Comparison of the Intestinal Bacterial Flora in Healthy and Intestinal‐diseased Seahorses Hippocampus trimaculatus,Hippocampus erectus,and Hippocampus spinosissimus

This investigation examined the intestinal microbial flora among healthy and intestinal‐diseased seahorses Hippocampus trimaculatus, Hippocampus erectus, and Hippocampus spinosissimus by utilizing polymerase chain reaction‐denaturing gradient gel electrophoresis (DGGE) and densitometric analysis. Results demonstrated that 16 disparate DGGE bands belong to six major bacterial groups, which were Vibrionace, Enterobacteriacea, Rhodobacteraceae, Sphingomonadaceae, Flavobacteriaceae, and Alcaligenaceae. It was found that Vibrionaceae was the dominant population among the healthy and intestinal‐diseased seahorses. Vibrio ponticus strain XJ3 and Vibrio neptunius strain WT82, especially V. ponticus strain XJ3 of high abundance, were identified for the first time in seahorses and concluded to be intestinal disease pathogens because of their co‐existence in three intestinal‐diseased seahorse species and other reported fish or oyster. In comparison, uncultured bacterium clone Alcaligenaceae, Vibrio sp., uncultured bacterium clone Rhodobacteraceae, Serratia nematodiphila strain, and Serratia marcescens strain comprised the basic intestinal bacterial flora of all healthy seahorses. This study is the first to report the presence of S. nematodiphila in seahorses.     

Biochemical composition of the wild and cultured seahorses, Hippocampus kuda Bleeker and Hippocampus trimaculatus Leach

The biochemical composition of wild and cultured seahorses Hippocampus kuda Bleeker and Hippocampus trimaculatus Leach was analysed in this study. The crude protein contents (% dry weight) of wild seahorses were high: 72.7±2.5% in H. kuda and 78.5±4.2% in H. trimaculatus . The crude lipid contents (% dry weight) of wild and cultured seahorses (1.1±0.1 vs. 1.4±0.2 for H. kuda and 1.2±0.1 vs. 1.2±0.2 for H. trimaculatus ) were low and did not differ significantly ( F _3, 12=1.461, P =0.12). The essential amino acids and flavour-enhancing amino acids in wild seahorses were higher than those in cultured seahorses, although the essential amino acid index in wild and cultured H. kuda and H. trimaculatus were generally low. The total amino acid content decreased with growth in cultured H. trimaculatus ( F _3, 12=14.927, P <0.05). The poly-unsaturated fatty acid (PUFA) contents in wild and cultured H. kuda and H. trimaculatus were 21.69%, 37.72%, 21.39% and 33.89% respectively. The fatty acid content in seahorses first decreased and then increased with growth both in wild and in cultured H. trimaculatus . The PUFA/saturated fatty acid ratio was 1.31 in cultured H. kuda and 0.87 in cultured H. trimaculatus . The trace metal concentrations in the wild seahorses were relatively low. The results presented in this study provide biochemical information necessary for understanding the medicinal value of H. kuda and H. trimaculatus and for elucidating the potential dietary requirements for their culture.     

三斑海马的人工生态养殖

通过构建三斑海马的生态养殖环境、培育天然活体饵料,形成人工生态系统,提高了幼体的成活率。通过施用发酵鸡粪(即把备用的晒干鸡粪,加水发酵使其熟化)50g/m3或尿素10g/m3,5～7d后,投放海马幼体200ind/m3;放苗28d后,栽培菊花江蓠(密度0.5～2kg/m3)作为水质调控、遮光及养殖海马的缠绕物。江蓠的栽培构建了海马天然饵料的培育场所,藻丛中的小型甲类生物密度达450个/100g以上,形成了良好的养殖三斑海马的人工生态环境,经146d的养殖,生态养殖与投饵养殖模式比较,收获的三斑海马成活率和标准体长分别为70.8%、42.5%,11.13cm、10.04cm。     

Substrate‐attachment Preferences of Cultured Newborn Pot‐bellied Seahorses,Hippocampus abdominalis (Lesson, 1827)

During a series of observations, newborn pot‐bellied seahorses, Hippocampus abdominalis, were offered three size choices of diameter and density of substrate. The seahorses exhibited a marked preference for the greatest diameter and the lowest density substrates.     

