共查询到20条相似文献,搜索用时 31 毫秒
1.
C. A. G. Leal G. A. Carvalho-Castro P. S. C. Sacchetin C. O. Lopes A. M. Moraes H. C. P. Figueiredo 《Aquaculture International》2010,18(4):657-666
Flavobacterium columnare is a bacterial pathogen for many freshwater fish species. It is responsible for outbreaks in fish farms worldwide, causing
high mortality rates. Fish vaccination is a potential approach for prevention and control of disease, with oral vaccines suitable
for fish because of their easier application, low cost and minimum stress to fish. Alginate microparticles have been widely
used as controlled release systems, including for fish vaccination. The aim of this study was to evaluate the capacity of
oral and parenteral vaccines against F. columnare to induce a humoral response, as well as the in vivo efficiency in Nile tilapia fingerlings. The fingerlings were immunized
with bacterin by intraperitoneal (i.p.), intramuscular (i.m.), oral and immersion routes, as well as orally with alginate
microparticles containing formalin-killed bacteria. A sandwich ELISA was developed to detect specific antibodies against F. columnare. The animals were challenged with pathogenic strain BZ-1 to determine the relative percentage of survival. A significant
humoral response was induced by bacterin administered by i.p. and i.m. routes (P < 0.05). However, none of the vaccine preparations were effective in protecting fish against F. columnare infection (P < 0.05). In spite of high antibody levels, there was no relation between immunoglobulin titers and resistance to columnaris
for Nile tilapia fingerlings. These data suggest that use of serological analysis as the only method to determine vaccine
efficiency against F. columnare infection in Nile tilapia can lead to imprecise results for the usefulness of these products in vivo. 相似文献
2.
In this study, four essential oils—cinnamon oil, leech lime oil, lemongrass oil, and turmeric oil—were examined for their
antimicrobial activities against Streptococcus iniae, a bacterium that is pathogenic in fish, in which it causes streptococcosis. Cinnamon oil was the most potent antimicrobial
agent among these oils, with a minimal inhibitory concentration (MIC) of 40 μg/ml. By using gas chromatography–mass spectrometry
(GC–MS), it was found that the major components of cinnamon oil were cinnamaldehyde (90.24), limonene (2.42%), cinnamyl acetate
(2.03%), linalool (1.16%), and α-terpineol (0.87%). Of these compounds, only cinnamaldehyde exhibited antimicrobial activity
against S. iniae, with an MIC of 20 μg/ml. In an in vivo trial, no mortality was apparent in fish fed on fish diets supplemented with 0.4%
(w/w) of cinnamon oil and with 0.1% (w/w) of oxytetracycline 5 days prior to infection with S. iniae. These results indicate that cinnamon oil had a protective effect on experimental S. iniae infection in tilapia, and thus has the potential to replace the antibiotics used to control this disease. 相似文献
3.
Prasad M Kumar A Mishra D Srivastav SK Srivastav AK 《Fish physiology and biochemistry》2011,37(3):505-510
The present study aimed at investigating the effects of Nerium indicum leaf extract on the blood electrolytes of Heteropneustes fossilis for short- and long term. Fish were subjected to Nerium
indicum leaf extract for short term (11.27 mg/L i.e. 0.8 of 96 h LC50) and long term (2.81 mg/L i.e. 0.2 of 96 h LC50). Fish were killed on each time intervals from control and experimental (Nerium
indicum) groups after 24, 48, 72, and 96 h in short-term exposure and after 7, 14, 21, and 28 days in long-term experiment. Blood
samples were analyzed for calcium and inorganic phosphate levels. Acute exposure of Nerium
indicum leaf extract caused a progressive decrease in the serum calcium levels after 48 h in fish H. fossilis, which persists till the close of the experiment (96 h). The serum inorganic phosphate levels remain unaffected till 48 h
in the Nerium
indicum leaf extract–exposed fish. After 72 and 96 h, the levels exhibit a decrease. Chronic Nerium
indicum leaf extract treatment provoked a decrease in serum calcium levels at day 14. This decrease continues till 28 days. The serum
phosphate level of the Nerium
indicum leaf extract–treated fish decreases on day 14 and 21. However, on day 28, the levels become close to the normal values. We
conclude that Nerium indicum leaf extract exposure alters the blood electrolytes of the fish, thus causing physiological disturbances which might affect
seriously the normal vital functions, growth rate, reproduction, and their survival in nature. 相似文献
4.
