Larval ecology of Rana arvalis: an allopatric island population compared with a sympatric mainland population

1995 ◽  
Vol 16 (2) ◽  
pp. 101-111 ◽  
Author(s):  
Björn Lardner
Keyword(s):  
Competitive Ability ◽  
Rana Temporaria ◽  
Island Population ◽  
Larval Ecology ◽  
Rana Arvalis ◽  
Lower Growth ◽  
Mainland Population ◽  
Lower Growth Rate ◽  
The Baltic ◽  
Specific Species

AbstractRana arvalis has escaped its mainland competitor Rana temporaria on the Baltic island of Gotland. Larvae from mainland and island R. arvalis populations were raised in inter- as well as intraspecific regimes of different densities. Gotlandian larvae had a longer larval period and a lower growth rate than mainland conspecifics at the provided densities. The Gotlandian larvae did not respond more strongly to competition with R. temporaria than mainland larvae, but they seemed to have lost competitive ability in general. When competing with a stronger competitor, this loss of competitive ability in general is predicted to give the same effect as a loss of competitive ability towards that specific species.

scholarly journals A paradox of restoration: prey habitat engineering for an introduced, threatened carnivore can support native biodiversity

Oryx ◽  
2014 ◽  
Vol 49 (3) ◽  
pp. 559-562 ◽  
Author(s):  
Liina Remm ◽  
Asko Lõhmus ◽  
Tiit Maran
Keyword(s):  
Rana Temporaria ◽  
Island Population ◽  
Managed Forests ◽  
Rana Arvalis ◽  
The Public ◽  
Species Of Conservation Concern ◽  
Food Shortages ◽  
Management Project ◽  
Conservation Concern ◽  
The Cost

AbstractConservation of charismatic vertebrates in modern landscapes often includes habitat engineering, which is well supported by the public but lacks a consideration of wider conservation consequences. We analysed a pond management project for an introduced island population of captive-bred, Critically Endangered European mink Mustela lutreola. Ponds were excavated near watercourses in hydrologically impoverished forests to support the main prey of the mink (brown frogs Rana temporaria and Rana arvalis). A comparison of these ponds with other, natural, water bodies revealed that the (re)constructed ponds could reduce food shortages for the mink. Moreover, the ponds provided habitat for macroinvertebrates that were uncommon in the managed forests in the study area, including some species of conservation concern. The cost-effectiveness of the management of charismatic species can be increased by explicitly including wider conservation targets at both the planning and assessment stages.

scholarly journals Effects of Modification of Light Parameters on the Production of Cryptophycin, Cyanotoxin with Potent Anticancer Activity, in Nostoc sp.

Toxins ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 809
Author(s):  
Alexandros Polyzois ◽  
Diana Kirilovsky ◽  
Thi-hanh Dufat ◽  
Sylvie Michel
Keyword(s):  
Light Stress ◽  
Red Light ◽  
Major Effect ◽  
High Light Intensity ◽  
Efficient Production ◽  
Lower Growth ◽  
Noticeable Increase ◽  
Lower Growth Rate ◽  
Industrial Use ◽  
Effect Of Light

Cryptophycin-1 is a cyanotoxin produced by filamentous cyanobacteria. It has been evaluated as an anticancer agent with great potential. However, its synthesis provides insufficient yield for industrial use. An alternative solution for metabolite efficient production is to stress cyanobacteria by modifying the environmental conditions of the culture (Nostoc sp. ATCC 53789). Here, we examined the effects of light photoperiod, wavelength, and intensity. In light photoperiod, photoperiods 24:0 and 16:8 (light:dark) were tested while in wavelength, orange-red light was compared with blue. Medium, high, and very high light intensity experiments were performed to test the effect of light stress. For a 10-day period, growth was measured, metabolite concentration was calculated through HPLC, and the related curves were drawn. The differentiation of light wavelength had a major effect on the culture, as orange-red filter contributed to noticeable increase in both growth and doubled the cyanotoxin concentration in comparison to blue light. Remarkably, constant light provides higher cryptophycin yield, but slightly lower growth rate. Lastly, the microorganism prefers medium light intensities for both growth and metabolite expression. The combination of these optimal conditions would contribute to the further exploitation of cryptophycin.

scholarly journals Widespread variation in heat tolerance and symbiont load are associated with growth tradeoffs in the coral Acropora hyacinthus in Palau

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Brendan Cornwell ◽  
Katrina Armstrong ◽  
Nia S Walker ◽  
Marilla Lippert ◽  
Victor Nestor ◽  
...  
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Habitat Restoration ◽  
Natural Resistance ◽  
Lower Growth ◽  
Coral Reef Resilience ◽  
The Face ◽  
Lower Growth Rate ◽  
Acropora Hyacinthus ◽  
The Cost

