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1.
Tanja Yvonne Roessler Andrea Wirtz Matthew James Slater Joachim Henjes 《Aquaculture Research》2020,51(8):3205-3215
New and viable species for aquaponics and integrated multi‐trophic aquaculture (IMTA) in freshwater systems can improve yields and sustainability of aquaculture. Freshwater crayfish species such as Astacus astacus and Pontastacus leptodactylus are omnivorous feeders and considered candidates for feeding on faecal matters in existing aquaculture systems. Feeding trials were conducted to determine growth response and RNA/DNA ratio in freshwater crayfish fed fish waste. Carapace length and wet weight were measured to determine the growth response. Juvenile A. astacus was fed faeces of hybrid striped bass (Morone chrysops × Morone saxatilis) and rainbow trout (Oncorhynchus mykiss), while adult P. leptodactylus was fed with two commercial pellet diets and pikeperch (Sander lucioperca) faeces. The nutritional composition of hybrid striped bass faeces was close to optimal diet composition of A. astacus, and crayfish showed significantly higher carapace growth, weight gain and weight gain per moult as the group fed rainbow trout faeces. The growth of P. leptodactylus was significantly lower in terms of weight gain and weight gain percentage per moult for crayfish fed on pikeperch faeces. Thus, this study can recommend a co‐cultivation of hybrid striped bass and A. astacus within one system, but cannot recommend co‐cultivation of P. leptodactylus with pikeperch. Additionally, this study showed controversial results of RNA/DNA ratio and weight gain of both crayfish species. Thus, RNA/DNA ratio cannot be approved for investigations on crayfish physiological status in controlled feeding experiments if animals are fed with an inadequate diet. 相似文献
2.
Rocío González Jesús Domingo Celada Vanesa García José Manuel Carral Álvaro González María Sáez‐Royuela 《Aquaculture Research》2011,42(3):450-456
Recent advances on feeding in intensive rearing of juvenile astacids enable research of other factors influencing growth and survival without the confounding effect of inadequate feeding. Two experiments were conducted to evaluate the effects of the number of shelters per crayfish and to test different lighting conditions. Stage 2 juvenile Pacifastacus leniusculus were stocked in fibreglass tanks and fed a dry diet for salmonids combined with restricted amounts of decapsulated Artemia cysts. In experiment 1, four, two or one shelters per crayfish were tested for 80 days. No significant differences were found among groups either in survival (final mean: 86.67%) or in growth [final mean: 11.41 mm mean carapace length (CL), 355.45 mg mean weight]. In experiment 2, three lighting conditions were tested for 120 days: continuous lighting of 925 lx, continuous darkness and natural photoperiod. Survival rates ranged from 76.7% to 88.3%, with no significant differences among groups. The crayfish kept under continuous darkness grew faster (final mean: 12.70 mm CL, 543.08 mg weight) than those reared under the other two light conditions. This study shows that, under improved feeding conditions, a minimum number of shelters can be provided, and faster growth can be obtained in continuous darkness. 相似文献
3.
J.D. Celada J.B. Fuertes J.M. Carral M. Sáez‐Royuela Á. González Á. González‐Rodríguez 《Aquaculture Nutrition》2013,19(1):110-116
The aim of this study was to evaluate the effects of practical diets with different levels of vitamin C on survival and growth of juvenile crayfish (Pacifastacus leniusculus). An 80‐day trial was conducted with stage 2 juveniles from the onset of exogenous feeding. Four practical diets differing in the content of l ‐ascorbyl‐2‐monophosphate‐Na were prepared: 0, 0.2, 0.4 or 0.8 g kg?1 diet. Each diet was tested on grouped or individually isolated crayfish. Diets had no significant effects on survival of crayfish held in groups (average: 73.1%) neither on the isolated ones (average: 90%). Crayfish fed the diet with 0.2 g kg?1 of l ‐ascorbyl‐2‐monophosphate‐Na had the highest growth (groups: 13.64 mm carapace length (CL), 542.4 mg weight; isolated: 17.05 mm CL, 1213.2 mg weight) and the lowest feed conversion ratio (average of grouped and isolated: 0.99). This study provides the first data on vitamin C requirements of freshwater crayfish. A level of 0.2 g l ‐ascorbyl‐2‐monophosphate‐Na kg?1 diet (0.07 g ascorbic acid equivalent) can be recommended for juvenile P. leniusculus during the first period of intensive rearing. 相似文献
4.
