Abstract:In this paper, two microalgal strains (Isochrysis galbana 3011 and 8701) were used to study the difference of chlorophyll a fluorescence parameters under high temperature stress (35-50 ℃). The results showed that the maximal photochemical efficiency of PSⅡ(F_v/F_m), the potential activity of PSII (F_v/F_o), the relative electron transport rate (rETR), the actual photochemical efficiency of the PSII reaction centers of light adapted cells (ΦPSII) and the photochemical quenching (qP) all decreased under high temperature stress in the two microalgal strains. The changed degree of the above parameters increased with the increase of temperature and the increasing exposure time. NPQ in the two microalgal strains exhibited different patterns of variation with high temperature stress, the values in 3011 first increased then decreased, while that in 8701 increased with stress time at 35 ℃and 40 ℃, but first increased then decreased at 45 ℃. There are some heattolerance varieties between the two microalgal strains 3011 and 8701. For 3011, the parameters F_v/F_m, F_v/F_o, ΦPSII, rETR and qP could almost recover to the control values in the normal temperature after 10 min high temperature treatments at 40 ℃, but could not recover when the stress temperature are at 45 ℃ and 50 ℃. As to 8701, the parameters F_v/F_m and F_v/F_o could almost recover to the control values at 25 ℃ after 10 min high temperature stress at 35 ℃ and 40 ℃, but all parameters could not recover to the control values when the temperature is above 45 ℃. The responsive mechanism of Isochrysis galbana to high temperature stress as well as the possibility of determining the high temperature resistance in microalgae using chlorophyl fluorescence induction kinetics was also discussed in this paper.

Abstract:Through laboratory cultivation and observation, the life history of Ulva linza which includes apomixis, asexual and sexual reproductions was found. Apomixis was completed by biflagellated gametes which were released from gametophytes. Biflagellate neutral zoospores and quadriflagellate neutral zoospores were observed. Biflagellate neutral zoospores released from zoosporangia were settled after moving for about an hour. Settled biflagellate neutral zoospores could develop into sporophytes. The newly developed sporophytes also released this kind of biflagellate neutral zoospores to complete asexual reproduction. The asexual reproduction completed by quadriflagellate neutral zoospores was the same as biflagellate neutral zoospores. Sexual reproduction was completed by an alternation of gametophytes and sporophytes. Mature dioecious gametophytes released biflagellated female and male gametes. The zygotes were formed after conjugation between female and male gametes. Then the zygotes developed into sporophytes. When sporophytes were matured, quadriflagellate zoospores were released from zoosporangia, and developed into new gametophytes. Life history of Ulva linza was typically an alternation of isomorphic, unisexual haploid gametophytes and diploid sporophytes, of which apomixis and asexual reproduction were dominant. Without conjugation between female and male gametes, the life history of Ulva linza was curtailed. The gametes could develop instantly after being settled. Moreover, the quantities of gametes released form gametangia and the quantity of zoospores from zoosporangia were very large. Under appropriate conditions, Ulva linza would reproduce rapidly. Perhaps, this is one of the reasons for the ourbreak of the “green tide” in the Yellow Sea.

Abstract:In this study, artificial induction of testicular development and maturation in male marble eels was carried out by muscular injection of HCG ( 6 weekly injection of HCG at a dose of 500 U/kg per body weight) and the rate of sexual maturation reached 80.0%. The long diameter and the short diameter of the spermic head was （3.81±0.69）μm, and （1.24±0.15）μm, respectively. The length of the spermic tail was （24.83±3.05） μm. The pH value of sperm was 7.3-7.5. The density of spermatozoa from marble eels was 1.02×10¹⁰ ind/mL. The range of suitable salinity was 15-20, when the salinity of water was 15, the spermatozoa had the best motility, and the spermatozoa had the longest life. The suitable pH of spermatozoa was 6.0-8.0, high or low pH value could restrain the mobility and shortened the longevity. The trends that affected the spermatozoa mobility and life span were almost consistent by four kinds of metallic ions (Mg²⁺, Ca²⁺, Na⁺, and K⁺). When the concentration of solution was too low or too high, the spermatozoa mobility was restrained, and the spermatozoa quick movement time and life span were shortened. When the concentration of MgCl₂, CaCl₂, KCl, and NaCl solutions were 0.4-0.6 g/mL, the spermatozoa mobility was the best, and the highest initiated rate of the spermatozoa reached 41.0%-60.0%.

