scholarly journals Effects of warming winter embryo incubation temperatures on larval cisco (Coregonus artedi) survival, growth, and critical thermal maximum

2021 ◽  
Author(s):  
Taylor R. Stewart ◽  
Mark R. Vinson ◽  
Jason D. Stockwell
Keyword(s):  
Incubation Temperature ◽  
Phenotypic Variability ◽  
Lake Superior ◽  
Natural Habitat ◽  
Larval Growth ◽  
Lake Ontario ◽  
Critical Thermal Maximum ◽  
Thermal Maximum ◽  
Coregonus Artedi ◽  
Incubation Temperatures

Freshwater whitefishes, Salmonidae Coregoninae, are cold stenothermic fishes of ecological and socio-economic importance in northern hemisphere lakes that are warming in response to climate change. To address the effect of warming waters on coregonine reproduction we experimentally evaluated different embryo incubation temperatures on post-hatching survival, growth, and critical thermal maximum of larval cisco (Coregonus artedi) sampled from lakes Superior and Ontario. Embryos were incubated at water temperatures of 2.0, 4.4, 6.9, and 8.9C to simulate present and increased winter temperatures, and hatched larvae were reared in a common environment. For both populations, larval survival and critical thermal maximum were negatively related to incubation temperature, and larval growth was positively related to incubation temperature. The magnitude of change across incubation temperatures was greater in the population sampled from Lake Superior than Lake Ontario for all traits examined. The more rapid decrease in survival and critical thermal maximum across incubation temperatures for larval cisco in Lake Superior, compared to those from Lake Ontario, suggests that Lake Superior larvae may possess a more limited ability to acclimate to and cope with increasing winter water temperatures. However, the rapid increase in growth rates across incubation temperatures in Lake Superior larvae suggests they could recover better from hatching at a small length induced by warm winters, as compared to Lake Ontario larvae. Our results suggest propagation and restoration programs may want to consider integrating natural habitat preferences and maximizing phenotypic variability to ensure offspring are set up for success upon stocking.

scholarly journals Shining a light on Laurentian Great Lakes cisco (Coregonus artedi): how ice coverage may impact embryonic development

2021 ◽  
Author(s):  
Taylor R Stewart ◽  
Mark R Vinson ◽  
Jason D Stockwell
Keyword(s):  
Light Intensity ◽  
Great Lakes ◽  
Light Exposure ◽  
Lake Superior ◽  
Lake Ontario ◽  
Yolk Sac ◽  
Laurentian Great Lakes ◽  
Embryo Survival ◽  
Ice Coverage ◽  
Coregonus Artedi

Changes in winter conditions, such as decreased ice coverage and duration, have been observed in the Laurentian Great Lakes over the past 20+ years and hypothetically linked to low Coregonus spp. survival to age-1. Most cisco (Coregonus artedi) populations are autumn spawners whose embryos incubate under ice throughout the winter. The quantity and quality of light during winter is regulated by ice and snow coverage, and light has been shown to affect embryo survival and development in some teleosts. We experimentally evaluated how cisco embryos from lakes Superior and Ontario responded to three light treatments that represented day-light intensity under 0-10, 40-60, and 90-100% ice coverage. Embryonic response measures included two developmental factors (embryo survival and incubation period) and two morphological traits (length-at-hatch and yolk-sac volume). Embryo survival was highest at the medium light treatment and decreased at high and low treatments for both populations suggesting cisco may be adapted to withstand some light exposure from inter-annual variability in ice coverage. Light intensity had no overall effect on length of incubation. Length-at-hatch decreased with increasing light in Lake Superior, but had no effect in Lake Ontario. Yolk-sac volume was positively correlated with increasing light in Lake Superior and negatively correlated in Lake Ontario. Contrasting responses in embryo development between lakes suggests differences in populations' flexibility to light. These results provide a step towards better understanding the recent high variability observed in coregonine recruitment and may help predict what the future of this species may look like under current climate trends.