The immediate-early gene (egr-1) expression was used to examine the neuron’s response in telencephalon of goldfish during spatial learning in small space.
Fishes were pre-exposed in the experimental apparatus and trained to pick food from the tray in a rectangular-shaped arena.
The apparatus was divided into identical compartments comprising three gates to provide different spatial tasks. After the
fish learned to pass through the gate one, two more gates were introduced one by one. Fish made more number of attempts and
took longer time (P < 0.05) to pass through the first gate than the gate two or three. This active learning induces the expression of egr-1 in telencephalon as established by western blot analysis. Subsequently, the fish learn quickly to cross the similar type
of second and third gate and make fewer errors with a corresponding decline in the level of egr-1 expression. As the fish learned to pass through all the three gates, third gate was replaced by modified gate three. Interestingly,
the level of egr-1 expression increased again, when the fish exhibit a high exploratory behavior to cross the modified gate three. The present
study shows that egr-1 expression is induced in the telencephalon of goldfish while intensively acquiring geometric spatial information to pass
through the gates. 相似文献
5.
Unal G Erdoğan E Oğuz AR Kaptaner B Kankaya E Elp M 《Fish physiology and biochemistry》2008,34(4):447-454
Chalcalburnus tarichi is an endemic cyprinid species living in the Lake Van basin, in eastern Anatolia, Turkey. The present study was undertaken
to determine which hormones induce oocyte maturation in C. tarichi. The levels of 17α,20β,21-trihydroxyprogesterone (20β-S), progesterone (P), 17α-hydroxyprogesterone (17α-HOP), 11-deoxycortisol
(11-DOC), and 17α-hydroxy-20β-dihydroprogesterone (17,20β-P) were measured in fish caught from Lake Van and the Karasu River,
and injected with human chorionic hormone (hCG) (1,000 and 1,500 IU/kg). Oocytes of fish caught from the lake were also incubated
in vitro with different doses (50, 200, and 1,000 ng/ml) of 20β-S, 17α-HOP, 11-DOC, and 17,20β-P. 11-DOC was found to be the
most effective hormone among those measured for inducing oocyte maturation in vivo and in vitro. 17,20β-P could not be determined
in the plasma of any fish in vivo (P < 0.05). 1,000 IU/kg dose of hCG given by injection caused a statistically significant increase in all plasma hormone levels
(P < 0.05). It was found that there was a significant decrease in the P level only at 1,500 IU/kg dose of hCG injected (P < 0.05), while the level of other hormones increased at this dose (P < 0.05). It was also determined that all the hormones were effective in germinal vesicle breakdown (GVBD) in in vitro oocyte
culture (P < 0.05). However, 11-DOC was found to be the most effective hormone in GVBD at a dose of 200 ng/ml (70% GVBD). In conclusion,
11-DOC synthesized during final oocyte maturation in C. tarichi was found to be a potent inducer of GVBD, which shows that 11-DOC may be described as an oocyte maturation steroid in this
species. 相似文献
6.
The effect of aqueous extract of Cratoxylum formosum on innate immune response and disease resistance in tilapia Oreochromis niloticus was investigated. The fish were fed diets containing 0% (control), 0.5% (diet 1), 1% (diet 2), and 1.5% (diet 3) of C. formosum aqueous extract for 30 days. At the end of the experimental period, parameters of innate immune response including phagocytosis
of blood leukocytes, lysozyme activity in plasma, and respiratory bust activity were examined. Feeding the fish with diet
2 and diet 3 for 20 days enhanced phagocytic activity and for 30 days stimulated lysozyme and respiratory burst activities.