Abstract:In order to study if cytoplasm of UV-irradiated heterogenous sperm affected the development of “fertilized” egg during gynogenesis, the embryonic development of Cynoglossus semilaevis haploid induced by UV-irradiated heterogenous and homogenous sperm were compared. The embryonic development course of haploid induced by UV-irradiated heterogenous and homogenous sperm was alike at the stages of blastodisc formation, 2-cell stage, multi-cell stage and blastula stage. After the stage of early gastrula, the developmental velocity of haploid embryo induced by UV-irradiated heterogenous sperm was slower than that of haploid embryo induced by UV-irradiated homogenous sperm. But, the morphology of haploid embryos induced by UV-irradiated heterogenous and homogenous sperm was alike at the corresponding stage. After stage of somite, the developmental velocity of haploid induced by UV-irradiated heterogenous and homogenous sperm was identical. A great deal of haploid embryos died after somite stage and the death rate of haploid embryos induced by UV-irradiated heterogenous sperm was larger than that of haploid embryos induced by UV-irradiated homologous sperm. The larvae hatched from haploid embryo induced by UV-irradiated heterogenous and homogenous sperm have haploid syndrome. The ploidy level of 30 gastrula embryos induced by UV-irradiated heterogenous and homogenous sperm was determined in order to verify that UV light completely irradiated sperm. The result of ploidy analysis showed that the embryos induced by UV-irradiated heterogenous and homogenous sperm were all haploid.

Abstract:A onemonth starvation experiment was conducted to investigate its influence on the female Odontobutis potamophila during overwintering period. The control group was fed with satisfaction of living Cardina sinensis. By the end of the experiment, a significant decrease in the body weight (P<0.05) and an extremely significant decrease in the hepatopancrea somatic index (P<0.01) were observed respectively in the starving group. The percentage of the middle phase 3 oocytes and the late phase 3 oocytes which had potential to become maturation eggs soon had reduced sharply in ovaries of the starving group. And their ovaries had also developed more slowly than those phase Ⅳ ovaries of control group, just reaching middle phase Ⅲ. All those results showed the negative effects of starvation on gonadic development of female O. potamophila overwintering. On the other hand, there was no significant difference (P>0.05) found in the gonadosomatic index of the starving group within 28 d. The variations of the ovary lipovitellin concentration, the VTG gene expression in livers and the serum vitellogenin concentration of the starving group entirely showed highlowhigh trend, and in 28 d the values of the ovary lipovitellin concentration and the VTG gene expression reached (14.31±1.11) μg/mg and 2 081.08±124.86 respectively in the starving group, showing no significant difference (P>0.05) compared to the fullfed control. Resorbing and reusing evidences of the degraded yolk granules were observed in the starving fish’s ovaries. Those results suggested that there was a compensatory mechanism existing in the starving female O. potamophila, just like in some seawater fishes, to ensure reproductive success by consuming its energy deposition, and that the compensatory mechanism was characterized in several ways.