The ability of Loligo opalescens paralarvae to resist and recover from starvation was examined by measuring their survival, growth rate and RNA/DNA ratios during starvation and refeeding. Paralarvae were fed Artemia sp. nauplii, zooplankton and mysid shrimp. Fourteen days after hatching they were separated into five feeding treatments: a control treatment (food was always available) and treatments starved for 2, 3, 4 and 5 days, and then refed. Each day, 5–7 paralarvae from each treatment were anesthetized to measure mantle length and wet weight (WW), and then RNA and DNA were extracted using an ethidium bromide fluorometric technique. Paralarvae did not survive 4 and 5 days of starvation, showing that at 15 days of age and at 16 °C the limit to recovery was 3 days of starvation. Paralarvae starved for 2 and 3 days showed compensatory growth that mitigated the effects of starvation, in that at the end of the experiment (10 days), they attained mean final body weights similar to the control treatment. Differences in the RNA/DNA ratios between control and starved paralarvae were detected within 2 days of food deprivation. For paralarvae starved 2 and 3 days, it took 1 day after refeeding to attain RNA/DNA ratios not significantly different from the control treatment. Additionally, RNA/DNA ratios were highest during the day (0800, 1200, 1600 h) and lowest at night (0000, 0400 h), suggesting daytime feeding activity. Growth rates ranged from − 14% to 21% WW day− 1 and the resulting equation between RNA/DNA ratio and growth rate (GR) of paralarvae was GR = 1.74 RNA/DNA − 11.79 (R2 = 0.70). After starvation, there was a reduction in growth variability in all starved treatments, while growth variability remained high in the control treatment. Findings from the present study indicate that nucleic acids are a valid indicator of nutritional condition and growth in squid paralarvae. 相似文献
5.
J.B. Fuertes J.D. Celada J.M. Carral M. Sáez‐Royuela Á. González‐Rodríguez 《Aquaculture Nutrition》2014,20(1):36-43
The aim of this study was to evaluate different replacement levels of fishmeal (FM) by feather meal (FeM) on survival and growth of juvenile crayfish (Pacifastacus leniusculus). An 80‐day experiment was conducted with stage 2 juveniles from the onset of exogenous feeding. Four practical diets (500 g kg?1 protein) differing in the level of replacement of FM protein by FeM protein were prepared: 0% (control diet), 15% (8.2% dietary FeM), 25% (13.7% dietary FeM) or 35% (19.2% dietary FeM). Each diet was tested on grouped or individually isolated crayfish. Crayfish fed the control diet or 15% replacement achieved the highest survival (average of grouped and isolated: 88.2%) and growth (grouped and isolated: 13.58 mm carapace length, 523.2 mg weight) and the lowest feed conversion ratio (average of grouped and isolated: 1.11). Final growth of isolated crayfish was significantly higher than that of grouped crayfish for all diets. This study provides the first data on the substitution possibilities of FM by FeM in diets for freshwater crayfish. An 8.2% of FeM (15% replacement of FM protein) can be included in extruded diets for juvenile P. leniusculus during the first 80 days of intensive rearing without impairing growth or feed conversion. 相似文献
6.
7.
J.B. Fuertes J.D. Celada J.M. Carral M. Sáez‐Royuela Á. González‐Rodríguez 《Aquaculture Nutrition》2014,20(2):213-218
The aim of this study was to evaluate the effects of practical diets with different levels of vitamin A on survival and growth of juvenile crayfish (Pacifastacus leniusculus). An 80‐day trial was conducted with stage 2 juveniles from the onset of exogenous feeding. Four diets differing in the level of retinyl acetate were tested: 0, 0.0025, 0.0050 or 0.0100 g kg?1 diet, equivalent to 0, 2500, 5000 or 10 000 IU vitamin A kg?1 diet, respectively. Each diet was tested on grouped or individually isolated crayfish. Crayfish fed the diet with 5000 or 10 000 IU vitamin A kg?1 diet achieved the highest survival (average of grouped and isolated: 88.9%) and growth (grouped and isolated: 13.45 mm carapace length, 533.4 mg weight). Final growth of isolated crayfish was significantly higher than that of grouped crayfish for all diets. This study provides the first data on vitamin A requirements of freshwater crayfish. A level of 5000 IU vitamin A kg?1 can be recommended for juvenile P. leniusculus during the first period of intensive rearing. 相似文献
8.
