Length‐ and age‐based demographics of exploited populations of stout whiting,Sillago robusta Stead, 1908

This study assessed variability in the length and age compositions, longevity, length‐at‐age and rates of growth and mortality of the east Australian stout whiting Sillago robusta Stead, 1908 population harvested by demersal trawl fisheries. Sampling was done over 2 years and was spatially stratified across three depth strata between 11 and 90 m at two locations approximately 400 km apart. There were no consistent depth‐related differences in length and age compositions, but the mean and median length and age of the population was greater at the lower latitude location. Age classes 2 and 3 years dominated samples in the north, and 1 and 2 years in the south. Observed longevity was 10 years in the north, and 6 years in the south. Mean length‐at‐age was not consistently different between sexes, years or locations, nor did the von Bertalanffy growth function differ significantly between sexes, even though females had a greater estimated L_∞ (23.45 cm FL) compared to males (22.36 cm FL). Estimated natural mortality (M) ranged between 0.42 and 0.77, using age‐ and length‐based methods. Age‐based catch‐curve analyses identified the instantaneous rate of total mortality (Z) to range between 1.48 and 2.70, with subsequent estimates of fishing mortality (F) ranging between 1.15 and 2.00, being greater than M. Exploitation rates (E) were greater than 0.7, indicating that S. robusta at the study locations was heavily fished. The data provided here can be used as a basis to evaluate future fishery‐ and climate‐related changes in the population demographics of east Australian S. robusta.     

Spawning,maturity, growth and movement of Platycephalus fuscus (Cuvier, 1829) (Platycephalidae): fishery management considerations

The dusky flathead (Platycephalus fuscus) is an important teleost harvested by recreational and commercial fishers throughout its endemic distribution along eastern Australia. This study indicates that the species has an extended spawning period throughout the austral summer, with females in spawning condition occurring in lower estuarine and coastal waters. Total length (L₅₀) and age (A₅₀) at which 50% (±1 SE) of the population was mature was 31.72 (±1.08) cm TL and 1.22 (±0.44) years for males and 56.75 (±0.60) cm TL and 4.55 (±0.13) years for females. The von Bertalanffy growth parameters differed significantly between sexes; females grew faster and attained a greater maximum TL and age than males. The largest female was 98.5 cm TL (7.5 kg), and the oldest 16 years, whereas the largest male was 61.5 cm TL (1.58 kg) and 11 years of age. A tag‐and‐release study identified the exchange of sub‐adult and mature‐sized individuals among estuaries. Determinations of length‐based management regulations for the species are compounded by the large gender‐based differences in growth and length‐at‐maturity. Current minimum legal lengths of 30–40 cm TL protect approximately 3–9% of the female spawning population. Alternative management options, including harvest slot sizes, need to be investigated and tested.     

Getting to the core: Internal body temperatures help reveal the ecological function and thermal implications of the lions’ mane

It has been proposed that there is a thermal cost of the mane to male lions, potentially leading to increased body surface temperatures (T_s), increased sperm abnormalities, and to lower food intake during hot summer months. To test whether a mane imposes thermal costs on males, we measured core body temperature (T_b) continuously for approximately 1 year in 18 free‐living lions. There was no difference in the 24‐hr maximum T_b of males (n = 12) and females (n = 6), and males had a 24‐hr mean T_b that was 0.2 ± 0.1°C lower than females after correcting for seasonal effects. Although feeding on a particular day increased 24‐hr mean and 24‐hr maximum T_b, this phenomenon was true of both male and female lions, and females had higher 24‐hr mean and 24‐hr maximum T_b than males, on both days when lions did not feed, and on days when lions did feed. Twenty‐four‐hour T_b was not influenced by mane length or color, and 24‐hr mean T_b was negatively correlated with mane length. These data contradict the suggestion that there exists a thermal cost to male lions in possessing a long dark mane, but do not preclude the possibility that males compensate for a mane with increased heat loss. The increased insulation caused by a mane does not necessarily have to impair heat loss by males, which in hot environments is primarily through respiratory evaporative cooling, nor does in necessarily lead to increased heat gain, as lions are nocturnal and seek shade during the day. The mane may even act as a heat shield by increasing insulation. However, dominant male lions frequent water points more than twice as often as females, raising the possibility that male lions are increasing water uptake to facilitate increased evaporative cooling. The question of whether male lions with manes compensate for a thermal cost to the mane remains unresolved, but male lions with access to water do not have higher T_b than females or males with smaller manes.     