Abstract:Crayfishes (Cherax quadricairnatus) were collected from artificial ponds in Zhejiang Institute of Freshwater Fisheries. The samples were observed under microscope after being sacrificed and investigated with histological, histochemical, biochemical methods and chromatography. The C. quadricarinatus spermatophore comprises a highly convoluted tube and a firm membrane forming a cordlike mass, and this spermatophoric ribbon is embedded in a gelatinous matrix. The structure of C. quadricarinatus spermatophore was observed under the electron microscopy, which consists of sperm mass, spermatophore matrix and spermatophore wall. Sperm mass is embedded in a dense fibrillar matrix and with an acellular wall surrounding both of them. In this study, the structure of the spermatophore wall in the vas deferens was also investigated using electron microscopy and biochemical test. The wall of the spermatophore is composed of two concentric layers: a thin primary spermatophore layer which is a fibrillar structure that directly surrounds the sperm mass and spermatophore matrix, and a thick secondary layer which contains heterogeneous vesicles and loose filament surrounds the primary spermatophore layer. The vas deferens of C. quadricarinatus consists of an anterior vas deferens, a middle vas deferens, and a posterior vas deferens. The histology of the inner epithelial cells of the vas deferens contributing to the spermatophore mass is described. The inner epithelial cell of the coiling anterior vas deferens secretes the weakly acidophilic filament that forms the equable primary layer of spermatophore. Neutral muopolysaccharides and protein are the main components of the primary layer. There are incrassate epithelial cells of middle vas deferens, which are fasciculate high cellula columnoepithelialis. In the middle of epithelial cells, some secretory vacuoles were observed with acidophily vesicular secretion, which formed the inequable secondary layer. Acidic muopolysaccharides and protein are the main components of the secondary layer. Spermatophores structure are complete in posterior vas deferens which has a simpler structure than the former two but incrassate muscular layer and larger tube. The posterior vas deferens links with ejaculatory duct. Between the posterior vas deferens and the ejaculatory duct, there is a bottleneck with two valves inside. The ejaculatory duct has an incrassate muscular layer and protuberant inner epithelial cells. No spermatophore in the ejaculatory duct is visible.

Abstract:This study is based on the material of Japanese scallop (Patinopecten yessoensis Jay) phenotypic characters, and the objective is to analyse correlation relationship, define degree of correlation among characters, establish the regression equation, and to lay a foundation of selective breeding. Data for this study were collected from 126 Japanese scallops at three years old in Zhangzidao Island of Dalian City. The shell length (X₁), shell height (X₂), shell width (X₃), live body weight (Y), soft tissue weight (Z) and adductor weight (W) of 63 male scallops and 63 female scallops were measured individually. The correlation coefficient matrix was calculated respectively. Three body shape traits were used as independent variables, the softtissue weight and adductor weight were used as dependent variable for path analysis, and path coefficients (P_i), determination coefficients (d_i) and correlation index (R²) were calculated. The results show that correlation coefficients between each body shape trait and the live body weight (Y), softtissue weight (Z) and adductor weight (W) are all significantly different (P<0.01). Shell length (X₁) and shell height (X₂) give predominant direct effect and determinacy on the softtissue weight of female scallops; it is the key effective factor. Shell length (X₁) and shell width (X₃) give predominant direct effect and determinacy on the softtissue weight of male scallops; it is the key effective factor. But the key effective factors of mixed scallops are shell length (X₁), shell height (X₂) and shell width (X₃). The key effective factor on adductor weight (W) is only shell width (X₃), shell length (X₁) and shell height (X₂) give slightly direct effect and significant indirect effect through shell width (X₃), is the secondary factor. It was clear from the result of high correlation index that the path coefficient analysis could reveal the truthful relationship between the independent variables and the dependent variable. Eliminate inconspicuousness factor, the multiple regression equation obtained to estimate two anatomical traits as: 1) For female Z= -128.573+1.355 X₂+1.407 X₃; W= -8.216+ 0.869 X₃; 2) For male Z = -138.493 +1.082 X₁+2.524X₃; W = -11.855+0.955 X₃；3) For mixed Z= -133.939 +0.606 X₁+0.679 X₂+ 1.709 X₃; W= -9.525+ 0.896X₃. Efficient scheme of multiple trait selection will be made if we obtain definite quantitative relationship between each two characters. This study provides theoretical evidence and perfect measure target for breeding of Japanese scallop.

