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1.
Larvae and juveniles of the green abalone grow and survive well at temperatures in the range 20–28°C. A program of hatchery research with this species utilizing thermal effluent has been in progress since 1979 at the Redondo Beach Electric Power Facility, Southern California Edison Company. All life stages may be cultured in the effluent seawater with temperature regulation by admixture of ambient seawater when required. Using thermal effluent, growth rates of juveniles are increased by a factor of 1.5–2.0 over those reared at ambient temperatures (14–20°C) characteristic of southern California. The time to harvest for seed 1–2 cm is reduced from about one year to six months. While optimal temperatures for larvae and postlarvae fall in the range 20–24°C, juveniles are more broadly tolerant of heat and exhibit a growth optimum in the range 24–28°C. The upper lethal limit for juveniles is 31.5°C (LD50, 48 hours). Postlarvae, juveniles and adults have exhibited no indications of unfavorable conditions in power plant effluent. Young adults at 1.5 years (4–5 cm) became reproductively mature and yielded viable larvae. Both hatchery-reared and wild-caught adult green abalone were conditioned to spawning readiness during winter months (natural period, spring-fall) when held in a mixture of effluent and ambient seawater at 20–24°C. Progeny from this research were provided to the California Department of Fish and Game for release in experimental plants. Approximately 30,000 juveniles were produced in 1980–81.  相似文献   

2.
The upper incipient lethal temperatures of the freshwater mullet, Rhinomugil corsula, acclimated to 15, 20, 25, 30 and 35°C in fresh water, were 32.4, 34.1, 36.0, 36.2 and 36.5°C respectively, and the corresponding lower lethal temperatures were 10.5, 11.5, 13.2, 15.8 and 19.5°C. The mullet has a total tolerance (area of thermal polygon) of 569°C with an upper and lower thermal tolerance of 253 and 316°C2. Likewise, the total resistance of the mullet was 391°C2, with upper and lower resistance zones of 181 and 210°C respectively. The upper critical temperatures of swimming inhibition of R. corsula (17.2 cm; acclimation 30°C), determined in a swimming tunnel, were 35.2, 34.6 and 34.2 for water current velocities of 38, 62 and 77 cm s?1 respectively. The corresponding lower critical temperatures were 26.2, 27.5 and 28.1°C. These results indicated the stenothermal nature of the mullet by comparison with other fishes, e.g. Tilapia mossambica.In tests on the influence of ambient salinity on thermal resistance, R. corsula survived longest at 7‰ (iso-osmotic salinity). At salinities above and below this point, survival times were shorter at any lethal temperature. In a tentative scheme for quantification of stress due to temperature and salinity at death (after acclimation to 30°C and tested at 37°C), the hypo-osmotic and hyper-osmotic stress were estimated to be 50 and 31% of the thermal stress (100%) respectively.  相似文献   

3.
Cobia are a migratory marine species that have recently gained popularity as foodfish in the aquaculture market and for stocking. Unfortunately, when culturing these species, aquaculturalists may unknowingly expose these fish to temperature extremes not normally experienced in situ. We set out to test for the critical thermal minimum temperatures of juvenile cobia by exposing them to a simulated freeze, at a drop rate of 0.33°C per hour. We observed and documented behavioral effects due to low temperature exposure using criteria for loss of equilibrium and death. We determined that the median temperature for loss of equilibrium was 12.1 ± 0.40°C and the median lethal temperature was 9.7 ± 0.28°C for low temperature tolerance. We recommend that precautions be taken well before water temperatures reach 13°C in a freeze scenario.  相似文献   

4.
To investigate the interactive effects of temperature and photoperiod on the growth performance, feeding parameters and muscle growth dynamics in juvenile Atlantic halibut (Hippoglossus hippoglossus L.), a total of 1212 juvenile halibut, including 383 tagged fish (mean initial weight of tagged individuals: 17.6 ± 0.3 g SE), were reared under a simulated natural light regime for Bergen (60°25′N) or continuous light at 9, 12 and 15 °C from 3 December 2007 until 11 March 2008. The mean weight and growth rate were significantly higher at 12 and 15 °C than at 9 °C. In addition, significantly higher mean weight and growth rate were observed in halibut reared under continuous light at a low temperature, indicating an interactive effect of temperature and photoperiod on growth performance. No effect of temperature or photoperiod was found with respect to feed conversion efficiency, whereas a higher feed consumption at increasing temperature and a higher overall daily feeding rate at continuous light at a low temperature were observed. Indications of continuous light having a stronger effect at low temperatures on muscle growth dynamics were found. A difference in the size class distribution of fibre diameter was found between photoperiod treatments at 9 °C, suggesting that continuous light resulted in elevated hypertrophic growth at low temperature. This may suggest that the increased growth rate found at continuous light at 9 °C may be a result of hypertrophic growth in juvenile halibut.  相似文献   

