Baffinella frigidus gen. et sp. nov. (Baffinellaceae fam. nov., Cryptophyceae) from Baffin Bay: Morphology, pigment profile, phylogeny, and growth rate response to three abiotic factors

2018 ◽  
Vol 54 (5) ◽  
pp. 665-680 ◽  
Author(s):  
Niels Daugbjerg ◽  
Andreas Norlin ◽  
Connie Lovejoy
Keyword(s):  
Growth Rate ◽  
Abiotic Factors ◽  
Baffin Bay ◽  
Pigment Profile

scholarly journals ADDITION OF SHELTERS TO CONTROL THE PHYSIOLOGICAL RESPONSES AND PRODUCTION OF MUD CRAB Scylla serrata IN RECIRCULATION AQUACULTURE SYSTEM

2020 ◽  
Vol 12 (1) ◽  
pp. 299-310
Author(s):  
Yuni Puji Hastuti ◽  
Priyo Handoyo Wicaksono ◽  
Wildan Nurusallam ◽  
Siska Tridesianti ◽  
Yuli Siti Fatma ◽  
...  
Keyword(s):  
Growth Rate ◽  
Abiotic Factors ◽  
Physiological Responses ◽  
Scylla Serrata ◽  
Growth Responses ◽  
Aquaculture System ◽  
Total Hemocyte Count ◽  
Recirculation System ◽  
Recirculation Aquaculture System ◽  
Mud Crabs

The availability of shelters in a specific density is expected to increase the production of mud crabs (Scylla serrata) in a recirculation system. Shelter, as one of the abiotic factors, plays a pivotal role in reducing death caused by cannibalism of crab and suppressing the stress levels of biota. Recirculation Aquaculture System (RAS), with the culture box capacity 60 L supported by the shelters, is predicted to produce the best physiological and growth responses of mud crabs. This present study aims to evaluate the effect of shelter addition in the environmental recirculation system on the physiological responses and production of mud crabs S. serrata with a density of 10 crabs per one culture box containing 60 L of seawater. The research was set up with three treatments of shelter addition, i.e., two shelters (S2), four shelters (S4), six shelters (S6), and control without shelter (C). Results showed that S6 was the best treatment with a survival rate of 73.33 ± 5.8%, a specific growth rate of 0.886 ± 0.014%, the growth rate of carapace width 0.024 ± 0.004 cm/day, and the lowest feed conversion ratio than those of other treatments. S6 treatment significantly influenced the total hemocyte count of crabs at the early cultivation (P <0.05). Addition of six shelters could optimize the growth of mud crabs with a stocking density of 10 crabs in one culture box. 

scholarly journals Influence of abiotic factors on seed quality of maize hybrids in the process of its storage

2021 ◽  
Vol 5 (1) ◽  
pp. 30-37
Author(s):  
M. Ya. Kyrpa ◽  
Yu. S. Bazilieva ◽  
O. F. Stasiv
Keyword(s):  
Growth Rate ◽  
Moisture Content ◽  
Chemical Treatment ◽  
Seed Quality ◽  
Abiotic Factors ◽  
Seed Mass ◽  
Seed Storage ◽  
Maize Hybrids ◽  
Storage Methods

The research results of influence of various abiotic factors on seed quality of maize hybrids during long storage are given. The most effective of them are: temperature regime, seed moisture content and oxygen access. The storage methods (dry and cold, and controlled atmosphere storage) that have the greatest impact on the seed quality were established. It was found that the optimal moisture content of seed depends on the storage duration, if for 1–2 years – 10–11 %, 3 years and more – 7–8 %. In order to stabilize the moisture content, it is recommended to store the seeds in airtight containers, limiting the humidity access from the outside. During the long-term seed storage, particularly for the breeding purposes, the temperature range should advisably maintain within 8–10 °C in seed storage place. With that the laboratory germination of seeds increased by 3–5 %, field germination – by 6–8 %, growth rate by number of sprouts– by 5–9 % and by the weight of sprouts – by 2–5 g compared to the 18–20 °C temperature in a typical storage. Methods of pre-sowing improvement of seed quality were established – it is separation and chemical treatment (seed dressing). Separation is the sifting of the seed mass through sieves with round holes in order to divide from the smallest fraction, the content of which was 15–23 % depending on the seed uniformity of maize hybrids. It was found that in order to assess objectively the effectiveness of different chemicals and establish their suitability for presowing seed treatment, it is necessary to determine laboratory germination, especially the growth rate by the number of sprouts and weight of 100 sprouts. Premature chemical treatment of seed should be avoided. Key words: maize hybrids, storage methods, abiotic factors, seed quality, presowing treatment.