Melanogenesis‐Inhibitory and Cytotoxic Activities of Limonoids,Alkaloids, and Phenolic Compounds from Phellodendron amurense Bark

Four limonoids, 1  –  4 , five alkaloids, 5  –  9 , and four phenolic compounds, 10  –  13 , were isolated from a MeOH extract of the bark of Phellodendron amurense (Rutaceae). Among these, compound 13 was new, and its structure was established as rel‐(1R,2R,3R)‐5‐hydroxy‐3‐(4‐hydroxy‐3‐methoxyphenyl)‐6‐methoxy‐1‐(methoxycarbonylmethyl)indane‐2‐carboxylic acid methyl ester (γ‐di(methyl ferulate)) based on the spectrometric analysis. Upon evaluation of compounds 1  –  13 against the melanogenesis in the B16 melanoma cells induced with α‐melanocyte‐stimulating hormone (α‐MSH), four compounds, limonin ( 1 ), noroxyhydrastinine ( 6 ), haplopine ( 7 ), and 4‐methoxy‐1‐methylquinolin‐2(1H)‐one ( 8 ), exhibited potent melanogenesis‐inhibitory activities with almost no toxicity to the cells. Western blot analysis revealed that compound 6 inhibited melanogenesis, at least in part, by inhibiting the expression of protein levels of tyrosinase, TRP‐1, and TRP‐2 in α‐MSH‐stimulated B16 melanoma cells. In addition, when compounds 1  –  13 were evaluated for their cytotoxic activities against leukemia (HL60), lung (A549), duodenum (AZ521), and breast (SK‐BR‐3) cancer cell lines, five compounds, berberine ( 5 ), 8 , canthin‐6‐one ( 9 ), α‐di‐(methyl ferulate) ( 12 ), and 13 , exhibited cytotoxicities against one or more cancer cell lines with IC₅₀ values in the range of 2.6 – 90.0 μm . In particular, compound 5 exhibited strong cytotoxicity against AZ521 (IC₅₀ 2.6 μm ) which was superior to that of the reference cisplatin (IC₅₀ 9.5 μm ).     

Estimation of growth parameters from published data for several Mediterranean fishes

Two sets of von Bertalanffy growth parameter (VBGP) estimates are provided for several Mediterranean fish stocks. All estimates are based on the non‐linear least square regression and accompanied by uncertainty measures (i.e. standard errors). The first set consists of growth parameters estimated from 73 published length‐at‐age data with no previous VBGP estimations; in this case, fitting was possible for 30 length‐at‐age sets, corresponding to 22 species, two estimates of which (Mycteroperca rubra and Myctophum punctatum) are the first for the Mediterranean. The second set refers to the re‐estimation of VBGPs from 69 published length‐at‐age data with available original VBGP estimates derived from linear methods (i.e. Ford‐Walford, von Bertalanffy and Gulland‐Holt plots); in this case, fitting was possible for 50 sets. Overall VBGP estimation was not possible for 43 and 19 cases for the first and second sets, respectively. This was because either (a) <4 mean length‐at‐age data were available, or (b) fitting was not possible because of an exponential or a very slow linear increase of length with age, or (c) estimates were unrealistic (i.e. L_max/L_∞ < 0.7) mainly because of unrealistic length‐at‐ages and/or insufficient sampling of older individuals. These estimations and re‐estimations enrich the available data on growth parameters of Mediterranean fishes, both in terms of quantity and quality of information.     