Abstract:An experiment was conducted to study the effects of dietary vitamin E on growth（weight gain rate，feed efficiency ratio，specific growth rate and survival rate），vitamin E concentration in tissue and immune responsed（lysozyme activity and total complement activity）of Japanese seabass（Lateolabrax japonicus）. Five iso-nitrogenous and iso-energetic diets were formulated to contain graded level of vitamin E (0.6，24.7，49.0，98.9，and 198.2 mg•kg-1 diet，respectively ) and fed to15 floating netcages（1.5×1.0×1.0 m）with 20 fish (initial weight: 10.5g) each twice daily（09:30，16:30）for 8 weeks. Results indicated that after 8 weeks of the feeding trial，weight gain rate，feed efficiency ratio，specific growth rate and survival rate of the fish fed with the control diet were significantly lower than those with vitamin E supplemented diets. The weight gain rate and specific growth rate increased significantly with increasing dietary vitamin E from 0.6 to 49.0 mg•kg-1 and the optimal vitamin E content for maximum growth is about 60.5 mg/kg；Moisture and fat concentration in whole body of Japanese seabass were not affected by the supplemental levels of dietary vitamin E，but the protein concentration increased significantly with increasing dietary vitamin E from 0.6 to 49.0 mg•kg-1，Meanwhile，the vitamin E concentration in liver and musle increased significantly with increasing dietary vitamin E from 0.6 to 49.0 mg•kg-1, but no significant differences were observed among fish fed the diets with equal to or higher than 49.0 mg•kg-1 of vitamin E. The serum lysozyme activity and total complement activity of the fish fed with the control diet were significantly lower than those with vitamin E supplemented diets，the serum lysozyme activity and total complement activity of Japanese seabass increased significantly with increasing dietary vitamin E supplement，and the Japanese seabass had the maximal level of lysozyme activity and total complement activity when fed 98.8 mg•kg-1. Based on the information above, the optimal dietary vitamin E level for optimum growth performance and immune responses in Japanese seabass is about from 60.5 to 98.8 mg•kg-1.

Abstract:360 juvenile carps were allocated to 3 treatments. Each treatment containing 120 was randomly divided into 4 groups, respectively fed with the purified diets containing selenium 0, 0.15, 0.30 and 0.45mg/kg . The test indicated that the morbidity and mortality of the test groups were negatively correlated to the level of selenium in the diets. The morbidity and mortality were respectively 46.7%, 33.3%, 13.3%, 0% and 26.7% 16.7%, 6.7%, 0%. The diseased fishes exhibited some specially pathological changes, such as "thin back disease" and lordosis. Histologically, the anaplasia of the organs and tissues was obvious, such as nutritional myopathy, nutritional hepatopathy, pancreatic degeneration and necrosis and so on. Ultrastructurally, in addition to the mitochondria of the cardiac muscle cells, the liver cells and renal tubular epithelial cells, were swollen. The disintegration and lysis were noted in the cristaes of the mitochondria which formed vesiculation. The activity of the serum AST and ALT rose, the activity of the serum GSH-Px and the serum SOD decreased, whereas the serum MDA concentration raised.

Abstract:Abstract: Immunoreactive substances can stimulate the immune system of shrimps, and enhance the immunocompetence of animal. The influence of egg yolk immunoglobulin on the immunity-related enzyme activities and WSSV resistance of shrimps has not been reported. In this research, we fed basic diets containing three levels(1%, 0.5%, 0.1%)(M/M) of Ig-Guard(shrimp) to Litopenaeus vannamei continuously for 20 days, and the basic diets as blank control. Then detected phenoloxidase(PO), acid phosphatase(ACP) and lysozyme(UL) activities of the serum and superoxide dismutase(SOD) activity of the muscle, and protein concentration of the serum and the muscle on days 5, 10, 15 and 20. All the immune parameters of the test groups measured were higher(P<0.05) than the control group. After 20 days, we fed white spot syndrome virus(WSSV) to shrimps, and recorded the mortalities of challenging test in seven days. The relative percent survival(RPS) value of the test groups was 17.95%, 23.08%, 35.90%. This experiment indicates that Ig-Guard(shrimp) can effectively enhance the shrimps’ immunity-related enzyme activities, and it can also promote shrimps’ WSSV resistance. Based on the results of immunity-related enzyme activities and cumulative mortality, the enzyme activities of the lower concentration group was higher than the higher concentration group, and it’s cumulative mortality was lower, so we suggests that feed the lower concentration Ig-Guard(shrimp) properly is reasonable.

