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1.
Tetsuya Umino Teruyuki Kajihara Hiroshi Shiozaki Toshiyuki Ohkawa Dal-Sang Jeong Kenichi Ohara 《Fisheries Science》2009,75(4):909-919
Twelve populations of Girella punctata, from widespread locations of the species’ range in Japan and Korea, were screened for sequence variability within the mitochondrial
DNA (mtDNA) control region (n = 128) and at five polymorphic microsatellite loci (n = 547) to determine the genetic structure maintaining population integrity. mtDNA variability of 132 variable sites within
a 334-bp region reveals shallow genetic differentiation across populations. The weak differentiation of G. punctata was partly supported by the screening of five polymorphic microsatellite loci. However, hierarchical analysis of molecular
variance and principal component analysis on the basis of allele frequencies in microsatellite loci extracted a subtle substructure
in a subsidiary population and in near-subsidiary populations in the semi-enclosed Seto Inland Sea. 相似文献
2.
Within the framework of a larger project aimed to assess the potential of second generation hybrid striped bass for German
aquaculture the genotypic segregation of five microsatellite loci was analysed in two progeny lots (n = 74 and 76, respectively). There was no consistent correlation between microsatellite genotypes and phenotypic category
(white bass, hybrid, or striped bass). None of the individuals expressed neither only white bass nor only striped bass genotypes
at all five loci. On the other hand, only hybrid genotypes at all five loci were detected in three individuals of lot 1 and
four individuals of lot 2. Single loci tests for conformity of microsatellite genotypic segregation with Mendelian rules revealed
significant deviations (P < 0.05) in four cases for lot 1 and in three cases for lot 2. If pooled over all five loci, both lots displayed highly significant
deviations (P < 0.01) with an excess of hybrid genotypes and a deficiency of white bass genotypes. It is concluded that stabilizing selection
performed on hybrid genotypes might be a suitable approach for practical aquaculture in Europe if the goal is to become independent
of first generation hybrid fry supply and/or if establishing domesticated brood stocks of both parental species is impossible.
However, more detailed studies on the characteristics and performance of multiple hybrid generations are needed. 相似文献
3.
The effect of trawling on fish size and on different quality parameters of cod (Gadus morhua) and haddock (Melanogrammus aeglefinus) was evaluated after conducting 16 valid hauls using two trawls in a double rig fitted with a traditional and a novel ‘T90’
codend, respectively. The total catch volume during the fishing period was 47.6 metric tons, with an average catch per codend
of 1.5 (range 0.5–2.9) tons. The mean haul duration was 5 h. The catch was assessed according to fish size, mortality, external
damage, initial white muscle pH and development of rigor mortis. Fillet quality (colour, blood spots, gaping) was assessed
after 1 week of freeze-storage. Our results showed there was no difference between the two types of nets in terms of catch
volume, but significantly slightly bigger fish were caught with T90 than with the traditional trawl net (p < 0.05). Haddock caught with the traditional trawl net had more external injuries related to the trawl gear than haddock
caught with the T90 gear (p < 0.05). The gaping frequency for cod caught with the traditional trawl net tended to be higher than cod caught with the
T90 gear, but the difference was not significant (p = 0.07). No other differences in fish quality between fish caught in the trawl nets were observed. 相似文献
4.
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
5.
Wei-Ji Wang Han-Ping Wang Hong Yao Geoff K. Wallat Laura G. Tiu Qing-Yin Wang 《Aquaculture International》2010,18(5):825-835
Genetic linkage maps were constructed for bluegill sunfish, Lepomis macrochirus, using AFLP in a F1 inter-population hybrid family based on a double-pseudo testcross strategy. Sixty-four primer combinations produced 4,010
loci, of which 222 maternal loci and 216 paternal loci segregated at a 1:1 Mendelian ratio, respectively. The female and male
framework maps consisted of 176 and 177 markers ordered into 31 and 33 genetic linkage groups, spanning 1628.2 and 1525.3 cM,
with an average marker spacing of 10.71 and 10.59 cM, respectively. Genome coverage was estimated to be 69.5 and 69.3% for
the female and male framework maps, respectively. On the maternal genetic linkage map, the maximum length and marker number
of the linkage groups were 122.9 cM and 14, respectively. For the paternal map, the maximum length and marker number of the
linkage groups were 345.3 cM and 19, respectively, which were much greater than those on the maternal genetic linkage map.
