• Volume 32,Issue 3,2008 Table of Contents
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    • Effect of salinity stress and following recovery on the growth, energy allocation and composition of juvenile Paralichthys olivaceus

      2008, 32(3):402-410. DOI: 10.3724/SP.J.00001

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      Abstract:Salinity is an environment factor with important effects on the growth and energy allocation of brown flounder, Paralichthys olivaceus. An energetic method was used to investigate the effects of salinity manipulating on the growth and compensatory growth of juvenile P. olivaceus following salinity manipulating in the present experiment. In the experiment I, juvenile P. olivaceus with an average body weight of 2.6 g were kept in seawater with different salinities (12–S12, 19–S19, 26–S26, 33–S33, 40–S40) for 30 d. In the experiment II, Juvenile P. olivaceus with body weight of 6.9 g stocked in seawater with salinity 5 (IS5), 19(IS19), and as high as 47(IS47) during the first 10 d. Then the salinity was adjusted to 19 in 3 d at a steady rate and the fish experienced a recovery period of 30 d. It was found that the growth of juvenile P. olivaceus would not changed significantly within the salinity range between 12 and 40. Juvenile P. olivaceus stocked in seawater with salinity 5 (IS5) and 47(IS47) would grow significantly slower than that fish stocked in salinity of 19. Fish in IS5 achieved completely compensatory growth in 30 d after the salinity was switched to 19. But Fish in IS5 failed to catch up the weight of fish in IS19. Salinity manipulating changed the energy ingestion and its allocation among respiration and feces lost, but not significantly affected the energy lost in excretion. Compare to fish in S40, fish in S19 allocated more energy to growth. Fish in IS47 fed less than fish in IS19 over the different salinity-treating period. Fish in IS5 and IS47 allocated significant lower percentages of energy to growth than IS19. But the portions of respiration energy of them were significantly higher than IS19. In the recovery period, IS47 fed less than the other two. But the portions of growth energy were not significantly different from each other. IS5 consumed more energy in respiration than IS19 in this period. The energy lost in feces of IS19 was significantly higher than others. For unit body weight daily energy budget (J·g-1·d-1), fish in S33 fed less than S12, S19, and S26. The highest value of unit body daily energy allocated to growth appeared in S19. Daily unit body weight energy ingestion and energy used to growth were both the highest in IS19 over the stressing period. The energy lost in respiration in IS5 was higher than IS47. During the recovery period, fish in IS5 ate more than S47 and allocated more energy to growth compare to IS19 and IS47. Unit body weight daily energy lost in feces of IS47 was significantly more than other treatments over the recovery period. Studies on the composition of fish found that salinity manipulation put no significant effects on the moisture and protein content. But the lipid content and gross energy were affected by salinity manipulation. Energetic analysis indicated that the compensatory growth of juvenile P. olivaceus following low salinity stress was achieved by improved energy ingestion of feed. These results indicated that the optimal salinity for the growth of juvenile P. olivaceus would be about 19 and P. olivaceus is extremely tolerant to salinity, especially to low salinity.

    • Effects of dietary peptidoglycan on growth and non-specific defence of Pseudosciaena crocea

      2008, 32(3):411-416. DOI: 10.3724/SP.J.00001

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      Abstract:A feeding experiment was conducted to examine the effects of dietary peptidoglycan on growth, non-specific immunity and disease resistance for large yellow croaker, Pseudosciaena crocea. The basal diet was supplemented with 0, 100 and 500 mg·kg-1 peptidoglycan, respectively, to formulate three experimental diets. Each diet was fed to triplicate groups of fish in seawater floating cages (1.5 m×1.5 m×2.0 m), and each cage was stocked with 40 fish (with initial weight of (30.8±1.33) g. Fish were fed twice daily (05:00 and 17:30) to apparent satiation for 8 weeks. The water temperature fluctuated from 27.5 to 30.5 ℃, the salinity from 34 to 35‰ and dissolved oxygen content was approximately 7 mg·L-1 during the experimental period. Results showed that survival and growth were significantly (P<0.05) affected by dietary peptidoglycan. Fish fed diets with 100 and 500 mg·kg-1 peptidoglycan supplementation had significantly (P<0.05) higher survival (95.8% and 95.0%) than the control group (88.3%). specific growth rate (SGR) in fish fed the diets with peptidoglycan (1.44 and 1.41%·d-1, respectively) was significantly (P<0.05) higher compared with the control group (1.21 %·d-1). Phagocytic index (PI) and lysozyme activity (LA) of fish fed the diets with peptidoglycan were also higher than those of control group, and there were no significant (P>0.05) differences between two peptidoglycan supplementation groups. However, alternative complement pathway activity (ACH50) significantly (P<0.05) increased with increasing dietary peptidoglycan. The results of Vibrio harveyi challenge showed that the fish fed diets with peptidoglycan supplementation had significantly lower cumulative mortality (25.0% and 25.7%, respectively) than the control group (64.3%). The results suggested the dietary peptidoglycan significantly improved the growth, non-specific immunity and disease resistance of large yellow croaker. Therefore, peptidoglycan could become a safe and efficacious immunostimulate supplemented to the diets for large yellow croaker.

