To feed or flee: early life-history behavioural strategies of juvenile lake sturgeon (Acipenser fulvescens) during risk-sensitive foraging

2020 ◽  
Vol 98 (8) ◽  
pp. 541-550
Author(s):  
F. Bjornson ◽  
M. Earhart ◽  
W.G. Anderson
Keyword(s):  
Predation Risk ◽  
Early Life History ◽  
Lake Sturgeon ◽  
Whole Body ◽  
Acipenser Fulvescens ◽  
Reduced Body ◽  
Risk Sensitive ◽  
Partial Cover ◽  
Risk Sensitive Foraging ◽  
Behavioural Strategies

Balancing foraging opportunities with predation risk can promote complex behavioural strategies in juvenile fishes, particularly in northern temperate environments with short growing seasons. To test how predation experience may influence foraging effort and risk assessment of juvenile lake sturgeon (Acipenser fulvescens Rafinesque, 1817), flight response and substrate preference behavioural measurements were taken during critical life periods of early exogenous feeding (∼60 days post fertilization (dpf)) and pre-winter (∼160 dpf). Lake sturgeon were placed in arenas with partial cover and exposed white plastic bottom. Chemical alarm cue (AC) was introduced to predator naïve individuals in the presence or absence of food over the exposed portion of the arena to simulate risk sensitive foraging over diurnal and seasonal periods. The same protocol was run on predator-experienced individuals, which were classically conditioned to predator cue (PC) prior to the trials. Whole-body cortisol measures were also taken to determine the physiological response to predation experience. Results suggest a propensity to forage in spite of predation risk during the naïve ∼60 dpf trials and highlight context-specific anti-predator responses of naïve and experienced lake sturgeon. Elevated basal whole-body cortisol levels and reduced body condition (p < 0.05) were observed with increased predator experience.

scholarly journals Response in Growth, Scute Development, and Whole-Body Ion Composition of Acipenser fulvescens Reared in Water of Differing Chemistries

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1419
Author(s):  
Janet Genz ◽  
Rachael Hicks
Keyword(s):  
River Water ◽  
Growth And Development ◽  
Lake Sturgeon ◽  
Whole Body ◽  
Acipenser Fulvescens ◽  
Water Type ◽  
Ion Composition ◽  
Ion Concentrations ◽  
Before And After ◽  
Yolk Absorption

In fishes, environmental ion availability can have substantial effects on growth and development. This study examined the development of Lake Sturgeon in response to the varying environmental ion availability that they experience as part of a conservation stocking program. We reared sturgeon in natural water from the Coosa River, which had higher concentrations of Mg2+, Na+, and Zn2+ than standard hatchery conditions, while [Ca2+] at the Warm Springs National Fish Hatchery was 2× higher than in the Coosa River. Eggs were hatched in each water type and the larvae were sampled at time points before and after yolk absorption during the first 8 weeks of development. Total length and weight in WSNFH larvae were significantly higher than larvae in Coosa River water starting at 8 dph, indicating that growth was dependent on the different environmental ion levels. Concentrations of the ions of interest were also determined for whole-body acid digests of the exposed Lake Sturgeon. We found that Lake Sturgeon reared in Coosa River water had significantly higher magnesium and zinc than Lake Sturgeon reared in WSNFH water (p < 0.05), while calcium was significantly higher in WSNFH than Coosa River water. This difference shows that different environmental ion concentrations also impact the overall development of larval Lake Sturgeon.

scholarly journals Nutritional state reveals complex consequences of risk in a wild predator–prey community

2017 ◽  
Vol 284 (1858) ◽  
pp. 20170757 ◽  
Author(s):  
Philip D. DeWitt ◽  
Matthew S. Schuler ◽  
Darcy R. Visscher ◽  
Richard P. Thiel
Keyword(s):  
Predation Risk ◽  
Nutritional State ◽  
Prey Population ◽  
Adult Survival ◽  
Predator Prey ◽  
Animal Populations ◽  
Risk Sensitive ◽  
Risk Sensitive Foraging ◽  
Insight Into ◽  
Prey Populations

Animal populations are regulated by the combined effects of top-down, bottom-up and abiotic processes. Ecologists have struggled to isolate these mechanisms because their effects on prey behaviour, nutrition, security and fitness are often interrelated. We monitored how forage, non-consumptive effects (NCEs), consumptive predation and climatic conditions influenced the demography and nutritional state of a wild prey population during predator recolonization. Combined measures of nutrition, survival and population growth reveal that predators imposed strong effects on the prey population through interacting non-consumptive and consumptive effects, and forage mechanisms. Predation was directly responsible for adult survival, while declining recruitment was attributed to predation risk-sensitive foraging, manifested in poor female nutrition and juvenile recruitment. Substituting nutritional state into the recruitment model through a shared term reveals that predation risk-sensitive foraging was nearly twice as influential as summer forage conditions. Our findings provide a novel, mechanistic insight into the complex means by which predators and forage conditions affect prey populations, and point to a need for more ecological studies that integrate behaviour, nutrition and demography. This line of inquiry can provide further insight into how NCEs interactively contribute to the dynamics of terrestrial prey populations; particularly, how predation risk-sensitive foraging has the potential to stabilize predator–prey coexistence.

Risk sensitive foraging: an experimental study of a solitary marsupial.

