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1.
Kelp forests dominate temperate and polar rocky coastlines and represent critical marine habitats because they support elevated rates of primary and secondary production and high biodiversity. A major threat to the stability of these ecosystems is the proliferation of non-native species, such as the Japanese kelp Undaria pinnatifida (‘Wakame’), which has recently colonised natural habitats in the UK. We quantified the abundance and biomass of U. pinnatifida on a natural rocky reef habitat over 10 months to make comparisons with three native canopy-forming brown algae (Laminaria ochroleuca, Saccharina latissima, and Saccorhiza polyschides). We also examined the biogenic habitat structure provided by, and epibiotic assemblages associated with, U. pinnatifida in comparison to native macroalgae. Surveys conducted within the Plymouth Sound Special Area of Conservation indicated that U. pinnatifida is now a dominant and conspicuous member of kelp-dominated communities on natural substrata. Crucially, U. pinnatifida supported a structurally dissimilar and less diverse epibiotic assemblage than the native perennial kelp species. However, U. pinnatifida-associated assemblages were similar to those associated with Saccorhiza polyschides, which has a similar life history and growth strategy. Our results suggest that a shift towards U. pinnatifida dominated reefs could result in impoverished epibiotic assemblages and lower local biodiversity, although this could be offset, to some extent, by the climate-driven proliferation of L. ochroleuca at the poleward range edge, which provides complex biogenic habitat and harbours relatively high biodiversity. Clearly, greater understanding of the long-term dynamics and competitive interactions between these habitat-forming species is needed to accurately predict future biodiversity patterns.  相似文献   

2.
This study uses survey and tagging data and cluster analysis to interpret dynamics of ontogenetic movements and seasonal migrations in snow crab (Chionoecetes opilio) along the Newfoundland and Labrador (NL) continental shelves. Most historic literature from Atlantic Canada suggests snow crab undertake small-scale ontogenetic movements while observations of seasonal migrations had been near-exclusive to the inshore. Information on both types of movement in the most spatially expansive offshore region of Atlantic Canada, in NL, was lacking. We find that that both ontogenetic movements and seasonal migrations occur in most areas of the NL offshore, with ontogenetic movements generally down-slope and seasonal migrations generally up-slope. Conservative estimates of average ontogenetic movements range from 54 to 72 km for both males and females in the largest offshore regions while seasonal migrations are slightly smaller, with two independent studies on the Grand Bank producing average estimates of 43–46 km and an adjacent tagging study in a smaller inshore bay producing an average estimate of 25 km. Ontogenetic movements appear associated with a search for warm water while seasonal migrations appear associated with both mating and molting in shallow water. On average, morphometrically mature crab of both sexes move less vertical distance than morphometrically immature crab during seasonal migrations. We investigate plausible explanations for ontogenetic movements and spring migrations and detail how bottom temperature affects crab distribution and life history dynamics. We further document movement patterns from tagging studies on the burgeoning snow crab stock in the Eastern Barents Sea toward establishing consistencies in species behaviour on the global scale. Finally, we discuss explanations for historical disparities in the literature between scales of movement for snow crab in the Eastern Bering Sea of Alaska versus Atlantic Canada and advance perspectives on life history theory for the species.  相似文献   

3.
The early life stages of Boreogadus saida and Arctogadus glacialis are morphologically similar, making it difficult to assess differences in their ecological niche. The present study documented for the first time the early life stage ecology of A. glacialis, compared it to that of B. saida, and identified the factors separating the niches of the two sympatric species. The 10,565 larval gadids collected in the Beaufort Sea from April to August of 2004 and 2008 were identified to species either directly by genetics and/or otolith nucleus size, or indirectly with a redistribution procedure. Between 8.0 and 8.7 % of all gadids were assigned to A. glacialis. Larvae of A. glacialis were longer at hatch and experienced lower mortality rates than those of B. saida. The two species shared similar spatiotemporal and vertical distributions, hatching season, and growth rate. Under the ice, feeding incidence of B. saida was low (14 %) relative to A. glacialis (88 %). At lengths <15 mm, both species specialized on different prey. The diet of fish >15 mm overlapped (Schoener’s index = 0.7), with Calanus glacialis and C. hyperboreus providing >50 % of the carbon intake of both species. The higher mortality in B. saida may be explained by the smaller size at age from hatching to metamorphosis and a lower under-ice feeding incidence. The early larval stage appears to be the key period of niche divergence between the two species.  相似文献   