    • Dietary zinc requirement of juvenile large yellow croaker,Pseudosciaena crocea R.

      2008, 32(3):417-424. DOI: 10.3724/SP.J.00001

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      Abstract:A growth experiment was conducted to determine the dietary zinc requirement for juvenile large yellow croaker (initial average weight 1.78 ± 0.02 g). Six semi-purified diets were formulated to contain 9.68, 30.63, 48.94, 91.28, 167.49 and 326.81 mg zinc ∕ kg diet, supplied as ZnSO4•H2O. Each diet was randomly assigned to triplicate groups of fish in flow-through system, and each tank was stocked with 40 juvenile fish. Fish were fed twice daily (05:30 and 17:30) to apparent satiation for 8 weeks. The water temperature fluctuated from 26.5 to 29.5°C, salinity from 25‰ to 28‰ and dissolved oxygen was approximately 7 mg l-1 during the experimental period. No significant differences in survival were found among dietary treatments. Specific growth rate (SGR) significantly increased with increasing dietary zinc from 9.7 to 48.9 mg ∕ kg of diet (P<0.05), and then leveled off. Zinc content in the vertebrae, whole body and serum were significantly affected by dietary zinc level (P<0.05). Broken-line analysis showed that the optimum dietary zinc requirement for large yellow croaker juveniles, using SGR and vertebrae zinc saturation as response criteria, was 59.6 and 84.6 mg zinc ∕ kg diet, respectively. Key words: Pseudosciaena crocea R.; zinc requirement; feeding and nutrition

    • Genetic diversity of introduced Barfin flounder (Verasper moseri) populations by AFLP analysis

      2008, 32(3):321-326. DOI: 10.3724/SP.J.00001

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      Abstract:Amplified fragment length polymorphism (AFLP) technology was used to evaluate the genetic diversity of three introduced populations (Yantai, Dalian and Laizhou) of introduced barfin flounder(Verasper moseri). The genetic distances and identity index were calculated, and according to them, the UPGMA dendrogram was constructed. A total of 827 loci ranged from 50-700 bp were detected using 10 primer combinations, and 8-37 polymorphic loci were detected per primer combination. The percentage of polymorphic loci of three introduced populations of barfin flounder were 29.14%, 15.60% and 20.31%, respectively. The Shannon’s information index were 0.1799, 0.0949 and 0.1231, respectively, and the Nei’s gene diversity were 0.1225, 0.0658 and 0.0848, respectively. The total genetic diversity level of three introduced populations was low, of which YT population was the highest, LZ population was lower, and DL population was the lowest. The genetic distance between YT introduced population and DL introduced population was the highest(0.0230), whereas, the genetic distance between LZ introduced population and DL population was the lowest(0.0129). The coefficient of gene differentiation(Gst) value was 0.219, showing a certain extent of differentiation among three populations of Barfin flounder.

    • Effects of dietary protein level on growth, survival, body composition and hepatopancreas histological structure of the white shrimp, Litopenaeus vannamei, at different ambient salinities

      2008, 32(3):425-433. DOI: 10.3724/SP.J.00001

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      Abstract:An 8-week trial was conducted to investigate the effects of dietary protein levels which were 20.61, 30.52, 40.43 and 50.34% (named CP20, CP30, CP40 and CP50 respectively) on the growth, survival, body composition of the white shrimp, Litopenaeus vannamei, at three ambient salinities which were 2, 22 and 32 respectively. The results showed that ambient salinity had significant effects on shrimp growth, survival, conditional factor(CF) and body ash, while no significant differences were observed in the hepatosomatic index (HSI), body crude protein, lipid and moisture. Shrimps at 22 were the highest in all the parameters followed by these at 32 and 2. Weight gain, specific growth rate for both weight and body length of shrimps at 32 and 22 were significantly higher than those at 2, while no differences were found in shrimps at 32 and 22. Dietary protein levels only significantly affected the growth performance, body crude protein, CF and HSI of the shrimps. Weight gain and the body crude protein content of shrimps increased with the increasing of dietary protein level, and shrimps fed with CP20 showed significant lower growth performance and body crude protein. CF and HSI increased firstly with the dietary protein levels increasing to CP40 firstly, and then decreased slightly when fed with CP50. Dietary protein levels had no effect on the survival shrimp at all the ambient salinities. Ambient salinity and dietary protein level only had significant interaction on the body ash content, while no significant interaction effects were observed in other parameters. Tubules of shrimp fed with CP30 and CP40 had the normal structure, though CP40 increased the number of R cells. Tubules of shrimps fed with CP20 had relatively fewer R cells and arranged incompactly. And the basal membranes of partial tubules were in disrepair. While tubules of shrimps fed with CP50 compactly arranged with much ambiguous materials in B cells. The results indicated that though the growth performance and conditional factor could be increased by increasing dietary protein level, low survival rate at low salinity did not enhanced. And improper content of dietary protein, especially extremely lower dietary protein, would results in pathological changes of the hepatopancreans’ histological structure.