Diet 1 increased the phagocytic activity at 30 days, but did not affect the other measured parameters. All parameters were
not significantly changed (P > 0.05) in the control group throughout the experiment. Following 30 days of feeding, fish were infected with S. agalactiae. The cumulative mortalities of bacterial-infected tilapia that were fed diet 1, diet 2, and diet 3 were 56, 12, and 10%,
respectively, compared with 85% in the control group. These results indicate that the aqueous extract of C. formosum may elevate the innate immune response and enhance disease resistance in tilapia. 相似文献
7.
Jatropha curcas is a multipurpose and drought-resistant shrub or small tree widespread all over the tropics and subtropics. Its seeds are
rich in oil, and the Jatropha kernel meal obtained after oil extraction is rich in protein. However, presence of toxic and
antinutritional constituents restricts its use in fish feed. Jatropha kernel meal was detoxified. Common carp, Cyprinus carpio, fingerlings (15; av. body mass 10.9 ± 0.65 g) were randomly distributed in three groups with five replicates. A 6-week feeding
experiment was conducted in a respirometer system to evaluate the growth performance, nutrient utilisation and energy budget.
Fish were fed isonitrogenous diets (38% crude protein): control diet (C
ontrol group) containing fish meal (FM) protein based protein and two other diets replacing 75% FM protein with detoxified Jatropha
kernel meal (DJKM, J
atropha group) and soybean meal (SBM, S
oybean group). At the end of the experiment, body mass gain, metabolic growth rate, protein efficiency ratio, protein productive
value, energy retention, efficiency of metabolised energy for growth and efficiency of energy retention were determined. These
parameters were high and statistically similar for C
ontrol and J
atropha groups and significantly lower (P < 0.05) for S
oybean group. Whereas a reverse trend was observed for energy expenditure per g protein retained in fish body. No significant differences
were found in heat released, gross energy uptake, metabolised energy intake, metabolisability, energy expenditure, energy
expenditure per g protein fed and apparently unmetabolised energy. Conclusively, common carp–fed plant protein (DJKM and SBM)
and FM protein–based diets exhibited equal average metabolic rate. 相似文献
8.
The influence of Tribulus terrestris on the activities of testicular enzyme in Poecilia latipinna was assessed in lieu of reproductive manipulation. Different concentrations of (100, 150, 200, 250, and 300 mg) Tribulus terrestris extract and of a control were tested for testicular activity of enzymes in Poecilia latipinna for 2 months. The testis and liver were homogenized separately in 0.1 mol/l potassium phosphate buffer (0.1 mol/l, pH 7.2).
The crude homogenate was centrifuged, and supernatant obtained was used as an enzyme extract for determination of activities.
The activities of testicular functional enzyme ALP, ACP, SDH, LDH, and G6PDH levels were changed to different extent in treated
groups compared with that of the control. The total body weight and testis weight were increased with the Tribulus terrestris-treated fish (Poecilia latipinna). These results suggest that Tribulus terrestris induced the testicular enzyme activity that may aid in the male reproductive functions. It is discernible from the present
study that Tribulus terrestris has the inducing effect on reproductive system of Poecilia latipinna. 相似文献
9.
Qing-Kui Wang Cheng-Xun Chen Yong-Jun Guo Hai-Yun Zhao Jing-Feng Sun Shen Ma Ke-Zhi Xing 《Aquaculture International》2011,19(5):945-956
The purpose of this study was to determine the effect of Angelica sinensis polysaccharide (ASP) supplemented in diet on the innate cellular immune response and disease resistance in grouper, Epinephelus malabaricus. Fish were fed diets containing different doses of ASP (0, 500 and 3,000 mg kg−1 diet) for 12 weeks. After 12 week feeding, the respiratory burst activity, phagocytic activity, and leukocytes proliferation
in head kidney were assayed. The functional immunity in terms of cumulative mortality was also assessed by a challenge with
live Edwardsiella tarda. Results showed that the respiratory burst activities in ASP-supplemented groups were increased significantly. The respiratory
burst index was the highest in fish-fed 3000 mg kg−1 diet and the lowest in control. The phagocytic activities in ASP-supplemented groups were significantly higher than that
of control. No significant difference in phagocytic activity was observed between ASP-supplemented groups. ASP stimulated
the head kidney leukocytes proliferation significantly, despite the absence of lipopolysaccharide (LPS) or not. The cumulative
mortalities of fish fed with 3000 mg ASP kg−1 diet were significantly lower than those fed with 500 mg ASP kg−1 diet and control diet after 96 h of challenge. In conclusion, dietary ASP enhanced some cellular immune parameters and disease
resistance against E. tarda in grouper. 相似文献
10.
