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1.
The heart rate of jack mackerel [16.5–21.2 cm fork length (FL), n = 24] was examined through forced swimming exercise in a flume tank by 10-min step-ups of speed levels in 1.5–6.0 FL/s range at different temperatures of 10, 15, and 22 °C. Electrocardiograph (ECG) monitoring was conducted by comparing the heartbeat pattern in still water without flow as a control, and continuously during exercise by speed levels until fatigue and during the recovery phase. Average heart rates in the control at each temperature were 36.5 beats/min at 10 °C, 56.1 beats/min at 15 °C, and 75.2 beats/min at 22 °C. The heart rate of jack mackerel significantly increased as the swimming speed was increased in each temperature. At the lower swimming speed of 1.5–2.4 FL/s, the heart rate was the same level as the control value at each respective temperature. The heart rate started to increase at swimming speeds of 2.3–2.5 FL/s at all temperatures. The higher heart rate in the range of 150–200 beats/min was achieved at a swimming speed of 6.0 FL/s at 22 °C. The recovery time after the maximum heart rate at high speed became longer at high temperatures.  相似文献   

2.
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   

3.
A 30-day acclimation trial was conducted using Tor putitora to elucidate its thermal tolerance, oxygen consumption, haemato-biochemical variables and selected enzymatic activities at five acclimation temperatures (AT). Juveniles of T. putitora were randomly distributed among five treatment groups (20, 23, 26, 29 and 32 ± 0.5 °C). There was a significant curvilinear increase in critical thermal maxima (CTmax) (y = ?0.0693x 2 + 1.7927x + 34.628, R 2 = 0.996) and lethal thermal maxima (LTmax) (y = ?0.1493x 2 + 2.3407x + 35.092, R 2 = 0.991) with increasing AT. The oxygen consumption rate increased significantly with increasing AT. The Q 10 values were 1.16 between 20 and 23 °C, 3.09 between 23 and 26 °C, 1.31 between 26 and 29 °C and 1.76 between 29 and 32 °C of AT. The acclimation response ratios were ranged between 0.37 and 0.59. Catalase, superoxide dismutase and ATPase activities were increased linearly in liver, gill and kidney, while brain acetylcholine esterase activity decreased linearly with increasing AT. Blood glucose remained unchanged up to AT of 26 °C and increased significantly at AT of 29 and 32 °C. Haemoglobin content was increased linearly with increasing AT. The highest WBC count was observed at 20 °C, and no significant changes found till AT of 26 °C and significantly decreased at 32 °C. Total serum protein and globulin were significantly decreased with increasing AT. Highest values were observed at 20 °C and remained consistent till 26 °C, then decreased significantly. There was no significant change in A/G ratio through the AT 20–29 °C and increased significantly at 32 °C. The increase in CTmax, LTmax and oxygen consumption rate with increasing AT may suggest that the thermal tolerance of T. putitora is dependent on its prior thermal exposure history, and it could adapt to higher AT by altering its haemato-biochemical variables.  相似文献   

4.
A thermally selected strain of rainbow trout has been established by selective breeding since 1966 in Miyazaki, Japan. In the present study, we compared the critical thermal maxima (CTMs), the temperatures at which organisms reach a predefined sublethal endpoint and lose their equilibrium, between a thermally selected and two normal (Donaldson) strains of rainbow trout. The CTM of one normal strain from Nikko (Nikko strain) acclimated to 20 °C (29.7 °C) was significantly lower than those of the thermally selected strain (30.0 °C) and the other Donaldson strain from Aomori (29.9 °C) (P?<?0.05). The F1 generations, F1T and F1N, were produced by crossing thermally selected strain females with Nikko strain males and Nikko strain females with thermally selected strain males, respectively. No significant difference was observed in the CTM between F1T [30.1?±?0.15 °C (n?=?30)] and F1N [30.1?±?0.16 °C (n?=?30)] (P?>?0.05) for fish acclimated to 20 °C, suggesting that the F1 offspring inherited the thermal tolerance trait from one thermally selected strain parent irrespective of whether it was the male or female. F2 offspring of F1T or F1N also showed the thermal tolerance trait. The coefficients of variation for CTM were also compared among all the datasets obtained in the present study and their values for F1 hybrids were lower than those of the parental generation of the Nikko strain (P?<?0.05). In contrast, the coefficients of variation of F2s were the same as those of their parental generation. Furthermore, the thermally selected strain and Nikko strain as a reference family provide a F2 generation for segregating phenotypes, which is required for in-depth genetic analysis of the thermally selected rainbow trout strain.  相似文献   