The other genetic linkage map parameters of the paternal genetic linkage map were similar to those in the maternal genetic
linkage map. For both the female and male maps, the number of linkage groups was greater than the haploid chromosome number
of bluegill (2n = 48), indicating some linkage groups may distribute on the same chromosome. This genetic linkage mapping is the first step
toward to the QTL mapping of traits important to cultured breeding in bluegill. 相似文献
6.
To find out whether or not the locomotor activity of the Japanese sea catfish, Plotosus lineatus, shows a circadian rhythmicity, the locomotor activity of this catfish was recorded in a laboratory. All of the catfish recorded
(n = 20) showed a nocturnal locomotor activity rhythm under a light–dark (LD) cycle (LD 12:12). The locomotor activity started
after the light was turned off, and declined during the period of darkness. In five of the six catfish we examined, locomotor
activity shifted gradually over the course of 3–4 days in order to synchronize to the LD cycle after it was advanced by 6 h.
Locomotor activity persisted within a constant darkness (DD) in all eight of the catfish. The average free-running period
of locomotor activity under DD lasted for 24.2 ± 0.4 h (mean ± SD). Thus, the present results demonstrate that the Japanese
sea catfish has an endogenous circadian oscillator entrained by an LD cycle. 相似文献
7.
The Japanese population of the cyprinid minnow Aphyocypris chinensis is nearing extinction in the wild. The genetic diversity of three microsatellite loci in five captive populations was investigated,
and an effective breeding strategy to reduce inbreeding from pairwise relatedness (R
xy
) between each captive line is discussed. The average number of alleles ranged 2.33–4.67 and the average heterozygosity ranged
0.283–0.602. The pairwise relatedness observed in most combinations showed a significant decrease between the populations.
It is suggested that exchange of individuals between different breeding lines should effectively stop inbreeding. Studies
show that the effective population size (N
e
) estimated from the number of parental individuals was 8.54 in one captive population, which is insufficient to maintain
genetic diversity. It is recommended that more parental individuals should be used, and to exchange fish in a rotating mating
mode between institutions participating in captive breeding of A. chinensis. 相似文献
8.
Dal-Sang Jeong Enrique Blanco Gonzalez Kagayaki Morishima Katsutoshi Arai Tetsuya Umino 《Fisheries Science》2007,73(4):823-830
The genetic contribution of 51 broodstock, comprising 29 females and 22 males, reared at Hiroshima City Marine Products Promotion
Center for the production of stocked black sea bream was monitored during two consecutive years using seven microsatellite
DNA loci. The high discrimination ability of these markers was reflected in the polymorphic identification content (PIC=0.831), the exclusion probability (Q≈1), and the low probability of identity index (I=3.635−10). The total number of breeders contributing to the mating process was estimated at 32 (62.7%) in 2000 and 30 (58.8%) in 2001.
On pedigree reconstruction, 69.3% of the offspring were successfully assigned to a single broodstock pair. Loss of alleles
accounted for 16.9% during seed production; nevertheless, 90.9% of males and 69.0% of females participated in the mating process.
Based on microsatellite genetic tagging, 58.9% of the fish sampled during the two months after release were identified as
hatchery stock, presenting no significant differences from wild conspecifics in either fork length or body weight. 相似文献
9.
Pavarot Noranarttragoon Yuji Ueda Tsutomu Hattori Takashi Matsuishi 《Fisheries Science》2011,77(4):497-502
The yield-per-recruit (YPR) analysis has been used to assess growth overfishing of exploited fish stocks. Since the ex-vessel
price per weight widely depends on the size of the fish, the result of the YPR does not imply the revenue. The value-per-recruit
(VPR) analysis, which is an economic expansion of the YPR analysis, was conducted for bighand thornyhead Sebastolobus macrochir caught off the Pacific coast of northern Honshu, Japan. The results showed that, for the current age at first capture (t
c = 3), the current fishing mortality (F = 0.12) was close to the optimum level. However, for the current F, optimum t
c in the VPR model was 8 years and would lead to a 47% increase compared to the current revenue. The maximum YPR was obtained
at t
c = 6 years, but the revenue at t
c = 6 only gave a 20% increase in the maximum revenue. The difference was caused by the size dependency of the ex-vessel price
per weight. The VPR model would generate fisheries management plans with both economical and biological consideration and
would help in making general consensus of fisheries management strategies. 相似文献
10.