Zehra Selcuk Serap Ustaoglu Tiril Fikret Alagil Volkan Belen Mustafa Salman Sena Cenesiz Omer Hakan Muglali Feraye Berkay Yagci 《Aquaculture International》2010,18(2):213-221
An experiment was conducted to determine the effects of supplemental dietary l-carnitine, chromium picolinate (Cr-Pic) and their combination on growth performance and serum total protein, cholesterol,
triglyceride and glucose of rainbow trout (Oncorhynchus mykiss). A total of 276 rainbow trout were randomly allocated to four groups. Fish (average initial body weight = 151 ± 1.69 g)
were fed a basal diet without supplemental l-carnitine and chromium picolinate in the control group. The basal diet was supplemented with either 500 mg/kg l-carnitine, 1.6 mg/kg chromium picolinate or 500 mg/kg l-carnitine plus 1.6 mg/kg chromium picolinate for experimental groups 1 (C), 2 (Cr-Pic) and 3 (C + Cr-Pic), respectively.
Fish were fed twice a day to apparent satiation for 58 days. Weight gain, growth rate, feed consumption and feed conversion
ratio (feed/gain) were calculated for the whole period. At the end of the study, six fish were chosen randomly from each tank
to represent the experiment and frozen at −20°C for subsequent dorsal muscle analysis. The results showed no significant differences
in final body weight, weight gain or feed conversion ratio among groups. There were also no significant differences in serum
total protein, cholesterol, triglyceride or glucose concentrations among groups. Significantly higher lipid concentration
of dorsal muscle was observed in experimental groups 1 and 3. In conclusion, supplemental dietary l-carnitine, chromium picolinate and their combination have no beneficial effects on improving growth performance and feed
conversion ratio in rainbow trout. However, dietary l-carnitine slightly increased lipid concentration in dorsal muscle of rainbow trout. 相似文献
11.
Cadmium (Cd) compounds are widely distributed toxic environmental and industrial pollutants, and they may bring danger to
growth and development of aquatic organisms. In China, the Oujiang color common carp, Cyprinus carpio var. color, is a very important fish, from an economic point of view, and is well used for fish culture in paddy fields. The purpose
of this study was to show the low concentrations of cadmium-induced oxidative stress response and DNA damage in the livers
of Cyprinus carpio var. color. Superoxide dismutase (SOD), malondialdehyde (MDA), and glutathione (GSH) in liver were measured after exposure to Cd levels
(0.41, 0.52, 0.69, 1.03 and 2.06 mg/L, respectively) for 7 days and compared with the control groups. DNA damage, including
indicators of damage percentage, DNA tail length (TL) and DNA tail moment (TM) were also analyzed by comet assays. Results
showed that MDA and GSH levels in all treatment groups increased significantly relative to the controls (P < 0.01). Treatment with Cd at concentration of 0.41 mg/L increased SOD activity, while treatment with Cd at concentrations
>0.41 mg/L inhibited SOD activities. DNA damage percentage, TL and TM also significantly increased when the Cd level was >0.41 mg/L.
Positive correlations were also found between DNA damage levels and MDA levels (r = 0.74 for DNA damage percentage, r = 0.83 for TL, r = 0.84 for TM; P < 0.01 for all) as well as between GSH and MDA levels (r = 0.77, P < 0.01). These results strongly suggested that Cd-induced DNA damage in the livers of Cyprinus carpio var. color was due to lipid peroxidation and oxidative stress. 相似文献
12.