Phytotoxic Effect of Decaying Quackgrass (Agropyron repens) Residues

Weed Science ◽  
1979 ◽  
Vol 27 (6) ◽  
pp. 595-598 ◽  
Author(s):  
T. V. Toai ◽  
D. L. Linscott
Keyword(s):  
Incubation Temperature ◽  
Soil Surface ◽  
Water Soluble ◽  
Water Extracts ◽  
Phytotoxic Activity ◽  
Phytotoxic Effect ◽  
Effects Of Temperature ◽  
Incubation Temperatures ◽  
Toxin Formation ◽  
Agropyron Repens

We studied the effects of temperature (5, 10, 20, and 30 C) on the phytotoxic activity of decaying quackgrass [Agropyron repens (L.) Beauv.] leaves and rhizomes that were incubated in soils for 0, 1, 2, 4, and 6 weeks. Alfalfa (Medicago sativa L.) seeds were grown for 96 h in water, water extracts of control soils, and water extracts of soil with quackgrass rhizomes or leaves. Dried quackgrass rhizomes and leaves contained water-soluble toxins that inhibited alfalfa seedling development and growth. There was a strong interaction between incubation time and temperature on the development of additional toxins by decomposing quackgrass. High incubation temperature (30 C) accelerated toxin formation and ultimate decay. Intermediate temperature (20 C) delayed toxin formation and decay. Low incubation temperatures (5 C and 10 C) prevented formation of additional toxin. In all extracts of quackgrass and soil that had been incubated for 6 weeks, normal alfalfa seedling number equaled that in water. However, seedling growth varied with incubation temperatures.Treatment of quackgrass with glyphosate [N-(phosphonomethyl) glycine] in the greenhouse did not influence the toxicity of decaying quackgrass leaves. The highest toxic effect was noted after 1 week of decay on the soil surface.

Thermal and water source effects upon the stability of enteroviruses in surface freshwaters

1989 ◽  
Vol 35 (4) ◽  
pp. 474-480 ◽  
Author(s):  
Christon J. Hurst ◽  
William H. Benton ◽  
Kim A. McClellan
Keyword(s):  
Bacterial Growth ◽  
Incubation Temperature ◽  
Water Source ◽  
Inactivation Rate ◽  
Human Enterovirus ◽  
Strongly Correlated ◽  
Artificial Lake ◽  
Viral Inactivation ◽  
Term Survival ◽  
Incubation Temperatures

The long-term survival of three human enterovirus serotypes, Coxsackievirus B3, echovirus 7, and poliovirus 1 was examined in samples of surface freshwater collected from five sites of physically different character. These were an artificial lake created by damming a creek, a small groundwater outlet pond, both a large- and a medium-sized river, and a small suburban creek. Survival was studied at temperatures of −20, 1, and 22 °C. The average amount of viral inactivation was 6.50–7.0 log10 units over 8 weeks at 22 °C, 4–5 log10 units over 12 weeks at 1 °C, and 0.4–0.8 log10 units over 12 weeks at −20 °C. The effect of incubation temperature upon viral inactivation rate was statistically significant (p < 0.00001). As determined by pairing tests, survival was also significantly related to both viral serotype and water source at each of the three incubation temperatures (p ≤ 0.05). Efforts were made to determine whether the rate of viral inactivation observed at the different incubation temperatures was related to characteristics inherent to the water that was collected from the different locations. The characteristics examined included physical and chemical parameters, indigenous bacterial counts, and the amount of bacterial growth that the waters would support (measured as the maximum number of generations which seeded bacteria could undergo after being placed into either pasteurized or sterile-filtered water samples). Analysis of viral inactivation rate versus these characteristics revealed three apparent effectors of viral persistence. These were (i) hardness and conductivity, both of which strongly correlated with one another; (ii) turbidity and suspended solids content, both of which strongly correlated with one another; and (iii) the number of generations of bacterial growth that a sample was capable of supporting, which also correlated with hardness and conductivity.Key words: virus, survival, inactivation rate, water.

Nest temperature´s influence on morphology of Dermochelys coriacea hatchlings incubated in hatcheries in Oaxaca, Mexico

2021 ◽  
Author(s):  
Jesús García-Grajales ◽  
Juan Francisco Meraz ◽  
José Luis Arcos García ◽  
Eustacio Ramírez Méndez
Keyword(s):  
Incubation Temperature ◽  
Carapace Width ◽  
Principal Component ◽  
Dermochelys Coriacea ◽  
Egg Mass ◽  
Natural Environments ◽  
Data Logger ◽  
Geometric Morphometric ◽  
Low Weight ◽  
Incubation Temperatures

