scholarly journals The effect of water temperature on the number of moults and growth of juvenile signal crayfish Pacifastacus leniusculus Dana

2009 ◽  
Vol 54 (No. 6) ◽  
pp. 286-292 ◽  
Author(s):  
P. Kozák ◽  
M. Buřič ◽  
J. Kanta ◽  
A. Kouba ◽  
P. Hamr ◽  
...  

The growth rate, frequency of moulting, and intermoult intervals of juvenile <I>Pacifastacus leniusculus</I> were studied under experimental conditions over a period of 3 months. Juveniles were reared individually in small boxes at two different temperatures: 14.31 ± 0.64°C (cold water) and 20.54 ± 0.69°C (warm water). Although the average weight and length of consecutive stages were similar at both temperatures, juveniles in warm water attained more moults. Within the age group juveniles achieved a higher length and weight in warm water than in cold water. Three month-old juveniles reached 147 mg and 18.5 mm in cold water at the 6<sup>th</sup> stage of development, and 259 mg and 22.2 mm in warm water at the 8<sup>th</sup> stage. Specific growth rate (SGR) decreased (5.6 and 10.4 for cold and warm water in the first stage, respectively) and reached final values of 1.4 and 1.5 after 3 months of growth. SGR was significantly higher in warm water and showed negative correlations with the number of days after hatching and number of moults. Duration of intermoult periods was significantly influenced by water temperature, with five moults attained in cold water compared to seven in warm water. All intermoult periods were significantly longer in cold water than in warm water. The average percent weight and length increments decreased with increasing number of moults, length, weight and number of days after hatching. In warm water increments were higher (89.8% and 21.8% for weight and length, respectively) than in cold water (68.5% and 20.3% for weight and length, respectively), and the decrease was faster. However, the final values were similar at both temperatures (about 36% and 11% for weight and length, respectively). The mean absolute weight and length moult increments were not significantly influenced by water temperature. Although the temperature influenced growth due to the number of moults, the duration of individual intermoult periods did not affect the weight and length of juveniles in particular stages.

1973 ◽  
Vol 133 (4) ◽  
pp. 735-738 ◽  
Author(s):  
Ian A. Johnston ◽  
Neil Frearson ◽  
Geoffrey Goldspink

1. Myofibrillar adenosine triphosphatase (ATPase) activities were measured for white myotomal muscle of 19 species of fish. 2. The activity was measured at different temperatures and after periods of preincubation at 37°C. 3. The inactivation half-life at 37°C depended on environmental temperature, increasing as the temperature increased. 4. Cold-water fish had higher myofibrillar adenosine triphosphatase activity at low temperatures than had warm-water fish. 5. The significance of these results is discussed.


2020 ◽  
Vol 45 (7) ◽  
pp. 563-572
Author(s):  
Kristen E Kay ◽  
Laura E Martin ◽  
Kimberly F James ◽  
Sashel M Haygood ◽  
Ann-Marie Torregrossa

Abstract Increasing evidence suggests that stimulus temperature modifies taste signaling. However, understanding how temperature modifies taste-driven behavior is difficult to separate as we must first understand how temperature alone modifies behavior. Previous work has suggested that cold water is more rewarding and “satiating” than warm water, and water above orolingual temperature is avoided in brief-access testing. We explored the strength of cold water preference and warm water avoidance by asking: (1) if cold temperature alone was sufficient to condition a flavor preference and (2) if avoidance of warm stimuli is driven by novelty. We addressed these questions using custom-designed equipment that allows us to monitor and maintain solution temperatures. We conducted two-bottle preference tests, after pairing Kool-Aid flavors with 10 or 40 °C. Rats preferred the flavor paired with cold temperature, both while it was cold and for 1 day while solutions were presented at 22 °C. We then examined the role of novelty in avoidance of 40 °C. Rats were maintained on 10, 22, or 40 °C water in their home cage to increase familiarity with the temperatures. Rats were then subject to a series of brief-access taste tests to water or sucrose at 10 to 40 °C. Rats that had 40 °C experience licked more to 40 °C water, but not sucrose, during brief-access testing. In a series of two-bottle preference tests, rats maintained on 40 °C water had a decreased preference for 10 °C water when paired opposite 40 °C water. Together, these data contribute to our understanding of orosensory-driven behavior with water at different temperatures.