5.
Puerulus stage individuals of Panulirus interruptus from coastal waters off San Diego, California, were cultured through juvenile stages at constant temperatures of 22 and 28 °C in closed-system aquaria. In these laboratory trials juveniles exhibited average growth rates of approx. 3.3 mm increase in carapace length (CL) per month at 22 °C, and approximately 4.5 mm per month at 28 °C. These rates, respectively, are about two and three times greater than estimated growth rates of juveniles in nature at ambient southern California ocean temperatures. Accelerated growth at elevated temperatures was associated with increased moulting rates (reduced intermoult periods) rather than with greater increments per moult. Aquaculture of P. interruptus juveniles at elevated temperatures appears feasible, but currently is dependent on locating areas where puerulus or post-puerulus stages can be obtained in quantity without adversely affecting natural populations.  相似文献   

6.
This study evaluated the effect of different environmental temperatures in the physiology of Lutjanus guttatus juveniles by analysing their thermoregulatory behaviour, thermal tolerance, oxygen consumption rates and thermal metabolic scope. Jointly, the effect of acclimation and critical temperatures on heat shock protein 70 (Hsp70) and lactate dehydrogenase (Ldh‐a) gene expressions were also analysed using acclimation temperatures of 20, 23, 26, 29 and 32°C. The results showed that the final preferred temperature in juvenile snapper was 26°C with a thermal window of 336.5°C2, which was related to an optimal temperature for their physiology determined by the routine metabolic rate and thermal metabolic scope. At temperatures from 20 to 26°C, the routine metabolic rate and Hsp70 and Ldh‐a genes had the lowest values related to a basal expression level. At acclimation temperatures from 29 to 32°C and after critical thermal maximum (CTmax) limit, the relative expression of Hsp70 and Ldh‐a genes increased significantly, but the main response at CTmax was the upregulation of Hsp70 gene.  相似文献   

7.
Effects of different rearing temperatures (16, 21 and 26°C) on growth, metabolic performance and thermal tolerance of juvenile sea cucumber Apostichopus japonicus (initial body weight 7.72 ± 0.96 g, mean ±SD) were investigated in this study. During the 40‐day experiment, growth, metabolic performance, food intake and energy budget at different reared temperatures were determined. Sea cucumbers rearing at 16°C obtained better growth (final body weight 11.96 ± 0.35 g) than those reared at 21 (10.33 ± 0.41 g) and 26°C (8.31 ± 0.19 g) (P < 0.05), and more energy was allocated for growth at 16°C (162.73 ±11.85 J g?1 d?1) than those at 21(79.61 ± 6.76 J g?1 d?1) and 26°C (27.07 ± 4.30 J g?1 d?1) (P < 0.05). Critical thermal maxima (CTmax) values of juvenile sea cucumbers reared at 16, 21 and 26°C were 33.1, 34.1 and 36.6°C, respectively, and the upregulation of hsps in sea cucumbers reared at 26°C was higher than those acclimated at lower temperatures (16 and 21°C), indicating that temperature acclimation could change the thermal tolerance of the sea cucumber, and CTmax and hsps were sensitive indicators of the sea cucumber's thermal tolerance.  相似文献   