Abstract:The skin ulcer syndrome is a serious disease causing massive mortality and economic losses in cultured sea cucumber (Apostichopus japonicus). The causative agent was identified as Vibrio splendidus. As V. splendidus DNA was gained, the 16s-23s rDNA intergenic spacers were amplified by PCR, and cloned into pMD19-T vectors and finally sequenced. A fragment (about 177bp) was obtained by PCR, and it was labeled with digoxigenin-dNTP to form a dot-blot hybridization probe for V. splendidus DNA. The results showed that the probe was only positive for V. splendidus DNA, while it was all negative for DNAs of bacteria V. fluvialis, V. anguillarum, V. alginolyticus, V. parahaemolyticus, V. harveyi, V. vulnificus and Aeromonas hydrophila. The sensitivity test illustrated that the detection limit of the dot-blot hybridization probe was 6.25pg V. splendidus DNA. In addition, the probe was considered to be accurate in the detection of V. splendidus as the positive ratio was as high as 100% for the total samples from Qingdao, Weihai and Yantai areas. This probe was the first time to be established and applied in China to detect V. splendidus in A. japonicus. As it is sensitive and accurate in detection of V. splendidus, it would be helpful in the disease control and health management in cultured A. japonicus.

Abstract:An indirect fluorescent antibody technique(IFAT) has been developed to detect Hematodinium sp. in the haemolymph of swimming crab and mud crab. The polyclonal antiserum was derived from rabbits immunized with trophonts of Hematodinium sp. in the diseased Portunus trituberculatus. Antiserum titer, detected by indirect ELISA, was 7680 after reacted with the haemolymph of healthy swimming crab. 18 Samples, including cultured swimming crab, mud crab and wild-caught swimming crab, were tested for Hematodinium sp. by microscopic observation, PCR and IFAT. And the detecting positive rate was 33.3%, 77.8%, 77.8% separatly. The positive compatibility rate of the PCR and IFAT was 100%. Results showed that Hematodinium sp. was speccific labelled with bright fluorescence under UV epifluorescence ,while the haemocytes remained dark. Three different life stages, the trophont , dinospore, sporont of Hematodinium.sp, were also detected by IFAT. In conclusion, IFAT is rapid and specific for the detection of Hematodinium sp., and it’s a practical method for the epidemiology investigation of marine crab and study on the life cycle of Hematodinium sp.

Abstract:Gas chromatography with electron capture detection method was developed for the determination of 7 pyrethroids residues in aquatic products. Pyrethroids were extracted with cyclohexane and ethylacetate（1:1,V/V）and lipids were removed with petroleum ether. Cleanup was performed on a LC-Florisil column. The working curves for the pyrethroids were linear (r＞0.992) in the range of 1 to 100 μg/L. When spiked with 5, 10 and 20 μg/kg of pyrethroids, the average recoveries were 70.0%～114.8% and the intra-day RSD(n=5) were 1.2%～9.8% and the inter-day RSD(n=3) were 3.8%～11.2%. The detection limit as estimated by 2 times signal to noise method for bifenthrin, fenpropathrin, lambdacyhalothrin, permethrin was 1 μg/kg and for permethrin, fenvalerate, deltamethrin was 2 μg/kg respectively.

