Floating, switching, or nonswitching as different behaviours when Arctic char (Salvelinus alpinus) are visiting two feeding tanks

1999 ◽  
Vol 56 (6) ◽  
pp. 1068-1077 ◽  
Author(s):  
Eva Brännäs ◽  
Torleif Eriksson
Keyword(s):  
Growth Rate ◽  
Salvelinus Alpinus ◽  
Ideal Free Distribution ◽  
Individual Characteristics ◽  
Arctic Char ◽  
Feed Ratio ◽  
Single Group ◽  
Lower Growth ◽  
Significant Difference ◽  
Time To Learn

The following questions were addressed. Will individual Arctic char (Salvelinus alpinus) differ in their visiting strategies when given a choice between two feeding tanks? If so, will the choice of strategy depend on individual characteristics (size) and will it affect their success (growth)? Further, will their allocation of visits to the two feeding tanks correspond to the food ratio? The passages between the nonfeeding tank and the two equally rich feeding tanks were recorded for four separate groups during a 3-week period. In an additional study, a single group was continuously monitored for 5 months using the same setup, but the feed ratio between the two feeding tanks was changed. Certain individuals in both studies consistently visited the same feeding tank (nonswitchers) and these were the most successful ones in terms of growth rate. Other individuals either kept visiting both tanks (switchers) or spent most of their time in the nonfeeding tank (floaters). These behaviours were applied by individuals that had a lower growth rate and are therefore likely to have lower competitive ability or feeding motivation. No significant difference in initial weight between the behavioural categories was found in either of the two studies. In the four-group study, the proportion of visits into the two feeding tanks matched the food ratio among the switchers only and the distribution of the groups failed to match the food ratio. In the single-group study, the group distributed according to the food ratio (ideal free distribution) if they were given sufficient time to learn the quality of the patches. A change in the relative food ratio caused the switchers and floaters to alter their visiting behaviour, always favouring the more profitable tank, whereas the nonswitchers continued to visit the same tank.

Is boldness towards predators related to growth rate in naïve captive-reared Arctic char (Salvelinus alpinus)?

2007 ◽  
Vol 64 (4) ◽  
pp. 665-671 ◽  
Author(s):  
Mika VM Laakkonen ◽  
Heikki Hirvonen
Keyword(s):  
Growth Rate ◽  
Captive Breeding ◽  
Salvelinus Alpinus ◽  
Antipredator Behavior ◽  
Underlying Mechanism ◽  
Arctic Char ◽  
Individual Growth ◽  
Detailed Knowledge ◽  
Individual Growth Rate ◽  
Slow Growing

Previous studies have shown that the antipredator responsiveness of fish degenerates through generations in captive breeding. However, detailed knowledge of the underlying mechanism is still largely lacking. We tested the hypothesis that hatchery fish supposedly selected for faster growth in the hatchery environment are bolder towards predators than their slower-growing conspecifics. This was examined by comparing the antipredator behavior of predator- naïve fast- and slow-growing individuals of a captive-bred Arctic char (Salvelinus alpinus) population to chemical cues from natural predators burbot (Lota lota) and pikeperch (Sander lucioperca). As behavioral responses depended on char body size, we compared boldness towards predators of size-matched fast- and slow-growing char. We found no differences in four behavioral antipredator traits between size-matched groups of fast- and slow-growing char. According to these results, boldness to predator cues is not related to individual growth rate in captive-bred Arctic char.

Cardiorespiratory responses of seawater-acclimated adult Arctic char (Salvelinus alpinus) and Atlantic salmon (Salmo salar) to an acute temperature increase

2014 ◽  
Vol 71 (7) ◽  
pp. 1096-1105 ◽  
Author(s):  
Chantelle M. Penney ◽  
Gordon W. Nash ◽  
A. Kurt Gamperl
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Temperature Increase ◽  
Thermal Tolerance ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Acclimation Temperature ◽  
Atlantic Salmon Salmo Salar ◽  
Interspecific Differences ◽  
Significant Difference