9.
Rocío González Jesús Domingo Celada José Manuel Carral Vanesa García María Sáez‐Royuela Álvaro González 《Aquaculture Research》2011,42(9):1385-1392
Recent advances in crayfish feeding have enabled the development of size grading studies from the start of first‐feeding. A 180‐day experiment aimed at intensive rearing of Pacifastacus leniusculus was carried out under controlled conditions, evaluating the effects of size grading at two different periods from the onset of exogenous feeding. Stage 2 juveniles were stocked in fibreglass tanks at a density of 100 m2, and fed a dry diet for salmonids combined with restricted amounts of Artemia cysts. Five groups were tested: no grading, grading at 60 days (large and small size) and grading at 100 days (large and small size). After 6 months, no significant differences were found in the survival among groups (mean: 73.06%). The highest final growth (pooled results from upper and lower classes: 17.39 mm carapace length, 1.43 g weight) was achieved by the crayfish sorted at 60 days, showing significant differences from the ungraded group. Smaller crayfish graded at 60 days grew significantly faster than smaller crayfish graded at 100 days. The food conversion ratio was lower in the graded groups (mean: 2.64), showing significant differences from the ungraded group (3.23). This study shows that size grading allows a better performance and an improved feeding efficiency. 相似文献
10.
This study aimed to determine the effect of feeding rates and water temperatures on the growth, feed utilization and size heterogeneity changes in subadult pikeperch. Fish with an average weight of 84±19 g were fed with a commercial trout diet for 18 weeks at a water temperature of 20 °C and 25 °C. Four feeding rates (PSFR) were predicted at both temperatures, which corresponded to 1.0%, 1.25%, 1.50% and 2.0% of body weight per day (bw day−1 ) for the first, and to 0.8%, 1.0%, 1.2% and 1.4% of bw day−1 for the second 9 weeks respectively. At the end of the experiment, the individual weight averaged 273±82 g. Pikeperch showed a better growth rate [specific growth rate (SGR)] and apparent feed conversion rates (AFCR) at the higher temperature. Thermal-unit growth coefficient (TGC) was better at the lower temperature. The values of SGR, TGC and AFCR significantly increased with increasing PSFR at both temperatures. The values of TGC plotted against the computed feeding rates allowed estimation of the maximum feeding rates (1.25% and 1.15% of bw day−1 for pikeperch of 150–180 g at 25 and 20 °C respectively). Size heterogeneity changes were affected neither by the feeding rate nor by temperature. 相似文献
11.
Mohammad Sudagar Abbas Hajibaglo Hamed Kolangi Miandare 《Journal Of Applied Aquaculture》2013,25(1):81-87
This study was carried out to determine the effect of feeding time on growth parameters, food conversion ratio, and survival rate of Huso huso fingerlings (2.11 ± 0.03 g) over a period of five weeks. Fish in triplicate tanks were fed a commercial pelleted diet four times every 24 h on one of four schedules: at 08:00, 11:00, 14:00, and 17:00 h (day feeding); at 08:00, 12:00, 18:00, and 22:00 h (day/night feeding); at 18:00, 21:00, 24:00, and 06:00 h (night feeding); or at 08:00, 12:00, 18:00, and 22:00 h (full dark feeding). At the end of the experimental period, fish in the day-fed group had significantly (P < 0.05) better final weight, daily growth rate, specific growth rate, survival, condition factor, and food conversion ratio than day/night and night-fed groups. Performance of fish fed under full dark conditions was intermediate between day-fed and the other groups. In terms of rearing costs, daytime feeding of Huso huso is the most efficient. 相似文献
12.
The effects of feeding rates on growth, feed conversion, protein deposition and carcass quality of fingerling Catla catla (3.61 ± 0.03 cm; 0.71 ± 0.04 g) were worked out by conducting a 16‐week feeding trial. Fingerlings were fed with a casein‐gelatin‐based purified diet (40% crude protein CP; 14.95 MJ kg?1 digestible energy; DE) at 1%, 2%, 3%, 4%, 5%, 6% and 7% body weight per day. The absolute weight gain (AWG; 10.50 g fish?1) and feed conversion ratio (FCR; 1.41) were highest at the feeding rate of 5% body weight per day. However, protein gain (PG; 0.36 g fish?1) and carcass protein content attained the maximum values at 4% BW day?1. Quadratic regression analyses of AWG g fish?1 and PG g fish?1 at 95% maximum response indicated that these parameters attained the best values at 4.19% and 3.81% BW day?1. On the basis of the above results it is recommended that the feeding rate in the range of 3.81–4.19% BW day?1 with a P:E ratio of 26.69–27.74 mg protein MJ?1 DE is optimum for maximum growth, efficient feed conversion and best carcass quality in fingerling C. catla. 相似文献
13.
