Effects of Replacing Fishmeal with Animal By-products Meal Supplementation in Diets on the Growth and Nutrient Utilization of Mangrove Red Snapper

A feeding trial was conducted for 75 d to evaluate the nutritive value of a mixture of animal by-products(MAB) as a possible protein source in diets for juvenile mangrove red snapper,Lutjanus argentimaculatus(mean initial body weight,30 g). Fish were fed one of five isonitrogenous diets(40% crude protein) replacing 0,25%(MAB25),50%(MAB50),75%(MAB75) and 100%(MAB100) of fish meal protein with similar percentages of MAB. The MAB consisted of 25% cow liver meal,20% leather meal,20% meat and bone meal,15% blood meal,10% APC(poultry feather meal),8% poultry manure dried,1.5% choline and 0.5% chromic oxide. After 75 d of feeding,fish fed with diets MAB50,MAB75 and MAB100 exhibited significantly lower growth per-formance than that of fish fed with control and MAB25 diets. The optimum level of MAB was estimated to be 23%. Replacement of fish meal by MAB23% showed the following performance:maximum weight gain,510%;SGR,2.39% and FCE,2.83%. The MAB substitution up to 75% of fish meal protein in diets did not show differences in apparent protein digestibility(83.6% for MAB25,79.2% for MAB50,78.7% for MAB75) compared with control(83.4%),whereas in MAB100 group digestibility(65.3%) was sig-nificantly lower than in other groups. The apparent phosphorus absorption of test diet groups was significantly higher(37.1% for MAB25,28.5% for MAB50,55.6% for MAB75 and 54.5% for MAB100) than that of control(11.2%). The levels of protein and ash in the whole body,carcass and viscera increased as MAB substitution in diets increased,whereas lipids and moisture remained con-sistent among all treatment groups. These results showed that approximately 23% of fish meal protein could be replaced by a mixture of animal by-products for juvenile snapper growing from 30 g to 167 g in 75 d without compromising growth performance and feed efficiency.     

Effects of Pseudoalteromonas sp.BC228 on Digestive Enzyme Activity and Immune Response of Juvenile Sea Cucumber （Apostichopus japonicus）

A marine bacterium,Pseudoalteromonas sp.BC228 was supplemented to feed in a feeding experiment aiming to determine its ability of enhancing the digestive enzyme activity and immune response of juvenile Apostichopusjaponicus.Sea cucumber individuals were fed with the diets containing 0 （control）,105,107 and 109 CFU g-1 diet of BC228 for 45 days.Results showed that intestinal trypsin and lipase activities were significantly enhanced by 107 and 109 CFU g-1 diet of BC228 in comparison with control （P〈0.01）.The phagocytic activity in the coelomocytes of sea cucumber fed the diet supplemented with 107 CFUg-1 diet of BC228 was significantly higher than that of those fed control diet （P〈0.05）.In addition,105 and 107 CFUg-1 diet of BC228 significantly enhanced lysozyme and phenoloxidase activities in the coelomic fluid of sea cucumber,respectively,in comparison with other diets （P 〈 0.01）.Sea cucumbers,10 each diet,were challenged with Vibrio splendidus NB 13 after 45 days of feeding.It was found that the cumulative incidence and mortality of sea cucumber fed with BC228 containing diets were lower than those of animals fed control diet.Our findings evidenced that BC228 supplemented in diets improved the digestive enzyme activity of juvenile sea cucumber,stimulated its immune response and enhanced its resistance to the infection of V.splendidus.     

Effects of Dietary Protein Level on Growth and Utilization of Protein and Energy by Juvenile Mangrove Red Snapper (Lutjanus argentimaculatus )

1Introduction The mangrove red snapper,Lutjanus argentimacu-latus(Forsskal,1775)is a carnivorous,warm-watereuryhaline fish that is considerably cultured in South-east Asia,Southern China and the Middle East(Le-ung et al.,1999;Estudillo et at.,2000;Ng et al.,2000;Catacutan et al.,2001).In Pakistan,it isknown for its good quality meat and also for its highconsumption rate.Although it fetches a premiumprice at local markets(Anonymous,2002),the in-creasing demand has generated interest towar…     