8.
Electronically tagged juvenile Pacific bluefin, Thunnus orientalis, were released off Baja California in the summer of 2002. Time‐series data were analyzed for 18 fish that provided a record of 380 ± 120 days (mean ± SD) of ambient water and peritoneal cavity temperatures at 120 s intervals. Geolocations of tagged fish were estimated based on light‐based longitude and sea surface temperature‐based latitude algorithms. The horizontal and vertical movement patterns of Pacific bluefin were examined in relation to oceanographic conditions and the occurrence of feeding events inferred from thermal fluctuations in the peritoneal cavity. In summer, fish were located primarily in the Southern California Bight and over the continental shelf of Baja California, where juvenile Pacific bluefin use the top of the water column, undertaking occasional, brief forays to depths below the thermocline. In autumn, bluefin migrated north to the waters off the Central California coast when thermal fronts form as the result of weakened equatorward wind stress. An examination of ambient and peritoneal temperatures revealed that bluefin tuna fed during this period along the frontal boundaries. In mid‐winter, the bluefin returned to the Southern California Bight possibly because of strong downwelling and depletion of prey species off the Central California waters. The elevation of the mean peritoneal cavity temperature above the mean ambient water temperature increased as ambient water temperature decreased. The ability of juvenile bluefin tuna to maintain a thermal excess of 10°C occurred at ambient temperatures of 11–14°C when the fish were off the Central California coast. This suggests that the bluefin maintain peritoneal temperature by increasing heat conservation and possibly by increasing internal heat production when in cooler waters. For all of the Pacific bluefin tuna, there was a significant correlation between their mean nighttime depth and the visible disk area of the moon.  相似文献   

9.
An experiment was conducted to evaluate the effect of temperature on the acute toxicity of copper sulfate to juvenile channel catfish (Ictalurus punctatus). Alkalinity and hardness were 30 and 26 mg l−1, respectively. The 7–10-g fingerlings were acclimated in four climate chambers at test temperatures of 21, 23, 25, and 27 °C for 2 weeks. After determining an acutely lethal copper dose, aerated tanks of 7.6 l were placed in each climate chamber in quadruplicate. To each, seven acclimated channel catfish fingerlings were added. The 72-h cumulative mortality from 20 mg l−1 copper sulfate was significantly lower in the 27 °C treatment (25%) compared to the 21, 23, and 25 °C treatments, where cumulative mortality was 79–96%. Total mortality at 72 h was significantly correlated (P<0.05) with decreasing temperatures (r=−0.91). This provides evidence of an inverse relationship between toxicity of copper sulfate and water temperature. Survival time, however, decreased with increasing temperatures.  相似文献   

10.
The effect of thermal history (11°C and 14°C) on growth of juvenile halibut, Hippoglossus hippoglossus (L.) (initial mean weight 140 g, n= 254), was studied. Fish were divided into four groups, two groups remaining at constant temperature (C11, Cl4), and fish in the other groups being transferred from either 11°C to 14°C (F11:14) or from 14°C to 11°C (F14:11). Twenty fish in each tank were tagged (PIT) at the start of the experiment. The final mean weights were significantly higher in F14:11 (384 g) than in F11:14 (308 g) and C14 (317 g). Further, F14:11 had significantly higher length growth rate (SLGR) than both F11:14 and C14. No significant differences between the experimental groups within each temperature (F14.11 vs. C11, and F11:14 vs. C14) were, however, found. Growth rate (SGR) declined rapidly with increasing size (from 1.4–1.8% day?1 to 0.4–0.8% day?1). It is concluded that the optimal temperature for growth of juvenile halibut declines with increasing size. Thus, as halibut grow larger, the temperature should be reduced to take advantage of this change in optimal temperature for growth.  相似文献   

11.
Grouper have to face varied environmental stressors as a result of drastic changes to water conditions during the storm season. We aimed to test the response of brown-marbled grouper to drastic and gradual changes in temperature and salinity to understand the grouper’s basic stress response. The results can improve the culture of grouper. Brown-marbled grouper, Epinephelus fuscoguttatus (6.2 ± 0.8 g) were examined for temperature and salinity tolerances at nine different environmental regimes (10, 20, and 33 ‰ combined with 20, 26 and 32 °C), in which the fish were subjected to both gradual and sudden changes in temperature and salinity. The critical thermal maximum (50 % CTMAX) and the upper incipient lethal temperature (UILT) were in the ranges of 35.9–38.3 and 32.7–36.5 °C, respectively. The critical thermal minimum (50 % CTMIN) and the lower incipient lethal temperature (LILT) were in the ranges of 9.8–12.2 and 14.9–22.3 °C, respectively. The critical salinity maximum (50 % CSMAX) and the upper incipient lethal salinity (UILS) were in the ranges of 67.0–75.5 and 54.2–64.8 ‰, respectively. Fish at temperature of 20 °C and a salinity of 33 ‰ tolerated temperatures as low as 10 °C when the temperature was gradually decreased. Fish acclimated at salinities of 10–33 ‰ and a temperature of 32 °C tolerated salinities of as high as 75–79 ‰. All fish survived from accumulating salinity after acute transfer to 20, 10, 5, and 3 ‰. But all fish died while transferred to 0 ‰. Relationships among the UILT, LILT, 50 % CTMAX, 50 % CTMIN, UILS, 50 % CSMAX, salinity, and temperature were examined. The grouper’s temperature and salinity tolerance elevated by increasing acclimation temperature and salinity. On the contrary, the grouper’s temperature and salinity tolerance degraded by decreasing acclimation temperature and salinity. The tolerance of temperature and salinity on grouper in gradual changes were higher than in drastic changes.  相似文献   

