform fishes, Bovichtus chilensis (Bovichtidae), Girella laevifrons and Graus nigra (Kyphosidae), Helcogrammoides chilensis (Tripterygiidae) and Hypsoblennius sordidus and Scartichthys viridis (Blenniidae). YOY collected in intertidal pools from June to December 2008 in Central Chile, ranged from 24 to 76 mm total length and from 25 to 390 days of age. In the six species, sagittal otoliths showed a slightly oval shape, symmetrical and laterally compressed and showed micro-increments distinguishable after a two-side polishing. Increment width of sagittae showed two patterns irrespective of hatch month and species: (i) a parabolic growth with wider increment widths (during the first 150 of YOY life, e.g. B. chilensis, G. nigra and G. laevifrons); and (ii) a more irregular pattern with lower increment widths during most of the seasons in H. chilensis and H. sordidus. Further results were: (i) a unique central primordium enclosed by two checks after which distinctive increments were deposited; (ii) low instantaneous growth rates estimated through the slope of the length-at-age relationship (range 0.1–0.21 mm d−1); and (iii) a linear fish size–otolith size relationship.


2010 ◽  
Vol 67 (8) ◽  
pp. 1574-1586 ◽  
Author(s):  
M. Pilar Tugores ◽  
Magdalena Iglesias ◽  
Núria Díaz ◽  
Dolores Oñate ◽  
Joan Miquel ◽  
...  

Abstract Tugores, M. P., Iglesias, M., Díaz, N., Oñate, D., Miquel, J., and Giráldez, A. 2010. Latitudinal and interannual distribution of the European anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) in the western Mediterranean, and sampling uncertainty in abundance estimates. – ICES Journal of Marine Science, 67: 1574–1586. On the Spanish Mediterranean continental shelf, late-autumn echo-integration acoustic surveys have been performed annually since the 1990s. The surveys coincide with the recruitment season of anchovy (Engraulis encrasicolus) and the start of the spawning season of sardine (Sardina pilchardus), and they provide estimates of stock size for the main fisheries in the area. Latitudinal distribution of the abundance of the two species from 2003 till 2006 is evaluated, and transitive geostatistical techniques applied to estimate the sampling uncertainty of the overall abundance estimate. The anchovy stock was found mainly in areas influenced by river run-off, in well-known anchovy spawning areas, suggesting that anchovy remained on their spawning grounds until late autumn or that survival was higher in these regions of enhanced productivity. By the time of the surveys, sardine were already occupying their spawning grounds over the continental shelf. The precision of the abundance estimates was generally high. The few cases of low precision were re-examined and found to stem most probably from processing errors, so the re-examination has contributed to an improvement in the accuracy of the estimates. The greater precision obtained in the southern subarea suggested a greater homogeneity in the spatial distribution of both species.


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