In this first study examining the thermal tolerance of adult Arctic char (Salvelinus alpinus) acclimated to seawater, we measured their critical thermal maximum (CTMax) and several cardiorespiratory parameters (oxygen consumption (MO2), heart rate (fH), stroke volume (SV), cardiac output (Q), ventilatory frequency (VF), opercular pressure (PO), and ventilatory effort (VE)) when exposed to a temperature increase of 2 °C·h−1. Further, we directly compared these results with those obtained for the eurythermal Atlantic salmon (Salmo salar) under identical conditions. There was no significant difference in cardiorespiratory values between the two species at their acclimation temperature (9.5–10 °C). In contrast, the slope of the MO2–temperature relationship was lower (by 27%) in the char as compared with that in the salmon, and the char had significantly lower values for maximum fH (by 13%), maximum MO2 (by 35%), absolute metabolic scope (by 39%), and CTMax (approximately 23 versus 26.5 °C, respectively). Although not a focus of the study, preliminary data suggest that interspecific differences in mitochondrial respiration (oxidative phosphorylation), and its temperature sensitivity, may partially explain the difference in thermal tolerance between the two species. These results provide considerable insights into why Atlantic salmon are displacing Arctic char in the current era of accelerated climate change.

Accumulation of Persistent Pollutants in Normal and Dwarfed Arctic Char (Salvelinus alpinus sp. complex)

1993 ◽  
Vol 50 (12) ◽  
pp. 2574-2580 ◽  
Author(s):  
Johan Hammar ◽  
Per Larsson ◽  
Maris Klavins
Keyword(s):  
Growth Rate ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Individual Growth ◽  
The Arctic ◽  
Growth Strategies ◽  
Sympatric Populations ◽  
Fast Growing ◽  
Persistent Pollutants ◽  
Slow Growing

Two extreme growth fractions of introgressed sympatric populations of the Arctic char (Salvelinus alpinus) species complex from Lake Blåsjön, northern Sweden, were sampled for individual concentrations of persistent pollutants originating from atmospheric deposition. Slow growing char (dwarfs) had significantly higher levels of SPCB (sum of PCB congeners found) and p,p-DDE (dominating DDT-compound) than fast growing char (normals). Besides demonstrating a highly divergent growth pattern the introgressed populations also inhabit a great range of depths, and the seasonal food consumption rates may differ between extreme growth fractions, although the same major invertebrates (introduced Mysis relicta and Pallasea quadrispinosa) are consumed over the year. However, of the life history parameters differing in late spring, individual growth rate was the most important factor explaining the variation in the levels of the pollutants studied. The results support the hypothesis of a biomass "dilution" of pollutants in fish, illustrated by lower levels in fast growing char and higher levels in the slow-growing dwarfs. Individuals with alternative growth strategies in sympatric conspecific communities thus provide unique opportunities to study growth rate as a variable influencing levels of persistent pollutants in fish.

scholarly journals Short-term deleterious effects of standard isolation and cultivation methods on new tropical freshwater microalgae strains

2017 ◽  
Author(s):  
M. Magdalena Aray-Andrade ◽  
Miguel I Uyaguari-Diaz ◽  
J. Rafael Bermúdez Monsalve
Keyword(s):  
Growth Rate ◽  
Lipid Content ◽  
Genetic Characterization ◽  
Potential Effect ◽  
Tropical Species ◽  
Freshwater Microalgae ◽  
Lower Growth ◽  
Tropical Regions ◽  
Significant Difference ◽  
Tropical Freshwater