Abstract:Extraction yield of collagen was regarded as an index to research on preparation of collagen from squid skin by hot water, acid, and enzyme, respectively. The optimum processing conditions of extraction were determined by orthogonal experiment design. The optimum conditions by hot water were temperature of extracting 80 ℃, volume of water 20 folds, and time of extracting 12 h. The extraction yield of collagen was 90.26%. The optimum conditions of extraction by acid were temperature of extracting 24 ℃, 0.5 mol/L acetic acid, and time of extracting 48 h. The extraction yield of collagen was 95.16%. To hydrolyze the squid skin, trypsin, and papain were choosed to apply in the experiment. The optimum processing conditions of extraction by trypsin were temperature 55 ℃, enzyme dosage 1 200 U/g, concentration of substrate 1∶20, pH 8.0, and time 4 h, respectively. The extraction yield of collagen was 95.16%. The results of extracting collagen by papain show that the optimal reactive temperature, enzyme dosage, concentration of substrate, pH and time were follows: 50 ℃, 3 200 U/g, 1∶20, pH 6.0, and 6 h, respectively. The extraction yield of collagen was 97.56%. The character absorption spectra and molecular weight of extracted collagens were determined by ultraviolet spectrophotometry and SDS-PAGE methods．Functional properties including solubility, water-binding capability, wetting capability, oil-holding capability, emulsifying capability, emulsion stability, foaming capacity and foaming stability of collagen from squid skin were investigated. The results showed that：(1) The maximum absorption wavelength of extracted collagens was 220 nm and the molecular weight of prepared collagen from squid skin was about 220 ku．(2) The water-solubility of extracted collagen by hot water and papain was higher than that by acetic acid. (3) Extracted collagen by hot water, acetic acid and papain has definite water-binding capability, the value was 0.54％, 0.52％ and 0.55％, respectively.（4） Wetting capability of extracted collagen by hot water and papain was better than by acetic acid.（5）Extracted collagens had all excellent oil-holding capability, the value was 2.7 mL/g, 3.0 ml/g and 3.3 mL/g, respectively. (6) Extracted collagen had all excellent emulsifying capability and emulsion stability. Emulsifying capability of extracted collagen by acetic acid was the best, the value was 72%. Emulsifying stability of extracted collagen by papain was the highest. (7) Extracted collagen had foaming capacity and foaming stability. The strongest foaming capacity and foaming stability of extracted collagen by acetic acid was 83% and 67%, respectively.

Abstract:Abstract：Objective: In order to utilize the waste effectively in Katsuwonus pelamis processing, we studied the effects of the enzymatic hydrolyte of Katsuwonus pelamis liver (KPLH) on lipid metabolism in rats. Material: Fresh Katsuwonus pelamis liver was homogenized and auto- enzymatic hydrolyzed in 25℃ for 12hours. After percolation, the enzymatic hydrolyte of Katsuwonus pelamis liver was freeze-dried. Animal experiment: The Male SD rats were fed high fructose basic diet (AIN 76) for 1 week. Then rats were randomly divided into 3 groups and fed 5% or 10% freeze-dried KPLH containing high fructose basic diet（KPLH group）or high fructose basic diet (control group). After 4 weeks, serum triglyceride (TG), total cholesterol (TC)，high density lipoprotein cholesterol (HDL-C), Free fatty acid (NEFA) levels, and hepatic lipid concentrations (TG, TC) were determined. To resolve the mechanism of lipids lowing effect of KPLH in rats, the activities of key enzymes related in lipids metabolism, malic enzyme (ME), glucose-6-phosphate dehydrogenase (G6PDH), fatty acid synthase (FAS) and carnitin palmitoyl transferase (CPT) were determined. Results: After 4 weeks feeding, KPLH did not affect the food intake, body weight gain, liver weight in rats. The abdominal white adipose tissue weights were lower in KPLH group compared with the control group (no statistical difference, p>0.05). The serum TG levels and atherogenic index (AI) were significantly decreased in KPLH group compared with the control group (P <0.05, P <0.01), and the serum HDL-C levels were significantly up-regulated by KPLH (P <0.05). The concentration of serum total cholesterol was lower in KPLH group than that in control group, but there was not significant difference between KPLH group and control group (p>0.05). On the other hand, KPLH did not alter serum glucose and NEFA levels in rats. Those results showed that the enzymatic hydrolyte of Katsuwonus pelamis liver is beneficial to prevent hyperlipidemia and artheroschlerosis. In liver, KPLH decreased significantly the TG concentration (P <0.001) but not total cholesterol and phospholipids levels. Furthermore, the activities of G6PDH, ME and FAS were decreased by 5% KPLH in liver (P <0.05, P <0.01 and P <0.05). On the other hand, KPLH did not alter the activity of CPT in liver. These suggested that the serum lipids lowing effect of KPLH is related to the down-regulation of hepatic fatty acid synthesis. Conclusion: This study indicated that the KPLH have anti-atherogenic and anti-fatty liver effects by reduced hepatic fatty acid sythesis.