Biotic and abiotic factors influencing growth rate and production of traps by the nematode-trapping fungus Duddingtonia flagrans when induced by Cooperia oncophora larvae

1999 ◽  
Vol 73 (2) ◽  
pp. 129-136 ◽  
Author(s):  
J. Grønvold ◽  
J. Wolstrup ◽  
P. Nansen ◽  
M. Larsen ◽  
S.A. Henriksen ◽  
...  
Keyword(s):  
Growth Rate ◽  
Abiotic Factors ◽  
Corn Meal ◽  
Corn Meal Agar ◽  
Duddingtonia Flagrans ◽  
Anaerobic Conditions ◽  
High Concentration ◽  
Cooperia Oncophora ◽  
Anaerobic Stress ◽  
Series Of Experiments

A series of experiments on corn meal agar was carried out to evaluate the efficacy of the nematode-trapping fungus Duddingtonia flagrans in different abiotic and biotic conditions which occur in cow pats. Above a concentration of 50 parasitic larvae (L3) cm–2 the fungus produced a maximum of between 500 and 600 nets cm–2 at 20°C in 2 days on the surface of corn meal agar. There were no differences in the trap-producing capacity of three strains of D. flagrans (CIII4, CI3 and Trol A). On agar at 30° and 20°C, the fungus responded to Cooperia oncophora L3 very quickly producing a maximum of trapping nets 1 day after induction. At 10°C, traps were produced slowly starting on day 4 after induction and continued over the following week. Duddingtonia flagrans (CI3) grew at a normal rate at least down to an oxygen concentration of 6 vol.% O2, but it did not grow anaerobically. On agar, D. flagrans (CI3) did not produce trapping nets in an anaerobic atmosphere. Moreover, C. oncophora L3 stopped migration under anaerobic conditions. When the fungal cultures were transferred to a normal aerobic atmosphere, after 1 and 2 weeks under anaerobic conditions, the C. oncophora L3 resumed migrating on the agar and, in response, D. flagrans produced traps in the same amount as when it had not been under anaerobic stress. Under microaerophilic conditions (6 vol.% O2) D. flagrans was able to grow, but the C. oncophora L3 were not able to induce trapping nets in D. flagrans (Trol A) because of larval immobility. But, as under anaerobic conditions, the fungus could return to a nematode-trapping state when transferred to a normal aerobic atmosphere within 1 or 2 weeks if migrating nematodes were present. Under natural conditions in the cow pat it is expected that the fungus will be ready to attack parasitic larvae, when the oxygen tension increases as a result of, for example the activity of the coprophilic fauna. Artificial light giving 3000–3400 Lux on the surface of the agar significantly depressed the growth rate and the production of trapping nets in D. flagrans (CI3). On agar, D. flagrans (CI3) could grow and produce trapping nets at pH levels of 6.3 to 9.3. Net-production has its optimum between pH 7 and 8. On dry faeces mycelial growth was 7–10 mm during a 15 day period while on moist faeces the fungus expanded 15–20 mm during the same period. Based on the parameters investigated, D. flagrans is expected to be especially active in the well aerated surface layer of a cow pat, an area which normally contains a high concentration of infective nematode parasite larvae, but also an area where the temperature can be high and the water content low.

scholarly journals Testing a New Approach to Quantify Growth Responses to Pruning Among Three Temperate Tree Species

2016 ◽  
Vol 42 (3) ◽  
Author(s):  
Matt Follett ◽  
Charles Nock ◽  
Christian Buteau ◽  
Christian Messier
Keyword(s):  
Growth Rate ◽  
Growth Response ◽  
Abiotic Factors ◽  
Growth Conditions ◽  
Accurate Estimation ◽  
Cycle Duration ◽  
Growth Responses ◽  
Laser Measurements ◽  
Branch Growth ◽  
Highly Correlated