Algae with potential biotechnological applications in different industries are commonly isolate from the environment in order to obtain pure (axenic) stocks that can be safely stored for long periods of time. To obtain axenic cultures, antibiotics are frequently used, and cryopreservation is applied to keep standing stocks. However, many of these now standard methods were developed using strains coming from pristine-to-low intervened environments and cold-to-temperate regions. Thus, it is still not well understand the potential effect of said methods on the life cycle and biochemical profile of algae isolates from hiper-eutrophic and constant high-temperature tropical regions, which could potentially render them unsuitable for their intended biotechnological application. In this study, we conducted a genetic characterization (18S rRNA) and evaluated the effect of purification (use of the antibiotic chloramphenicol, CPA) and cryopreservation (dimethyl sulfoxide (DMSO)-sucrose mix and Glycerol) on the growth rate and lipid content of four new tropical freshwater algal isolates: Chorella sp. M2, Chlorella sp. M6, Scenedesmus sp. R3, and Coelastrella sp. A2, from the Ecuadorian coast. The genetic characterization showed a clear discrimination between strains. All strains cultured with CPA had a lower growth rate. After cryopreservation Coelastrella sp. A2 did not grow with both methods; Chorella sp. M2, Chlorella sp. M6 and Scenedesmus sp. R3 presented no significant difference in growth rate between the cryopreservants. A significantly higher lipid content was observed in biomass cryopreserved with glycerol in relation to DMSO-sucrose, with Chorella sp. M2 and Chlorella sp. M6 having twice as much in the first treatment. The results highlight the relevance of choosing an appropriate method for storage as the materials used can affect the biological performance of different tropical species, although is still to determine if the effects observed here are long lasting in subsequent cultures of these algae.

scholarly journals Short-term deleterious effects of standard isolation and cultivation methods on new tropical freshwater microalgae strains

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5143
Author(s):  
M. Magdalena Aray-Andrade ◽  
Miguel I. Uyaguari-Diaz ◽  
J. Rafael Bermúdez
Keyword(s):  
Growth Rate ◽  
Lipid Content ◽  
Potential Effect ◽  
Morphological Characterization ◽  
Tropical Species ◽  
Freshwater Microalgae ◽  
Lower Growth ◽  
Tropical Regions ◽  
Significant Difference ◽  
Tropical Freshwater

Algae with potential biotechnological applications in different industries are commonly isolated from the environment in order to obtain pure (axenic) stocks that can be safely stored for long periods of time. To obtain axenic cultures, antibiotics are frequently employed, and cryopreservation is applied to preserve standing stocks. However, many of these now standard methods were developed using strains derived from pristine to near-pristine environments and cold to temperate regions. The potential effect of the said methods on the life cycle and biochemical profile of algae isolates from hyper-eutrophic and constant high-temperature tropical regions is not well understood. These effects could potentially render them unsuitable for their intended biotechnological application. In this study, we conducted a genetic characterization (18S rRNA) and evaluated the effect of purification (the use of the antibiotic chloramphenicol, CAP) and cryopreservation (dimethyl sulfoxide; DMSO–sucrose mix and glycerol) on the growth rate and lipid content of three new tropical freshwater algal isolates: Chorella sp. M2, Chlorella sp. M6, and Scenedesmus sp. R3, obtained from the Ecuadorian coast. The genetic and morphological characterization revealed a clear discrimination between these strains. All strains cultured with CAP exhibited a lower growth rate. Subsequent to cryopreservation, Chorella sp. M2, Chlorella sp. M6, and Scenedesmus sp. R3 presented no significant difference in growth rate between the cryopreservants. Further, a significantly higher lipid content was observed in the biomass cryopreserved with glycerol in relation to the DMSO–sucrose, with Chorella sp. M2 and Chlorella sp. M6 having twice as much as they had in the first treatment. These results highlight the relevance of selecting an appropriate method for storage, as the materials used can affect the biological performance of different tropical species, although it is still to be determined if the effects observed in this study are long lasting in subsequent cultures of these algae.

scholarly journals Short-term deleterious effects of standard isolation and cultivation methods on new tropical freshwater microalgae strains

2017 ◽  
Author(s):  
M. Magdalena Aray-Andrade ◽  
Miguel I Uyaguari-Diaz ◽  
J. Rafael Bermúdez Monsalve
Keyword(s):  
Growth Rate ◽  
Lipid Content ◽  
Genetic Characterization ◽  
Potential Effect ◽  
Tropical Species ◽  
Freshwater Microalgae ◽  
Lower Growth ◽  
Tropical Regions ◽  
Significant Difference ◽  
Tropical Freshwater