Ofelia S. Reyes Marietta N. Duray Corazon B. Santiago Manuele Ricci 《Aquaculture International》2011,19(1):155-164
The free-living nematode, Panagrellus redivivus, was tested as live food for grouper Epinephelus coioides larvae during the first feeding stage. A series of experiments were conducted to determine the acceptability of the free-living
nematodes in grouper larvae at first feeding, the optimum nematode density and the response of the larvae to nutritionally
enriched nematode. All experiments were conducted in 200-L conical tanks filled with 150-L filtered seawater and stocked at
15 larvae L−1. Duration of feeding experiments was up to day 21 (experiment 1) and 14 days (experiment 2 and 3). Brachionus plicatilis and Artemia (experiment 1) and Brachionus plicatilis alone (experiment 2 & 3) was used as the control treatment. Observations indicated that the grouper larvae readily fed on
free-living nematodes as early as 3 days posthatching, the start of exogenous feeding. Optimum feeding density for the larvae
was 75 nematodes ml−1. The enrichment of cod liver oil or sunflower oil influenced the total lipids and n-3 highly unsaturated fatty acids of P. redivivus, which in turn influenced those of the grouper larvae, however, growth and survival of the larvae were not affected (P > 0.05). The results from this investigation showed that the nematode, P. redivivus, can be used as first live food for grouper larvae from the onset of exogenous feeding until they could feed on Artemia nauplii. 相似文献
13.
We monitored feeding behavior and survival of starved juvenile olive flounder experimentally infected with the gill monogenean
Neoheterobothrium hirame. Infected flounder increased amount of the time spent in the water column by 117% when trying to capture live mysids, Neomysis sp. They also showed different feeding patterns from those of uninfected fish and made fewer attacks towards prey during
one feeding attempt. Although the average numbers of mysids captured by individuals were similar between infected and uninfected
fish, heavily infected fish tended to catch less prey. These results indicate that N. hirame reduces the feeding efficiency of the host for capturing live prey and possibly makes them more vulnerable to predation during
feeding. We could not detect any obvious difference in survival rates between uninfected, lightly and heavily infected fish
during 3 months of starvation. There was no evidence that starvation makes fish more susceptible to N. hirame. The present study provides first experimental evidence that N. hirame affects feeding behavior of juvenile olive flounder and supports the idea that this parasite indirectly reducing the host’s
survival and may be responsible for the recent reduction of the flounder population in Japan. 相似文献
14.
Suchanit Ngamkala Kunihiko Futami Masato Endo Masashi Maita Takayuki Katagiri 《Fisheries Science》2010,76(5):833-840
The present study histologically examined the effects of glucan-containing and Lactobacillus rhamnosus GG (LGG)-containing diets on intestinal damages inflicted on Nile tilapia by Aeromonas challenges. Tilapia were fed control, glucan, and LGG diets for 2 weeks and were subsequently challenged with Aeromonas. The intestines were then histologically examined at 1, 7, 14, and 21 days post-infection. Mortality following the challenge
was lower for the fish fed the glucan and LGG diets. The intestines of these groups also showed increased inflammatory cell
infiltration and reduced intestinal damage from Aeromonas. Moreover, inflammatory cell infiltration occurred more rapidly in the glucan-fed than in the LGG-fed fish following the
challenge. Before the challenge, the dominant mucous cell was the acid type in all the tests. After the challenge, the main
mucus cell type in the proximal intestine of the glucan-fed fish shifted to AB-PAS double-staining cells, while in the LGG-fed
fish, it remained the acid type throughout the test period, and the number of double-staining cells was smaller than in the
control fish after the challenge. Thus, the different mucous cell and inflammatory cell responses show that glucan and LGG
might have different immunostimulative effects, although they both reduced the intestinal damage following Aeromonas challenges. 相似文献
15.