12.
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13.
Male ninespine sticklebacks, Pungitius pungitius, acclimated to 3°C have higher activities of mitochondrial enzymes in their axial muscles than males acclimated to 20°C. Phosphofructokinase and pyruvate kinase activities tended to be higher in cold than warm acclimated males. For females, warm acclimation tended to decrease only mitochondrial enzyme activities. As thermal acclimation did not change the physical condition and most anatomic parameters of the sticklebacks, the enzymatic changes do not seem due to mobilization of somatic reserves. Field acclimatization to warm temperatures led to a marked decrease in physical condition in both males and females. This decrease in physical condition could largely be attributed to atrophy of the carcass mass. Spring males had higher activities of phosphofructokinase, citrate synthase and cytochrome oxidase in the axial muscle than summer males. Again, females showed a less marked response. These data suggest that environmental temperature is a major determinant of muscle aerobic capacity, at least for male ninespine sticklebacks. Thus, these northern temperate zone fish retain the capacity for thermal compensation, much like their temperate zone counterparts.  相似文献   

14.
To elucidate the post-release movement and emigration of juvenile spotted halibut Verasper variegatus, ten hatchery-reared age-0 individuals (10 months old, 17.0–19.7 cm total length) surgically implanted with acoustic transmitters were released near the center of Matsukawa-ura, a shallow brackish lagoon, on 25 November 2009 (water temperature 13.8 °C). They were monitored by ten acoustic receivers for 5 months. Of ten individuals, eight left the release site during December–March. Three of these emigrated to the outer ocean on 17 and 29 January and 30 March 2010, respectively. Juveniles probably started wintering migration in December and January when water temperatures decreased considerably in the lagoon (mean 9.5 and 6.0 °C, respectively). They stopped their migration in the coldest month, February (mean 5.7 °C), and restarted it in March when water temperatures frequently exceeded a plausible threshold for movement (≥6 °C). Statistical analyses revealed that the fish started migration significantly more frequently at nighttime. The migration track of an individual recorded from 11 to 30 March showed gradual nocturnal movements and a slow migration speed (estimated maximum speed 2.2 m/min). Our results revealed that water temperature primarily governed the seasonal timing of nocturnal migratory movements of juvenile spotted halibut.  相似文献   

15.
The effects of thermal amplitudes of diel fluctuating temperature on growth and oxygen consumption of the juvenile sea cucumber Apostichopus japonicus (Selenka) were studied at the average temperatures of 15 and 18°C with three diel different fluctuating amplitudes of ±2, ±4 and ±6°C. The optimum thermal amplitudes for growth of the juvenile sea cucumber at the sizes of this experiment, at average temperatures of 15 and 18°C, were estimated to be ±1.38 and ±1.67°C respectively. In the constant temperature regimes, the growth rate at 15°C was higher than that at 18°C. However, the growth rate at 18±2°C was higher than that at 15±2°C. The results from this study suggested that fluctuating temperatures enhanced the optimum temperature for the growth of sea cucumbers compared with that at constant temperatures. Therefore, accurate predictions of the optimum temperature of sea cucumbers in the natural environment, in which water temperatures fluctuate daily and seasonally, should be made from data obtained at fluctuating temperatures.  相似文献   