4.
Carrageenan yield, physicochemical properties, and antiviral activity of the carrageenan from Solieria chordalis (Rhodophyceae, Solieriaceae) harvested at the Brittany coast (France) were investigated. S. chordalis carrageenan was extracted by conventional and the microwave-assisted extraction (MAE) methods. The effect of different parameters during MAE extraction such as alkali concentration (0, 0.5 and 1% KOH), extraction time (10, 20, and 25 min) and temperature (90 and 105 °C) were evaluated. Native carrageenan extracted by MAE had the highest yield (29.3%) after 10 min at 90 °C. After alkali treatment, carrageenan yield ranged from 10.7 to 18.4%. No significant differences in the carrageenan yield were observed between MAE and conventional method under alkaline conditions. Chemical analysis and FTIR spectra revealed the presence of a predominant iota-carrageenan. Evaluation of the antiviral activity of S. chordalis carrageenan against HSV-1 (Herpes simplex virus type 1) showed a EC50 of the iota-carrageenans fractions in the range of 3.2 to 54.4 μg mL?1 (MOI 0.01 ID50 mL?1) without cytotoxicity in that range of concentrations.  相似文献   

5.
Breeding and rearing the offspring through successive generations are mandatory in order to study evolutionary responses to anthropogenic impact in marine organisms. However, fish offer a limited number of marine model species that allow performing multigenerational experimental approaches. Here, we propose a novel breeding and rearing experimental model based on the marbled goby Pomatoschistus marmoratus (Risso 1810) which is representative of small (up to 65 mm total length), benthic species with a short life cycle. We devised a ‘full-sib/half-sib’ breeding design, and the resulting offspring were reared in captivity using a complex feeding protocol and a creative design of the tanks. Three families survived up to 160 days post-hatching (dph); one was reared at 24 °C and two at 18 °C. The families reared at 18 °C reached sexual maturity and spawned. The size range at sexual maturity of individuals reared in captivity was consistent with the one observed in nature. The possibility to complete the entire life cycle, from hatching to sexual maturity and spawning in P. marmoratus offers great perspectives for experimental evolution and quantitative genetics studies aimed at understanding the role of evolutionary processes in response to global changes.  相似文献   

6.
The introduction of alien species is a global phenomenon that alters ecosystems structure and functioning. Invasive species are responsible for substantial economic and ecological losses. Invasive species impact resource availability, outcompeting and even causing extinction of native species. The management of invasive species requires knowledge on the ecology, physiology and population dynamics of these species. In a world where environmental conditions are changing fast due to global climate change and other anthropogenic stressors, a more comprehensive knowledge of the life history and physiology of these species is urgently needed. The DEB theory is unique in capturing the metabolic processes of an organism through its entire life cycle, and thus, is a useful tool to model lifetime feeding, growth, reproduction, and responses to changes in biotic and abiotic conditions. In this work, we estimated the parameters of a DEB model for Asterias amurensis. This starfish was introduced in Tasmania and is considered the most serious marine pest in Australia where it has caused local extinctions of several species. Asterias amurensis is a major predator and is a keystone species exerting top-down control of its prey populations by achieving large densities. We determined the influence of biotic and abiotic factors on the performance of A. amurensis. The DEB model presented here includes energy handling rules to describe gonad and pyloric caeca cycles. Model parameters were used to explore population dynamics of populations of A. amurensis in Australia. The DEB model allowed us to characterise the ecophysiology of A. amurensis, providing new insights on the role of food availability and temperature on its life cycle and reproduction strategy. Moreover it is a powerful tool for risk management of already established invasive populations and of regions with a high invasion risk.  相似文献   

