汤浦水库浮游甲壳类动物群落结构特征研究

于2011年1-12月对汤浦水库浮游甲壳动物的群落结构组成及现存量进行了调查研究。结果表明,汤浦水库共鉴定出浮游甲壳动物52种,其中枝角类27种,桡足类25种;浮游甲壳动物种类春季最多,其次是夏秋季,冬季最少;枝角类年均密度为7.93个/L,最高值出现在7月,为20.60个/L,桡足类年均密度为13.51个/L,最高值出现在11月,为36.13个/L;水平分布上,枝角类和桡足类年均密度最高值均出现在双江溪,分别为12.55个/L和21.70个/L,库中心最低,分别为4.51个/L和6.67个/L;浮游甲壳动物Margalef多样性指数的季节变化与种类变化规律类似,最大值出现在5月的春季(5.32),最小值出现在2月的冬季(1.76);多样性指数的水平分布范围为3.97~4.96,均值为4.53,以取水口最高(4.96),王化溪最低(3.97)。根据浮游甲壳动物Margalef多样性指数及前人研究成果判定汤浦水库应属于β中污-寡污型水体。     

Carbohydrate and lipid digestibility of animal and vegetal ingredients and diets for juvenile Australian redclaw crayfish, Cherax quadricarinatus

Carbohydrate and lipid digestibility of three vegetal and four animal ingredients, and diets in which they were included, were evaluated for juvenile Australian redclaw crayfish, Cherax quadricarinatus. The ingredients were: soy paste, textured wheat, sorghum meal, sardine meals (67% and 58% crude protein), squid meal and red crab meal. A basal diet was formulated, and then seven experimental diets were created, including 150 g kg^?1 of each ingredient in the reference diet. Digestibility was measured in vivo, using chromic oxide as marker. A single‐factor, completely randomized experimental design with three replicates per treatment was performed. Mean carbohydrate digestibility of vegetal ingredients and the corresponding diets was better than carbohydrate digestibility of animal ingredients. Sorghum meal had a carbohydrate digestibility over 94%, and the diet in which it was included over 92%. Soy paste and wheat meals also presented excellent carbohydrate digestibility (around 88% for ingredients and over 90% for diets). Mean carbohydrate digestibility of animal ingredients and their corresponding diets were very poor (from 18% to 32%) and this affected the carbohydrate digestibility of diets in which they were included (87–89%). Lipid digestibility was also better for vegetal ingredients. Soy paste and wheat meal recorded values over 93% and their diets over 94%. Sorghum lipid presented slightly lower digestibility. Some of the animal ingredients, especially red crab, had an excellent lipid digestibility (92.1%).     

Protein from Northern krill (Thysanoessa inermis), Antarctic krill (Euphausia superba) and the Arctic amphipod (Themisto libellula) can partially replace fish meal in diets to Atlantic salmon (Salmo salar) without affecting product quality

The main objective of the present study was to evaluate the effect of using three different crustacean meals (Tysanoessa inermis, Euphausia superba, Themisto libellula) on product quality of Atlantic salmon (Salmo salar L.). In order to do this, a total of six iso‐protein, iso‐lipid and iso‐carotenoid diets were prepared. Two experimental diet series were prepared. In the first series, a control feed (K0) was compared with diets where 20%, 40% and 60% of the fish meal protein were replaced with protein from Northern krill T. inermis (K20, K40 and K60, respectively). In the second series, control feed (K0) was compared with diets where 40% of the dietary protein was replaced by protein from T. inermis (K40), Antarctic krill E. superba (AK40) and the Arctic amphipod T. libellula (AMP40). The salmon groups were fed the various diets for 160 days and the average weight of the fish increased from 410 g to around 1500 g. Fish given diets containing krill displayed a general better growth compared with the ones given pure fish meal diet. Replacing fish meal protein with protein from the crustacean sources had, in general, only minor effects on the flesh quality measured both by technical and sensory methods. However, some significant effects were noted. Postmortem muscle pH was generally lower (P < 0.05), for K20, K40, AMP40 in fish fed crustacean diets compared with those receiving the control diet. Increasing the replacement level of non‐fish meal protein from Northern krill (K20, K60) significantly reduced the rigor contraction. Fish given K20 had a slightly firmer meat texture, measured as resistance to post‐rigor compression, especially when compared with K60 (P < 0.05). Fish from the K20 and AMP40 groups had a deeper red flesh coloration [both light reflection (A*‐value and chroma) and flesh astaxanthin concentration] than fish fed K0 and higher inclusions of krill meal. The groups with the highest astaxanthin flesh content also showed the best growth and had the highest feed intake. Finally, a sensory panel analysis differed slightly from the technical measurements in that K0, rather than K20 was given the highest score for hardness and colour. In comparison with K0, AK40 got the lowest salty taste and hardness scores from the panellists relative to the control fish (P < 0.05). Despite minor effects on the present quality measures, it is concluded that meal from three different crustacean species can successfully replace fish meal up to 60% with Northern krill, and 40% of Antarctic krill and amphipod meal of dietary proteins.     