In settled areas, electrical line safety is maintained by pruning encroaching trees. Identifying key predictors of branch elongation growth rate following pruning would assist in developing predictive models and optimizing pruning cycles. However, measuring branches in trees near electrical lines is complex and challenging. This paper describes an innovative approach using a handheld laser rangefinder to safely and accurately estimate growth from the ground. In-tree and ground-based laser measurements were highly correlated. This was followed by testing for correlations between branch growth response over a number of years after pruning and many biotic and abiotic factors for Fraxinus pennsylvanica, Acer platanoides, and Acer saccharinum, in the city of Montreal, Canada. In a sample of 59 trees, A. saccharinum had the greatest branch growth, followed by F. pennsylvanica, and finally A. platanoides. Branch growth increased following pruning and subsequently strongly declined, with A. platanoides declining the fastest. Branch inclination angle was positively correlated with growth rate for two species, but not for A. saccharinum. Among the types of pruning used, directional pruning techniques resulted in the least branch regrowth rate. Tree diameter was weakly related to branch growth rates. These results suggest that while growth conditions for street trees may be perceived as homogenous, there is substantial variation in branch growth response. This variation may be related to pruning history, or unmeasured abiotic or biotic variables. Estimating pruning cycle duration is a complex task and further work is needed to develop a predictive model for more accurate estimation of return times.

Multivariate control of heterotrophic bacterial abundance and zooplankton grazing in Labrador fjords (northeastern Canada)

2020 ◽  
Vol 84 ◽  
pp. 105-120
Author(s):  
AG Simo-Matchim ◽  
M Gosselin ◽  
C Belzile
Keyword(s):  
Growth Rate ◽  
Heterotrophic Bacteria ◽  
Abiotic Factors ◽  
Mean Value ◽  
Phytoplankton Growth ◽  
Heterotrophic Nanoflagellates ◽  
Organic Substrates ◽  
Bacterial Growth Rate ◽  
Phytoplankton Growth Rate ◽  
Substantial Control

This study was conducted in 4 Labrador fjords (Nachvak, Saglek, Okak, and Anaktalak) during the summers of 2007 and 2013, early fall 2010, and late fall 2009. Our results show that water temperature combined with the availability of nutrients and organic substrates are the main abiotic factors controlling the abundance of heterotrophic bacteria in Labrador fjords. Bacterivory also played a crucial role, with heterotrophic bacteria exerting a significant bottom-up control on the abundance of heterotrophic nanoflagellates (r = 0.35, p < 0.05) and ciliates (r = 0.70, p < 0.01). During summer 2013, the intrinsic phytoplankton growth rate varied between <0 and 0.64 d-1, with a mean value of 0.36 d-1. The herbivory rate was highly variable, ranging from 0.01 to 0.86 d-1, with a mean value of 0.31 d-1. Grazing mortality was 6-fold higher than phytoplankton growth rate. Mean phytoplankton growth and herbivory rates in Labrador fjords were comparable to the Barents and Bering seas. The intrinsic growth rate of total heterotrophic bacteria ranged between <0 and 0.68 d-1, with a mean value of 0.30 d-1. Bacterivory varied from 0.01 to 0.95 d-1, with a mean of 0.30 d-1. Mortality due to grazing was up to 2.3 times higher than total bacterial growth rate. This study improves our understanding of the factors influencing the dynamics of heterotrophic bacteria and indicates that herbivory and bacterivory exert substantial control on microbial communities in Labrador fjords.

scholarly journals Penentuan pH optimum untuk pertumbuhan kepiting bakau Scylla serrata dalam wadah terkontrol

2016 ◽  
Vol 15 (2) ◽  
pp. 171 ◽  
Author(s):  
Yuni Puji Hastuti ◽  
Horas Nadeak ◽  
Ridwan Affandi ◽  
Kurnia Faturrohman
Keyword(s):  
Growth Rate ◽  
Survival Rate ◽  
Specific Growth Rate ◽  
Specific Growth ◽  
Abiotic Factors ◽  
Scylla Serrata ◽  
Ph Optimum ◽  
Mangrove Crab ◽  
Mangrove Crabs ◽  
Osmotic Load