The effect of feeding rate on the growth performance of green sturgeon (Acipenser medirostris) fry 
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下载免费PDF全文 Four one‐week growth trials were conducted on green sturgeon fry to determine the effect of feeding rate on their growth performance at 18 °C when they were fed a salmonid soft moist feeds containing 445–457 g kg?1 of crude protein and 201–207 g kg?1 of lipid. The fry used in Trials I‐IV were 5–8 weeks after their initiation of exogenous feeding. Their average initial body weights were 1.63 ± 0.01, 2.63 ± 0.03, 5.08 ± 0.08 and 7.49 ± 0.05 g, respectively. Six feeding rates used were as follows: 2.5–15.0% body weight per day (% BW day?1) with a 2.5% increment in Trial I; 1.25–7.50% BW day?1 with a 1.25% increment in Trial II; and 2.0–7.0% BW day?1 with a 1.0% increment in Trials III and IV. Four replicates with 50 fry per tank in Trials I‐III and 30 fry per tank in Trial IV were assigned randomly to each feeding rates. The final body weight, specific growth rate, feed efficiency, protein retention, and whole‐body moisture, lipid, and energy contents were significantly (P < 0.05) affected by the feeding rates. The optimum feeding rates determined by the broken‐line model were 7.1, 5.7 and 5.3% BW day?1 for Trials I, II and IV, when the fry were 5, 6 and 8 weeks after their initiation of exogenous feeding, respectively. 相似文献
14.
Abstract – To assess the consequences of unpredictability in the availability of food, this study measured the effect of timing of the daily feeding on food consumption and growth rates of juvenile Gasterosteus aculeatus. The experiment lasted 21 days at 14 °C and a photoperiod of 10 hours of light and 14 hours of dark. Fish were housed individually and allocated at random to three treatments. The mean initial weight of fish was 0.402 g. Group 1 were fed live enchytraeid worms for 2 h after lights came on ("morning"), group 2 was offered food for 2 h randomly at any time of the day ("random") during the light period and group 3 received food for 2 h before the lights went off ("evening"). There was no significant effect of timing of feeding on mean daily food consumption, which was 0.052 g day−1 . Daily consumption on the random schedule was more irregular than on the two fixed schedules. Timing of feeding had no significant effect on mean specific growth rate (G) (2.42% day−1 ), gross growth efficiency (23.3%), white muscle RNA:DNA ratio (5.6), carcase lipid content (31.7% dry wt) and carcase dry matter content (27.4% wet wt). Thus, a lack of predictability in the availability of food during the light period of the day did not impose a detectable cost on the growth performance of the stickleback. 相似文献
15.
Guoqiang Huang Shuanglin Dong Fang Wang Shaoshuai Dong Yingchun Mu & Xiangyi Liu 《Aquaculture Research》2008,39(9):934-944
Three experiments were designed to investigate the heat increment of feeding (HiE) in Chinese shrimp, Fenneropenaeus chinensis . (1) Four groups of shrimp with different weight were fed at four rations to measure oxygen consumption in the following 24 h. (2) Four groups of shrimp with different weight were fed with four rations for 28 days. (3) Fish flesh, shrimp flesh, clam foot, polychaette worm, formulated diet and mixed diet were provided to six groups of shrimp for 30 days. The coefficient of heat increment of feeding ( C HiE ) values within 24 h after ingesting 1 g digestible protein (DP) and 1 kJ digestible energy (DE) were 18.57 kJ and 0.45. C HiE values of 1 g DP and 1 kJ DE achieved in the second experiment were 25.06 kJ and 0.57. The energy cost of 1 g wet weight gain, 1 g protein gain and 1 kJ recovered energy were 13.94, 32.16 and 1.07 kJ. They accounted for 69.28%, 26.71% or 40.23% of HiE of the meals needed for these growths. The present results indicated that HiE was a fundamental property of the feed and the energy cost of growth accounted for different fraction when different feeds were ingested. 相似文献
16.
