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161.
Gene expression pattern of digestive and antioxidant enzymes during the larval development of reared Atlantic bluefin tuna (ABFT), Thunnus thynnus L.
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162.
Izquierdo MS Robaina L Juárez-Carrillo E Oliva V Hernández-Cruz CM Afonso JM 《Fish physiology and biochemistry》2008,34(2):117-127
The Δ6 and Δ5 desaturases and elongases show only very limited activity in marine fish, and little is known of the possibility
of enhancing Δ6 desaturase gene expression in these fish. The use of plant oils in marine fish diets is limited by their lack
of n−3 highly unsaturated fatty acids (HUFA) despite an abundant content of the 18C fatty acid precursor linoleic and α-linolenic
acids. The objective of the present study was to determine the ability of larval gilthead seabream to utilize vegetable oils
and assess the nutritional regulation of Δ6 desaturase gene expression. Seventeen-day-old gilthead seabream larvae were fed
during a 17-day period with one of four different microdiets formulated with either sardine fish oil (FO), soybean, rapeseed
or linseed oils, respectively, or a fifth diet containing defatted squid meal and linseed oil. Good larval survival and growth,
both in terms of total length and body weight, were obtained by feeding the larvae either rapeseed, soybean or linseed oils.
The presence of vegetable oils in the diet increased the levels of 20:2n−9 and 20:2n−6, 18:2n−9, 18:3n−6, 20:3n−6 and 20:4n−6, in larvae fed rapeseed and soybean oils in comparison to those fed FO. In addition, a sixfold increase in the relative
expression of Δ6 desaturase-like gene was found in larvae fed rapeseed and soybean oils, denoting the nutritional regulation
of desaturase activity through its gene expression in this fish species. However, feeding linseed oil did not increase the
expression of the Δ6 desaturase gene to such a high extent. 相似文献
163.
T. T. Chen L. B. Agellon C. M. Lin H. J. Tsai Peijun Zhang L. I. González-Villasénor D. A. Powers 《Fish physiology and biochemistry》1989,7(1-6):381-385
The primary structures of two rainbow trout growth hormone mRNAs (GH1 and GH2) have been deduced by direct sequencing of their
respective cDNA clones and portions of the mRNA. Both GH1 and GH2 mRNA contain open reading frames comprised of 630 nucleotides
and encode 210 amino acid residues of which 11 are variant. The translated regions of both mRNA are flanked by a short but
rather conserved 5′-end, and a relatively long but highly diverged 3′-end. The differences at translated and 3′-untranslated
regions suggest that the GH1 and GH2 mRNA originate from different loci. The GH1 and GH2 mRNA are likely transcribed from
two distinct loci which were duplicated during tetraploidization of salmonid genome between 50 to 100 million years ago.
The GH2 gene has been isolated and sequenced from a rainbow trout genomic library. This gene spans a region of approximately
4 kilobases. The trout GH gene is comprised of 6 exons and 5 introns, in contrast to 5 exons and 4 introns in mammals. The
additional intron in the trout gene interrupts the translated regions that are analogous to the last exon of the mammalian
counterpart. The alleged internally repeating sequences in mammalian GH, prolactin (Pr1) and placental lactogen (PL) are not
observed in the predicted polypeptide sequence of trout GH. In addition, direct repeats that flank exons I, III and V of mammalian
GH, Pr1 and PL genes are absent in trout gene. These findings indicate that the rainbow trout GH gene structure does not support
the current hypothesis that internally repeated regions in GH, Pr1 and PL arose from a small primordial gene. 相似文献
164.