16.
The effects of temperature on growth and survival of juvenile blackfoot abalone, Haliotis iris, were investigated. Animals of 10, 30 or 60 mm initial shell length were exposed to ambient (6–10°C), 14, 18, 22 and 26°C for 112 days in a flow‐through culture system. Maximum growth occurred at 22°C for the 10 and 30 mm size classes and at 18°C for the 60 mm size class. Regression analysis identified the optimal temperature for growth (ToptG) at around 21°C for the 10 and 30 mm size classes and at 17–18°C for the largest size class. In a second experiment, the critical thermal maximum of H. iris was determined as a measure of thermal tolerance. Abalone were subjected to increasing water temperatures at a rate of 2°C h?1 until they detached from the substrate. Abalone of 10 mm displayed greater thermal tolerance than abalone of 30 and 60 mm in length. CT50 temperatures were 28.8, 27.7 and 27.8°C, yielding deduced ToptG values of 19.7, 18.3 and 18.4°C for the 10, 30 and 60 mm size classes respectively. The size‐dependent nature of the relationship between growth and temperature could be capitalized upon in recirculating aquaculture systems.  相似文献   

17.
Critical thermal maxima (CTMax) and minima (CTMin) were determined for Prochilodus scrofa Steindachner of two sizes (19.5 ±7.2 g and 249 ± 42.4 g). acclimated at 15. 20, 25, 30 and 35 ± 1°C. The CTMax and the CTMin for the smaller fish were 33.9. 36.7. 38.7, 40.3. 42.0°C and 5.0, 7.2. 9.2. 10.3. 13.4oC and for the larger (Ish 33.3, 35.7, 38.2. 40.6. 42.6°C and 6.5, 8.2. 10.8. 12.4, 14.6°C. respectively, at each acclimation temperature. The CTMin from smaller fish were significantly lower than those from larger ones but the CTMax did not show any such difference. These results indicate that P. scrofa is suitable for culture in south-eastern and even in southern Brazil where winter temperatures may drop to very low levels, mainly at night. The zone of thermal tolerance calculated by CTMax and CTMin was equivalent to 1046°C2 and 964.2°C2, respectively, for smaller and larger fish, showing a high degree of eurythermicity.  相似文献   

18.
To determine the optimal temperature for juvenile (0 year old) marbled flounder Pseudopleuronectes yokohamae, juveniles of 40–54 mm standard length were reared at six temperature conditions in the range of 8–26 °C, using group- and individual-based methods. Growth of juveniles increased from 8 to 20 °C but decreased from 20 to 26 °C, irrespective of the rearing method used. Food intake was greatest at 20 and 24 °C compared with other temperatures, while feed conversion efficiency was greater at 20 °C than 24 °C in individual rearing. Individual rearing provided more information such as individual variations in growth and food consumption, suggesting the importance of individual-based experiments for exploring the optimal temperature for fish.  相似文献   

19.
Exposure to heat‐shock protein (Hsp) stimulating factors induces Hsp accumulation and confers tolerance to lethal ammonia stress on the common carp Cyprinus carpio. This study investigated whether a non‐lethal heat shock bestowed similar protective effects against ammonia and induced thermotolerance, both thought to be rendered by increased amounts of Hsps. The 30‐min lethal temperature (30 min LHT) and 1‐h lethal ammonia concentration (1 h LCT) for this species occurred at 41°C and 14.2 mg/L NH3 respectively. Heating juvenile carp (5 cm) from 28°C to 32, 34 and 38°C, with a subsequent 8‐h recovery period augmented tolerance to lethal heat and ammonia perturbation by two to threefold as compared with animals held at 28°C. Protection occurred in conjunction with Hsp70 accumulation in gills, substantiating the role of this Hsp in enhancing the stress tolerance of common carp.  相似文献   

20.
Juvenile Atlantic halibut (Hippoglossus hippoglossus L.) and turbot (Scophthalmus maximus L.) acclimated to 8–9 °C sea water were transferred to sea water at 1 °C for 7 days. An immediate spasm-like response was noticed in the turbot after the transfer, but not in the halibut. None of the fish died. The turbot suffered from substantial physiological disturbances after the transfer. Their blood plasma Cl– concentration increased and muscle water content decreased markedly. The plasma glucose concentration was several times higher than the control level from day one onwards. A decrease in the haematocrit was recorded some hours after transfer, followed by a marked increase on day 7. In halibut, the plasma Cl– concentration fell somewhat during the first days, but returned thereafter to its pretransfer level. The muscle water content was unchanged. Both haematocrit and plasma glucose concentration were unchanged until day 7, when both were significantly higher. The differences in the response to low-temperature challenge between halibut and turbot are probably related to genetic differences in temperature tolerance, which reflect differences in the distribution of the species.  相似文献   

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