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121.
Laddawan Krongpong Kunihiko Futami Takayuki Katagiri Makoto Endo Masashi Maita 《Fisheries Science》2008,74(5):1055-1061
Furazolidone, an antibacterial drug that was once widely used in the livestock industry and aquaculture, is now prohibited
in numerous countries. It is difficult to detect residual furazolidone because it is readily metabolized in animal tissues
but, by using and liquid chromatography coupled with tandem mass spectrometry, its metabolite, 3-amino-2-oxazolidinone (AOZ)
can be detected. Here we describe the validity of an enzyme-linked immunosorbent assay (ELISA) kit to detect AOZ in Japanese
eel Anguilla japonica tissue. ELISA is capable of detecting AOZ at 1.0 μg/kg in an eel sample with excellent accuracy and precision. Our results
show that ELISA is suitable for regulatory purposes and for studying the fate of AOZ residues in eel treated with furazolidone.
To measure the persistence of AOZ in eel tissues, eels (1.4–6.5g) were immersed in tanks containing 2 and 10 mg furazolidone/L
for 3 h, and then maintained in a tank supplying well water for the next 160 days. The half-lives of AOZ, calculated from
the linear terminal part of the excretion curve, were 25.0 days in muscle and 21.6 days in liver from fish exposed to 2 mg/L
furazolidone. In the eels treated with 10 mg/L furazolidone, by contrast, high levels of AOZ were detected in liver and muscle,
but the half-lives of AOZ were similar to those in fish treated with 2 mg/L furazolidone. The half-lives of AOZ in eel tissues
were prolonged by the condition of low water temperature. 相似文献
122.
The phospholipid class composition, fatty acid composition and phospholipase A1 (PLA1) activity from the ovaries of skipjack tuna were compared with those of six other species of marine fish. In the skipjack
ovaries, the lysophosphatidylcholine (LPC) proportion for the phospholipid, the docosahexaenoic acid (DHA) percentage for
the total fatty acids of the phospholipids and the PLA1 activity of the crude enzyme were the highest among those of the seven species. The optimum pH and temperature for the PLA1 activity of the crude enzyme from the skipjack ovaries were in the range of pH 6–7 and 20–30°C, respectively, and calcium
ions were not required. As a substrate, phosphatidylcholine was more easily hydrolyzed than phosphatidylethanolamine by this
enzyme, and the plasmalogen-type phospholipid was much lower than the acyl-type phospholipid. After a 6-h hydrolysis reaction
of the purified phospholipid extracted from the mixed ovaries of skipjack and yellowfin tuna by this enzyme, the LPC ratio
of the phospholipid increased from 20 to 72.6% and the percentage of DHA for the total fatty acids of the phospholipid also
increased. Thus, skipjack ovaries might possibly be used as a source of PLA1. 相似文献
123.
Information about reproductive season, size at sexual maturity and size-dependent reproductive potentials is important for
efficient resource management. Such information is necessary to determine seasonal closures and minimum legal size limits.
To conserve resources of coconut crab Birgus latro, which are in danger of extinction due to excessive exploitation, their reproductive season, female size at functional maturity
and relationship between female size and reproductive potentials were investigated. The reproductive season started in early
June and ended late August, and females with higher reproductive potentials showed a tendency to spawn early in the reproductive
season. The prohibition of exploiting the resources during the reproductive season, especially early in the season, would
be appropriate for sustainability of high reproductive outputs. Fifty percent of investigated females matured functionally
at 24.5-mm thoracic length (TL). However, the size at which all females reached functional maturity was 32.3 mm TL, and there
was a wide variation in the size of functional maturity among individuals. We must determine minimum legal size by taking
the variation into account to allow all individuals to mate at least once before they are caught, which may prevent serious
depression in reproductive rate and genetic diversity. 相似文献
124.
This study was performed to obtain information on the occurrence of multiple paternities in three species of viviparous Japanese
surfperch using allelic markers of microsatellite DNA loci. Direct evidence for multiple fertilizations was established by
reconstructing paternal genotypes from the progeny of gravid females. Multiple paternities were ascertained in five of 10
broods of Ditrema temmincki and in three of nine broods of Neoditrema ransonneti, but not in Ditrema viride. The number of patrilines detected in the progeny of D. temmincki and N. ransonneti females were two or three, respectively, as determined by the GERUD v2.0 algorithm for reconstructing parental genotypes
from half-sib progeny arrays. 相似文献
125.