The effects of tank bottom substrates and presence of shelter on growth, survival and condition of cheliped in the juvenile (stage 2) signal crayfish, Pacifastacus leniusculus (Dana), with an initial stocking density of 200 individuals m?2 were investigated. In the first trial, three different tank bottom substrates with or without shelter were used. The three bottom types were loose gravel, glued gravel and bare bottom. The fastest growth both in terms of wet weight and carapace length was observed on loose gravel bottom. Also survival (range 30.1% to 49.8%) was affected by bottom type being higher on gravel bottoms than on bare bottom. Shelter improved survival only on loose gravel bottom. Bottom type influenced also the number of animals with cheliped injuries. The highest proportion of animals with no injuries (59.5%) was found on bare bottom and the proportion was about 12% and 13% units less on loose gravel and on glued gravel bottom. The presence of shelter had a marginal probability in increasing the number of animals without injuries. In the second trial, the substitution of ordinary gravel as tank bottom substrate with crushed limestone was studied. The mean final wet weights were 0.517 g on ordinary gravel bottom and 0.481 g on limestone bottom. The survivals were about 74% and 80% respectively. Limestone bottom decreased marginally final wet weight, and increased survival but did not affect the final carapace length that had a mean value of 13.6 mm. We conclude from the present experiments that the type of tanks and the rearing system used supported good growth of juvenile signal crayfish. The best growth results could be obtained by using loose gravel (or loose limestone) on the bottom of the tanks with a sufficient quantity of hiding places. However, there appears to be an increased risk for cheliped injuries on bottoms with loose materials. 相似文献
17.
Stavros Chatzifotis Adriana Villamor Martin-Prat Nikos Limberis Nikos Papandroulakis Pascal Divanach 《Fisheries Science》2006,72(1):83-88
ABSTRACT: Brown meagre Sciaena umbra Linnaeus 1758 is a demersal species living at depths of 0–200 m with a wide distribution in the Mediterranean Sea, Black Sea and eastern Atlantic Ocean. It exhibits nocturnal behavior and occupies bottom caves and seabeds covered with vegetation. This study presents the first data on brown meagre growth under culture conditions and contributes some basic information on its dietary protein requirement by feeding isoenergetic diets with different protein–lipid ratios by means of self-feeders. Fish with 78.8 ± 15.8 g (mean ± standard deviation) body weight were divided into four groups and subjected to four different feeding regimes with three replications for 77 days. In the first group, fish were supplied with a high protein and low fat diet (HPLF, 52 : 8 w/w fat–protein ratio), the second one a medium protein and medium fat diet (MPMF, 42 : 14), the third with a low protein and high fat diet (LPHF, 31 : 23). In the fourth group, fish had access to both HPLF and LPHF diets. Fish fed on HPLF and MPMF diets showed significantly better growth and feed conversion ratios than fish fed on the LPHF diet. Fish with access to HPLF and LPHF diets exhibited comparable growth to the HPLF group but their feed conversion ratio was significantly higher. The condition factor and hepatosomatic index revealed no significant differences between dietary regimes. The liver of brown meagre may serve as a depository organ for energy, judging from its relatively high lipid content (39–43%). 相似文献
18.
2018年12月—2019年3月间,定期从温棚养殖和稻田养殖的克氏原螯虾中采集599尾样本,测量克氏原螯虾的体质量(y)、全长(x1)、头胸甲长(x2)、头胸甲宽(x3)、腹节总长(x4)、第一腹节长(x5)、第一腹节宽(x6)、尾节长(x7)、第六腹节长(x8)、第六腹节宽(x9)和螯长(x10),探明温棚养殖幼虾与稻田养殖幼虾以及温棚养殖雌雄幼虾的生长特性,以期为克氏原螯虾温棚养殖及单性养殖提供参考。试验结果表明,克氏原螯虾全长(L)和体质量(m)呈幂函数,回归方程为:m=0.0209L3.1132;温棚养殖和稻田养殖克氏原螯虾幼虾均在2—3月生长最快,1月生长最慢;克氏原螯虾幼虾各时期各生长指标温棚养殖幼虾均大于稻田养殖幼虾,至3月,温棚养殖的克氏原螯虾体质量接近稻田养殖的2倍;在温度较低的12月—翌年2月期间,温棚养殖的克氏原螯虾幼虾的平均体质量增加率比稻田养殖的克氏原螯虾幼虾的平均体质量增加率高14.00%,温棚养殖的克氏原螯虾幼虾全长平均增长率比稻田养殖的高3.96%。温棚养殖的各时期雄虾体质量均略高于雌虾,但差异不显著(P>0.05);在所有生长指标中,只有雄性克氏原螯虾螯长一直大于雌性,且自12月后,雌、雄虾螯长间一直存在极显著差异(P<0.01)。 相似文献
19.