    • Preliminary study on mutation breeding of

      2008, 32(3):327-334. DOI: 10.3724/SP.J.00001

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      Abstract:Porphyra haitanensis has degenerated in breed and has a reduced outcome and descent quality recent ten years. The blades were guided to variation in order to select and cultivate new strains of Porphyra haitanensis that were high quality and high yield. 60Co-γray was a useful mutagen in induced mutation breeding .After treated with 60Co-γray ,free-living conchocelis of wild Porphyra haitanensis were induced and represented in offsprings. Purple mutant and excellent practical characters strains were selected from a lot of gametophytic blades. Single cell clone and enzymolysis were used to propagate fast in pure strains of induced mutations. Moreover, the central practical characters of mutant strains were studied: ①The first one was 7-I , which were wide blades (2.99±0.61)cm, grew faster (the length mean daily increase was 6.51 cm and it was 55.3% faster than control group when the length of the blades beyond 30 cm), was a high temperature resistant strain (it was grew normally at 29 ℃ and the resistant temperature was 2℃ more than control group ) and total phycobiliprotein content was high (104.858 mg·g-1 of dry sample, improved by 39.0%). ② The second one was 7-Ⅱ, which were narrow blades, had quick growth (the length mean daily increase was 4.26 cm and it was 58.7% faster than control group when the length of the blades beyond 30 cm), was a thin-blade strain (it was 22.5-27.5 μm in the middle part of the blade and was 29.6% thinner than control group) and total phycobiliprotein content was high (104.239 mg·g-1 of dry sample, improved by 39.4%) ③The third one was pigementation mutant, 3-I, which possessed of purple and thin blade(25.0-32.5 μm).④The yield of 7-I and 7-Ⅱ was 291.5-309.6 kg·666.6 m-2,which was 29%-37% higher than control group. The results laid a solid foundation for germplasm improvement and exploitation of fine variety of Porphyra haitanensis.

    • Effect of Du-zhong (Eucommia ulmoides Oliver) leaf on growth, serum non-specific immune index and meat quality of grass carp

      2008, 32(3):434-440. DOI: 10.3724/SP.J.00001

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      Abstract:void

    • Evaluation of the growth, salt tolerance and parents’ heterosis contribution in reciprocal hybrids F2 between Oreochromis niloticus and Sarotherodon melanotheron

      2008, 32(3):335-341. DOI: 10.3724/SP.J.00001

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      Abstract:In order to select a good breed both with ideal culture performance and high salt tolerance, taking Nile tilapia (O. niloticus) and black-chip tilapia (S. melanotheron) as compared groups, two reciprocal hybrids, e.g., O. n. ♀×S. m. ♂ (F2) and S. m.♀×O. n. ♂ (F2) as trial groups, a comparisons were conducted under 4 salinities (0, 15, 20 and 25 ppt). The major results were: (1) Both O. n. ♀×S. m. ♂ (F2) and S. m.♀×O. n.♂ (F2) showed a better growth under 20 and 25 salinities, equal to about 75% of growth of O. niloticus under 0 salinity, and 4 times of growth of S. m. under 25 salinity. It indicated that the growth of hybrids close to O. n., but much better than S. m. Under 25 salinity, O. n. ♀×S. m. ♂ (F2) showed 7% faster growth than S. m. ♀×O. n. ♂ (F2). (2) under 15 and 20 salinity, the heterosis showed higher in growth rate and coefficient variation of body weight, and It was found that 0、15、20、25 salinity could not cause a significant difference in survival of two hybrids.(3)It is founded that, the superior traits from different parent fish species, such as the fast growth of Nile tilapia, and the high salt tolerance of black-chip tilapia, are of different contribution for different traits of hybrids under different salinities. Estimated by the formula F1a1P1+a2P2,the contribution for growth of hybrids from Nile tilapia is 3~4 times higher than that from black-chip in 15-25 salinity, and the contribution for survival of hybrids in 25 salinity is almost 0 from Nile tilapia, but 100% from black-chip.