Vikingstad E Andersson E Norberg B Mayer I Klenke U Zohar Y Stefansson SO Taranger GL 《Fish physiology and biochemistry》2008,34(3):289-298
Atlantic salmon (Salmo salar L.) females (2 SW), maturing for the first time, were reared under one of three temperature regimes (high: 14.3 ± 0.5°C;
natural: 10.6 ± 1.0°C; and cold: 6.9 ± 1.0°C) in combination with one of two experimental treatments; an injection of GnRH
analogue (GnRHa) contained in biodegradable microspheres, or a sham injection (microspheres only). The six experimental groups
were then reared under simulated natural photoperiod for 4 weeks. Blood samples were drawn for analysis of plasma steroid
levels and the fish were inspected for ovulation weekly. Batches of stripped eggs were incubated in triplicate incubators
in raceways until the eyed stage. Treatment with GnRHa resulted in a substantial advancement and synchronization of ovulation
at all temperatures, while exposure to cold water also appeared to advance ovulation slightly. While 75% (warm and cold) to
90% (natural) of GnRHa fish ovulated during the 4-week trial, only 30% of sham-treated females exposed to cold water, and
none of the sham-treated fish held at higher temperatures, ovulated during this period. Survival rates of embryos to the eyed-stage
were significantly higher for broodstock exposed to cold water. Plasma levels of testosterone (T), 17β-oestradiol (E2), and 17α,20β-dihydroxy-4-pregnen-3-one (17,20βP) were all significantly affected by treatment with GnRHa and, to a lesser
extent, temperature. The efficiency of GnRHa in counteracting the negative effects of high temperature on ovulation and the
associated changes in circulating sex steroids suggest that temperature inhibition operates at least in part at the brain
or pituitary. 相似文献
126.
Teleost fish lack the enzyme for endogenous synthesis of ascorbic acid (AA), an essential micronutrient for fish. The aim
of this study was to examine the effect of higher levels of dietary vitamin C on growth, nutritional quality, and immunomodulation
in the Indian major carp, rohu (Labeo rohita). Four groups of L. rohita were fed experimental diets containing either no vitamin C (control) or supplemented with vitamin C at 500 mg kg−1 (Exp-1), 1000 mg kg−1 (Exp-2), or 1500 mg kg−1 (Exp-3) for 60 days. Growth parameters (NWG, ADG, and SGR), serological parameters (TSP, TSA, TSG, and A:G), haematological
parameters (TLC, TEC, Hct, MCV, and MCH), and different non-specific immunological parameters (PR, PI, respiratory burst activity,
and bactericidal activity) were evaluated during the experimental trial. Fish fed a vitamin C-supplemented diet showed higher
specific growth rate (SGR) up to 1000 mg kg−1 compared with control fish. Different haematological and serological parameters along with non-specific immune parameters
were influenced by vitamin C supplementation. Among the non-specific immune parameters phagocytic activity (PR and PI) and
respiratory burst activity (NBT cells) were significantly (P ≤ 0.05) enhanced by increasing doses of vitamin C supplementation. Higher levels of dietary vitamin C significantly (P ≤ 0.05) enhanced protection against Aeromonas hydrophila (AH1) infection compared with controls. Results from this study help to establish the beneficial effect of vitamin C on growth
and immunmodulation in rohu (L. rohita). 相似文献
127.