Acclimation conditions modify physiological response of the diatom Thalassiosira pseudonana to elevated CO2 concentrations in a nitrate‐limited chemostat

Diatoms are responsible for a large proportion of global carbon fixation, with the possibility that they may fix more carbon under future levels of high CO₂. To determine how increased CO₂ concentrations impact the physiology of the diatom Thalassiosira pseudonana Hasle et Heimdal, nitrate‐limited chemostats were used to acclimate cells to a recent past (333 ± 6 μatm) and two projected future concentrations (476 ± 18 μatm, 816 ± 35 μatm) of CO₂. Samples were harvested under steady‐state growth conditions after either an abrupt (15–16 generations) or a longer acclimation process (33–57 generations) to increased CO₂ concentrations. The use of un‐bubbled chemostat cultures allowed us to calculate the uptake ratio of dissolved inorganic carbon relative to dissolved inorganic nitrogen (DIC:DIN), which was strongly correlated with fCO₂ in the shorter acclimations but not in the longer acclimations. Both CO₂ treatment and acclimation time significantly affected the DIC:DIN uptake ratio. Chlorophyll a per cell decreased under elevated CO₂ and the rates of photosynthesis and respiration decreased significantly under higher levels of CO₂. These results suggest that T. pseudonana shifts carbon and energy fluxes in response to high CO₂ and that acclimation time has a strong effect on the physiological response.     

Reproductive traits of shovelnose sturgeon Scaphirhynchus platorynchus (Rafinesque, 1820) in the lower Platte River,Nebraska

We assessed reproductive status, fecundity, egg size, and spawning dynamics of shovelnose sturgeon Scaphirhynchus platorynchus in the lower Platte River. Shovelnose sturgeon were captured throughout each year during 2011 and 2012 using a multi‐gear approach designed to collect a variety of fish of varying sizes and ages. Fish were collected monthly for a laboratory assessment of reproductive condition. Female shovelnose sturgeon reached fork length at 50% maturity (FL₅₀) at 547 mm and at a minimum length of 449 mm. The average female spawning cycle was 3–5 years. Mean egg count for adult females was 16 098 ± 1103 (SE), and mean egg size was 2.401 ± 0.051 (SE) mm. Total fecundity was positively correlated with length (r² = 0.728; P < 0.001), mass (r² = 0.896; P < 0.001), and age (r² = 0.396; P = 0.029). However, fish size and age did not correlate to egg size (P > 0.05). Male shovelnose sturgeon reached FL₅₀ at 579 mm and at a minimum length of 453 mm. The average male spawning cycle was 1–2 years. Reproductively viable male and female sturgeon occurred during the spring (March–May) and autumn (September–October) in both years, indicating spring and potential autumn spawning events. Shovelnose sturgeon in the lower Platte River are maturing at a shorter length and younger age compared to populations elsewhere. Although it is unknown if the change is plastic or evolutionary, unfavorable environmental conditions or over‐harvest may lead to hastened declines compared to other systems.     

Changes in smolt traits of Atlantic salmon (Salmo salar Linnaeus, 1758) and linkages to parr density and water temperature

Smolt traits (length, age) and timing of smolt migration of wild Atlantic salmon, Salmo salar L., were investigated in the Simojoki River, northern Baltic Sea. The aim was to determine whether they responded to changes in parr length, parr density and temperature from 2000 to 2014. Annual electrofishing surveys and smolt numbers determined parr densities by springtime trapping in the river mouth. During the smolt trapping period captured parr and smolts were aged from scales. Water temperature was measured daily. Mean length decreased from 137 mm (TL) to 129 mm among 2‐year‐old smolts, and from 150 mm to 139 mm among 3‐year‐olds. Median date of the smolt migration was 10 days earlier, from early June to late May during the study period, linked to the rise in air temperature in May at the nearby Kemi‐Tornio airport. However, the median day temperature and the mean daily water temperatures during the second (Q₂) and third (Q₃) migration quartiles did not change. This implied that migration began when a suitable water temperature was reached, independent of the date.     

Chemical Composition,Antioxidant Properties, α‐Glucosidase Inhibitory,and Antimicrobial Activity of Essential Oils from Acacia mollissima and Acacia cyclops Cultivated in Tunisia