    • Characteristic of adherence of pathogenic Vibrio fluvialis to the skin mucus of Epinephelus awoara

      2008, 32(3):441-448. DOI: 10.3724/SP.J.00001

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      Abstract:In order to understand the adhesion characteristic of pathogenic Vibrio fluvialis to the skin mucus of Epinephelus awoara, isotope tracer method was introduced to investigate the bacterial adhesion of the pathogen to the mucus after different treatment. A significant enhancement in the adhesion rate of V. fluvialis to the skin mucus was observed after heating the mucus at 40, 60 and 80 ℃ for 10 min. However, an extremely significant inhibition in the bacterial adhesion was observed when the mucus had been heated at 100 ℃ for 10 min. No remarkably effect on the bacterial adhesion was found after treating the mucus with protease K and trypsin, whereas the bacterial adhesion was extremely significant enhanced by treating the mucus with periodic acid; It was observed that pretreating the mucus with glucose, mannose, mannitol and maltose enhanced the bacterial adhesion extremely significantly, and other 3 carbohydrates enhanced the bacterial adhesion significantly; while galactose could not enhance the bacterial adhesion significantly. Surface extract of V. fluvialis with high concentration inhibited the bacterial adhesion significantly, whereas the surface extract with relative low concentration enhanced the bacterial adhesion. 3 protein peaks were obtained by fractionating the mucus with a Sephadex G-100 column, and the strong adhesion was observed to the first peak. The results indicated that: pathogenic V. fluvialis adhere to the skin mucus of E. awoara strongly; there were specific adhesive receptors within the mucus; the adhesive receptors were likely to be macromolecules with relative stability to heating and protease.

    • Morphological and genetic identification of Japanese halfbeak (Hyporhamphus sajori) eggs

      2008, 32(3):342-352. DOI: 10.3724/SP.J.00001

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      Abstract:A larger number of fertilized eggs with attaching filaments attached to some seaweeds were collected in the southern Yellow Sea (33°49′N, 122°10′E). In order to make an accurate identification of the fish eggs, light microscope, scanning electronic microscopy (SEM), and genetic analysis were used. Under light microscope, the egg is an oblated and agglutinated demersal with a narrow perivitelline space; eggs ranged in diameter from 1.95 to 2.38 mm with a mean of 2.18 ± 0.03 mm; their membrane are smooth and they have 5 to 7 cannular keratose egg-filaments; the oil globules are multiple, ranged in diameter from 0.05 to 0.50 mm and in number from 7 to 145 with a mean of 28±2, the position of them migrate during embryonic development; the yolks are ivory-white with no segments, ranged in diameter from 1.00 to 2.30 mm with a mean of 1.90 ± 0.03 mm; the development phases of the embryo are variable. So they were identified as the eggs of one Beloniformes. Under scanning electric microscopy (SEM): the egg’s micropyle is apparent, it lines in the middle of the attaching filaments and the outer diameter of it is about 12.3μm; the pores on the envelope are unapparent, but there are many grain substances on it, with the density was about 50 pieces/100μm2. The result of genetic analysis conveyed that in partial sequences of mtDNA Cyt b gene there were no variable sites between the eggs and Japanese halfbeak, and the genetic distance between them was 0, however, many variable sites between the eggs and the other fishes of Beloniformes were exised, the variable rate was 18.72-21.3%, and the genetic distance between them were 21.9-26.4%. The result of Neighbor-joining(NJ) molecular phylogenetic tree also indicated that the eggs and the Japanese halfbeak were assembled at the same embranchment, they shared one haplotype, but the eggs were assembled at different embranchments with the other species of Beloniformes so the fish eggs were alienated from them. Based on the results above, it is suggested that the fish eggs to be Japanese halfbeak.

    • Research on the identification and taxonomic status of nocardia in snakehead, Ophiocephalus argus Cantor

      2008, 32(3):449-454. DOI: 10.3724/SP.J.00001

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      Abstract:A bacterial-like tubercular disease broke out in reared snakehead, Ophiocephalus argus Cantor, in Xiaoshan in Zhejiang Province in June, 2006. Pure bacteria was isolated from liver and kidney in diseased fish and numbered W060622. Experimental infection indicated that the isolated bacterium was the pathogen responsible for the mortalities. Cultures from liver and kidney were incubated for 4-6 days at 28 ℃. Weakly pigmented yellowish adherent colonies 1-3 mm in diameter appeared as a heavy, almost pure growth on TSA. The bacteria were Gram-positive, aerobic, weakly acid-fast, bead-like or long, slender, and filamentous rods observed in virtue of microscope and electron microscope. The organism was found to be catalase-positive, oxidase-negative, urea-produced, and could reduce nitrate and aesculin but not degrade adenine, xanthine, hypoxanthine, tyrosine, gelatin, elastin, starch and casein. It could utilized the citrate as sole carbon source but not mannitol, arabinose and sorbitol. The traditional physiological and biochemical methods showed that most of the phenotypes of strain W060622 were similar to Nocardia. A partial sequence of 16S rRNA gene of the bacteria was determined following PCR amplification and sequencing. The GenBank Accession No. is EF192033. The sequence was aligned with those available for nocardiae and phylogenetic trees inferred using N-J method. The unrooted evolutionary tree shows that strain W060622 forms a monophyletic clade with Nocardia seriolae JCM 3360 T (Z36925). This relationship was highlighted in the analyses by the high nucleotide similarity value (99.9%) and the high bootstrap value (1000) based on the neighbour-joining method. Thus, the pathogenic organism was identified as Nocardia seriolea. This is the first discovery on Nocardia sp.-infected snakehead in aquaculture. Fish tubercular diseases were reported causing by the pathogen of Corynebacterium sp., Mycobacterium sp., Rickettsia-like organism, Nocardia sp., et al. We could differentiate them through the morphology, stain, physiological and Biochemical characters. A kidney with nodular lesions was made ultrathin sections and observed under transmission electron microscope and no other prokaryotes were found except bacteria of nocardia. Based on the high morbidity and mortality and the difficulty of being detected, we consider the pathology, immunology, detection and medication of nocardiosis in snakehead warrants further investigation.