<p class="NoParagraphStyle"><strong>ABSTRACT</strong><strong></strong></p><p class="NoParagraphStyle"> </p><p class="NoParagraphStyle">One of the abiotic factors that affects the growth and the survival of crabs is pH. The optimum pH media will give maximum impact on mangrove crabs because it is related with the osmoregulation process. This study aimed to examine the effect of pH on the survival rate (SR) and specific growth rate (SGR) of mangrove crab <em>Scylla serrata</em> through the reaction of physiological condition. This study consisted of the treatments with the pH medium 5 (A), pH medium 6 (B), pH medium 7 (C), and pH medium 8 (D).  The crab’s maintenance in different pH gave a significant effect (P&lt;0.05) on the survival rate of the crabs. The pH treatments also gave a significant effect (P&lt;0.05) on the SGR of the crabs. The low level of crab stress at pH 7 was described by  the total value of high hemocyte and the high osmotic load so that the pH 7 was the optimum condition for the crabs.</p><p class="NoParagraphStyle"> </p><p class="NoParagraphStyle">Keywords: pH, survival, specific growth rate, mangrove crabs</p><p class="NoParagraphStyle"> </p><p class="NoParagraphStyle"> </p><p class="NoParagraphStyle"><strong>ABSTRAK</strong><strong></strong></p><p class="NoParagraphStyle"> </p><p class="NoParagraphStyle">Salah satu faktor abiotik yang mempengaruhi pertumbuhan dan kelangsungan hidup kepiting adalah pH. Media pH optimum akan memberikan dampak maksimum pada kepiting bakau karena terkait dengan proses osmoregulasi. Penelitian ini bertujuan untuk menguji pengaruh pH pada tingkat kelangsungan hidup (SR) dan laju pertumbuhan spesifik (SGR) kepiting mangrove <em>Scylla serrata</em> melalui reaksi kondisi fisiologis. Penelitian ini terdiri atas perlakuan dengan media pH 5 (A), sedang pH 6 (B), sedang pH 7 (C), dan menengah pH 8 (D). Pemeliharaan kepiting di pH yang berbeda memberikan pengaruh yang signifikan (P&lt;0,05) pada tingkat kelangsungan hidup kepiting. Perlakuan pH juga memberikan efek yang signifikan (P&lt;0,05) pada SGR dari kepiting. Rendahnya tingkat stres kepiting pada pH 7 digambarkan oleh nilai total hemosit tinggi dan beban osmotik tinggi sehingga pH 7 adalah kondisi optimum untuk kepiting.</p><p class="NoParagraphStyle"> </p><p>Kata kunci: pH, kelangsungan hidup, laju pertumbuhan spesifik, kepiting mangrove</p>

scholarly journals Variability of Fusarium oxysporum f. sp. lycopersici from different altitudes in East Java, Indonesia

2021 ◽  
Vol 226 ◽  
pp. 00023
Author(s):  
Henik Sukorini ◽  
Erfan Dani Septia ◽  
Netnapis Khewkhom
Keyword(s):  
Growth Rate ◽  
Abiotic Factors ◽  
Wilt Disease ◽  
Acid Base ◽  
Tomato Plants ◽  
Pathogenicity Tests ◽  
Infected Tomato ◽  
Colony Color ◽  
Fusarium Sp ◽  
Different Altitudes

Fusarium wilt disease attacks the tomato plants, and Solanaceae plants with losses can reach 90 %. Thus, this disease was tough to control. The morphology and pathogenicity variation caused failure disease control. Both variations could be affected by the altitude of the planting site. Therefore, it also required special handling of management as well. The specific objectives of this study to investigate the Fusarium isolate from different altitude response of physical properties (acid-base pH, low-high temperature, and fungicides of other active ingredients) and growth rate of Fusarium. All Fusarium sp. were isolated from the leaves, soil, roots, and stem of infected tomato plants. Before a series of tests were carried out, all of the isolates were tested for pathogenicity, then tested for the influence of abiotic factors. This study obtained four isolates from high altitude, four isolates from medium altitude, and five lowland isolates. In morphological observations, there were striking differences in colony color and growth rate among isolates on several media and pathogenicity tests. Each isolate had different pathogenicity, although from the same location but other parts of the plant. Knowing the characteristic morphology and Fusarium sp. response of the three areas can be used as references in controlling.