5.
This study investigated the effect of continuous temperature decrease on hemocyte apoptosis of the white shrimp Litopenaeus vannamei. In the stress group, water temperature decreased from 26 to 17 °C at a rate of 1 °C/h. Shrimp kept at 26 ± 0.5 °C were used as control group. Total hemocyte count (THC), reactive oxygen species (ROS) production, cytoplasmic free-Ca2+ (CF-Ca2+) concentration, mitochondrial membrane potential (MMP), apoptotic cell ratio, and caspase-3 activity of L. vannamei hemocytes were determined when water temperature decreased to 23, 20, and 17 °C, respectively. Increased ROS production in hemocytes was observed when water temperature decreased to 20 and 17 °C. Decreased THC and cellular MMP, increased CF-Ca2+ concentration, apoptotic cell ratio, and caspase-3 activity were shown when water temperature decreased to 17 °C. These results indicate that water temperature decrease can induce oxidative stress on shrimp hemocytes and then cause mitochondria and caspase-3 mediated hemocyte apoptosis and THC reduction, when water temperature decreased to an unconformable level.  相似文献   

6.
We determined through morphological and rbcL phylogenetic analyses that a previously unidentified, but introduced species of macroalga, which has been easily cultivated in indoor tanks in Japan, is Agardhiella subulata (Solieriaceae). Additionally, the photosynthetic biology of this alga was examined by inducing photosynthetic activity under a variety of water temperatures and photosynthetic active radiation (PAR) to clarify the optimal conditions needed for its efficient cultivation. Photosynthetic activity was evaluated by using both dissolved oxygen (DO) and pulse amplitude modulated-chlorophyll fluorometric (PAM) techniques, and focused on elucidating temperature and PAR levels that would potentially maximize productivity. The DO method revealed that the net photosynthetic rates at 24 °C quickly increased as PAR increased, and approached a P max of 27.8 mg O2 g ww ?1  min?1 (95 % Bayesian credible interval, BCI 23.8–32.1). The maximum gross photosynthetic rate occurred at 26.7 °C (BCI 24.4–28.3 °C). However, PAM experiments indicated that for the maximum quantum yield, the optimal temperature was 23.7 °C (BCI 22.7–24.6) and the maximum relative electron rates occurred when the water temperature was 31.0 °C (BCI 30.6–31.5). This study suggests that the broad tolerance of maximal photosynthetic activity to temperature (22.7–31.5 °C) is one of the main reasons why this alga can be successfully cultivated year-round.  相似文献   

7.
The effect of irradiance and temperature on the photosynthesis of two Japanese agarophytes, Gelidium elegans and Pterocladiella tenuis (Gelidiales), was determined using dissolved oxygen sensors and pulse amplitude modulated (PAM) fluorometry. Gross photosynthesis and dark respiration rates were determined over a range of temperatures (8–36 °C). The highest gross photosynthetic rates were 40.3 and 37.0 mg O2 g ww ?1  min?1 and occurred at 24.3 and 25.5 °C [95 % Bayesian credible interval (BCI) 20.7–28.0 and 23.4–28.3 °C], respectively. The dark respiration rate in G. elegans and P. tenuis increased with increasing temperature at a rate of 0.10 and 0.31 mg O2 g ww ?1  min?1 °C?1 , respectively. Modeling the net photosynthesis–irradiance (P–E) responses of G. elegans and P. tenuis at 20 °C revealed that the net photosynthetic rates quickly increased at irradiance levels below the estimated saturation irradiance of 88 and 83 µmol photons m?2 s?1, with a compensation irradiance of 14 and 19 µmol photons m?2 s?1, respectively. The highest value of the maximum effective quantum yield (Φ PSII) occurred at 20.1 °C (BCI 18.9–21.5 °C) and 21.3 °C (BCI 20.2–22.5 °C) for G. elegans and P. tenuis and was 0.49 and 0.45, respectively. These optimal temperatures of Φ PSII were relatively lower than those determined by the photosynthesis–temperature model of oxygen evolution. The temperature response of these species indicates that they are probably well adapted to the current range of seawater temperatures in the study site but that they are near the boundary of their tolerable limits.  相似文献   