7.
The study of how climatic niches change over evolutionary time has recently attracted the interest of many researchers. Different methodologies have been employed principally to analyze the temporal dynamics of the niche and specially to test for the presence of phylogenetic niche conservatism. Menonvillea, a genus of Brassicaceae including 24 species, is distributed primarily along the Andes of Argentina and Chile, with some taxa growing in southern Patagonia and others in the Atacama Desert and the Chilean Matorral. The genus is highly diversified morphologically but also presents a remarkably wide ecological range, growing from the high Andean elevations, to the dry coastal deserts in Chile, or the Patagonia Steppe in Argentina. In this study, we used molecular phylogenies together with climatic data to study climatic niche evolution in the genus. The results show that the main climatic niche shifts in Menonvillea occurred between the sections Cuneata-Scapigera and sect. Menonvillea throughout the Mid-Late Miocene, and associated with the two main geographical distribution centers of the genus: the highlands of the central-southern Andes and the Atacama Desert-Chilean Matorral, respectively. Climatic niches in these lineages were mainly differentiated by the aridity and potential evapotranspiration, the minimum temperatures of the coldest month, and the temperature annual range and seasonality. Niche evolution in Menonvillea deviated from a Brownian motion process, with most of the climatic dimension best-fitting to an Ornstein-Uhlenbeck model of multiple adaptive peaks. Our results also indicated that higher aridity levels and lower annual temperature ranges were associated with the evolution of the annual habit, as exemplified by the distribution of sect. Menonvillea. Finally, the results suggested that climatic niche evolution in Menonvillea exhibited some degree of phylogenetic niche conservatism, fundamentally within the two main lineages (sect. Menonvillea and sects. Cuneata-Scapigera).  相似文献   

8.
The ants L. semenovi has been found to belong to species with endogenous-heterodynamic seasonal life cycles with the obligate diapause induced predominantly by factors internal for a colony, whereas external ecological factors (photoperiods and temperature) produce merely modifying effects by accelerating or delaying the diapause onset. The photoperiodic and temperature regulation of diapause induction in larvae and queens is shown. Under effect of short days and low temperature the periods of larval pupation and queen oviposition in a colony are shortened markedly, i.e., the diapause of larvae and queens occurs earlier. The daily rhythms of temperature 15/25°C and particularly 20/30°C as compared with constant temperatures 20 and 25°C that correspond to the mean circadian temperatures of the thermorhythm, inhibit manifestations of the short day effects by stimulating the non-diapause development and increasing duration of the seasonal development cycle of ant colonies. The L. semenovi photoperiodic reaction is quantitative, as development and pupation of larvae and egg-laying of queens cease sooner or later under both the short and the long days, but in the latter case significantly later. Thus L. semenovi is one more example among very rare ant species that are revealed to have the photoperiodic regulation of the colony development seasonal cycle.  相似文献   

9.
The gastric evacuation rate (GER) of the delicate loach Niwaella delicata was estimated experimentally under four temperature conditions (10, 15, 20, and 25 °C). The GER was relatively high under the ≥20 °C condition and was nearly zero under the ≤15 °C condition. The relationship between GER and water temperature was estimated following the method of Elliot (1972) as follows: GER = exp (0.436 × temperature ? 10.59). This physical characteristic might affect the seasonal activity of this species.  相似文献   

10.
Off-channel temporary pools on riverbanks have characteristic seasonal wet–dry cycles resulting from direct inflow of river water or hyporheic flow seepage. This study addressed two questions regarding the role of temporary pools in supporting diversity of riparian vegetation in a regulated river in Japan: (1) do temporary pools maintain high native riparian plant species diversity? And, (2) how do physical environmental factors affect the pattern of plant species distribution? The study was conducted on a 1-km section of the Hayade River alluvial fan in Niigata Prefecture, central Japan. Two to five transect belts consisting of 20 contiguous plots (1 m × 1 m) were laid out in two off-channel temporary pools and six other sites classified by physiognomy. Vascular plant presence, relative elevation, and substratum type were recorded in all plots. Species richness, Simpson’s reciprocal index (1/D), and Shannon–Wiener function (H′) were calculated by life form to estimate plant species diversity. Two conclusions could be drawn from the results. First, the temporary pools maintained high native riparian plant species diversity in this regulated river floodplain. Second, several environmental factors (seasonal wet–dry cycle, low elevation, complex micro-topography, and fine substrata) created spatial and seasonal heterogeneity of moisture conditions in the temporary pools, supporting plant species diversity. For sustainable maintenance of riparian plant species diversity, progressive river-management should restore original riverine dynamics to generate a shifting mosaic of diverse geomorphology.  相似文献   

11.
Pomacea canaliculata is a South American freshwater snail considered as one of the world’s worst invasive alien species. A temperature of around 25 °C has usually been considered to be optimal for rearing P. canaliculata. Nevertheless, snails have not been reared under a wide range of temperatures to reveal the optimum for performance in terms of population increase. We investigated the effect of temperature on growth, survival and reproduction, estimating demographic parameters for P. canaliculata in the wide range of temperatures at which these snails are active (15–35 °C). No reproductive activity was evidenced for the snails reared at 15 °C, probably explained by the small sizes attained at this temperature. Temperatures above 25 °C did not promote a significant acceleration in growth so higher temperatures will not result in a reduction in time to reach maturity. In fact, snails from 25 and 30 °C began reproduction at the same age. We report here for the first time a detrimental effect of high temperatures that provoked a significant decrease in the contribution of snails to the next generation: the viability of eggs from the snails reared at 30 °C was very low and the snails exposed to a constant water temperature of 35 °C were unable to produce eggs. Our findings reveal a new environmental constraint that could be a determinant of the range limits of this species in invaded regions, especially during the coming decades, anticipating the scenario predicted from global warming.  相似文献   