The genus Acacia is quite large and can be found in the warm subarid and arid parts, but little is known about its chemistry, especially the volatile parts. The volatile oils from fresh flowers of A. mollissima and A. cyclops (growing in Tunisia) obtained by hydrodistillation were analyzed by GC then GC/MS. Eighteen (94.7% of the total oil composition) and 23 (97.4%) compounds were identified in these oils, respectively. (E,E)‐α‐Farnesene (51.5%) and (E)‐cinnamyl alcohol (10.7%) constituted the major compounds of the flower oil of A. mollissima, while nonadecane (29.6%) and caryophyllene oxide (15.9%) were the main constituents of the essential oil of A. cyclops. Antioxidant activity of the isolated oils was studied by varied assays, i.e., 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) and 2,2‐azinobis 3‐ethylbenzothiazoline‐6‐sulfonic acid (ABTS); the isolated oils showed lowest IC₅₀ (4 – 39 μg/ml) indicating their high antioxidant activity. The α‐glucosidase inhibitor activity was also evaluated and Acacia oils were found to be able to strongly inhibit this enzyme with IC₅₀ values (81 – 89 μg/ml) very close to that of acarbose which was used as positive control. Furthermore, they were tested against five Gram‐positive and Gram‐negative bacteria and one Candida species. Essential oil of A. mollissima was found to be more active than that of A. cyclops, especially against Pseudomonas aeruginosa (MIC = 0.31 mg/ml and MBC = 0.62 mg/ml).     

Effect of astaxanthin and aluminum chloride on erythrocyte G6PD and 6PGD enzyme activities in vivo and on erythrocyte G6PD in vitro in rats

In this study, we investigated the effect of astaxanthin (Ast) and aluminum (Al) on the erythrocyte glucose‐6‐phosphate dehydrogenase (G6PD) and 6‐phosphogluconate dehydrogenase (6PGD) enzymes activities in vivo and on G6PD enzyme in vitro in rats. For in vitro studies, G6PD enzyme was purified from rat erythrocyte by using 2′,5′‐ADP‐Sepharose 4B affinity gel. The effects of Ast and Al³⁺ ion were investigated on the purified enzyme. It was determined that Ast increased the enzyme activity, whereas Al³⁺ inhibited the enzyme activity noncompetitively (IC₅₀ values; 0.679 mM, K_i values 1.32 mM). For in vivo studies, the rats were divided into the groups: control (Cont.), Al, Ast, and Al + Ast. The last three groups were compared with the control group. In Al group, a significant degree of inhibition was observed in the activity of G6PD and 6PGD enzymes when compared with the control group (P < 0.05), whereas there was an increase in the activities of G6PD and 6PGD enzymes in Ast and Al + Ast groups (P < 0.05).     

Combined effects of elevated CO2 concentration and Wolbachia on Hylyphantes graminicola (Araneae: Linyphiidae)

The increasing concentration of carbon dioxide in atmosphere is not only a major cause of global warming, but it also adversely affects the ecological diversity of invertebrates. This study was conducted to evaluate the effect of elevated CO₂ concentration (ambient, 400 ppm and high, 800 ppm) and Wolbachia (Wolbachia‐infected, W⁺ and Wolbachia‐uninfected, W^?) on Hylyphantes graminicola. The total survival rate, developmental duration, carapace width and length, body weight, sex ratio, net reproductive rate, nutrition content, and enzyme activity in H. graminicola were examined under four treatments: W^? 400 ppm, W^? 800 ppm, W⁺ 400 ppm, and W⁺ 800 ppm. Results showed that Wolbachia‐infected spiders had significantly decreased the total developmental duration. Different instars showed variations up to some extent, but no obvious effect was found under elevated CO₂ concentration. Total survival rate, sex ratio, and net reproductive rate were not affected by elevated CO₂ concentration or Wolbachia infection. The carapace width of Wolbachia‐uninfected spiders decreased significantly under elevated CO₂ concentration, while the width, length and weight were not significantly affected in Wolbachia‐infected spiders reared at ambient CO₂ concentration. The levels of protein, specific activities of peroxidase, and amylase were significantly increased under elevated CO₂ concentration or Wolbachia‐infected spiders, while the total amino content was only increased in Wolbachia‐infected spiders. Thus, our current finding suggested that elevated CO₂ concentration and Wolbachia enhance nutrient contents and enzyme activity of H. graminicola and decrease development duration hence explore the interactive effects of factors which were responsible for reproduction regulation, but it also gives a theoretical direction for spider's protection in such a dynamic environment. Increased activities of enzymes and nutrients caused by Wolbachia infection aids for better survival of H. graminicola under stress.     