8.
Volutharpa ampullacea perryi (false abalone) meats were water cooked at 75–100°C for 5–60 min, and the changes in weight loss, pH, color, in vitro digestibility, texture, microstructure, and sensory characteristics were investigated. The weight rapidly decreased in the initial cooking and decreased slightly with the extension of both heating temperature and time. Obvious differences in color were found compared between the raw and cooked meats with respect to ΔL*, Δa*, and Δb* values. Digestibility was significantly improved with the thermal treatments. Textual properties, such as hardness, springiness, chewiness, and resilience, improved with the increasing of thermal intensity, but reduced with overcooking, and the variations were further confirmed by the scanning electron microscopy analysis. The samples boiled at 90–95°C for 10–15 min and 100°C for 5–10 min acquired better acceptance in the sensory evaluation. The complex relationship among cooking conditions and physicochemical and histological characteristics of meat as well as the consumer perceptions was illuminated by the principal components regression analysis. These results could provide useful information for quality control in V. a. perryi meat cooking.  相似文献   

9.
Abalone Haliotis discus hannai Ino is a popular delicacy consumed as a luxury food owing to its unique flavor and texture. In this study, we investigated the effects of heating conditions on the fatty acids and volatile compounds in its foot muscle based on gas chromatography–mass spectrometry (GC–MS) and solid-phase microextraction (SPME)–GC–MS. The contents of fatty acids significantly decreased after heating at 80 °C for 2 h. In total, 52 volatile compounds, including aldehydes, aromatic compounds, alkanes, alcohols, ketones, and furans, were detected in the heated samples. Principal component analysis revealed an interaction between heating temperature and time. Heating at 80 °C for 0.5–2 h generated higher contents of volatile compounds. In particular, the contents of hexanal, heptanal, octanal, nonanal, and undecanal mainly derived from autoxidation of fatty acids during heating increased at least fourfold.  相似文献   

10.
Some species belonging to Ostreopsis, a benthic dinoflagellate genus, are known to produce palytoxin analogues. Around the coastal regions of Japan, the toxic Ostreopsis sp. 1 and Ostreopsis sp. 6 which are genetically divergent from other species of Ostreopsis are present from the southern to northern regions and in the southern region, respectively. The present study examined the growth responses of these strains to seven temperatures (15–35 °C) in combination with five salinities (20–40) and discusses the effects of temperature and salinity on their distribution and bloom dynamics in Japan. Tolerable temperatures and salinities ranged 15–30 °C and 25–40 for Ostreopsis sp. 1, and 17.5–30 °C and 20–40 for Ostreopsis sp. 6. The optimal temperature ranges which gave growth rates of >90 % of maximal growth rate of each strain were 22–25 °C for Ostreopsis sp. 1 and 24–30 °C for Ostreopsis sp. 6. Therefore, Ostreopsis sp. 1 is putatively tolerant to lower temperatures and thus possesses adaptability to colder waters of relatively higher latitude regions of Japan, whereas Ostreopsis sp. 6 presumably possesses adaptability to warmer waters of the southern region. We conclude that growth responses of Japanese toxic Ostreopsis sp. 1 and Ostreopsis sp. 6 to temperature-salinity affect their distribution and bloom dynamics in Japan.  相似文献   