12.
The thermal sensitivities of organisms regulate a wide range of ecological interactions, including host–parasite dynamics. The effect of temperature on disease ecology can be remarkably complex in disease systems where the hosts are ectothermic and where thermal conditions constrain pathogen reproductive rates. Amphibian chytridiomycosis, caused by the pathogen Batrachochytrium dendrobatidis (Bd), is a lethal fungal disease that is influenced by temperature. However, recent temperature studies have produced contradictory findings, suggesting that our current understanding of thermal effects on Bd may be incomplete. We investigated how temperature affects three different Bd strains to evaluate diversity in thermal responses. We quantified growth across the entire thermal range of Bd, and beyond the known thermal limits (T max and T min). Our results show that all Bd strains remained viable and grew following 24 h freeze (?12 °C) and heat shock (28 °C) treatments. Additionally, we found that two Bd strains had higher logistic growth rates (r) and carrying capacities (K) at the upper and lower extremities of the temperature range, and especially in low temperature conditions (2–3 °C). In contrast, a third strain exhibited relatively lower growth rates and carrying capacities at these same thermal extremes. Overall, our results suggest that there is considerable variation among Bd strains in thermal tolerance, and they establish a new thermal sensitivity profile for Bd. More generally, our findings point toward important questions concerning the mechanisms that dictate fungal thermal tolerances and temperature-dependent pathogenesis in other fungal disease systems.  相似文献   

13.
Understanding fig consumption patterns is important because figs are regarded as a keystone resource for many frugivorous species in the tropics. While much work on fig consumption has been conducted in tropical regions, temperate forests are particularly interesting for study owing to pronounced seasonal variations in temperature and community-level fruiting phenology. We studied frugivore consumption of Ficus superba (Miq.) Miq. var. japonica Miq syconia in a warm-temperate forest in Yakushima, southern Japan. We conducted 141 4-h focal observations of fruiting F. superba trees over 12 months. We aimed to assess the relative quantitative contribution of each species of frugivore to F. superba consumption over a year as well as factors affecting seasonal variation in consumption. Japanese macaques were by far the most important F. superba syconia consumer (87.6 %), followed by brown-eared bulbuls (5.0 %), and varied tits (4.2 %). Japanese macaques increased their F. superba consumption when the temperature was high and fruit availability (F. superba and other species) was low. Macaques seemed to avoid searching for rare F. superba trees during winter and used F. superba syconia as a fallback food during fruit scarcity. Birds showed the opposite pattern: they increased F. superba syconia consumption when the temperature was low and fruit availability was high. This was probably because birds eat insects as their main food in the summer and switch to fruit as autumn turns to winter.  相似文献   

14.
Ontogenetic niche theory predicts that individuals may undergo one or more changes in habitat or diet throughout their lifetime to maintain optimal growth rates, or to optimize trade-offs between mortality risk and growth. We combine skeletochronological and stable nitrogen isotope (δ15N) analyses of sea turtle humeri (n = 61) to characterize the growth dynamics of juvenile loggerhead sea turtles (Caretta caretta) during an oceanic-to-neritic ontogenetic shift. The primary objective of this study was to determine how ontogenetic niche theory extends to sea turtles, and to individuals with different patterns of resource use (discrete shifters, n = 23; facultative shifters n = 14; non-shifters, n = 24). Mean growth rates peaked at the start of the ontogenetic shift (based on change in δ15N values), but returned to pre-shift levels within 2 years. Turtles generally only experienced 1 year of relatively high growth, but the timing of peak growth relative to the start of an ontogenetic shift varied among individuals (before, n = 14; during, n = 12; after, n = 8). Furthermore, no reduction in growth preceded the transition, as is predicted by ontogenetic niche theory. Annual growth rates were similar between non-transitioning turtles resident in oceanic and neritic habitats and turtles displaying alternative patterns of resource use. These results suggest that factors other than maximization of size-specific growth may more strongly influence the timing of ontogenetic shifts in loggerhead sea turtles, and that alternative patterns of resource use may have limited influence on somatic growth and age at maturation in this species.  相似文献   