    • Isolation and characterization of microsatellite markers for Zhikong scallop by screening SSR-enriched library

      2008, 32(3):353-361. DOI: 10.3724/SP.J.00001

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      Abstract:In this study, 40 microsatellite markers were isolated and characterized for Zhikong scallop (Chlamys farreri) using the method of screening SSR-enriched library. DNA fragments containing microsatellites were captured by a piece of nylon membrane (Hybond N+) bound with the probe combinations of (AG)15 and (AC)15. The nylon membrane was washed three times in 2 ×SSC, 1% SDS at 62°C, two times for 15 min with the final wash for 30 min. The captured DNA was eluted in 0.1 × TE buffer and used to construct an SSR enrichment library. After transformation, the clones were regularly re-arrayed in a new agar plate with the density of about 300 clones per plate and screened with (AG)15 and (AC)15 probes labelled by the ECL system (Amersham). A total of 1200 clones derived from the enrichment library were screened and 532 clones gave the positive response. One hundred clones were randomly selected for sequencing and the results showed that all of the clones contain at least one microsatellite. Sixty-five primer pairs were designed using the software Primer Premier 5.0, of which 40 pairs can be amplified scorable PCR products. The polymorphisms of these scorable loci were assessed using 48 Chlamys farreri individuals, and the results showed that 37 loci were polymorphic. The number of alleles per polymorphic locus ranged from 2 to 14 with an average of 7.0 alleles per locus, and the values of Ho, He and PIC varied from 0.1000 to 1.0000, 0.1197 to 0.9831 and 0.1172 to 0.9782, respectively. The results indicated that the method of screening SSR-enriched library is efficient and suitable to isolate a large amount of microsatellite markers for the target species of interest.

    • Influence of anthraquinones extracted from Rheum officinale Bail promoting Macrobrachium rosenbergii's resistance to Vibrio anguillarum

      2008, 32(3):455-463. DOI: 10.3724/SP.J.00001

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      Abstract:In aquaculture Chinese herbal medicines could promote specific and nonspecific immune functions of fish to control fish diseases. In mammal, Chinese herbs could promote antioxidant enzymes activity and hepatic lipid peroxide contents, alleviate free radical and reduce the lipid peroxidation injury. Howwever the effcet of anthraquinones extracted from Rheum officinale Bail on fish immunity has hardly been found in research reports and few reports have been found to study the immune and antioxide effects of anthraquinones extract gave Macrobrachium rosenbergii certain protection against Vibrio anguillarum. In view of this, Marcobrachium rosenbergii were allotted into five groups randomly. The control group were fed with basal diet, the others were the treated groups fed with basal diet supplemented with 0.05%, 0.1%, 0.20%, 0.4% anthraquinones extracts for 8 weeks, respectively. At the end of feeding period, M. rosenbergii of each group were infected with V. anguillarum. The growth index and lysozyme, maleic dialdehyde (MDA), superoxide dismutase (SOD), total antioxidative capacity (T-AOC) were determined. The results of growth test showed that, compared with the control, 0.1% and 0.4% dose group elevated weight gain rates, specific growth rates and decreased feed conversion rates significantly. Hepatopancreas SOD activities were a trend mounted up

    • Variational characteristics of ecological parameters of Upeneus bensasi in southern Taiwan Strait