Population dynamics of brown trout (Salmo trutta) in Spruce Creek Pennsylvania: A quarter‐century perspective

相似文献   

New Furanone Derivatives and Alkaloids from the Co‐Culture of Marine‐Derived Fungi Aspergillus sclerotiorum and Penicillium citrinum

Six new compounds including two furanone derivatives sclerotiorumins A and B ( 1 and 2 ), one novel oxadiazin derivative sclerotiorumin C ( 3 ), one pyrrole derivative 1‐(4‐benzyl‐1H‐pyrrol‐3‐yl)ethanone ( 4 ), and two complexes of neoaspergillic acid aluminiumneohydroxyaspergillin ( 5 ) and ferrineohydroxyaspergillin ( 6 ) were isolated from the co‐culture of marine‐derived fungi Aspergillus sclerotiorum and Penicillium citrinum. Compound 3 was the first natural 1,2,4‐oxadiazin‐6‐one. Compound 5 showed significant and selective cytotoxicity against human histiocytic lymphoma U937 cell line (IC₅₀ = 4.2 μm ) and strong toxicity towards brine shrimp (LC₅₀ = 6.1 μm ), and oppositely increased the growth and biofilm formation of Staphylococcus aureus.     

Telomere length and aging‐related outcomes in humans: A Mendelian randomization study in 261,000 older participants

Inherited genetic variation influencing leukocyte telomere length provides a natural experiment for testing associations with health outcomes, more robust to confounding and reverse causation than observational studies. We tested associations between genetically determined telomere length and aging‐related health outcomes in a large European ancestry older cohort. Data were from n = 379,758 UK Biobank participants aged 40–70, followed up for mean of 7.5 years (n = 261,837 participants aged 60 and older by end of follow‐up). Thirteen variants strongly associated with longer telomere length in peripheral white blood cells were analyzed using Mendelian randomization methods with Egger plots to assess pleiotropy. Variants in TERC, TERT, NAF1, OBFC1, and RTEL1 were included, and estimates were per 250 base pairs increase in telomere length, approximately equivalent to the average change over a decade in the general white population. We highlighted associations with false discovery rate‐adjusted p‐values smaller than .05. Genetically determined longer telomere length was associated with lowered risk of coronary heart disease (CHD; OR = 0.95, 95% CI: 0.92–0.98) but raised risk of cancer (OR = 1.11, 95% CI: 1.06–1.16). Little evidence for associations were found with parental lifespan, centenarian status of parents, cognitive function, grip strength, sarcopenia, or falls. The results for those aged 60 and older were similar in younger or all participants. Genetically determined telomere length was associated with increased risk of cancer and reduced risk of CHD but little change in other age‐related health outcomes. Telomere lengthening may offer little gain in later‐life health status and face increasing cancer risks.     

Gross primary production responses to warming,elevated CO2, and irrigation: quantifying the drivers of ecosystem physiology in a semiarid grassland

Determining whether the terrestrial biosphere will be a source or sink of carbon (C) under a future climate of elevated CO₂ (eCO₂) and warming requires accurate quantification of gross primary production (GPP), the largest flux of C in the global C cycle. We evaluated 6 years (2007–2012) of flux‐derived GPP data from the Prairie Heating and CO₂ Enrichment (PHACE) experiment, situated in a grassland in Wyoming, USA. The GPP data were used to calibrate a light response model whose basic formulation has been successfully used in a variety of ecosystems. The model was extended by modeling maximum photosynthetic rate (A_max) and light‐use efficiency (Q) as functions of soil water, air temperature, vapor pressure deficit, vegetation greenness, and nitrogen at current and antecedent (past) timescales. The model fits the observed GPP well (R² = 0.79), which was confirmed by other model performance checks that compared different variants of the model (e.g. with and without antecedent effects). Stimulation of cumulative 6‐year GPP by warming (29%, P = 0.02) and eCO₂ (26%, P = 0.07) was primarily driven by enhanced C uptake during spring (129%, P = 0.001) and fall (124%, P = 0.001), respectively, which was consistent across years. Antecedent air temperature (Tair_ant) and vapor pressure deficit (VPD_ant) effects on A_max (over the past 3–4 days and 1–3 days, respectively) were the most significant predictors of temporal variability in GPP among most treatments. The importance of VPD_ant suggests that atmospheric drought is important for predicting GPP under current and future climate; we highlight the need for experimental studies to identify the mechanisms underlying such antecedent effects. Finally, posterior estimates of cumulative GPP under control and eCO₂ treatments were tested as a benchmark against 12 terrestrial biosphere models (TBMs). The narrow uncertainties of these data‐driven GPP estimates suggest that they could be useful semi‐independent data streams for validating TBMs.     