Sanjoy Banerjee Helena Khatoon Mohamed Shariff Fatimah Md. Yusoff 《Fisheries Science》2010,76(3):481-487
We have investigated the possibility of using a consortium of marine bacterium and periphytic microalgae to improve the water
quality and increase the growth and survival of the shrimp Penaeus monodon in a hatchery system. Three treatments were evaluated for their effect on P. monodon postlarvae (PL) when the culture water was not changed: Bacillus
pumilus alone (B); periphytic microalgae alone (M); B. pumilus + periphytic microalgae (BM). P. monodon PL raised in a tank of unchanged water without bacterium and periphytic microalgae served as the control. The water in tanks
of the M and BM treatments had significantly low levels of total ammonia-nitrogen (TAN) (0.03 and 0.01 mg l−1, respectively) and nitrite-nitrogen (NO2-N) (0.03, 0.01 mg l−1, respectively) than that in the B (TAN 0.80, NO2-N 0.68 mg l−1) and control (TAN 1.11, NO2-N 1.12 mg l−1) tanks. Moreover, PL cultured in tanks M and BM had significantly higher survival and specific growth rates and a significantly
higher resistance to the reverse salinity stress test than those in the B and control tanks. Compared to the control PL, the
PL cultured in the BM tanks had significantly higher levels of protein, lipid, polyunsaturated fatty acids, ecosapentaenoic
acid, and docosahexaenoic acid. The culture water in tanks BM also contained significantly less Vibrio than the control water. Our results illustrate the beneficial effects of a B. pumilus and periphytic microalgae consortium on improving the water quality and the growth and survival of shrimp PL grown in a hatchery
system. 相似文献
16.
Shude Xu Liang Zhang Qingyang Wu Xuebing Liu Shuqi Wang Cuihong You Yuanyou Li 《Aquaculture International》2011,19(5):1007-1018
In order to evaluate the feasibility of dried seaweed Gracilaria lemaneiformis (Bory) as a dietary ingredient for the rabbitfish Siganus canaliculatus (Park), juvenile fish (average weight 15.64 ± 0.15 g) were fed with two isonitrogenous (32% crude protein) and isolipid (8%
lipid) diets for 8 weeks, with one diet incorporating 33% of dried G. lemaneiformis (DGL), which accounted for 6% protein and 17% carbohydrate (DGL-diet), and the other containing no DGL (control diet). After
8 weeks, the growth performance and feed utilization efficiency of fish fed with the DGL-diet were inferior to fish fed with
the control diet, although some non-specific immunity parameters were better in fish fed with the DGL-diet compared with those
of fish fed control diet. Nutritional composition (whole body composition, amino acid, and fatty acid composition in dorsal
muscle) except methionine and tyrosine in muscle showed no differences between the two groups. Furthermore, the survival rate
of fish and apparent digestibility coefficient of diets were the same between the two groups. These results indicated that
incorporation of DGL in diet of S. canaliculatus is feasible, and further studies are recommended to optimize the level of DGL in diet of S. canaliculatus to improve growth performance. 相似文献
17.
We analysed the genetic diversity of Melicertus kerathurus (Penaeidae), a commercially valuable penaeid shrimp that is distributed in the Mediterranean Sea and eastern Atlantic Ocean.
We examined the polymorphism of a 494 bp DNA segment of the mitochondrial COI region in 173 individuals, sampled in nine Mediterranean
and two Atlantic samples, covering the whole range of the species from the tropical waters of the Gulf of Guinea to the eastern
part of the Mediterranean Sea. The mean nucleotide and haplotype diversities were π = 0.00275 and h = 0.718, respectively, for the global data set, with the highest values occurring in the African samples and the lowest in
the Adriatic Sea. A clear sample differentiation was found (F
st = 0.194), but this did not reflect a geographical pattern and there were only faint traces of an Atlantic–Mediterranean subdivision.
Mismatch analysis and a high significant negative value of Tajima’s D suggested that M. kerathurus is not at mutation drift-equilibrium, but underwent a recent expansion after a period of low effective sample size. A postglacial
recolonisation of the Mediterranean from an Atlantic refuge could be hypothesised based on these data. 相似文献
18.