      2008, 32(3):362-368. DOI: 10.3724/SP.J.00001

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      Abstract:According to the biological data of Upeneus bensasi(Temminck et Schlegel) collected by trawl boats in the southern Taiwan Strait during 2000-2002, this paper studied the population structure, growth and mortality character. Comparing with the studies in 1977 and 1994, this paper discussed the population dynamics of U. bensasi. The results showed that the fork length of the fish population ranged from 65-169 mm, with 101-130 mm being predominant, and the average was 116.3 mm. The body weight ranged from 6-86 g, with 21-40 g being predominant, and the average was 34.4 g. The age ranged from 0 to 5-year, with 1 year being predominant, and the average was 1.12-year. The parameters of growth were: L=182.73 mm, W=131.42 g, K=0.4204, t0= -1.0424(t0 is the age when the theory fork length is 0), tr=1.5933 (tr is the age of the inflexion point of body weight growth), the exploitation rate is 0.4934, and the rates of total mortality, natural mortality and fishing mortality were found to be 2.1077, 1.0677and 1.0400 respectively. Comparing with 1977, the fish in 1994 were early matured and their growth speed increased, while the individuals of catch stock were smaller and in low-aged size, the inflexion of weight was ahead the schedule. It is showed that the population resource was heavily fragile. Comparing with 1994, the individuals of catch stock in 2002 were bigger in size, the growth speed decreased and the fork length of the first maturity were a little increased, it is showed that the resource is better than 1994. But the inflexion of weight was also ahead the schedule, the fishing mortality was still increased and , the exploitation rate was also very high, the ecological parameters were worse than 1977. It is showed that the fish resource is still fragile. The changes of the ecological parameters were accordant with the variations of the input and output of the fishery resources in trawl boats, especially the fishing intensity in this area has been enhanced since 1994, and the juvenile U. bensasi was caught heavily, both of which induced biggish pressure on the resources, and the ecological parameters inevitably reflect the vulnerability of population. Therefore, it is suggested that the protection and management of fish resources should be intensified, and powerful measures should be taken to control the fishing efforts and catches, thus to achieve sustainable development and sustainable use of fish resources. The suggested maximum sustained yield (MSY) of fishery resources in trawl boats is calculated to be 26.94×104 t, the maximum sustained yield is calculated to be 2180 standard trawl boats in Fujian, the minimum capture fork length and weight of U. bensasi are 91.67 mm and 16.89 g.

    • Purification and Antibody Preparation of Nebulin from the Skeletal Muscle of Sea Bream (Sparus latus)

      2008, 32(3):464-470. DOI: 10.3724/SP.J.00001

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      Abstract:As a giant actin-binding protein with molecular weight of approximately 500-900 ku, nebulin is thought to act as a molecular template that regulates the length of thin filaments and plays an essential role in the assembly and maintenance of I-Z-I bands in myofibrillar muscles. Though nebulins from mammals have been studied widely, much less study was performed on nebulin from fish muscle. In the present study, nebulin from the skeletal muscle of sea bream (Sparus latus) was first extracted with low ionic strength buffer, followed by applying to Sephacryl S-400 gel filtration chromatography and finally purified by electrophoretic elution. Purified nebulin revealed a single protein band on sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), suggesting its high homogeneity. A polyclonal rabbit anti-nebulin antibody was thus prepared by immunizing rabbit with purified nebulin and immunoglobulin G (IgG) was purified by Protein A-Sepharose affinity column. The immunogeneicity of the purified antibody was further identified by Dot-Blot and Western-Blot. The potency of anti-nebulin antibody reached 5×104 by Dot-Blot analysis. Western-Blot revealed that the antibody immunologically reacted with purified nebulin and nebulin in myofibrils while no cross reaction with other myofibrillar proteins was detected, suggesting the high specificity of the polyclonal antibody. Thus, the antibody prepared in the present study will surely beneficial for further study concerning the detection of this protein immunologically. The degradation of nebulin during fish storage at two temperatures of 4 ℃ and 18 ℃ was also investigated by SDS-PAGE. At 4 ℃, protein degradation could be detected after storage for 9 d and after 18 d, more than 70% of the nebulin original band disappeared. However, at 18 ℃, nebulin deterioration could be detected even at 24 h and after 120 h, the original protein band disappeared completely. The decomposition of nebulin as detected by SDS-PAGE was in accordance with sensory freshness change, suggesting the completeness of nebulin is an index of fish muscle freshness. Interestingly, the largest protein (titin) almost did not change even after storage at 4 ℃ for 18 d or at 18 ℃ for 188 h. In conclusion, our present study, especially the anti-nebulin antibody prepared provided an effective tool for the investigation of fish freshness.

    • void

      2008, 32(3):369-378. DOI: 10.3724/SP.J.00001

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      Abstract:void

    • Preparation and bioactivity of Ca2+ chelate of hydrolysate by enzymolysis from the waste fish proteins

      2008, 32(3):471-477. DOI: 10.3724/SP.J.00001

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      Abstract:This paper focuses on the preparation and bioactivity of Ca2+ chelate of hydrolysate which from the waste fish proteins through compound enzymolysis. The optimum formation conditions of the hydrolysate chelating Ca2+ are 5% of DH, 7.0 of pH, 293 K of temperature and 15 min of chelating time for FM (material not being defatted). Three types of hydrolysate chelating Ca2+ including CA (deposit after chelating), CB (deposit in 50% of absolute alcohol solution) and CC (deposit in 80% of absolute alcohol solution) were obtained through fractional precipitation with absolute alcohol from FM. Structure analysis through IR revealed that Ca2+ had been combined strongly with amino-group and carboxyl-group in each of chelates and each of Ca2+ could form 2 five-memberd ring structures in CA, however, Ca2+ had been only combined strongly with carboxyl-group in CB and CC. Among all of the chelates, the CA possesses the most effective antioxidative activity and the activity is 94% as high as that of a-tocopherol, and only CC possesses the most effective antibacterial activity against E. coli, S. aureus and B. subtilis and the activity depends on the size of the dissolvability in aqueous system and the strength of the electron buffering capability of the electron relaying system for CC. These researches provide a more effective way for the utilization of waste fish proteins and the essential information for the enzymatically hydrolyzed waste fish protein chelating Ca2+ as additive for food industry.