Efficacy of silicone-coated ascorbic acid and ascorbyl-2-polyphosphate to fast-growing tiger shrimp (Penaeus monodon)

Growth, survival, tissue ascorbate concentration and collagen content were studied in fast-growing Penaeus monodon fed two ascorbic acid (AA) derivatives. Prior to the experimental trial, shrimp (initial body weight: 0.9 ± 0.4 g) were fed on a diet lacking vitamin C for 5 weeks. During the following 13-week experiment, the shrimp (initial body weight: 8.2 ± 0.7 g) were given one of five squid-meal-based diets. The dietary treatments consisted of a diet lacking vitamin C, two diets supplemented with either 500 or 1000 mg AA kg⁻¹ in the form of silicone-coated AA, and two diets supplemented with either 500 or 1000 mg AA kg⁻¹ in the form of ascorbyl-2-polyphosphate. Shrimp gained 18.3 g in 13 weeks. The AA-free diet group exhibited the lowest growth rate, feed intake and survival (26.8%) after 4 weeks. Hepatopancreatic ascorbate and muscle collagen content were significantly ( P < 0.05) lower in AA-deprived shrimp. At the end of the feeding trial, growth rate and survival were not significantly ( P > 0.05) different among groups fed AA-supplemented diets. Hepatopancreatic and haemolymphatic ascorbate concentrations were significantly ( P < 0.05) higher in groups given ascorbyl-2-polyphosphate than in groups given silicone-coated AA. A supplement of 500 mg AA kg⁻¹ diet in the form of either silicone-coated AA or ascorbyl-2-polyphosphate was adequate for optimal growth. But ascorbate concentrations in tissues remained much below saturation levels with a supplement of 1000 mg AA kg⁻¹ diet. It is questionable whether the established vitamin C requirements for P. monodon are adequate to maintain tissue ascorbate in fast-growing juveniles.     

Molecular characterization of myostatin‐like genes expressed highly in the muscle tissue from Morotoge shrimp,Pandalopsis japonica

Myostatin is one of the transforming growth factor (TGF)‐β family members and plays inhibitory roles in the development and growth of muscle in mammals. Mammalian myostatins have been studied intensively, considering its medical and industrial potential use. Still, limited information is available about myostatin homologues in crustaceans. In the present study, we isolated for the first time cDNA that encodes for myostatin‐like protein (Pj‐MSTN) from Morotoge shrimp, Pandalopsis japonica. The putative mature peptide of Pj‐MSTN was composed of 109 amino acids, which contains an additional amino acid residue compared with mammalian myostatins. Pj‐MSTN exhibited 32% amino acid sequence identity and 52% similarity to human myostatin. Multiple sequence alignment analysis indicated that Pj‐MSTN shared the conserved proteolytic cleavage site (RXXR) for its maturation and nine cysteine residues for disulphide bridges. These results suggest that Pj‐MSTN has conserved the three‐dimensional structure of TGF‐β family members in vertebrates. Phylogenetic analysis suggests that Pj‐MSTN is a primitive form of vertebrate myostatin and GDF11. The expression of Pj‐MSTN was not just identified in muscular tissues, suggesting that Pj‐MSTN functions differently from mammalian myostatin. Ablation of the X‐organ/sinus gland complex significantly reduced the expression of Pj‐MSTN in most tissues, suggesting its potential association with moulting.     