1990 ◽  
Vol 68 (3) ◽  
pp. 442-450 ◽  
Author(s):  
Dale R. Calder

Hydroids investigated in estuaries of Virginia and South Carolina, USA, were characteristically seasonal in occurrence. Of 20 species studied in Virginia, 14 were active only during warmer months and 6 only during colder months of the year. Seven of the 18 species examined in South Carolina were active all year, whereas 9 were active only in warmer months and 2 only during colder months. Reflecting the differing temperature regimes of the two study areas, warm-water species were active for a longer period of time in South Carolina than in Virginia; cold-water species were active longer in Virginia than in South Carolina. Warm-water species commenced activity in late winter or spring at higher temperatures than those coinciding with hydranth regression in autumn or early winter. Activity in cold-water species began at lower temperatures than those observed at regression in spring. Correlations were apparent in the seasonality, water temperature tolerances, and latitudinal distribution of most species. Field observations and laboratory experiments demonstrated that a number of species survived unfavourable periods as dormant coenosarc in stems and stolons. With the return of favourable conditions, new growth began and hydranths were regenerated from dormant tissue. Water temperature is considered the prime factor influencing the seasonal activity–inactivity cycles of hydroids in the two study areas.


Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 951 ◽  
Author(s):  
Bo Jiang ◽  
Fushan Wang ◽  
Guangheng Ni

Reservoirs change downstream thermal regimes by releasing water of different temperatures to that under natural conditions, which may then alter downstream biodiversity and ecological processes. The hydropower exploitation in the mainstream Lancang-Mekong River has triggered concern for its potential effects on downstream countries, especially the impact of the released cold water on local fishery production. However, it was observed recently that the annual water temperature downstream of the Jinghong Reservoir (near the Chinese border) has increased by 3.0 °C compared to its historical average (1997–2004). In this study, a three-dimensional (3D) model of the Jinghong Reservoir was established to simulate its hydro- and thermodynamics. Results show that: (1) the impoundment of the Jinghong Reservoir contributed about 1.3 °C to the increment of the water temperature; (2) the solar radiation played a much more important role in comparison with atmosphere-water heat exchange in changing water temperatures; and (3) the outflow rate also imposed a significant influence on the water temperature by regulating the residence time. After impoundment, the residence time increased from 3 days to 11 days, which means that the duration that the water body can absorb solar radiation has been prolonged. The results explain the heating mechanism of the Jinghong Reservoir brought to downstream water temperatures.


2018 ◽  
Vol 65 ◽  
Author(s):  
R. Jayakumar ◽  
M. Sakthivel ◽  
A. K. Abdul Nazar ◽  
G. Tamilmani ◽  
P. Rameshkumar ◽  
...  

The impact of increase in temperature and light intensity on development and metamorphosis of hatchery produced larvae of silver pompano <em>Trachinotus blochii</em> (Lacepede, 1801) was studied. Two sets of larviculture tanks (Set 1 and Set 2) in triplicate were exposed to two different temperatures and varying light intensities. The growth of the larvae from day one to day 25 post-hatch (dph) and metamorphosis were studied. It was found that an increase of 2°C water temperature and increased light intensity significantly reduced the growth. The percentage of growth reduction gradually decreased and got stabilised towards the end of larviculture with a mean reduction of 15%. Further, a delay of three days in metamorphosis was also observed in Set 2. The reduced growth rate coupled with change in pigmentation of larvae can be considered as the resilience response of the larvae to combat temperature and light stress without compromising survival.