Climate change is dramatically changing ecosystem composition and productivity, leading scientists to consider the best approaches to map natural resistance and foster ecosystem resilience in the face of these changes. Here we present results from a large-scale experimental assessment of coral bleaching resistance, a critical trait for coral population persistence as oceans warm, in 221 colonies of the coral Acropora hyacinthus across 37 reefs in Palau. We find that bleaching resistant individuals inhabit most reefs but are found more often in warmer microhabitats. Our survey also found wide variation in symbiont concentration among colonies, and that colonies with lower symbiont load tended to be more bleaching resistant. By contrast, our data show that low symbiont load comes at the cost of lower growth rate, a tradeoff that may operate widely among corals across environments. Corals with high bleaching resistance have been suggested as a source for habitat restoration or selective breeding in order to increase coral reef resilience to climate change. Our maps show where these resilience corals can be found, but the existence of tradeoffs with heat resistance may suggest caution in unilateral use of this one trait in restoration.

scholarly journals Zur Bedeutung der ‚Grünbrücke Kiebitzholm‘ (Schleswig-Holstein) für Amphibien

2021 ◽  
Vol 10 ◽  
Author(s):  
Christian Winkler
Keyword(s):  
Rana Temporaria ◽  
Bufo Bufo ◽  
Rana Arvalis ◽  
Triturus Cristatus ◽  
Lissotriton Vulgaris ◽  
Epidalea Calamita

In den Jahren 2006 bis 2010 wurde die Amphibienfauna auf der Grünbrücke bei Kiebitzholm (Schleswig-Holstein, Norddeutschland), an den angrenzenden Straßensäumen beidseitig der Bundesautobahn (BAB) A21 sowie an Stillgewässern im 1,5 km Radius um die Grünbrücke untersucht. Im Untersuchungsgebiet konn- ten sieben Amphibienarten festgestellt werden, darunter Knoblauchkröte (Pelo- bates fuscus), Kreuzkröte (Epidalea calamita) und Moorfrosch (Rana arvalis), die landes- oder bundesweit als bestandsgefährdet gelten. Bei Knoblauchkröte und Moorfrosch handelt es sich zudem um bundesweit bedeutsame Zielarten für den Biotopverbund. Teichmolch (Lissotriton vulgaris), Erdkröte (Bufo bufo), Grasfrosch (Rana temporaria) und Moorfrosch wurden im Untersuchungszeitraum auf der Grünbrücke nachgewiesen. Der Kammmolch (Triturus cristatus) konnte nur auf der östlichen Rampe festgestellt werden. Die Grünbrücke diente den er- fassten Individuen offenbar in erster Linie zur Querung der BAB A21 und nur zum Teil auch als Sommerhabitat. Eine auf der östlichen Rampe angelegte Wildtränke wurde im Jahr 2010 erstmals von Teichmolch, Kammmolch und Moorfrosch als Laichgewässer genutzt. Knoblauchkröte und Kreuzkröte waren im Untersuchungsgebiet besonders selten. Sie traten in einem bzw. zwei Untersuchungsgewässern auf. Während die Kreuz- kröte auf beiden Seiten der Autobahn gefunden wurde, wurde die Knoblauchkröte nur westlich der Straße erfasst. Die übrigen festgestellten Amphibienarten traten in teilweise größeren Populationen auf beiden Seiten der BAB A21 auf. Die Funde dieser Arten auf der Grünbrücke zeigen, dass bereits ein Verbund zwischen diesem Que- rungsbauwerk und den Populationen in der Umgebung realisiert war.

scholarly journals Herpetofauna of the Pieprzowe Mountains Nature Reserve and adjacent areas

2019 ◽  
Vol 30 (2) ◽  
pp. 24-31
Author(s):  
Dariusz Wojdan ◽  
Ilona Żeber-Dzikowska ◽  
Barbara Gworek ◽  
Maciej Sadowski ◽  
Jarosław Chmielewski
Keyword(s):  
Nature Reserve ◽  
Rana Temporaria ◽  
Bufo Bufo ◽  
Rare Plants ◽  
Oxbow Lake ◽  
Tree Frog ◽  
Common Frog ◽  
Common Toad ◽  
Rana Arvalis ◽  
Triturus Cristatus