The influence of nest incubation temperatures on the carapace shape and morphological traits of Dermochelys coriacea (Vandelli 1761) hatchlings incubated in two hatcheries of Oaxaca, Mexico was evaluated. This study was carried out from October 2016 through May 2017. On each beach, there are community groups consisting of volunteers without association with universities, that protect and relocate the nests to increase hatching success. In each translocated nest, a data logger was placed in the centre of the egg mass. Hatchlings were collected as they emerged from each nest. The carapaces of the hatchlings were photographed and subjected to geometric morphometric analysis; later, hatchlings were weighed and their bodies were measured. The mean temperature of 12 nests in each hatchery were recorded, with no significant differences between hatcheries. The principal component analysis (PCA) revealed an overlapping of the carapace shape under different duration of temperature. Temperature had a significant influence on hatchling morphology. Higher mean incubation temperatures produced hatchlings with low weight, smaller appendage; narrower carapace width and shorter flippers length. Lower mean incubation temperatures produced hatchlings that had greater weight, greater appendage width, wider carapace width and longer flipper length. Results indicate that the D. coriacea hatchlings incubated in hatcheries demonstrate morphology that varies in relation to nest incubation temperature in a similar way to hatchlings produced in natural environments.

Critical thermal maximum in mice

1976 ◽  
Vol 40 (5) ◽  
pp. 683-687 ◽  
Author(s):  
G. L. Wright
Keyword(s):  
Heat Stress ◽  
Cooling Capacity ◽  
Heating Time ◽  
Critical Thermal Maximum ◽  
Thermal Limit ◽  
Ambient Temperatures ◽  
Thermal Maximum ◽  
Righting Reflex ◽  
Colonic Temperature ◽  
Extended Exposure

The critical thermal maximum (the colonic temperature of heat-induced convulsion and righting reflex loss) and thermoregulatory response of male mice were examined following I, exposure to colonic temperature (Tco) 42 degrees C; II, a single exposure to the critical thermal maximum (Tco 44 degrees C); AND III, acclimation at ambient temperatures of 15 or 30 degrees C for 14 days. The critical thermal maximum (CTM) was greater in 30 degrees C acclimated mice than 15 degrees C acclimated mice but was unchanged in mice surviving exposure to Tco 42 degrees C or the CTM. The heating time to apparent breakdown of thermoregulation coincident with an explosive rise in the Tco during exposure to ambient temperature 40.8 degrees C was increased (100%) during the 48-h period following exposure to Tco 42 degrees. It appeared that mice exposed to severe, short-term heat stress (Tco 42 degrees) undergo a compensatory increase in their thermoregulatory cooling capacity with little or no change in the upper temperature tolerated. The animals did, however, exhibit the capability for adaptive adjustments of the upper thermal limit during extended exposure to the more prolonged and less severe environmental heat stress of acclimation at 30 degrees C.

scholarly journals Water temperature affects aggressive interactions in a Neotropical cichlid fish

2018 ◽  
Vol 16 (1) ◽  
Author(s):  
Manuela L. Brandão ◽  
Gisele Colognesi ◽  
Marcela C. Bolognesi ◽  
Roselene S. Costa-Ferreira ◽  
Thaís B. Carvalho ◽  
...  
Keyword(s):  
Aggressive Behavior ◽  
Water Temperature ◽  
Elevated Temperatures ◽  
Cichlid Fish ◽  
Aquatic Organisms ◽  
Swimming Activity ◽  
Critical Thermal Maximum ◽  
Physiological Mechanisms ◽  
Aggressive Interactions ◽  
Thermal Maximum

ABSTRACT Changes in water temperature may affect the aggressive behavior of aquatic organisms, such as fish, either by changing some physiological mechanisms or by increasing the probability of encounters between individuals as a result of variation in their swimming activity. In our study, we evaluated the influence of increasing and decreasing temperature on the aggressive behavior of the Neotropical cichlid fish Cichlasoma paranaense. Firstly, we tested the critical thermal maximum (CTMax) tolerated by this species. Then, we tested the effect of decreasing or increasing the water temperature in 6o C (starting at 27° C) on the aggressive interactions of fish under isolation or housed in groups. We found a CTMax value of 39° C for C. paranaense. We also observe that a 6° C decrease in water temperature lowers swimming activity and aggressive interactions in both isolated and group-housed fish, as expected. On the other hand, the increase in temperature had no effect on the fish’s aggressive behavior, neither for isolated nor for grouped fish. We concluded that C. paranaense shows high tolerance to elevated temperatures and, in turn, it does not affect aggressive behavior. Nevertheless, we cannot dismiss possible effects of elevated temperatures on aggressive interactions over longer periods.