    • Purification and characteristics of sturgeon chondroitin sulfate

      2008, 32(3):478-483. DOI: 10.3724/SP.J.00001

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      Abstract:Condroitin sulfate (CS) has many functions and is widely used in food, medical and cosmetic industies. Elasmobranch is the main material source of fish chondroitin sulfate. Nowadays the main fish condroitin sulfate product is from shark cartilage. However, it can not be produced greatly for the limited resource of shark. Sturgeon has resource advantage because it can be fostered by manpower. But the characteristics of sturgeon chondroitin sulfate has not been learned so far. In the present paper, sturgeon chondroitin sulfate was purified by the methods of ethanol classification precipitation and column chromatography. The purified sturgeon CS (chromatographically pure) and shark CS (chromatographically pure) of Sigma company were comparatively studied in molecular weight, rotation, sulfate group content, UV and visible spectra. The results show that weight average, number average and Z average molecular weights of sturgeon CS are remarkably different from those of shark CS (P<0.05). Molecular weight distribution indicates that the purity of extracted sturgeon CS is more higher than the shark CS (P<0.05). It also shows that the sulfate group content of sturgeon CS is less than that of shark CS(P<0.01). The power rotations of the two CSs are proved to be very different, too (P<0.01). The strongest absorbance wavelength was 220 nm in UV and visible spectrum of sturgeon CS, while 230 nm in shark CS. These characteristics of sturgeon CS suggest its probable speciality in bioactivity and medical function. Presumably, sturgeon CS may have better anti-oxidation and anti-coagulant activities.

    • Relationship between the resource and fishing ground of Pnunmatophorus japonicus and environmental factors based on GAM and GLM models in the East China Sea and the Yellow Sea

      2008, 32(3):379-386. DOI: 10.3724/SP.J.00001

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      Abstract:Scomber japonicus and Scomber australasicus are important small pelagic fishes in the East China Sea and Yellow Sea. It is neccessary for us know the relationship between their fishery resource, fishing ground distribution and the factors such as time-space and marine environmental conditions, which are beneficial to exploit this resource. Based on the catch statistics of Pnunmatophorus japonicus from Chinese large purse seine vessels and environmental factors in the East China sea and Yellow sea from 1998 to 2004, the relationship between the abundance index and fishing ground distribution of mackerel and environmental factors are analyzed using generalized additive model (GAM) and general linear model (GLM). The results indicated that, the fishing ground are focused at the waters of 122.5°E-124°E and 26.5°N-28°N in the southern fishing area, in which this fish is concentrated near the waters of thermal fronts, and the optimum SST and SSS ranged from 26.5 to 30℃ and from 33.3 to 34.3 respectively. While in the north fishing area, the fishing ground is focused at the waters of 122.5°E-125.5°E and 33°N-37.5°N, in which this fish prefer to live near the colder water, and the optimum SST and SSS ranged from 15 to 20℃ and from 31.3 to 32.3 respectively. The relative abundance index (RAI) more than 0.5 are distributed in the waters of 122.5°E-124.5°E and 26.5°N-28°N, 122.5°E-125.5°E and 33°N-34.5°N, 124°E- 125°E and 34.5°N-37°N. It is conclude that it is obviously different for southern and northern fishing areas of this fish in the ranges of SST and SS. The importance impacting mackerel resource abundance is temporal, spatial, environmental and other factors in order.

    • >ROUNDUPS
    • A review on hemocyanins of Crustacean

      2008, 32(3):484-491. DOI: 10.3724/SP.J.00001

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      Abstract:Crustacean, especially crabs and shrimp have become more and more important objects in world aquaculture. Hemocyanins(Hcs) are the very important chromoprotein accounting for more than 90% of all the crustacean hemolymph protein. In recent years, many investigations have been focused on Hcs. In this paper, the research advances in crustacean hemocyanins were summarized following aspects: the basic structure, property of oxygen transport, immunity, anabolism of Hcs and so on. Hcs occurs as hexamers composed of six heterogeneous monomeric subunits. Each subunit holds an active site of two coppers, which corresponds to only one oxygen molecule. Resently, researchers put forward that Hcs hold important immune functions in crustacean. Hcs maybe exert their defence functions at least by two ways:one way is Hcs’s converting to phenoloxidase by cleavage of N-terminal sequences of Hcs; the other way is releasing antimicrobial fractions by cleavage of C-terminal of Hcs, which are broadly antimicrobial against a variety of bacteria and viruses. A newly-study proved that Hcs posess the property of agglutinin with low activity, which also contributes to immunity in crustacean to a certain extent. Hcs can also serve as carriers of metal ions, storage of protein. Besides Hcs can be used as a sign to observe the distribution of some molecules connecting with them. Hcs are synthesized in F-cell cytoplasm of the hepatopancreas. Evidence proved that ambient factors could also lead to Hcs’ anabolism.