Genetic variability in meiotic gynogenetic muskellunge,Esox masquinongy (Mitchell), estimated from segregation of microsatellite alleles
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Benjamin J Reading Paul S Wills Roy C Heidinger Edward J Heist 《Aquaculture Research》2016,47(9):2705-2715
Muskellunge, Esox masquinongy, is an important recreational freshwater fish native to North America. Since muskellunge populations are often maintained through stocking efforts, advances in muskellunge reproductive technologies are of direct relevance to fishery enhancement. We evaluated the efficiency of inbreeding through induced meiotic diploid gynogenesis. Eggs from six female muskellunge were manually stripped and activated using ultra violet‐irradiated yellow perch, Perca flavescens, sperm. Hydrostatic pressure shocking regimes (48 263 kPa) were then applied to the eggs to prevent second polar body expulsion producing unambiguous meiotic gynogens. Six female dams and samples of 12–20 of their gynogenetic progeny were genotyped at seven polymorphic microsatellite loci. Chromosomal recombination frequencies of microsatellite loci based on retention of heterozygosity among gynogens ranged from 0.043 to 0.839 (0.576 ± 0.237). There were no statistical differences in recombination frequency among females at any of the loci. The average inbreeding coefficient (F‐value) ranged from 0.581 to 0.979, equivalent to three to fourteen generations of full‐sibling crosses respectively. The average F‐value overall was 0.712, equivalent to between five and six generations of full‐sibling crosses. Centromere map distances of the seven microsatellite loci ranged from 2.15 to 41.95 cM and meiotic gynogenesis was useful in eliminating heterozygosity at loci proximal to the centromere, but not distal. Since the age at maturity of female muskellunge is approximately 5 years, gynogenesis may pose an expeditious alternative to traditional breeding strategies for creation of homozygous pedigrees for some loci that may be outcrossed to introduce positive heterozygosity effects in the offspring. 相似文献
165.
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
166.
Juana Durán Elena Pastor Amalia Grau José María Valencia 《Aquaculture Research》2012,43(12):1777-1786
The Mediterranean spider crab, Maja squinado, is depleted due to overfishing. The crab has virtually disappeared from areas where it was abundant, such as the Balearic Islands and the Catalan coast. Maja squinado, is economically and ecologically very valuable, and it is essential to obtain information on its biology and rearing conditions to attempt to repopulate the damaged stocks of the species in the Mediterranean basin. Herein, we describe the first successful rearing of M. squinado under laboratory conditions. Our results show that M. squinado is an excellent candidate for restocking using cultured juveniles. Two consecutive broods with a 1–4 day interbrood period were observed in the laboratory in wild‐caught females, the maximum observed duration of embryonic development of the egg mass being 32 days at 18.4 ± 0.9°C, and went through four different stages. The complete larval and first juvenile development was studied in laboratory cultures fed enriched Artemia metanauplius. At 19.6 ± 0.6°C, development from hatching to first crab moult took 17 days, and it comprised two zoeae stages and one megalopa stage. The survival rate at the different stages was monitored, and 7.13 ± 2.3% was achieved at the first crab instar. 相似文献
167.
Bruno L. Mourato Fábio Hazin Keith Bigelow Michael Musyl Felipe Carvalho Humberto Hazin 《Fisheries Oceanography》2014,23(1):32-44
Spatial and temporal trends of sailfish catch rates in the southwestern and equatorial Atlantic Ocean in relation to environmental variables were investigated using generalized additive models and fishery‐dependent data. Two generalized additive models were fit: (i) ‘spatio‐temporal’, including only latitude, longitude, month, and year; and (ii) ‘oceanographic’, including sea surface temperature (SST), chlorophyll‐a concentration, wind velocity, bottom depth, and depth of mixed layer and year. The spatio‐temporal model explained more (average ~40%) of the variability in catch rates than the oceanographic model (average ~30%). Modeled catch rate predictions showed that sailfish tend to aggregate off the southeast coast of Brazil during the peak of the spawning season (November to February). Sailfish also seem to aggregate for feeding in two different areas, one located in the mid‐west Atlantic to the south of ~15°S and another area off the north coast of Brazil. The oceanographic model revealed that wind velocity and chlorophyll‐a concentration were the most important variables describing catch rate variability. The results presented herein may help to understand sailfish movements in the Atlantic Ocean and the relationship of these movements with environmental effects. 相似文献
168.