Author(s):  
P.D. Muir ◽  
N.B. Smith ◽  
J.C. Lane

Abstract This study set out to demonstrate what could be achieved in terms of lamb growth rates under controlled experimental conditions. Ewes with high breeding values for progeny growth rate were selected from within a flock of 900 ewes and mated using AI to a ram with a high breeding value for progeny growth rate. Of the 70 ewes mated, 44 reared 75 lambs (170%) to 12 weeks of age. Lamb birth weights averaged 4.8 kg. Ewes and lambs were fed on pasture covers between 1800 and 2600 kg DM/ha throughout lactation. At 12 weeks of age, the average weight of all lambs in the mob averaged 39 kg. Average growth rate of all lambs from birth to 12 weeks was 409 g/d, with single, twin and triplet lambs averaging 437, 407 and 380 g/d respectively. The best individual lamb grew at 549 g/d and weighed 51.6 kg at 12 weeks. This demonstration sets a new benchmark for both mob and individual lamb growth rates and indicates what can be achieved with a combination of genetics for growth, ewes with good milking ability and good pasture feeding conditions. Keywords: breeding value, lamb growth rate, milking ability, pasture quality


Author(s):  
Ana Gay ◽  
Rodrigo Zacca ◽  
J. Arturo Abraldes ◽  
Esther Morales-Ortíz ◽  
Gracia López-Contreras ◽  
...  

AbstractThis study aimed to compare three swimming conditions in a swimming flume with water at 26 ℃ (using swimsuit) and 18 ℃ (randomly with swimsuit and wetsuit). Seventeen swimmers (32.4±14.7 years old, 175.6±0.06 cm height, and 70.4±9.8 kg body mass) performed three bouts until exhaustion at a 400-m front crawl pace (24 h intervals). ANOVA repeated measures compared the experimental conditions. Swimming at 26 ℃ with swimsuit evidenced a higher metabolic demand (total energy expenditure; (E)), comparing to 18 ℃ swimsuit (p=0.05) and with 18 ℃ wetsuit (p=0.04). The 26 ℃ swimsuit condition presented higher peak oxygen uptake (VO2peak), blood lactate concentrations ([La-]peak), rate of perceived exertion (RPE), maximal heart rate (HRmax), anaerobic lactic energy (AnL), E, energy cost (C), V̇O2 amplitude (Ap), and stroke rate (SR), but lower stroke length (SL) and stroke index (SI) than 18 ℃ wetsuit. The 18 ℃ swimsuit condition (comparing to wetsuit) lead to higher V̇O2peak, [La-]peak, HRmax, E, C, Ap, and SR but lower SL and SI. Swimming at aerobic power intensity with swim and wetsuit at 18 ℃ does not induce physiologic and biomechanical disadvantages compared to 26 ℃. The results suggested that the use of wetsuit might increase performance at 18 ℃ water temperature for competitive master swimmers. Its use is thus recommended in open water swimming competitions when the water temperature is 18–20 ℃.


1986 ◽  
Vol 61 (5) ◽  
pp. 1885-1890
Author(s):  
D. R. Knight ◽  
T. Santoro ◽  
K. R. Bondi

We found a difference between the venous hematocrits of immersed and nonimmersed arms during immersion of the lower body in cold water but not during a comparable exposure to warm water. Fourteen healthy men were exposed to three different experimental conditions: arm immersion, body immersion, and control. The men always sat upright while both upper extremities hung vertically at their sides. During arm immersion, one forearm was completely immersed for 30 min in either cold water (28 degrees C, n = 7) or warm water (38 degrees C, n = 7). This cold-warm water protocol was repeated on separate days for exposure to the remaining conditions of body immersion (immersion of 1 forearm and all tissues below the xiphoid process) and control (no immersion). Blood samples were simultaneously drawn from cannulated veins in both antecubital fossae. Hematocrit difference (Hct diff) was measured by subtracting the nonimmersed forearm's hematocrit (Hct dry) from the immersed forearm's hematocrit (Hct wet). Hct diff was approximately zero when the men were exposed to the control condition and body immersion in warm water. In the remaining conditions, Hct wet dropped below Hct dry (P less than 0.01, 3-way analysis of variance). The decrements of Hct diff showed there were differences between venous hematocrits in immersed and nonimmersed regions of the body, indicating that changes of the whole-body hematocrit cannot be calculated from a large-vessel hematocrit soon after immersing the lower body in cold water.