Abstract The study was focused on determining the sites of amphibian and reptile occurrence in the Pieprzowe Mountains Nature Reserve (area 18.01 ha) and adjacent areas (total area 58.81 ha). The investigations also involved the biology of breeding in the selected species, as well as determining threats and protection measures. Situated in the eastern part of the Świętokrzyskie Voivodeship, the steppe-like Pieprzowe (Pepper) Mountains Nature Reserve was established in 1979. Its aim is to protect xerothermic assemblages inhabited by many species of rare plants including the largest European aggregation of roses growing wild. The area is located on a steep, sometimes rugged escarpment, which is part of the Vistula River erosional margin. The escarpment exposes Cambrian black pepper-like shales. The slope base is overgrown by a narrow belt of willow thickets. Above occur assemblages of xerothermic thickets with a few trees. The highest parts of the nature reserve are overgrown with xerothermic grasslands with the prevalence of feathergrass steppe (Festuco-Stipion class). The reserve is surrounded by riparian forests, waterlogged meadows and reservoirs of the Vistula former riverbed, the largest of which is an oxbow lake (5.16 ha). The following species were documented in 2016-2017: smooth newt Lissotriton vulgaris L., great crested newt Triturus cristatus Laur., European fire-bellied toad Bombina bombina L., common toad Bufo bufo L., European green toad Bufotes viridis Laur., European tree frog Hyla arborea L., edible frog Pelophylax esculentus L., pool frog Pelophylax lessonae Cam., marsh frog Pelophylax ridibundus Laur., moor frog Rana arvalis Nilss., common frog Rana temporaria L., sand lizard Lacerta agilis L., grass snake Natrix natrix L. and common European adder Vipera berus L. The studies were focused on biology of breeding and phenology in common toad and common frog. The main threats posed on herpetofauna include: human presence, littering, fire raising and changes of water balance. © IOŚ-PIB

Settlement and Metamorphosis in Barnacles and Decapods

2020 ◽  
pp. 223-254
Author(s):  
Paulina Gebauer ◽  
Luis Giménez ◽  
Iván Hinojosa ◽  
Kurt Paschke
Keyword(s):  
Adult Population ◽  
Subsequent Development ◽  
Suitable Habitat ◽  
Pelagic Larva ◽  
Lower Growth ◽  
Settlement Behavior ◽  
Biphasic Life Cycle ◽  
Settlement And Metamorphosis ◽  
Lower Growth Rate ◽  
Adult Habitat

Settlement and metamorphosis are two crucial processes in organisms with a biphasic life cycle, forming the link between the pelagic larva and benthic juvenile-adult. In general, these processes occur during the final larval stage. Among crustaceans, settlement behavior and the cues that trigger settlement and metamorphosis have been studied in greater depth in barnacles than in decapods, likely a result of the former losing the ability to move after they join the benthic juvenile-adult population, undergoing metamorphosis. Both barnacles and decapods respond to different environmental cues associated with the adult habitat, such as substratum, biofilm, and the presence of conspecifics. In the absence of cues, larvae can delay their metamorphosis for a period of time. This ability to prolong the development can be advantageous because it increases the probability of settling in a suitable habitat. However, delayed metamorphosis has also associated costs (e.g., smaller size, lower growth rate, and higher mortality), which may be carried over to subsequent development stages, with consequences for recruitment.

Caecotrophes intake in growing rabbits estimated either from urinary excretion of purine derivatives or from direct measurement using animals provided with a neck collar: effect of type and level of dietary carbohydrate

2002 ◽  
Vol 74 (1) ◽  
pp. 135-144 ◽  
Author(s):  
A. Belenguer ◽  
J. Balcells ◽  
M. Fondevila ◽  
C. Torre
Keyword(s):  
Growth Rate ◽  
Dry Matter ◽  
Dry Matter Intake ◽  
Purine Derivatives ◽  
Lower Growth ◽  
Beet Pulp ◽  
Lower Growth Rate ◽  
Maize Grain ◽  
G Ratio ◽  
Microbial N

AbstractThe present study compares estimates of caecotrophes production from urinary purine derivatives (PD) excretion with that from preventing caecotrophy by using a neck collar. A total of 64 New Zealand growing male rabbits were used to study the effect of diet composition on caecotrophes production. Diets were formulated using two sources of structural carbohydrates (fibre): alfalfa hay (AH) and sugar-beet pulp (SBP), mixed at two constant proportions, (0·75: 0·25) AH diets and (0·25: 0·75) SBP diets. Both diets included either barley or maize grain at two fibre: grain ratios (F/G, 80: 20 and 45: 55). Diets were given ad libitum. Growth rate, dry matter intake and digestibility were not modified by the grain source, although high F/G diets resulted in a lower growth rate (19·8 v. 26·4 g/day; P < 0·001). Between fibre sources, dry-matter intake and growth were higher in AH than in SBP diets (122·5 and 25·6 v. 101·6 and 20·4 g/day, respectively, P < 0·001 and P < 0·01). Rabbits given high F/G ratio and AH diets excreted more caecotrophes than those given low F/G ratio and SBP diets (19·5 and 20·9 v. 16·3 and 14·85 g/day, respectively). Microbial-N recycling through the caecotrophy process was higher when considering data from PD excretion (1·33 g/d) than when estimated by preventing caecotrophy (0·72 g/day).