Gaspar Soria Miguel F. Lavín Iván Martínez‐Tovar Alberto Macías‐Duarte 《Aquaculture Research》2013,44(9):1383-1398
We evaluated recruitment of larvae of catarina scallop, Argopecten ventricosus, in the area of Puerto Peñasco, NE Gulf of California. We moored artificial collectors in six sites from June 2007 to August 2008 and replaced them every 2 months. We used monthly (July 2002–September 2011) sea surface temperature (SST, °C) and surface chlorophyll‐a concentration (SSChl, mg m?3) Aqua/MODIS satellite data to describe seasonal environmental behaviour study area. Also, we recorded bottom temperature at each site every 4 h, and every 2 months measured sea surface salinity, temperature and dissolved oxygen. We used a repeated measures anova to evaluate differences in the number of recruited spat between main factors, and analysed the presence of multimodal spat shell size frequency distributions. Overall, spat recruitment was negatively correlated with seawater temperature and showed higher spat recruitment abundances throughout winter, which is the season with the highest surface chlorophyll a concentration. We estimated multimodal shell size frequency distributions characterized by more than one modal size. The natural collection of A. ventricosus spat on artificial collectors in the area can be successfully performed over a protracted period (November–December to May–June). Our results extend the area where collection of A. ventricosus spat can be successful. 相似文献
169.
Monosex male culture of C. quadricarinatus is proposed for increasing yields because males reach a larger size at harvest than females. An experiment was done to evaluate
the effects of androgenic gland extract and temperature on sex reversal and somatic growth in early juvenile females. Females
were exposed to the following experimental conditions: C: control food and temperature maintained at 26 ± 1°C; HT (high temperature):
control food and temperature maintained at 28.5 ± 1°C; VHT (very high temperature): control food and temperature maintained
at 31 ± 1°C; AG: food with enriched with androgenic gland (1/10 dose for each juvenile per day) and temperature maintained
at (26 ± 1)°C. The juveniles were weighed, sexed, and growth increment (GI) and growth rate (GR) were calculated twice a month.
The HT and AG groups differed from the C group in GI and GR indicating a greater somatic growth. At the end of the experiment,
the HT and AG groups had similar weight but only the HT group had enhanced oocyte diameter, with some vitellogenic oocytes
compared to the C group. In the HT group, there was significant sex reversal, as indicated by development of male and intersex
male characteristics in different individuals. Both temperature and AG diet have a high potential for culture of this species
because of their enhancement of somatic growth; higher temperature increases the proportion of males, a desirable characteristic
of cultured populations. 相似文献
170.
B. Piros J. Glogowski R. Kolman A. Rzemieniecki J. Domagala Á. Horváth B. Urbanyi A. Ciereszko 《Fish physiology and biochemistry》2002,26(3):289-295
This paper provides data concerning biochemical composition of milt of two sturgeon species, Siberian sturgeon bred in aquaculture
facility of Inland Fisheries Institute in North Poland and sterlet (from two different populations from Danube and Odra).
Milt plasma of Siberian sturgeon and sterlet, when compared to teleost fish, is characterized by much lower osmolality (up
70 to 96 mOsm kg−1) and protein concentration (0.24–0.58 g l−1). In spite of the presence of an acrosome and acrosin the antiproteinase activity of seminal plasma was low (12.79–25.40 U l−1). Activities of arylsulfatase and β-N-acetylglucosaminidase were found in spermatozoa. This agrees with the presence of an
acrosome in sturgeons sperm. Similarly to mammals, these enzymes are also present in milt plasma. We determined a range of
enzymatic activities from the minimal (seminal plasma) to the maximal damage (supernatants obtained after freezing-thawing
without cryoprotectant). Activities of arylsulfatase, β-N-acetylglucosaminidase, lactic dehydrogenase and acid phosphatase
were released from spermatozoa after freezing-thawing. For this reason they are good potential candidates as a markers of
cryoinjury to sperm acrosome and midpiece.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献