15.
The distribution of genetic diversity among natural populations is significantly shaped by geographical and environmental heterogeneity. The key objectives of this study were to outline the population genetic structure and to investigate the effects of historical and current factors in shaping the population structure of an endemic tropical tree, Hagenia abyssinica. We used 11 polymorphic microsatellites to estimate genetic variability and evaluate gene flow among natural populations of H. abyssinica. Further, we employed ecological niche modeling approaches, to analyze the demographic history and map potential distributions of H. abyssinica during the Last Glacial Maximum and the present. Significant levels of genetic diversity (H O = 0.477, H E = 0.439) were observed among the sampled locations. High coefficient of genetic differentiation (F ST = 0.32) and considerable genetic variation within the sampled locations (68.01%) were detected. Our results indicated the existence of three genetic groups with limited gene exchange and revealed positive correlations (r = 0.425, P < 0.05) between genetic diversity and geo-graphic distance. The ecological niche modeling (ENM) results support the existence of three distribution zones during the Last Glacial Maximum (LGM), with high probability of occurrence (0.8–1.0), and indicated slight distribution disturbances during and after the LGM. The fundamental patterns of genetic diversity and population structuring of H. abyssinica result from a combination of both environmental and geographical factors, including long-term isolation by distance and characteristic life history of this species. Our ENM results identified three zones that could have served as glacial refugia for this species and lay a foundation for further studies, outlining demographic histories and population structures of Afromontane species.  相似文献   

16.
Phenology, the study of stages within the life cycles of plants and animals, has served as a proxy for weather and climate throughout human history, but has only recently become its own field of environmental science. Phenological constraints are particularly demanding in avian species because of the necessity of matching chick provisioning with high food abundance, while allocating time for migration. Within avian species, seabird phenology is of particular interest because many seabird species exhibit colonial breeding behaviour. Penguins, representing roughly 90 % of the biomass in the Southern Ocean, are well studied in the context of population dynamics, prey abundance, and phenology. Here I review the annual cycles of Pygoscelis penguins, a genus including gentoo (Pygoscelis papua), chinstrap (Pygoscelis antarctica), and Adélie (Pygoscelis adeliae) penguins, to better understand what is known about their phenology, what causes known changes, and how their phenology influences fitness. Major differences exist between species, particularly in relation to winter migration, incubation shifts, and the timing of breeding. Even with the numerous studies examining phenology in Pygoscelis penguins, large gaps in our understanding of plasticity in the annual cycle remain. In particular, certain phases are neglected because they are logistically difficult to record or have erroneously been ignored. In addition, temporally, large gaps exist in our understanding of phenology, where studies have not been updated in over 20 years at a particular field site. Because phenology does vary greatly between years, depending on the colony, when possible, researchers should strive to update phenological records by recording the dates of phases each year.  相似文献   

17.
Whether or not species track native climatic conditions during invasions (i.e., climate match hypothesis) is fundamental to understand and prevent potential impacts of invasive species. Recent empirical work suggests that climatic mismatches between native and invasive ranges are pervasive. Whether these differences are due to adaptation to new climatic spaces in the invasive range or due to partial filling of the potential climatic space are still subject to debate. Here, we analyze climatic niche dynamics associated with the invasion of the two most common invasive plants in Brazilian semi-arid areas, Prosopis juliflora and Prosopis pallida. These species have been simultaneously introduced in the region, which creates a unique opportunity to compare their niche dynamics during invasion. Given that P. juliflora have a much wider native range size, we expect these species would present different dispersal potentials, which might translate into different unfilling levels. Using an ordination method with kernel smoother and null models, we contrasted climate spaces occupied by each species in both native and invasive ranges. We further used ecological niche models (ENMs) to compare reciprocal predictions of potentially suitable areas. Against our expectation based on differences in native range sizes, climatic niches of P. juliflora and P. pallida overlapped greatly, both in their native and invasive ranges. Our results support niche conservatism during the invasion process. Climatic mismatches among native and invaded ranges were exclusively attributed to unfilling of native climates in the invasive range. Both species showed similar unfilling levels. Likewise, ENMs predicted regions not yet occupied in the invasive range, revealing a potential for further expansion. We discuss colonization time lag and founder effect as potential mechanisms that may have prevented these species to fully occupy their native niches in the invasive range.  相似文献   