EFFECTS OF CO—CULTURE AND SALINITY ON THE GROWTH AND AGAR YIELD OF GRACILARIA TENUISTIPITATA VAR LIUI ZHANG ET XIA

Gracilaria tenuistipitata var Liui were mono-cultivated and co-cultivated with Pinctada martensii under high(33) and low(21) salinity conditions in laboratory.The daily growth rate of the alga was determined.Tissue carbon and nitrogen contents,the yield and fractional composition of agar were analyzed.Results showed that:1.Gracilaria grew better under low salinity conditions,the daily growth rate was twice that under high salinity conditions.Co-cultivated algae grew faster than mono-culti-vated algae under low salinity conditions,the daily growth rate was about 37.6?higher.2.Compared with mono-cultivated algae,tissue nitrogen contents of co-cultivated algae were higher,while the C:N ratios were much lower.3.The agar yields of co-cultivated algae were much lower than those of mono-culti-vated algae.Agar yield was found to be negatively correlated to the tissue nitrogen contents,and positively correlated to the C:N ratios.4.The highest fractional yields obtained from co-cultivated algae were extracted with 40?ethanol,while from mono-cultivated algae,the highest fractional yields obtained were extracted with distilled water at room temperature.     

CYTOLOGICAL COMPARISON OF GAMETOGENESIS OF SCALLOPS, ARGOPECTEN IRRADIANS AND CHLAMYS FARRERI

Histological characteristics of gametogenesis of two kinds of scallops, gonochoric Chinese scallop, Chlamys farreri and hermaphroditic bay scallop, Argopecten irradians were investigated in this study. Spermatogenesis in C. farreri has different developmental stages: spermatogonia, primary spermatocyte, second spermatocyte, spermatid and spermatozoon. A large number of same developmental stage spermatic cells converge at a definite area of the testis. Premeiotic, previtellogenic and vitellogenic oocytes can be found during oogenesis in C. farreri, where oocyte distribution is obviously irregular. The A. irradians gonad consists of two different parts in one individual: one part functions as testis, the other as ovary. Between these two parts is a special appearance area, where a large number of spermatic cells are bound with two layers of acellular substance with many oocytes in it.     

Competition Among Dinoflagellate Alexandrium Tam—arense, Raphidophyte Heterosigma Carterae and Diatom Skeletonema Costatum under Combinations ofTwo Temperatures and Five Salinities

Competition among HAB (Harmful Algal Bloom) species Dinoflagellate Alexandrium tamarense, Raphidophyte Heterosigma carterae, and Diatom Skeletonema costatum was studied in the laboratory. Experiments with these three major HAB species under combinations of different salinities (10, 18, 25, 30, 35) and temperatures (19℃, 25℃) were carried out. The results showed that S. costatum successfully competed with the other two species at salinities of 18, 25,30, and 35 at temperatures of 19℃ and 25℃. However, H. carterae showed its advantage at low salinity of 10 and became the single dominant species at salinity 10 and 25℃. A. tamarense could not compete successfully with the other two species especially at low salinities. However, it could remain at low density in the presence of higher densities of other algae.     

Isozymes Analysis of the Golden Cuttlefish Sepia esculenta（Cephalopoda ： Sepiidae）

Thirty-nine isozymes in four tissues (mantle muscle, buccal bulb muscle, eye and liver) of Sepia esculenta were screened for enzymatic analysis using starch gel electrophoretic technique. Eighteen enzymes (G3PDH, LDH, MDH, MEP, IDHP, PGDH, GRS, NP, AAT, CK, AK, EST, ALP, ACP, FBP, MPI, GPI and PGM) show strong activities and good convergence in zymogram. They are proved to be suitable genetic markers in Sepia esculenta. Among the tissues used, mantle muscle is the best for electrophoretic analysis of isozymes. Eye and liver are fairly good for some special enzymes, such as LDH, EST, MPI, etc. Twenty-six loci are detected. The proportion of polymorphic loci is 0.115 in the Qingdao sample and 0.153 in the Rizhao sample (P<0.99). The mean values of the observed and expected heterozygosity per locus of Qingdao sample are 0.016 and 0.017, while those of the Rizhao sample are 0.023 and 0.025 respectively.     