城市封闭湖泊浮游甲壳动物种类组成及优势种季节变化

为了解城市封闭湖泊浮游甲壳动物种类组成及优势种的季节变化,于2015年6月至2016年5月对扬州市蜀冈湖进行为期1周年的调查。结果表明,蜀冈湖共检出浮游甲壳动物13属15种,其中枝角类2属4种,桡足类11属11种,桡足类中哲水蚤目的球状许水蚤(Schmackeria forbesi)、汤匙华哲水蚤(Sinocalanus dorrii)和剑水蚤目的毛饰拟剑水蚤(Paracyclops fimbriatus)、广布中剑水蚤(Mesocyclops leuckarti)为优势种。4种优势种丰度春夏季高于秋冬季,体长秋冬季大于春夏季;Pearson相关性分析显示,4种优势种丰度与水温呈正相关,体长与水温呈负相关(P0.05);2种哲水蚤优势种丰度还与氨态氮、总氮和叶绿素a呈正相关,与透明度呈负相关,体长与透明度呈正相关,与叶绿素a呈负相关(P0.05)。线性回归分析显示,水温显著影响优势种丰度和体长的季节变化。     

SNP分子标记技术在经济甲壳动物中的应用进展

作为第三代分子标记,单核苷酸多态性标记(SNP)具有丰富度高、密度大、稳定性强、共显性等特点,成为目前虾、蟹等经济甲壳动物中应用最广泛的分子标记技术。本文对经济甲壳动物中SNP技术的发展及其在高密度遗传连锁图谱的构建、种质资源遗传多样性分析、分子辅助育种等方面的应用进展进行了综述,并提出了未来有待加强的研究方向,以期为经济甲壳动物种质资源的开发和利用提供理论指导。     

甲壳动物渗透调节生理学研究进展

Osmoregulation involves many aspects of physiological function in crustacean. Crustacean species exhibit almost all possible patterns of osmotic regulation and they are widely distributed in most of known biotopes. With the changes of liquid environment, the structure and function of the osmoregulation organs( such as gills, antennary glands) ,haemolymph osmotic pressure and ionic transport will turn to maintain the well-balanced metabolism, which are under the neuroendocrine regulation. The current research status of physiological mechanism of crustacean osmoregulation was reviewed in the following aspects. 1 ) Structure and function of gills and antennal glands(maxillary glands). The gills are very important organs and play a prominenet role in osmoregulatien; 2)Regulafien of ion transport in branchial epithelium. Ion transport enzymes (Na^ -K^ -ATPase, V-ATPase,HCO3^--ATPase and carbonicanhydrase)stimulated by bioamines and cAMP may participate in the ion transport of branchial epithelium in crustacean; 3 )Haemolymph composition and osmoregulation. Haemolymph concentration of ion and free amino acid accompanied by metabolites of blood can contribute to the most of haemolymph osmotic pressure; 4)Neuroendocrine control. Many neuropeptides may regulate the osraotic pressure of haemolymph and proteinsases activity of epithelial gill cells. Bioamines, cAMP and CaM have been proved to stimulate the uptake of Na^ and transport of Cl^-.     

甲壳动物幼体消化酶研究进展

通过研究近年来国内外学者关于甲壳动物幼体消化酶方面的研究现状,发现目前已测定出甲壳动物幼体消化酶的种类主要有：蛋白酶、胰蛋白酶、羧肽酶A、羧肽酶B、氨肽酶、胶原酶、弹性蛋白酶、胃蛋白酶、糜蛋白酶、酯酶、脂肪酶、淀粉酶、纤维素酶、几丁质酶、麦芽糖酶、蔗糖酶、昆布多糖酶等种类,初步归纳了甲壳动物幼体主要消化酶的分子量、最适pH和最适温度;分析了幼体发育过程中消化酶活力变化模式以及与食性的关系,并采用淀粉酶/蛋白酶活力（A/P）比值或淀粉酶/类胰蛋白酶（A/T）比值作为甲壳动物幼体的食性指标;观察了幼体消化器官的发育,阐明幼体消化酶的合成与分泌不仅由遗传控制、中肠腺发育程度等因子决定,而且还与饲料的营养水平有关,提出采用幼体消化酶对饲料组成的适应性研究幼体营养需求的新途径.[中国水产科学,2006,13（3）：492-501]