The effect of dietary digestible protein/digestible energy (DP/DE) ratios and feeding level on growth, feed efficiency, nutrient and energy usage by Atlantic salmon ( Salmo salar ; initial body weight, 7.0 g/fish) at 15°C was investigated in a 16-week feeding trial. Three diets, differing in their DP and DE contents, namely 37/18 (regular diet, RD), 37/21 (high fat diet, HF) and 44/ 22 (high nutrient-dense diet, HND) g/MJ of dry feed were formulated. DP/DE ratios were 20, 18 and 20 g/MJ for the RD, HF and HND diets, respectively. Salmon were hand-fed three times a day at either 100% or 85% of the feed requirement estimated by a bioenergetics model. At each feeding level, DE intake (kJ/fish) was similar for all three diets. Diet composition did not affect growth rate. However, increasing the digestible energy density from 18 to 22 MJ/kg of dry feed resulted in a significant increase ( P < 0.05) in feed efficiency. Restricting feed intake significantly decreased live body weight gains for all diets. However, feed efficiency was not affected by feeding level. Diet composition and feeding level did not affect carcass composition and nutrient and energy usage, with the exception of a higher ( P < 0.05) carcass lipid of fish fed the HF100 diet compared with the fish fed the RD and HND diets and a higher ( P < 0.05) lipid gain (g/fish) of fish fed the HF100 diet compared with fish fed all the diets at the restricted feeding level. Restricting feeding resulted in significantly lower ( P < 0.05) energy gain (kJ/fish) compared with fish fed at 100%. Increasing the DE and nutrient density of the diet had no effect on growth but improved feed efficiency and lowered solid wastes (g of solid wastes per kg of fish produced) while dissolved wastes were not affected by dietary ormulation. 相似文献
20.
The blue swimmer crab, Portunus pelagicus, is an emerging aquaculture species in the Indo-Pacific. Two experiments were performed to determine the effects of salinity on survival, growth and haemolymph osmolality of early juvenile P. pelagicus crabs. The salinities tested for the first experiment were 10, 15, 25 and 40 ppt, and for the second experiment 5, 20, 30, 35 and 45 ppt. Each salinity experiment was triplicated, with each replicate consisting of 10 stage 4 juveniles. Each experiment lasted 45 days. Mortalities and incidence of “molt death syndrome” were recorded daily, while the intermolt period, carapace length, carapace width and wet weight were measured at each molt. At the end of the experiments the haemolymph osmolality and dry weights were measured.
Results demonstrate that salinity significantly affects both the survival and growth of early P. pelagicus juveniles. Mortality was significantly higher (p < 0.01) for juveniles cultured at salinities ≤ 15 ppt and at 45 ppt. At a salinity of 5 ppt a complete mortality occurred on day 20. In all salinity treatments, the majority of mortalities were due to “molt death syndrome”. In experiment 1, immediate effects of salinity on growth and development were seen at 10 ppt as the intermolt period was significantly longer (p < 0.01) and the mean carapace size increase was significantly less (p < 0.01) at the first molt compared to the other treatments. Meanwhile, the specific growth rates (carapace length, width and wet weight) were significantly lower (p < 0.05) at high salinities (≥ 40 ppt) due to longer intermolt periods and significantly lower (p < 0.05) carapace size or wet weight increases.
The haemolymph osmolality exhibited a positive linear relationship with the culture medium with an isosmotic point of 1106 mOsm/kg, equal to a salinity of approximately 38 ppt. Based on the osmolality graph, high metabolic cost for osmoregulation due to increased hyper- and hypo-osmotic stress appeared to cause lower survival and specific growth rates of the crabs. The results demonstrate that a salinity range of 20–35 ppt is suitable for the culture of early juvenile P. pelagicus. 相似文献