Sex pheromone of the cloaked pug moth,Eupithecia abietaria (Lepidoptera: Geometridae), a pest of spruce cones

The sex pheromone of the cloaked pug moth, Eupithecia abietaria Götze, an important cone‐feeding pest in spruce seed orchards in Europe, was investigated. Chemical and electrophysiological analyses of pheromone gland extracts of female moths and analogous analyses of synthetic hydrocarbons and epoxides of chain length C₁₉ and C₂₁ revealed (3Z,6Z,9Z)‐3,6,9‐nonadecatriene (3Z,6Z,9Z‐19:H) and 3Z,6Z‐cis‐9,10‐epoxynonadecadiene (3Z,6Z‐cis‐9,10‐epoxy‐19:H) as candidate pheromone components, which were found in a gland extract in a ratio of 95 : 5. In field trapping experiments, conspecific males were only attracted to a combination of 3Z,6Z,9Z‐19:H and the (9S,10R)‐enantiomer of 3Z,6Z‐cis‐9,10‐epoxy‐19:H. The (9R,10S)‐enantiomer was not attractive, which is in agreement with studies on other Eupithecia species, for which males have only been attracted by the (9S,10R)‐enantiomer of epoxides. Subsequent experiments showed that E. abietaria males were attracted to a wide range of ratios of the two active compounds and that trap catches increased with increasing dose of the binary blend. A two‐component bait containing 300 μg 3Z,6Z,9Z‐19:H and 33 μg of the (9S,10R)‐enantiomer of 3Z,6Z‐cis‐9,10‐epoxy‐19:H was efficient for monitoring E. abietaria in spruce seed orchards in southern Sweden, where this species has probably been overlooked as an important pest in the past. With sex pheromones recently identified for two other moths that are major pests on spruce cones, the spruce seed moth, Cydia strobilella L., and the spruce coneworm, Dioryctria abietella Denis & Schiffermüller, pheromone‐based monitoring can now be achieved for the whole guild of cone‐feeding moths in European spruce seed orchards.     

Species diversity of the genus Osmundea (Ceramiales,Rhodophyta) in the Macaronesian region

Species diversity within the genus Osmundea in the Macaronesian region was explored by conducting a comprehensive sampling in the Azores, the Canary, and the Madeira archipelagos. Toward identification, all specimens were first observed alive to verify the absence of corps en cerise, a diagnostic character for the genus and morphometric data were measured (thallus length and width, first‐order branches length and width, branchlets length and width, cortical cell length and width in surface view, cortical cell length and width in transverse section). Specimens were sequenced for COI‐5P (39 specimens) and three species delimitation methods (Generalized Mixed Yule Coalescent, Automatic Barcode Gap Discovery method, and Poisson Tree Processes) were used to assess the threshold between infra‐ and interspecific relationships. Subsequently, one or several sequences of plastid‐encoded large subunit of RuBisCO (21 specimens) per delimited species were generated to assess the phylogenetic relationships among Macaronesian Osmundea. Moreover, for each delineated species, vegetative and reproductive anatomy was thoroughly documented and, when possible, specimens were either assigned to existing taxa or described as novel species. This integrative approach has provided data for (i) the presence of O. oederi, O. pinnatifida, and O. truncata in Macaronesia; (ii) the proposal of two novel species, O. prudhommevanreinei sp. nov. and O. silvae sp. nov.; and (iii) evidence of an additional species referred as “Osmundea sp.1,” which is a sister taxon of O. hybrida.     