scholarly journals Applying biomass and stem fluxes to quantify temporal and spatial fluctuations of an old-growth forest in disturbance

2009 ◽  
Vol 6 (2) ◽  
pp. 2723-2753
Author(s):  
S. Liu ◽  
Y. -L. Li ◽  
G. -Y. Zhou ◽  
K. O. Wenigmann ◽  
Y. Luo ◽  
...  
Keyword(s):  
Growth Rate ◽  
Abiotic Factors ◽  
Biomass Growth ◽  
Old Growth ◽  
Old Growth Forest ◽  
Spatial Fluctuations ◽  
Closed Canopy ◽  
Average Biomass ◽  
Annual Biomass ◽  
Temporal And Spatial

Abstract. A subtropical old-growth forest was analyzed over a twelve year period to investigate temporal and spatial fluctuations of biomass and stem fluxes under disturbances. Vegetations were categorized into three types caused by biotic factors and abiotic factors, including Castanopsis chinensis population, insect direct-influenced population, and insect indirect-influenced population according to disturbance scenarios. The biomass fluxes (including biomass growth and mortality) and stem fluxes (including stem recruitment and mortality) were used to quantify the fluctuation of population. The results showed that annual average biomass growth rate was stable throughout the three periods, 1992–1994, 1994–1999, and 1999–2004, while annual biomass mortality and stem fluxes kept increasing through the three periods. Castanopsis chinensis population contributed the most in biomass fluxes of the community. Biomass and stem mortalities of insect direct-influenced population increased significantly during the whole study period (1992–2004). Dynamics of indirect-influenced population were compared by dominate species, diameter classes, and spatial patterns of subplots, respectively. Results of indirect-influenced population showed that (1) the increase of biomass of the dominant species was well correlated between different intervals. Similar relationships were found in stem fluxes; (2) higher stem mortality was observed when DBH ranged from 1 to 10 cm as compared with individuals in other DBH classes; (3) stem fluxes in the canopy gaps were remarkably higher than those in closed canopy. The biomass growth rate in gaps increased remarkably after the formation of the gaps.

Intra-species variability in Fusarium langsethiae strains in growth and T-2/HT-2 mycotoxin production in response to climate change abiotic factors

2021 ◽  
pp. 1-8
Author(s):  
C. Verheecke-Vaessen ◽  
A. Lopez-Pietro ◽  
E. Garcia-Cela ◽  
A. Medina ◽  
N. Magan
Keyword(s):  
Climate Change ◽  
Growth Rate ◽  
Type Strain ◽  
Abiotic Factors ◽  
Stress Factors ◽  
Mycotoxin Production ◽  
Fusarium Langsethiae ◽  
The Impact ◽  
Species Variability ◽  
Lag Phases

The objective of this study was to evaluate the potential intra-species variability of 3 Fusarium langsethiae strains in response to extreme climate change (CC) conditions on an oat-based matrix. The impact of elevated temperature (25 vs 30-34 °C) coupled with increasing drought stress (0.98 vs 0.95 aw) and elevated CO2 (400 vs 1000 ppm) were examined on lag phases prior to growth, growth rate, and production of the mycotoxins T-2 and HT-2 and their ratio. In comparison to the control conditions (25 °C; 0.98; 400 ppm), exposure to increased temperature (30-34 °C), showed similar reductions in the lag phase and fungal growth rates of all 3 strains. However, with elevated CO2 a reduction in both lag phases prior to growth and growth rate occurred regardless of the aw examined. For T-2 and HT-2 mycotoxin production, T-2 showed the most intra-species variability in response to the interacting abiotic stress factors, with the 3 strains having different environmental conditions for triggering increases in T-2 production: Strain 1 produced higher T-2 toxin at 25 °C, while Strain 2 and the type strain (Fl201059) produced most at 0.98 aw/30 °C. Only Strain 2 showed a reduction in toxin production when exposed to elevated CO2. HT-2 production was higher at 25 °C for the type strain and higher at 30-34 °C for the other two strains, regardless of the aw or CO2 level examined. The HT-2/T-2 ratio showed no significant differences due to the imposed interacting CC abiotic conditions.

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