2021 ◽  
Author(s):  
Vini Simas ◽  
Wayne Hing ◽  
Evelyne Rathbone ◽  
Rodney Pope ◽  
Mike Climstein

Abstract BackgroundSurfing is a popular sport in Australia, accounting for nearly 10 percent of the population. External auditory exostosis (EAE), also referred to as surfer’s ear, is recognized as a potentially serious complication of surfing. Cold water (water temperature below 19⁰C) is a commonly cited risk factor, with prevalence of EAE in cold water surfers ranging from 61 to 80 percent.However, there is a paucity of studies reporting the prevalence of EAE in surfers exposed to water temperatures above 19⁰C. With mean water temperature ranging from 19°C to 28°C, the Gold Coast region of Australia provides the ideal environment to assess the main goal of this study: to assess the prevalence and severity of EAE in warm water surfers.MethodsEligible participants were surfers living and surfing on the Gold Coast (Queensland, Australia). Currently active surfers over 18 years of age, surfing year-round, with a minimum of five consecutive years of surfing experience were recruited to participate. Included individuals were asked to complete a questionnaire and underwent bilateral otoscopy.ResultsA total of 85 surfers were included, with mean age 52.1 years (standard deviation [SD] ±12.6 years) and mean surfing experience of 35.5 years (SD ±14.7 years). Nearly two-thirds of participants (65.9%) had regular otological symptoms, most commonly water trapping (66%), hearing loss (48.2%), and cerumen impaction (35.7%). Less than one-fifth of the surfers (17.7%) reported regular use of protective equipment for EAE. The overall prevalence of exostosis was 71.8%, with most of the individuals having bilateral lesions (59%) and a mild grade (grade 1, 47.5%). There was insufficient evidence for any significant associations between the main outcomes (presence and severity of EAE) and factors related to age, surfing experience, winter exposure, surfing ability, symptoms, and use of protective equipment.ConclusionTo the best of our knowledge, this is the first study assessing EAE in surfers exposed to warm waters (above 19oC). The prevalence of 71.8% highlights the high prevalence of the condition in the surfing population, regardless of water temperature. Future research should focus on ways to prevent EAE.


2019 ◽  
Vol 198 ◽  
pp. 195-208
Author(s):  
M. S. Myakishev ◽  
M. A. Ivanova ◽  
V. A. Kiselev ◽  
O. V. Zelennikov

Growing of cherry salmon juveniles under two different temperature regimes at the salmon farms Anivsky and Okhotsky in the fish-rearing cycle of 2016–2017 is analyzed. Data on cherry salmon growing for other fish farms of Sakhalin region collected in 1995–2017 are considered, as well. The periods of fish feeding and dynamics of their growth varied significantly in dependence on temperature conditions. The feeding started in April-May at the cold-water fish farms (Anivsky, Lesnoy, Sokolovsky, Urozhainiy) where the water temperature lowered in winter to 0.2–0.3 о С, but in February at Reidovo fish farm where the water temperature were not lower than 2 о С and in January at the most warm-water Okhotsky fish farm with the temperature never lower than 6.5 о С. In accordance with growing conditions, the growth rate of juveniles was high in winter month at the warm-water fish farms, where the ground water was used for rearing, but increased since May-June at the cold-water fish farms using natural heating of the river water. However, several cases were noted when the fish that accumulated less than 500–700 degree-days released from cold-water fish farms in June-July were larger than those from warm-water fish farms. Thus, cherry salmon is the only species among pacific salmons whose juveniles can be successfully grown at any temperature regime and consequently at any fish farm. This ability is reasoned by earlier spawning (along with pink salmon) and long period of development in rivers. At cold-water fish farms, the best results for cherry salmon growing could be achieved with the eggs planting in late August-September, whereas the time of eggs planting is not significant for warm-water fish farms.


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