Age,growth and reproduction of the white seabream Diplodus sargus sargus (Linneaus, 1758) off the eastern coast of Algeria

The objective of this study was to determine the basic population‐specific parameters necessary for fish stock assessment in the area and to compare these with data from other Mediterranean regions. White seabream Diplodus sargus sargus (n = 449) were caught along the Algerian coast between December 2005 and December 2006. Total length ranged from 12.2 to 34.6 cm, representing age classes between 0 and 10 years. Validity of the otolith readings for estimating age and growth was supported using the back‐calculation method. The von Bertalanffy growth parameters for all fish were calculated as: TL = 36.3 cm, k = 0.154 year⁻¹, t₀ = −0.488 year. The growth performance index (φ) showed a relatively slow growth of the local population. The length‐weight relationship showed an isometric growth (b = 2.98; r = 0.98). Subspecies Diplodus sargus sargus was characterized as being a proterandric hermaphrodite. Overall ratio of males to females was 1 : 1.4, with males predominant in the smaller size intervals and females in the larger ones. The reproductive season extended from January to May, with a March–April peak in spawning activity. Fifty per cent maturity of the tested cohort was reached at a total length of 20.2 cm for males and 20.0 cm for females.     

An oxygen isotope chronometer for cellulose deposition: the successive leaves formed by tillers of a C4 perennial grass

Multiannual time series of (palaeo)hydrological information can be reconstructed from the oxygen isotope composition of cellulose (δ¹⁸O_Cel) in biological archives, for example, tree rings, but our ability to temporally resolve information at subannual scale is limited. We capitalized on the short and predictable leaf appearance interval (2.4 d) of a perennial C₄ grass (Cleistogenes squarrosa), to assess its potential for providing highly time‐resolved δ¹⁸O_Cel records of vapour pressure deficit (VPD). Plants grown at low (0.63 kPa) or high (1.58 kPa) VPD were swapped between VPD environments and exposed to the new environment for 7 d with simultaneous ¹³CO₂ labelling. Then, leaves were sampled by age/position along individual tillers. Five leaves at different developmental stages were growing simultaneously. The period of most‐active leaf elongation, from 10 to 90% of final length, lasted 6.6 d, and ~80% of all carbon and oxygen incorporation in whole‐leaf cellulose occurred within 7 d. Cellulose deposition stopped at (or shortly after) full leaf expansion. The direction of change, low‐to‐high or high‐to‐low VPD, had no differential effect on new oxygen and carbon incorporation in cellulose. Successive leaves produced by tillers of C. squarrosa provide a δ¹⁸O_Cel record useful for reconstructions of short‐term hydrological dynamics.     

Sublethal effect of beta‐cypermethrin on development and fertility of the Asian multicoloured ladybird beetle Harmonia axyridis

The Asian multicoloured ladybird beetle, Harmonia axyridis, is utilized as a major natural enemy of aphids in the field, greenhouses and orchards. However, it has been looked as invasive predator distributing in worldwide. To refine integrated pest management (IPM) against aphids, it is important to evaluate the effects of insecticides on physiology and behaviour of the high adapted predators. Beta‐cypermethrin, a broad‐spectrum insecticide, not only kills aphids at lethal concentrations but also affects natural enemy of aphids. In our study, the age‐stage, two‐sex life table was used to evaluating sublethal effects of beta‐cypermethrin on the predatory ladybird beetle H. axyridis. In the parent generation, the pre‐oviposition period of H. axyridis was significantly shortened (8.93 days) after exposure to LC₅ beta‐cypermethrin (5% lethal concentration) as compared with control (10.06 days). However, the oviposition period was significantly longer (46.17 days instead of 43.90 days), and fecundity (eggs per female) was significantly increased by 49.64% when compared with control. In the F₁ generation, the length of the juvenile stage was not affected, but the oviposition period increased significantly (38.19 days compared to 31.39 days in the control). This positive effect was translated to the fecundity that increased significantly by 62.27% as compared with control. According to the life‐table analysis, the intrinsic rate of increase (r_m) was significantly higher in treatment (0.140 per day) than that in the control (0.123 per day). In addition, the net reproductive rate (R₀) increased significantly by 91.53%. These results would be useful in assessing the overall effects of beta‐cypermethrin on H. axyridis and even for discussing the ecological mechanism of the unexpected extension of H. axyridis during IPM programme.