Examination of direct daytime predation by Coregonus artedi on Bythotrephes longimanus in Harp Lake, Ontario, Canada: no evidence for the refuge hypothesis

2009 ◽  
Vol 66 (3) ◽  
pp. 449-459 ◽  
Author(s):  
Joelle D. Young ◽  
Ellis R. Loew ◽  
Norman D. Yan
Keyword(s):  
Cold Water ◽  
Lake Ontario ◽  
Planktivorous Fish ◽  
Bythotrephes Longimanus ◽  
Death Rates ◽  
Direct Observations ◽  
Coregonus Artedi ◽  
Selection Of ◽  
Gill Netting ◽  
Harp Lake

Since its introduction to Harp Lake, Ontario, Canada, summer abundance of the cladoceran zooplanktivore Bythotrephes longimanus has fluctuated substantially both among and within years. The principal planktivorous fish in Harp Lake is the cold-water Coregonus artedi (cisco). Previous studies hypothesized that Bythotrephes abundance was affected by the thickness of an ephemeral, dark, daytime refuge from cisco that potentially established at the bottom of the metalimnion. During summer of 2003, we estimated peak daytime refuge thickness by simulating light energy visible to cisco and found it was always negative and did not correlate with Bythotrephes death rates. Direct observations using gill-netting and acoustical methods suggested that cisco had frequent metalimnetic forays. Additionally, including years 2000–2004, the previous correlation between mean Bythotrephes abundance and refuge thickness no longer held. The refuge hypothesis appears to fail, as the amount of metalimnetic illumination was always above the level at which cisco reaction distance to prey is maximal. Selection of Bythotrephes by cisco instead appeared to increase once Bythotrephes became abundant, remaining consistent and nontrivial even after Bythotrephes population declined.

scholarly journals Effects of constant incubation regimes on eggs and hatchlings of the egg-laying skink, Oligosoma suteri

2021 ◽  
Author(s):  
◽  
Kelly Maree Hare
Keyword(s):  
Hatching Success ◽  
Incubation Temperature ◽  
Unit Length ◽  
Condition Index ◽  
Egg Laying ◽  
Maternal Influence ◽  
Temperature Dependent ◽  
Sprint Speed ◽  
Fitness Traits ◽  
Incubation Temperatures

<p>The conditions under which reptilian eggs are incubated affect survival probability and physiological attributes of the progeny. The egg-laying skink, Oligosoma suteri, is the only endemic oviparous lizard in New Zealand. No controlled laboratory incubation had previously been undertaken, and thus no information was available on the requirements for successful captive incubation. I studied the effects of incubation regime on the eggs and hatchlings of O. suteri to four months of age. Oligosoma suteri eggs (n = 174) were randomly distributed among three constant incubation temperatures (18°C, 22°C and 26°C) and two water potentials (-120 kPa and -270 kPa). Hatching success and hatchling survival were greatest at 22°C and 26°C, with hatchlings from 18°C incubation suffering from physical abnormalities. Incubation regime and maternal influence did not affect sex of individuals, with equal sex ratios occurring from each incubation treatment. Hatchlings from the 22°C and -120 kPa incubation treatments were larger, for most measurements, and warmer incubation temperatures resulted in increased growth rates. Juveniles from 22°C and 26°C and individuals with greater mass per unit length (condition index) sprinted faster over 0.25 m. Sprint speed was positively correlated with ambient temperature. At four months of age sprint speed decreased in 18°C individuals and individuals incubated at 26°C and -270 kPa compared to their performance at one month. The results suggest that the most successful captive incubation regime for O. suteri is 22°C and -120 kPa. This study also shows that temperature-dependent sex determination does not occur in O. suteri, but that fitness traits are influenced by incubation temperature.</p>

A late Lake Minong transgression in the Lake Superior basin as documented by sediments from Fenton Lake, Ontario

2010 ◽  
Vol 47 (3) ◽  
pp. 313-326 ◽  
Author(s):  
Andy Breckenridge ◽  
Thomas V. Lowell ◽  
Timothy G. Fisher ◽  
Shiyong Yu
Keyword(s):  
Lake Superior ◽  
Lake Ontario ◽  
Lake Minong
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