Algae with potential biotechnological applications in different industries are commonly isolate from the environment in order to obtain pure (axenic) stocks that can be safely stored for long periods of time. To obtain axenic cultures, antibiotics are frequently used, and cryopreservation is applied to keep standing stocks. However, many of these now standard methods were developed using strains coming from pristine-to-low intervened environments and cold-to-temperate regions. Thus, it is still not well understand the potential effect of said methods on the life cycle and biochemical profile of algae isolates from hiper-eutrophic and constant high-temperature tropical regions, which could potentially render them unsuitable for their intended biotechnological application. In this study, we conducted a genetic characterization (18S rRNA) and evaluated the effect of purification (use of the antibiotic chloramphenicol, CPA) and cryopreservation (dimethyl sulfoxide (DMSO)-sucrose mix and Glycerol) on the growth rate and lipid content of four new tropical freshwater algal isolates: Chorella sp. M2, Chlorella sp. M6, Scenedesmus sp. R3, and Coelastrella sp. A2, from the Ecuadorian coast. The genetic characterization showed a clear discrimination between strains. All strains cultured with CPA had a lower growth rate. After cryopreservation Coelastrella sp. A2 did not grow with both methods; Chorella sp. M2, Chlorella sp. M6 and Scenedesmus sp. R3 presented no significant difference in growth rate between the cryopreservants. A significantly higher lipid content was observed in biomass cryopreserved with glycerol in relation to DMSO-sucrose, with Chorella sp. M2 and Chlorella sp. M6 having twice as much in the first treatment. The results highlight the relevance of choosing an appropriate method for storage as the materials used can affect the biological performance of different tropical species, although is still to determine if the effects observed here are long lasting in subsequent cultures of these algae.

The Biology of Arctic Char (Salvelinus alpinus L.) in Northern Labrador

1956 ◽  
Vol 13 (6) ◽  
pp. 843-860 ◽  
Author(s):  
C. W. Andrews ◽  
E. Lear
Keyword(s):  
Salvelinus Alpinus ◽  
Age Determination ◽  
Market Value ◽  
Arctic Char ◽  
Flesh Colour ◽  
Food Items ◽  
Fin Ray ◽  
Significant Difference ◽  
Commercial Size

Arctic char (Salvelinus alpinus L.) from the commercial sea run were sampled at five stations in northern Labrador. Otoliths were used for age determination. In the southern part of the range—Adlatok and Nain—commercial size is reached at 6 years and at places farther north in 7 years. There is also a tendency for older fish to occur as one proceeds north.Age, weight, and length frequencies as well as their relationship to one another were determined.Vertebral counts indicate little, if any, intermingling of populations between: Adlatok and Nain, Okkak Bay and Hebron, Adlatok and Ramah, Nain and Hebron. Fin ray counts conform with the vertebral results but indicate no significant difference between Adlatok and Nain or Nain and Okkak Bay fish.Variations in flesh colour from white to deep red is a distinct characteristic of Arctic char in northern Labrador; flesh colour has a distinct bearing on the market value of the fish.Principal food items included capelin, launce, young of mailed sculpin, Amphipoda, and Euphausiacea.

Uncoupling of Somatic and Otolith Growth Rates in Arctic Char (Salvelinus alpinus) as an Effect of Differences in Temperature Response

1988 ◽  
Vol 45 (9) ◽  
pp. 1514-1524 ◽  
Author(s):  
Henrik Mosegaard ◽  
Henrik Svedäng ◽  
Kjell Taberman
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Salvelinus Alpinus ◽  
Somatic Growth ◽  
Arctic Char ◽  
Fish Growth ◽  
Effect Of Temperature ◽  
Otolith Growth ◽  
Different Temperatures ◽  
Wet Weight

Experiments were conducted to study the effect of temperature, fish size, and somatic growth rate on mean daily otolith growth rate in Arctic char (Salvelinus alpinus) fry fed maximum rations. Long-term experiments at two different temperatures (8 and 13 °C) showed exponential relationships between otolith weight and fish wet weight, with the exponent of wet weight for the higher temperature being significantly higher than for the lower temperature. Increasing exponents at each sampling date indicated a difference in growth rates of the char and its otoliths. Short-term experiments showed that specific growth rate of the fry at six different temperatures was that of an optimum curve whereas the otolith growth rate continued to increase with increasing temperatures. A clear uncoupling between otolith growth rate and fish growth rate was demonstrated whereas temperature and fish wet weight modeled otolith growth rate reasonably well. It was found that otolith growth rate expressed as daily increase in weight gave a model with better fit and higher generality than growth rate along various radii. Several examples of uncoupling between fish growth rate and otolith growth rate in the literature were reexamined, and an explanation of otolith growth rate in terms of a metabolic expression was suggested.