Compensatory growth following stress is a strategy aquatic animals use to adjust themselves to a variable environment. Studies
on the recovery growth of aquatic animals are not only of theoretical value in ecophysiology and evolution, but also important
to applications in aquaculture and fisheries resource management. In this experiment, juvenile Fenneropenaeus chinensis with an initial average body weight of about 3.72 g were exposed to hypoxic water (about 2.08 and 3.11 mg/l of dissolved
oxygen (DO) content) for 10 days and then switched to normoxic water (about 5.63 and 5.59 mg/l DO). Compared with juveniles
in normoxia, juveniles in the hypoxia period allocated a greater proportion of energy to metabolism and exuviations but allocated
less energy to daily metabolism per gram shrimp weight (J/g/day). This reduced feed conversion efficiency and feeding rate.
Finally, F. chinensis suffered growth depression. The juveniles completely compensated for hypoxia-induced growth depression in 30 days after being
switched into normoxic water and the compensation was achieved mainly by hyperphagia and slightly by improvement of feed conversion
efficiency. During the recovery period the hypoxic-stressed shrimp showed higher daily metabolic energy (J/g/day) than controls
(P < 0.05). Which means the stressed shrimp had more energy for feeding-related activities. So hyperphagia was observed. Energy
analysis indicated that F. chinensis improved feed-conversion efficiency mainly by reducing the percentage of energy lost in feces and exuviations. The results
showed that short-term non-lethal hypoxia would not affect the growth of juvenile F. chinensis if there were enough time for the stressed shrimp to recover. This suggested F. chinensis was capable of adapting to DO fluctuation to some extent and short-term non-lethal hypoxia would not have an obvious effect
on natural, released, and cultured shrimp stock. 相似文献
11.
Gary Fry David A. Milton Tonya Van Der Velde Ilona Stobutzki Retno Andamari Badrudin Bambang Sumiono 《Fisheries Science》2009,75(1):145-158
Red snappers were examined for reproductive biology and age-0 habitat preferences. Spawning in red snappers occurred throughout
the year in northern Australia and eastern Indonesia; at least 10–30% of females and 40–80% of males were in ripe or spawning
condition in most months. Northern Australian populations showed a spawning peak from July to December (L. erythropterus) and September to March (L. malabaricus). Eastern Indonesian L. malabaricus had a less defined pattern with two peaks: January–March and October. Size at first maturity was 240 mm for males and 250–300 mm
for females. L
50 estimates were similar between species in northern Australia: 270–280 mm (males) and 350–370 mm (females). Maximum batch
fecundity was 676,100 oocytes for L. erythropterus and 997,000 oocytes for L. malabaricus. Higher mean abundances of age-0 L. erythropterus were found in silty and coarse sand/rubble estuarine habitats of northern Australia (456 ± 119 fish/km2) compared with sandy coastal habitats (5 ± 3 fish/km2). Most age-0 snapper caught at Sape (eastern Indonesia) were L. malabaricus (91%) with mean abundances of 312 ± 14 fish/km2. The similarities in the reproductive characteristics of red snappers suggest that successful management approaches adopted
in northern Australia should be considered in eastern Indonesia. 相似文献
12.
The diet of juvenile (predominantly age 1) southern bluefin tuna Thunnus maccoyii (SBT, N = 720), caught over 11 years of the recruitment monitoring survey off southern Western Australia during summer, consisted
overwhelmingly of teleosts (97.4% by volume). Pilchard Sardinops sagax (27.4%V), blue mackerel Scomber australasicus (16.7%V), and jack mackerel Trachurus declivis (14.2%V) were the major taxa, with pilchard more abundant in coastal waters and jack mackerel more frequently encountered in fish
caught closer to the shelf-edge. Prey size varied from 5 to 240 mm, with 67% of ingested items measuring between 30 and 50 mm.
Pilchard dominated the prey size category 130–190 mm (84% by number), but the overall contribution of this species to the
diet of juvenile SBT was much lower than previously reported. Future research in relation to the feeding ecology of juvenile
SBT should focus on the biology and ecology of the young lifestages of the main prey species in this area and on prey distribution
and dynamics as a key factor linking environmental change and SBT distribution. 相似文献
13.