Abstract:Abstract: Myofibril fragmentation index, contents of collagen (total collagen, heat soluble collagen, heat insoluble collagen) and muscle fiber diameter were used to evaluate the histology characteristics, and meat tenderness of Chinese mitten crab from 4 different locations was analyzed by using the method of combination index. The results showed that: myofibril fragmentation index was 50～90, muscle fiber diameter 350～550 μm; total collagen 0.1～0.18 g•(100 g)-1; heat soluble collagen 0.03～0.12 g•(100 g)-1, heat insoluble collagen 0.04～0.1 g•(100 g)-1. Compared to beef, the muscle fiber diameter of crab muscle was large, and collagen content was low. These three methods can be used to classify the crab meat tenderness, but there was disagreement in the orders of the Chinese mitten crabs from different locations. Muscle fiber diameter was the most effective tenderness evaluation method, and content of collagen was the least effective tenderness evaluation method. Meat tenderness of Chinese mitten crabs by using combination index in order of large to small was B, C, A, D (male); A, C, B, D (female).

Abstract:Along with traditional world economic fisheries resource decline, the exploitation and utilization of Cephalopod resource have been recognized generally in the world and studies on resource condition and biology were made much progress. Beak with the features of steady structure, erode-resistant and better information storing is one of hard and main predation organs of Cephalopod, and it not only play an important role in taxonomy also as a good tool to study Cephalopod biology. Based on the studies conducted by some authors at home and abroad, our paper describe the morphological characteristics of beak and review the studies of beaks that applied in Cephalopod biology, taxonomy, stock estimation and feeding habits of predators. The results shows that some problems still exist in age identifying and stock estimating, which should be solved in the recent future although a certain progress has been made.

Abstract:The allotetraploid in cross-fertilized eggs of Chlamys farreri♀× Patinopecten yessoensis♂ was induced in this paper. In order to find out the appropriate duration time of 6-DMAP treatment, ploidy status of induction offspring was analyzed by flow cytometry. The results showed that the optimal duration time of 6-DMAP treatment was to treat the fertilized eggs with 50 mg/L 6-DMAP for 15min based on the integrated evaluation of the results of fertilization rate, survival rate of D-larvae, development status of larvae, and percentage of tetraploid. The results of flow cytometry showed that 17.3% tetraploid was obtained which showed that allotetraploid could be gotten with this method. The reasons of the problems in the work were also discussed in this paper.

Abstract:Bangia fusco-purpurea, a economic macroalgae, was often cultivated in Zhejiang and Fujian coast. Its cultivation in Guangdong coast and photosynthetic characteristics had not been well documented. In this paper it was transplanted from Fujian province to the sea area of Nan’ao Island in Guangdong province, and the photosynthetic characteristics and fatty acids compoment were investigated by using photosynthetic gas exchange and gas chromatography. The results showed that Bangia fusco-purpurea grew well in situ with a higher photosynthetic light saturation point of 210µmol•m-2•s-1. The lower light compensation point as well as dark respiration rate were also observed. The polyunsaturated fatty acids (PUFAs) accounted for more than half of the total fatty acids. The EPA content was 41.20% in the total fatty acids, and reached as high as 499.82mg per 100g dry weight, which was significantly higher than that of Porphyra haitanensis or Gracilaria lemaneiformis grown in the same sea area. In conclusion, it was practicable that Bangia fusco-purpurea was cultivated in the sea area of Nan’ao Island. The alga could be exploited as a new source of EPA production because of its higher EPA content.