Ana Teresa Gonçalves Masashi Maita Kunihiko Futami Masato Endo Takayuki Katagiri 《Fisheries Science》2011,77(4):633-642
To test the effects of probiotic bacteria against crowding stress, juvenile Nile tilapia Oreochromis niloticus were fed commercial feed supplemented with 1 × 1010 cfu/g pellets of Lactobacillus rhamnosus for 3 weeks. The fish were confined and subjected to crowding for 7 and 14 days after which their physiological condition
was investigated. The administration of probiotic prophylaxis improved growth performance even in the stressed fish. After
7 days of stress exposure, fish receiving probiotic-supplemented feed showed proactive behavior and coping responses to the
stressor, as evidenced by elevated plasma glucose levels and osmolality, stabilized plasma electrolytes, and a higher RNA:DNA
ratio. Fish stressed for 7 days and fed normal commercial diet showed impairment of plasma electrolytes; after 14 days, the
plasma osmolality, electrolytes, glucose, and RNA:DNA ratio decreased, indicating physiological maladaptation to the stressor.
The growth rate was also found to be reduced, suggesting that energy demand exceeded the energy available from metabolism
and dietary uptake. This latter effect was not observed in fish fed the probiotic-supplemented diet. The results suggest that
probiotic bacteria prophylaxis may increase energy availability for metabolic support of the crowding stress response and
improve the stress coping capacity of fish. 相似文献
19.
Yaowalux Ruttanapornvareesakul Yoshitaka Sakakura Atsushi Hagiwara 《Fisheries Science》2010,76(2):295-304
We conducted screening tests to determine whether enzyme activity is a suitable biomarker for assessing the physiological
condition of marine fish larvae. The rearing experiments consisted of three trials, of which two were conducted using the
seven-band grouper Epinephelus septemfasciatus for a period of 5 days after hatching (DAH), and one was conducted using the devil stinger Inimicus japonicus for 10 DAH. The trials were conducted under three different rearing-tank environments (shallow tank, intermediate tank, deep
tank) in a water volume of 100 l and an aeration rate of 50 ml/min. We determined survival, surface death, growth, and enzyme
activities (trypsin, esterase, and alkaline phosphatase). The highest survival rates and lowest surface deaths in both species
occurred among the larvae grown in the deep tank. There was a significant and negative correlation between survival at 5 DAH
and alkaline phosphatase activity at 0 DAH in the seven-band grouper. The same correlation was found between survival at 10 DAH
and trypsin and alkaline phosphatase activity at 1 DAH in the devil stinger. Based on these results, we conclude that the
activity of a specific enzyme is a candidate for assessing the physiological condition of marine fish larvae. 相似文献
20.
Prostaglandins are involved in the reproductive processes in a variety of animals, including crustaceans. It was found that
polychaetes, the best maturation diet for shrimp broodstock, possessed the greatest variation of prostaglandin E2 (PGE2) when compared with other live feeds. The level of PGE2 varied according to sizes, feed intake, sources and type of polychaete. The matured and also larger sand polychaete Perinereis sp. contained higher PGE2 levels than younger and smaller sand polychaetes (18.16 ± 5.82 ng PGE2 mg−1 protein for polychaetes at an average length of 10 cm up to 160.8 ± 37.09 ng PGE2 mg−1 protein for polychaetes at an average length of 17 cm). The PGE2 levels in ovaries and haemolymph of female shrimp fluctuated with the developmental stage of the ovaries. The highest concentration
of PGE2 in haemolymph was at stage 3 of ovarian development, whereas the highest concentration of PGE2 in shrimp ovaries was at stage 4. In vitro incubation of Penaeus monodon pre-vitellogenic oocytes with polychaete extract and synthetic PGE2 demonstrated that both PGE2s enhanced oocyte development, especially during late development and ovulation. The putative role of PGE2 from polychaetes or the presence of PGE2 in polychaetes may be a factor in their role as a dietary constituent required for shrimp oocyte development. 相似文献