11.
This study investigated the effects of long-term heat exposure on Japanese flounder (Paralichthys olivaceus) and its hybrids (P. olivaceus ♀ × summer flounder Paralichthys dentatus ♂). From 24 ± 0.5 °C, temperature was increased by 1 ± 0.5 °C in a day and was kept at that temperature for 5 days before next rise. Cumulative survival rate (CSR), cumulative survival rate under different temperature (CSR-T), histological alteration, and related enzyme activities were investigated. In P. olivaceus, mass mortality occurred at 29 and 32 °C (the CSR-T dropped to 42.39 %), and serious gill damages appeared at 30 and 32 °C. Meanwhile, the activities of superoxide dismutase (SOD), catalase (CAT), lysozyme (LZM), and pyruvate kinase (PK) declined around 29 and 32 °C (except for CAT). In comparison with P. olivaceus, the CSR of the hybrids was higher, the gill kept a better structural integrity, and the activities of SOD, CAT, LZM, and PK showed tiny fluctuations. The results suggested that during the process of chronic heat stress, P. olivaceus seemed to be more sensitive to 29 and 32 °C, and the manifestations in survival, histology, and enzyme activity were generally consistent. For the hybrids, the comparatively insensitivity to high temperature might imply its better heat tolerance.  相似文献   

12.
In the present study, selected temperature drops were examined to investigate the effects of live chilling on stress and welfare in turbot and sole. This study demonstrated that rapid temperature drops from 11°C–12°C and 18°C–18.7°C to 4°C–0°C in turbot resulted in higher blood sodium and potassium at 0°C (164 mmol l?1, 4.4 mmol ?1) compared to 4°C (153 mmol l?1, 3.1 mmol ?1), indicating osmoregulatory disturbance. A rapid temperature drop from 18°C to 0°C in Senegal sole also resulted in higher blood sodium and potassium at 0°C (164 mmol l?1, 4.8 mmol ?1) compared to the control group at 18°C (157 mmol l?1, 3.2 mmol ?1). Based on present findings, we conclude that immersion in ice water will have a negative effect on the animal osmoregulatory capacity, and we recommend that turbot and sole are stunned before slaughter.  相似文献   

13.
The effects of rearing temperature (23–29 °C) during the larval and juvenile stage on survival, growth and skeletal malformations in the seven-band grouper Epinephelus septemfasciatus were investigated. The survival rate of juveniles 30–40 mm in total length emerging from eggs was higher at 25 and 26 °C (0.1–1.3 %) than at 23 °C or 27–29 °C (0.004–1.5 %). Growth (increase in total length) was accelerated at higher temperatures. The frequency of malformed individuals was lower at 25–27 °C (36.0–61.5 %) than at 23, 28 or 29 °C (65.3–76.9 %). Specific incidences of spinal curvature and centrum fusion or defects in juveniles were not related to rearing temperature. However, incidences of twisted or compressed vertebrae (6.5–64.0 %) were higher at higher temperatures, while the incidence of bifurcated neural spine was significantly higher at 23 °C (43.6–54.4 %) than at other temperatures (3.3–22.7 %). The incidence rate of spinal curvature (23.3 %) was significantly higher in juveniles with a deflated swim bladder, regardless of rearing temperature. The results of this study suggest that the optimum culture temperature for seven-band grouper is 25–26 °C, collectively considering the survival, growth and incidences of abnormalities. Our results also demonstrate the significance of identifying the conditions for swim bladder inflation to prevent spinal curvature in seven-band grouper.  相似文献   