Dorafshan S Kalbassi MR Pourkazemi M Amiri BM Karimi SS 《Fish physiology and biochemistry》2008,34(3):195-200
The aim of this study was a comparison of key haematological features of diploid (2n) and triploid (3n) Caspian salmon (Salmo trutta caspius). Morphometric indices of erythrocytes were determined on blood smears by light microscopy. Triploidy significantly (P < 0.001) increased all morphometric indices measured in the erythrocytes including cell size, cell surface area, and cell
volume. The increase in cell size was larger for the major (27%) axis than for the minor (22%) axis, thus making erythrocytes
of 3n Caspian salmon more ellipsoidal. The estimated increase in erythrocyte nuclear volume (87%) was bigger than the theoretical
expected 50% increase. Haematological indices were measured manually by hemocytometry. Triploids had lower numbers of red
blood cells (RBC: 1,120,000 cells/mL in 2n vs. 700,000 cells/mL in 3n; P < 0.001) but they were larger in size (mean erythrocytic volume [MEV]: 363.1 nm3 in 2n vs. 483.3 nm3 in 3n; P < 0.001). The decrease in RBC number was not compensated by the increase in MEV and, thus, triploidy affected the haematocrit
(Hct: 38.8% in 2n vs. 33.06% in 3n; P < 0.05). Total blood hemoglobin concentration was lower in triploid fish (Hb: 9.9 g/dL in 2n vs. 8.9 g/dL in 3n; P < 0.05). In contrast, mean erythrocytic hemoglobin (MEH: 95 μg in 2n vs. 133.2 μg in 3n; P < 0.001) was higher for 3n Caspian salmon as a result of their larger erythrocytes, although MEH concentration (MEHC: 0.26 g/dL
in 2n vs. 0.27 g/dL in 3n) did not significantly differ (P > 0.05). White blood cell (WBC) counts (lymphocytes and neutrophiles) were measured and WBC/RBC ratios were calculated. There
were no significant differences in WBC (15,710 cells/mL in 2n vs. 12,683 cells/mL in 3n; P > 0.05), lymphocytes, and neutrophils as %WBC as well as WBC/RBC ratios between two ploidy levels (P > 0.05). Triploid Caspian salmon showed higher erythrocyte abnormalities such as ‘twisted’, ‘tailed’, and ‘anucleated’ cells
as well as high portions of immature RBC in blood smears in comparison with diploids (P < 0.001). 相似文献
128.
129.
In this study, the energy budget of the Manila clam, Ruditapes philippinarum, was evaluated after one-week acclimation periods at 5, 10, 15, 20, and 25°C. Small clams (151 ± 12 mg DW) and large clams
(353 ± 16 mg DW) were fed with the microalgae, Isochrysis galbana. Filtration rate, ingestion rate, assimilation efficiency, oxygen-consumption rate, and ammonia excretion rate were measured.
Both filtration rate and ingestion rate of small and large clams were found to be related to temperature. The highest Q
10 values were measured in the range 15–20°C for both small and large clams. Assimilation efficiency of both small and large
clams was not significantly influenced by temperature, although the maximum mean values were detected at 20°C. Oxygen consumption
rate and ammonia excretion rate of small and large clams were found to be related directly to temperature over the entire
range, with a maximum being detected at 25°C. The highest Q
10 value was estimated in the range 10–15°C with regard to oxygen consumption rate, and in the range of 15–20°C with regard
to ammonia excretion rate. Scope for growth (SFG) was positive at all temperatures, achieving a maximum value at 20°C in both
small and large clams, primarily as a consequence of the enhanced ingestion rate which offset the concomitant elevation in
the metabolic rate. In this study we have estimated the thermal optimum for this species at 20°C. 相似文献
130.
Pedro Domingues Ana Ferreira Lorenzo Marquez José P. Andrade Nelda López Carlos Rosas 《Aquaculture International》2008,16(3):215-229
The effects of feeding three natural frozen diets, grass shrimp (Palaemonetes sp.), crayfish (Procambarus clarkii) and fish (Sardina pilchardus) and two semi-humid artificial diets (based on fish powder) to mature cuttlefish, Sepia officinalis, were analysed. Growth and feeding rates (GR and FR, % BW day−1), food conversions (FC, %), and total protein and lipid composition of the diets were determined. Digestive gland to body
weight ratio and absorption efficiency were calculated for each diet. Cuttlefish fed shrimp and crayfish grew larger (1.5
and 1.1% BW day−1, respectively) compared to the other diets. Shrimp promoted the highest FC, followed by crayfish, and sardine. The highest
FR was obtained for cuttlefish fed crayfish (8.4% BW day−1). Although both artificial diets were accepted, none produced growth. A positive correlation (r = 0.96) between cuttlefish ingestion rate and digestive gland weight was obtained. Some cannibalism occurred among cuttlefish
fed the artificial diets during the last week of the experiment. According to the results obtained, P. clarkii could be used as an alternative prey to shrimp for rearing adult mature (>50 g) S. officinalis. 相似文献