Otolith microchemical analyses of the strontium (Sr) and calcium (Ca) concentrations in the eels Anguilla japonica and A. anguilla caught in Tokyo Bay were undertaken to reconstruct the eels’ migratory histories. A. japonica in the yellow stage (immature stage) were caught in a bay without any adjacent rivers or streams. A. anguilla was in the silver stage (early maturing stage), and the eel was confirmed to have just begun spawning migration to the open
ocean from Tokyo Bay based on the otolith Sr:Ca ratios, which showed a typical catadromous life history with low Sr:Ca ratio
values throughout the eel’s life after recruitment. The mean Sr:Ca ratios in A. japonica from the elver mark to the otolith edge indicated the eels belonged to several general categories of migratory histories,
including sea eels (average Sr:Ca ratio ≥6.0 × 10−3) and estuarine eels (average Sr:Ca ratio 2.5 to 6.0 × 10−3) based on the criteria reported previously in A. japonica. All eels had a certain freshwater life period, although the period was highly variable among fish. These results indicate
that A. japonica has a flexible pattern of migration, with the ability to adapt to various habitats and salinities. 相似文献
14.
Mohammad Reza Imanpoor Sayed Hadi Alavi Jacky Cosson 《Fish physiology and biochemistry》2009,35(4):701-707
We have determined a number of biological characteristics of the Persian sturgeon egg (including diameter, surface-to-volume
ratio, yolk sphere and perivitelline space) and of female brood stocks (including age, length, weight, condition and absolute
fecundity) in 420 specimens of the migratory population of Acipenser persicus in Gorgan bay of Iran from 2001 to 2004. In the hydrated egg, the average egg diameter, yolk diameter, surface-to-volume
ratio and yolk sphere-to-perivitelline space ratio values were: 3.64 ± 0.17 mm, 3.26 ± 0.25 mm, 1.65 ± 0.08 and 0.75 ± 0.01,
respectively. In this chondrostean species, the egg surface and volume were found to increase with increasing egg diameter,
but the egg surface-to-volume ratio decreased. In Persian sturgeon, the surface-to-volume ratio and yolk sphere-to-perivitelline
space ratio is very high; therefore, the metabolic rate is low and female spawning occurs in low-temperature waters. The statistical
Pearson correlation between egg diameter relative to a number of brood stock characteristics, including fork length (r = 0.059), weight (r = 0.140), age (r = 0.081) and absolute fecundity (r = 0.095), were not significantly different (P > 0.05). An extensive comparison of these results with data published on other fish species is presented and discussed. 相似文献
15.
16.
The age and growth of two Nematalosa species around Okinawa Island were examined using sectioned otoliths collected from September 2003 to April 2006. Monthly
changes in the frequency of the appearance of a translucent band on the outer margin of the otoliths indicated that ring formation
occurred once a year from January to July for Nematalosa come and from January to March for Nematalosa japonica. The von Bertalanffy growth equations for both species were as follows: N. come: L
t
= 365.5{1 − exp[−0.111 × (t + 0.288)]} for females and L
t
= 214.7{1 − exp[−0.700 × (t – 1.110)]} for males; N. japonica: L
t
= 205.1{1 − exp[−1.068 × (t − 1.180)]} for females and L
t
= 195.5 {1 − exp[−1.293 × (t − 1.269)]} for males. The maximum ages observed for N. come and N. japonica were 11 and 6 years old, respectively. The growth of these species was characterized by the slow growth of N. come over many years, resulting in a larger size than N. japonica. 相似文献
17.
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
18.
The present study was carried out to determine the antibacterial effect of caprylic acid in the culture system of Artemia franciscana nauplii inoculated with shrimp pathogens Vibrio harveyi and V. parahaemolyticus. To begin with, the antibacterial effect of different concentrations (1, 10 and 100 mM) of caprylic acid against V. harveyi and V. parahaemolyticus was assessed through bacterial growth study. This indicated that at 100 mM concentration, the growth of the pathogens was
completely inhibited within 5 h, whereas, in 1.0 and 10 mM concentrations, effective inhibition was observed with the extension
of time. Subsequently, the influence of pH variation on the growth inhibitory effect of 10 mM caprylic acid against V. harveyi and V. parahaemolyticus at different pH (5–7) was also made through bacterial growth study. At pH 5, the pathogen growth was very less, compared
with pH 6 and 7. The Artemia nauplii (instar II) reared in 10 mM caprylic acid supplemented medium were challenged with V. harveyi and V. parahaemolyticus, and the mortality was recorded at an interval of 6 h up to 60 h. In this study, the mortality of Artemia nauplii reduced to 20.61 and 16.30% in V. parahaemolyticus and V. harveyi challenged groups, respectively. The present results provide evidence for the potential antibacterial activity of caprylic
acid in aquaculture against luminescent vibrios. 相似文献
19.
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
20.
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