Modal and non-modal stability of boundary layers forced by spanwise wall oscillations

2015 ◽  
Vol 778 ◽  
pp. 389-427 ◽  
Author(s):  
M. J. Philipp Hack ◽  
Tamer A. Zaki
Keyword(s):  
Boundary Layers ◽  
Base Flow ◽  
Normal Velocity ◽  
Lower Growth ◽  
Stokes Layer ◽  
Time Harmonic ◽  
Inflection Points ◽  
Lower Growth Rate ◽  
Inviscid Instability ◽  
Perturbation Growth

Modal and non-modal perturbation growth in boundary layers subjected to time-harmonic spanwise wall motion are examined. The superposition of the streamwise Blasius flow and the spanwise Stokes layer can lead to strong modal amplification during intervals of the base-flow period. Linear stability analysis of frozen phases of the base state demonstrates that this growth is due to an inviscid instability, which is related to the inflection points of the spanwise Stokes layer. The generation of new inflection points at the wall and their propagation towards the free stream leads to mode crossing when tracing the most unstable mode as a function of phase. The fundamental mode computed in Floquet analysis has a considerably lower growth rate than the instantaneous eigenfunctions. Furthermore, the algebraic lift-up mechanism that causes the formation of Klebanoff streaks is examined in transient growth analyses. The wall forcing significantly weakens the wall-normal velocity perturbations associated with lift-up. This effect is attributed to the formation of a pressure field which redistributes energy from the wall-normal to the spanwise velocity perturbations. The results from linear theory explain observations from direct numerical simulations of breakdown to turbulence in the same flow configuration by Hack & Zaki (J. Fluid Mech., vol. 760, 2014a, pp. 63–94). When bypass mechanisms are dominant, the flow is stabilized due to the weaker non-modal growth. However, at high amplitudes of wall oscillation, transition is promoted due to fast growth of the modal instability.

Shape evolution of a spherical particle growing in supersaturated solution affected by straining flows

2016 ◽  
Vol 30 (06) ◽  
pp. 1650059
Author(s):  
Jingjing Gao ◽  
Mingwen Chen ◽  
Zidong Wang
Keyword(s):  
Growth Rate ◽  
Expansion Method ◽  
Supersaturated Solution ◽  
Shape Evolution ◽  
Interface Microstructure ◽  
Lower Growth ◽  
Ambient Flow ◽  
Multiple Variable ◽  
Lower Growth Rate ◽  
Asymptotic Expansion Method

The convection of ambient flow field has a significant influence on the pattern formation of growing particles. In this paper, we investigate the shape evolution of particles growing in supersaturated solution affected by straining flows. By using the multiple variable asymptotic expansion method, we obtain the asymptotic solution. The solution indicates that the interface microstructure is greatly affected by the straining flows. The flow results in a higher growth rate in the surface where it is incoming and a lower growth rate where it is outgoing. Besides, the flow also has effects on the concentration distribution.

scholarly journals Amphibians in an urban environment: a case study from a central European city (Wrocław, Poland)

2019 ◽  
Vol 23 (2) ◽  
pp. 235-243
Author(s):  
Agnieszka Konowalik ◽  
Anna Najbar ◽  
Kamil Konowalik ◽  
Łukasz Dylewski ◽  
Marzena Frydlewicz ◽  
...  
Keyword(s):  
Species Richness ◽  
Rana Temporaria ◽  
Bufo Bufo ◽  
High Ratio ◽  
Rana Arvalis ◽  
Amphibian Species ◽  
Triturus Cristatus ◽  
Lissotriton Vulgaris ◽  
Hyla Arborea ◽  
The City

AbstractIn 2016, we studied the occurrence of amphibians in 231 selected ponds in the city of Wrocław (Lower Silesia, Poland) and confirmed the occurrence of 10 species: Bombina bombina, Bufo bufo, Bufotes viridis, Hyla arborea, Pelobates fuscus, Pelophylax esculentus complex, Rana arvalis, Rana temporaria, Lissotriton vulgaris and Triturus cristatus. Among all studied sites, the most common were P. esculentus complex (146 occupied sites, 63.2%) and B. bufo (119, 51.5%), while the rarest was P. fuscus (8, 3.5%). The number of species at a single site varied from 0 (28 sites, 12.1%) to 9 (1 site, 0.4%). Frequency and mean amphibian species richness reached 87.9% and 2.7 ± 1.9, respectively. The composition of amphibian species did not change in comparison to previous studies conducted in the years 1997–2009, but declining trends in five species (B. bombina, B. viridis, H. arborea, P. esculentus complex, P. fuscus) were observed (28 compared sites). The results revealed that the permanency of ponds, their occurrence in the vicinity of river valleys, and a high ratio of watercourse length and green area around ponds are positively correlated and have a significant influence on amphibian species richness within the city. Thus, these identified factors should be considered in the course of sustainable urban planning in order to avoid potential conflicts between nature conservation and urban development.

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