14.
Hospital effluents contain myriad of mutagens and genotoxins capable of increasing DNA damage in aquatic biota. African mudfish, Clarias gariepinus, are exposed to genotoxins when cultured in swamps and derelict water bodies often contaminated by effluents. Moreover, its DNA is susceptible to xenobiotic-induced lesions since it lacks l-gulonolactone oxidase and hence cannot synthesize l-ascorbic acid. This study investigated 96-h acute toxicity and protective effects of dietary ascorbic acid (AA) against micronucleus (MN) and abnormal nuclear (NAs) formation in C. gariepinus exposed to sub-lethal concentrations of hospital effluent. Six concentrations (0.5–3.0%) of the effluent were selected to determine the 96-h acute toxicity of the effluent in C. gariepinus, after range finding test. Fish were exposed to sub-lethal concentrations (0.08–1.30%) of the 96 h LC50. Two other groups were exposed to the 96 h LC50 (1.30%) of the effluent +50 and +100 mg/kg of dietary ascorbic for 7 days, and MN and NAs assessed in peripheral erythrocytes. The 96 h LC50 (1.30%) was 1.18 times more toxic than the 24 h LC50 (1.54%), indicating that the toxicity of the effluent increased with exposure duration. MN, nuclear bud, enucleated, fragmented nucleus (apoptosis), and necrotic erythrocytes significantly increase in effluent treated fish. Dietary AA reduced MN from 6.35-fold (1.30% treated group) to 3.72-fold (1.30% + 50 mg AA) and 3.54-fold (1.30% + 100 mg AA). Also, AA reduced total NAs from 2.26-fold (1.30%) to 1.40-fold (1.30% + 50 mg AA) and 1.06-fold (1.30% + 100 mg AA) compared to the control. Heavy metals and physicochemical parameters analyzed in the tested effluent possibly induced the mortality and cytogenotoxicity in C. gariepinus, and this was ameliorated by dietary AA.  相似文献   

15.
Pikeperch, Sander lucioperca (L.), has been identified as one of the most perspective candidates for diversification of freshwater aquaculture. However, some aspects of production are still being developed, and controlled reproduction is one of the bottlenecks. The aim of the present study was to compare the effectiveness of different commercial spawning agents in the induction of final oocyte maturation (FOM) and ovulation in wild spawners. Within the study, four spawning agents [human chorionic gonadotropin (hCG), mixed human and horse gonadotropin (PG-600), carp pituitary (CPH) and mammalian GnRH analogue combined with metoclopramide (Ovopel)] in different thermal regimes (13 and 15 °C) were tested. In both thermal regimes, the highest (P < 0.05) ovulation rate among the treatment groups was obtained after stimulation with hCG (100 % in both cases). Latency time was the shortest in groups where CPH was used (2–3 and 3–4 days for 15 and 13 °C) and was similar in the remaining groups (3–4 and 4–5 days for 15 and 13 °C, respectively). Embryo survival was the highest in groups treated with hCG (78.9 and 81.3 % at hatching stage for 15 and 13 °C, respectively). Hormonal stimulation did not significantly affect spermiation rate or spermatozoa motility (P > 0.05). Based on the obtained results, hCG can be recommended for induction of FOM and ovulation in pikeperch. In addition, the thermal regime within the tested range seemed to have no effect on the reproduction outcome, and the application of lower temperature only prolonged the time of ovulation.  相似文献   

16.
The recruitment pattern of Anguilla japonica glass eels into the Yangtze Estuary, China was studied during five successive migration seasons (2012–2016). The variation in daily catch was analyzed in relation to environmental factors that affect inshore migration. Two large migration waves of glass eels were observed in each recruitment season: one in the winter (January/February) and the other in the spring (March/April). A generalized additive model indicated that daily changes in glass eel catch were partially affected by local water temperature and tidal range. Water temperature seemed to have a threshold effect in winter, and there were optimal temperature ranges of 6–8 °C and approximately 10.5–12.0 °C associated with different recruitment waves to the Yangtze Estuary. The influence of tides was complex, with an overall positive correlation. The annual glass eel catch fluctuated greatly, but generally did not show a significant downward trend. To achieve sustainable use of glass eels, it is proposed that relevant management and conservation activities be reinforced.  相似文献   

17.
The purpose of this study was to determine whether daily-elevated water temperature shifts during the embryonic period in spring-run chinook salmon (Oncorhynchus tshawytscha) could influence the phenotypic sex ratio. Three families of salmon embryos were divided into two groups; one was moved between 7.5 °C and 12 °C each day (6–8 hours) for 105 days while the other (control) remained at a constant 7.5 °C. Sex ratios varied between the three families, but no significant sex ratio differences were observed between the control and temperature shifted groups.  相似文献   