Bioaccumulation of Pb<Superscript>2+</Superscript> and its effects on growth,morphology and pigment contents of <Emphasis Type="Italic">Spirulina</Emphasis> (<Emphasis Type="Italic">Arthrospira</Emphasis>) <Emphasis Type="Italic">platensis</Emphasis>

A laboratory experiment was conducted to assess the bioaccumulation of Pb²⁺ and its effects on growth, morphology and pigment contents of Spirulina (Arthrospira) platensis. The specimen cultured in Zarrouk liquid medium was treated with various initial metal concentrations (0, 5, 10, 30, 50 and 100 μg mL⁻¹). The growth of S. platensis was adversely affected by Pb²⁺ at high concentrations (30, 50 and 100 μg mL⁻¹). However, at low concentrations (5 μg mL⁻¹), Pb²⁺ could stimulate its growth slightly. The pigment contents (chlorophyll α and β carotene) were decreased in a dose-dependent manner. The highest reductions (67% and 53% respectively in chlorophyll α and β carotene) were observed in 100 μg mL⁻¹ treatment group. The LC₅₀ (96 h) of Pb²⁺ was measured as 75.34 μg mL⁻¹. Apart from a few cases of filament breakages at elevated concentrations (50 and 100 μg mL⁻¹), morphological abnormalities are not specific. Metal bioaccumulation increased with Pb²⁺ concentrations, but decreased with exposure time. The maximum accumulated amount was 188 mg g⁻¹ dry weight. The bioconcentration factor (BCF) reached to a peak at day 2, followed by a gradual reduction for all the exposure concentrations. S. platensis is able to tolerate considerably high Pb²⁺ concentrations. Consequently it can be used as a potential species to remove heavy metal from contaminated waters.     

Chemical constituents of marine medicinal mangrove plant <Emphasis Type="Italic">Sonneratia caseolaris</Emphasis>

Twenty-four compounds including eight steroids (1–8), nine triterpenoids (9–16, 24), three flavonoids (20–22), and four benzenecarboxylic derivatives (17–19, 23) were isolated and identified from stems and twigs of medicinal mangrove plant Sonneratia caseolaris. The structures of the isolated compounds were determined by extensive analysis of their spectroscopic data. Among these metabolites, compounds 1, 4–20 and 22–24 were isolated and identified for the first time from S. caseolaris. In the in vitro cytotoxic assay against SMMC-7721 human hepatoma cells, compound 21 (3′,4′,5,7-tetrahydroxyflavone) exhibited significant activity with IC₅₀ 2.8 μg/mL, while oleanolic acid (14), 3,3′-di-O-methyl ether ellagic acid (18), and 3,3′,4-O-tri-O-methyl ether ellagic acid (19) showed weak activity. None of these compounds displayed significant antibacterial activites. Supported by the National Natural Science Foundation of China (No. 30770234); Knowledge Innovation Program of Chinese Academy of Sciences (KZCX2-YW-211-04); Department of Science and Technology of Shandong Province (No.2006GG2205023)     

A Fast and Indriect Fluorescent Antibody Assay for the Vibro in Large Yeelow Croaker Pseudosciaena Crocea (Richardson)

A fast and indirect fluorescnet antibody assay for the Vibrio alginolyticus and V.Parahaemolyticus infecting the large yellow croaker has been developed.The specific antisera for the two strains of vibrio were prepared with New Zealand rabbit and the antiserum and cross-reactive efficacy was tested by coagulation in tube.It showed that the goat anti-rabbit IgG had been labeled by fuorescence isothiocyanate(FITC).The results showed that positive reactions were 100% for the large yellow croaker Pseudosciaena crocea with typical symptom of vibrio infection,while the positive reaction to the pathogen in healthy yellow croakers reached 40%,but seemed negative for aquaculter water.The results demonstrated that this fast and indirect fluorescent antibody assay can be used not only to test the vibrio pathogen in diseased yellow croaker but also in infected animals with no symptom.