2005 ◽  
Vol 27 (2) ◽  
pp. 231 ◽  
Author(s):  
LN Evans ◽  
MA Elgar ◽  
KA Handasyde
Keyword(s):  
Experimental Study ◽  
Early Detection ◽  
Predation Risk ◽  
Trade Off ◽  
Risk Sensitive ◽  
Risk Of Predation ◽  
Foraging Decisions ◽  
Foraging Site ◽  
Risk Sensitive Foraging

DETECTION and avoidance of predators are the principle strategies employed by prey to evade attack; by scanning their environment, prey individuals can reduce the likelihood of a predator approaching to within striking distance (Elgar 1989; Lima and Dill 1990). However, vigilance is often incompatible with foraging behaviours, and thus animals may be forced to trade-off the risk of predation against acquiring food. Consequently, the quality of a particular resource patch and its associated predation risk may influence the foraging decisions of animals (Werner et al. 1983; Newman and Caraco 1987; Heithaus and Dill 2002). Cover is an important feature of a foraging site because it can provide a hiding place to escape potential predators (Lazarus and Symonds 1992). Thus, animals may prefer foraging sites that are close to cover, or adjust their level of vigilance at different distances from cover in order to compensate for changes in the chance of early detection and escape (Elgar 1989; Lima and Dill 1990; Lima et al. 1985; Kramer and Bonenfant 1997).

Reproduction, early life history, and characteristics of the spawning grounds of the lake sturgeon (Acipenser fulvescens) in Des Prairies and L'Assomption rivers, near Montréal, Quebec

1992 ◽  
Vol 70 (9) ◽  
pp. 1681-1689 ◽  
Author(s):  
Michel LaHaye ◽  
Alain Branchaud ◽  
Marc Gendron ◽  
Richard Verdon ◽  
Réjean Fortin
Keyword(s):  
Life History ◽  
Water Temperature ◽  
River Water ◽  
Early Life ◽  
Early Life History ◽  
Lake Sturgeon ◽  
Acipenser Fulvescens ◽  
Spawning Ground ◽  
Spawning Grounds ◽  
River Water Temperature

Spawning, early life history, and physical characteristics of lake sturgeon (Acipenser fulvescens) spawning grounds were compared between two rivers located in the Montréal region. The spawning grounds in Des Prairies River were enlarged in 1985, during the reconstruction of the Des Prairies power plant spillway. The L'Assomption River spawning ground has not been physically altered by human activities. In 1989, spawning occurred between May 14 and 27 in Des Prairies River (water temperature 11.6–15.4 °C) and between May 15 and 22 in L'Assomption River (water temperature 11–21.5 °C). On a given date, embryos were slightly more developed in L'Assomption River, where hatching began 3 days earlier than in Des Prairies River (26 vs. 29 May). The great similarity in the spawning and early development sequence suggests that spawners utilizing these two rivers cannot be differentiated on the basis of these biological characters. In 1990, larval emigration from the Des Prairies River spawning ground began on May 29, 11 days after peak spawning. The larvae drifted to the St. Lawrence River in June (peak on 16 June), at a mean length of approximately 20 mm. In both rivers the proportion of stations with eggs present tends to decrease as depth and current velocity increase. Egg deposition occurs on a wide variety of substrate types, ranging from fine- to medium-sized gravel to boulders. Although utilization varies with prevailing hydrological conditions, in 1990 the artificial spawning bed in Des Prairies River showed a high proportion of stations with eggs present.

Seasonal Variation in Plasma Nonesterified Fatty Acids of Lake Sturgeon (Acipenser fulvescens) in the Vicinity of Hydroelectric Facilities

1993 ◽  
Vol 50 (11) ◽  
pp. 2440-2447 ◽  
Author(s):  
R. S. McKinley ◽  
T. D. Singer ◽  
J. S. Ballantyne ◽  
G. Power
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Lake Sturgeon ◽  
Acipenser Fulvescens ◽  
Total Plasma ◽  
Nefa Concentration ◽  
Plasma Nefa ◽  
Nonesterified Fatty Acids ◽  
Plasma Nefa Concentration ◽  
Fatty Acid Species

To establish the effects of hydroelectric generation on the health of lake sturgeon (Acipenser fulvescens), seasonal variations in plasma nonesterified fatty acids (NEFAs) upstream and downstream from hydroelectric stations were measured over a 2-yr period. Plasma NEFA profiles were also compared up- and downstream of the stations for differences in utilization of individual NEFA species as substrates for lipid oxidation. Significantly higher levels of total plasma NEFA were found in lake sturgeon upstream (2355 ± 395.9 nmol/mL) compared with those downstream (798 ± 133.5 nmol/mL) of the generating stations during the spring. The NEFA profiles for several key fatty acid species differed significantly among seasons up- and downstream of the facilities. In particular, during spring and summer, the levels of oleic acid (18:1n9) were highest upstream of the stations and levels of a polyunsaturated fatty acid, docosahexaenoic acid (22:6n3), were higher below rather than above the stations. The differences in plasma NEFA concentration may be attributed to altered nutritional status due to the varying flow regime located downstream of the hydroelectric stations.

Environmental and lunar cues are predictive of the timing of river entry and spawning-site arrival in lake sturgeon Acipenser fulvescens

2012 ◽  
Vol 81 (1) ◽  
pp. 35-53 ◽  
Author(s):  
P. S. Forsythe ◽  
K. T. Scribner ◽  
J. A. Crossman ◽  
A. Ragavendran ◽  
E. A. Baker ◽  
...  
Keyword(s):  
Lake Sturgeon ◽  
Acipenser Fulvescens ◽  
Spawning Site
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