18.
The migration of Schizothorax prenanti, an ecologically important and commercially valuable species, is impeded by dams. Effective fishways would contribute to conservation of wild populations, and swimming performance data are necessary for fishway design. The swimming performance of S. prenanti was investigated at four temperatures (15, 19, 23, 27 °C), and numerical models were used to characterize the effect of temperature on swimming performance. As temperature increases, critical swimming speed (U crit) increases from 15 to 23 °C and then decreases significantly. The highest U crit (7.71 BL/s) occurs at 24 °C, as estimated by interpolation. Swimming efficiency was similar from 19 to 23 °C, but decreases significantly at 27 °C. The temperature range 15–23 °C is suitable for S. prenanti. However, the excess post-exercise oxygen consumption values of Q 10 for the four temperature increments indicate that 19–23 °C is the optimal range for swimming performance. Maximum tail beat amplitude increased >25 % (0.35–0.45 BL) over the temperature range considered, but variation of tail beat frequency was erratic. White muscle fiber begins to contribute to swimming at swimming speeds ~40 % U crit at the lower three temperatures, but increases to almost 60 % at 27 °C, and the contribution is relatively small. The results of this investigation advance the knowledge of fish metabolism while swimming provides data critical for fishway design.  相似文献   

19.
The effect of cold acclimation on growth performance, non-specific immune responses, and expression level of HSP21 and CSP gene were studied in red claw crayfish (Cherax quadricarinatus) using a 4-week stress trial. We set a four-temperature gradient, with water temperatures of 25, 20, 15, and 9 °C, respectively. With the gradual decrease of temperature, the survival rate, feeding rate, and hepatopancreas index (HIS) of the red claw crayfish showed a decreasing trend. Decreased total hemocyte count (THC) and hemocyanin concentration were observed when water temperature decreased. The activities of superoxide dismutase (SOD) and total antioxidant capacity (T-AOC) in the hepatopancreas and hemolymph all gradually declined with decreasing temperatures and then significantly lowered at 9 °C compared with those at 25 °C. The activity of glutathione peroxidase (GPx) in these two tissues showed in the opposite trend, indicating that they may have different regulation mechanisms. A gradual increase of malondialdehyde (MDA) concentration was detected in the hepatopancreas and hemolymph when the temperature decreased. Low temperature stress also affected the expression of heat shock proteins 21(HSP21) and cold shock domain protein (CSP). These results indicate that cold acclimation may induce oxidative stress on the crayfish and then cause oxidative damage and hemocyte apoptosis, as well as immunosuppression in Cherax quadricarinatus, which may finally affect the growth and survival of Cherax quadricarinatus.  相似文献   

20.
The behavior of juvenile yellowfin tuna Thunnus albacares in southwestern Japan was investigated using archival tag data from five fish (fork length 52.5–92 cm, days at liberty 26–280 days) released near the Nansei Islands (24–29°N, 122–130°E). Vertical behavior was classified into three patterns: “shallow” (≥50 % of daytime hours at depth of <50 m), “deep” (≥50 % of daytime hours at ≥100 m), and “intermediate” (other than “shallow” or “deep”). The pooled proportion of the number of days of each behavior was 29, 25 and 46 %, respectively. The proportion of “shallow” behavior increased with fish size. The proportion of time spent near the surface at nighttime increased in the colder season, when the thermal gradient was relatively small. Surface-oriented behavior (fish remained at a depth of <10 m for more than 10 min) occurred mainly during nighttime and between November and January. Dives exceeding 500 m were occasionally observed (0.02 day?1), and one fish dived to 1230 m. The results of our study show that yellowfin tuna were typically distributed in the mixed layer or upper thermocline where the water temperature was close to the sea surface temperature and that the vertical behavior was variable.  相似文献   

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