    • >PAPERS
    • Feeding behavior of Thunnus obesus in the west-central Indian Ocean

      2008, 32(3):387-394. DOI: 10.3724/SP.J.00001

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      Abstract:Based on the data collected in the west-central Indian Ocean during September 2005 to December 2005 and December 2003 to May 2004, the paper analyzed feeding behaviors of bigeye tuna Thunnus obesus preliminarily. The results indicated that diet composition of Thunnus obesus included Loligo, Sardina, Scomber, Penaeus, Portunus trituberculatus, Alepisaurus, Brama, Gempylus, Sepia officinalis, Balistes, Sparus, Physalia, Trachurus, and other species of fishes, in which Loligo (IRI=50.84%), Scomber (IRI=17.70%) and Penaeus (IRI=9.49%) are the main diets. The percentage of empty stomachs of T. obesus is 52.2% and 47.7% respectively to the male and female. Monthly fluctuation occurred in the diet compositions. Loligo pealei was dominant in the diet of T. obesus monthly, followed by Scomber japonicusSardina Antipa, Penaeus, and Portunus trituberculatus. Significant monthly fluctuations occurred in mean weight.

    • >RESEARCH NOTES
    • Analysis of genetic diversity of natural population in Pleuronectes yokohamae

      2008, 32(3):492-496. DOI: 10.3724/SP.J.00001

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      Abstract:Random amplified polymorphic DNA (RAPD) technique was employed to detect the DNA polymorphism in 30 individuals of natural population of Pleuronectes yokohamae. 20 arbitrary primers selected from 48 primer were used and 148 clear , repeatable RAPD bands were generated in which 94 bands were polymorphic. All the primers are polymorphic primer. Each primer used for the detection could produce 4~13 molecular markers with the average of 7.4. DNA fingerprints varying in length from 200~2 000 bp. The percentage of polymorphic fragments was 63.51 % , while the index of Shannon diversity was 0.2824 and the index of gene diversity was 0.1991. Every individual had genetic difference and the genetic distance between individuals was from 0.0148 to 0.1963. Comparing the genetic diversity of Pleuronectes yokohamae s with that of other fishes , the experiment revealed that the genetic diversity of Pleuronectes yokohamae was at middle level. This result will give date for the future study of genetic diversity in Pleuronectes yokohamae.

    • >PAPERS
    • A study on diet composition of dominant fishes in Lake Taihu

      2008, 32(3):395-401. DOI: 10.3724/SP.J.00001

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      Abstract:Based on the investigations from September to December in 2004 and during April in 2005, the diet composition of eight species of fishes in Lake Taihu was studied. The results were as follows: Coilia ectenes taihuensis Yen et Lin mainly fed on Cladocera accounting for 89.77±13.69% of individual composition in its food; Neosalanx tangkahkeii taihuensis Chen mainly fed on Copepoda accounting for 70.11%±10.57% of individual composition in its food; Microcystis occupied over 90% of volume composition of the food of Hypophthalmichthys molitrix (Cuvier et Valenciennes) and Aristichthys nobilos (Richardson); Water plant occupied over 70% of volume composition of the food of Cyprinus carpio Linnaeus; Microcystis accounted for 93.99±3.34% of volume composition of the food of Carassius auratus Linnaeus; Erythroculter ilishaeformis Bleeker and Erythroculte rmongolian Basilewsky mainly fed on Coilia ectenes taihuensis Yen et Lin and small-sized fishes. The conclusion was that the potential productivity of phytoplanktivores quickly increased, but the dominant fishes in fish catches were zooplanktivores fishes in Lake Taihu. For example, the potential productivity of phytoplanktivores was 10 234 t accounting for 37.0% of the total potential fish productivity in 2003. But phytoplanktivores catches were only 3637.7t accounting for 10.9% of the total fish catches in 2004, while zooplanktivores catches accounted for 80%-90% of the total fish catches. Therefore the present composition of fish catches was not consistent with the food resource in Lake Taihu. Additionally, the effects of the increases of zooplanktivores fishes maybe indirectly probably enhanced the development of Cyanobacteria by feeding on large amount of zooplanktons. The effects of Carassius auratus Linnaeus on environment should be revaluated because the fish mainly fed on Microcystis.

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