The Importance of Comparative Growth Rates in Determining the Canopy Composition of Tasmanian Rainforest

1995 ◽  
Vol 43 (3) ◽  
pp. 243 ◽  
Author(s):  
J Read
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
High Growth ◽  
Forest Stands ◽  
Lower Growth ◽  
Naturally Occurring ◽  
Significant Difference ◽  
Pot Trials ◽  
Canopy Composition ◽  
Study Sites

Growth rates of the rainforest canopy species Atherosperma moschatum Labill., Eucryphia lucida (Labill.) Baill., Nothofagus cunninghamii (Hook.) Oerst., Athrotaxis selaginoides D.Don and Phyllocladus aspleniifolius (Labill.) Hook.f. were measured in naturally-occurring seedlings and in seedlings grown in glasshouse pot trials. The highest field growth rates were recorded in N. cunninghamii on lowland sites on fertile, well-drained soils. On poorer soils, growth rates of N. cunninghamii were lower and there was little difference in growth rates between species. On the most acidic and probably infertile soil, the growth rate of P. aspleniifolius was 1.4 times higher than that of N. cunninghamii, although not significantly different at the 95% level. Similar trends in growth rates were recorded in pot trials. High growth rates were recorded in N. cunninghamii and E. lucida on fertile, well-drained soils, with generally lower growth rates in A. moschatum, P. aspleniifolius and A. selaginoides. No significant difference in growth rate was recorded among N. cunninghamii, E. lucida, A. moschatum and P. aspleniifolius when grown in poor soils or in low nutrient treatments. The trends in comparative growth rates correlate with the measured canopy composition of the study sites. Nothofagus cunninghamii dominates forest stands on sites where it has a clearly superior growth rate compared with co-occurring light-demanding species. Mixed canopies occur on sites where there is little or no difference between species' growth rates. However, not all patterns of canopy dominance can be explained by comparative growth rates alone. For example, P. aspleniifolius commonly dominates forest stands at low to mid-altitude where growth rates of all species are very low, but without necessarily a higher growth rate in P. aspleniifolius than in co-occurring species. The results of the growth rate studies are integrated with some other aspects of the biology of these species in a discussion of the mechanisms determining canopy composition of Tasmanian rainforests.

Movements and Growth of Arctic Grayling (Thymallus arcticus) and Juvenile Arctic Char (Salvelinus alpinus) in a Small Arctic Stream, Alaska

1975 ◽  
Vol 32 (5) ◽  
pp. 689-697 ◽  
Author(s):  
P. C. Craig ◽  
V. A. Poulin
Keyword(s):  
Growth Rate ◽  
Sexual Maturity ◽  
Salvelinus Alpinus ◽  
Arctic Char ◽  
Nursery Area ◽  
Fish Movements ◽  
Arctic Grayling ◽  
Thymallus Arcticus ◽  
Prudhoe Bay ◽  
Age Determinations

Fish movements were monitored in a small arctic stream that drains into the Kavik River near Prudhoe Bay, Alaska. The stream, which flows only during summer, served as a spawning and nursery area for Arctic grayling (Thymallus arcticus). Adult grayling entered the stream shortly after breakup and left again after spawning. Juvenile grayling also entered soon after breakup and many remained throughout the summer. Grayling fry emerged from the gravel in late June or early July and remained until freeze-up (mid-September). Small numbers of Arctic char (Salvelinus alpinus) juveniles also entered the stream to feed.The growth rate of grayling in the study stream was among the fastest recorded for arctic populations. Otolith-based age determinations were preferred as scales tended to underestimate the ages of old fish. Maximum observed age was 16 and age at sexual maturity ranged from 5 to 8.

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