18.
Adelphocoris triannulatus (Stål) (Heteroptera: Miridae) is a zoophytophagous bug that inhabits grasslands and crop fields, and is widely distributed in eastern Asia. In this study, the seasonal occurrence and environmental factors controlling the seasonal life cycle of this bug were investigated in a local population in southern Kyushu, Japan. When insects were reared under different photoperiods at 20 and 25 °C, they produced diapause or nondiapause eggs depending on the photoperiod: when reared under short-day photoperiods (≤?13 h/day), females laid diapause eggs, whereas they laid nondiapause eggs when reared under long-day photoperiods (≥?14 h/day). Because the developmental duration of the pre-adult stages and maturation (minimum duration of one generation) is estimated to be approximately 30 days at summer temperatures, these results suggest that this bug has a multivoltine seasonal life cycle. In agreement with the laboratory results, only nondiapause eggs were produced until mid-August in the field, and an increasing proportion of diapause eggs were produced from early September. In addition to these findings, field sampling from spring to autumn in 2009 indicated that three or four generations were produced in one year. These results suggest that egg diapause plays a role in preventing nymphs of A. triannulatus from developing in winter, and thereby ensures the survival of the population in adverse seasons.  相似文献   

19.
In many temperate ecosystems animal carcasses resultant from wildlife harvest can provide a high-quality food source for myriad facultative scavengers. We investigated scavenger use of human-provisioned ungulate carrion from a fall moose (Alces alces) hunt during 2010 and 2011 on the Gustavus Forelands, Alaska, USA. Using data from remote cameras, we (1) identified the scavenger species that used these resources and (2) evaluated their spatial and temporal responses to this seasonal resource event by indexing their activity patterns and relative order of arrival at carrion sites. We also quantified the length of time carrion persisted and estimated the amount of moose biomass provisioned to vertebrate scavengers by human hunters. Our results indicated that 11 vertebrate species (five birds and six mammals) scavenged moose carrion. We found that the common raven was the only species documented at all carrion sites and the most abundant species at moose carrion sites. As a species group, corvids [black-billed magpie (Pica hudsonia), common raven (Corvus corax); 0.1 ± 2.3 days] were the first to arrive at human-provisioned moose carrion sites, whereas ursids [brown bear (Ursus arctos), black bear (U. americanus); 1.3 ± 1.0 days] arrived after corvids but sooner than expected and canids [gray wolf (Canis lupus), coyote (C. latrans); 3.9 ± 3.0] arrived later than expected compared to our null model. On average, carrion persisted >20 days and hunters provided scavengers with a minimum of 2720 kg (82.7 kg/km2) and 1815 kg (64.8 kg/km2) of moose carrion during 2010 and 2011, respectively. Understanding how scavengers, particularly large carnivores, interact with human-provisioned moose carrion at the rural–wildland interface is essential for mitigating potential human–wildlife conflicts associated with humans subsidizing predators with a high-quality food resource.  相似文献   

20.
Edwardsiella tarda is one of the leading fish pathogens for the aquaculture industry. To realize efficient disease control of edwardsiellosis, a predictive model for E. tarda in seawater was developed. The modified logistic model was used to regress the growth curves of E. tarda JN at five different temperatures (range from 10 to 30 °C) and four organic nutrient concentrations (range from 5 to 40 mg l?1 measured by chemical oxygen demand (COD)). The modeling effects of temperature and COD on the specific growth rate (μ) were developed by square-root model and saturation-growth rate model, respectively. The growth model was validated in turbot aquaculture tanks by estimating the dynamics of inoculated E. tarda. The accurate feeding of probiotic Bacillus pumilus strain H2 was calculated based on the estimation of E. tarda. Results showed that the logistic model produced a good fit to the growth curves of E. tarda JN (average R2?=?0.962). The overall predictions based on above models agreed well with the growth curve of E. tarda JN observed by plate counting in the validation tests (average Af?=?1.16; average Bf?=?1.32). The use of predicted amount of B. pumilus (5.66 log CFU ml?1) successfully prevent the deterioration of disease for turbot with 13.3% mortality rate in a recirculating aquaculture system (RAS), while the feeding of 0 and 3.0 log CFU ml?1 of B. pumilus resulted in 53.7 and 75.3% of turbot mortality rate, respectively. In conclusion, accurate estimation of E. tarda realized the precise feeding of probiotics, which successfully prevent the rapid progression of the edwardsiellosis.  相似文献   

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