Effect of Temperature on Growth and Survival in Cultured Early Juvenile Pot‐bellied Seahorses,Hippocampus abdominalis

In Tasmania, Australia, commercial seahorse culture takes place in tank systems in which approximately 75% of the water is exchanged daily from the Tamar River estuary. As such, some water conditions such as temperature fluctuate on a daily and seasonal basis. The aim of this study was to examine the effect on growth, condition, survival of, and Artemia ingestion by, early juvenile seahorses, Hippocampus abdominalis, cultured for 6 wk at temperatures within the species' natural range (8–24 C) and above it (26 C). Seahorses cultured at 20 C were longer and heavier than those at 17 C, although not significantly different to 23 C. There were no differences in survival or Artemia ingestion of juveniles cultured at 17, 20, and 23 C. At 26 C, 100% mortality was reached on Day 15. This study demonstrates that H. abdominalis can be reared in captivity at a range of 17–23 C in early life stages without compromising growth and survival.     

Growth,Survivorship, Air‐bubble Disease,and Attachment of Feeble Juvenile Seahorses,Hippocampus kuda (Bleeker, 1852)

Seahorse aquaculture has been a focus for meeting the demand of traditional medicine and aquarium. Feeble (poor quality) juveniles are commonly found in the commercial seahorse culture. In this study, we compared the growth and survival performances of the feeble and healthy common seahorses Hippocampus kuda. The results show that the feeble juveniles had high growth and survival at the temperature of 27–29 C and salinity of 26–28‰ with frequent feeding (≥three times a day) during first 5 wk. Through a 12‐wk investigation, we found that the air‐bubble disease could significantly affect the specific growth rate and survival of the feeble juveniles. There was a positive and significant correlation between the substrate‐attachment rate and survival rate in the feeble juveniles, and substrate‐attachment rate may be used to assess the quality of the feeble populations in the seahorse H. kuda.     

Effects of Anesthetic Disposal on the Physiological and Behavioral Responses of the Lined Seahorses,Hippocampus erectus

Anesthetic disposal for fish often results in physiological and behavioral responses. There is limited information involved on the metabolic and behavioral responses of the seahorses. The lined seahorse, Hippocampus erectus, is of great interest in the sciences because of its unusual S‐shaped morphology and male pregnancy behavior. This study found that the lined seahorse could be effectively anesthetized into Stage II at the concentrations of 10 mg/L clove oil or 20 mg/L MS‐222 based on the comparison of six different treatments. The ventilation frequency, oxygen consumption, and ammonia‐N excretion of the seahorses were decreased significantly as soon as they were exposed to the anesthetic agents. A higher O : N ratio was found in seahorses anesthetized by clove oil as compared to those exposed to MS‐222. After the anesthetic treatment, the feeding frequencies of recovered seahorses were low at the beginning and then increased during the 7‐d culture. Moreover, there was no incremental difference of wet weights among the tested seahorses (P = 0.534). The findings indicate that the anesthetic process has few effects on the feeding and short‐term growth of seahorses in spite of the occurrence of physiological and behavioral responses.     

Proximate and Fatty Acid Compositions in Different Flesh Cuts of Cultured,Cultured Fasted,and Wild Pacific Bluefin Tuna (Thunnus orientalis)

This study was carried out to determine the differences in proximate and fatty acid (FA) compositions in different flesh cuts of the most valuable cephalic portion of cultured (full-cycle), cultured fasted (full-cycle), and wild Pacific bluefin tuna (PBT; Thunnus orientalis). Cultured fasted PBTs were fasted for 6 days to ensure empty stomachs during harvesting and to determine the influence of fasting on the lipid and FA composition in different flesh cuts. Significantly higher lipid contents were observed (p < 0.05) in the dorsal akami (lean part) and the ventral o-toro (very fatty part) flesh cuts in cultured and cultured fasted PBTs than in wild ones. However, monounsaturated fatty acid (MUFA) contents in all flesh cuts were significantly higher in cultured and cultured fasted PBTs than in wild PBT. Wild PBTs contained significantly higher (p < 0.05) polyunsaturated fatty acid (PUFA) contents than other cultured PBTs in all flesh cuts except for the dorsal akami and wakaremi (fatty part near dorsal fin) flesh parts, and contained higher n-3 FA content than other PBTs—especially docosahexaenoic acid (DHA, C22:6n-3)—in the lipid fraction from the dorsal chu-toro (medium fatty part), ventral akami, ventral chu-toro, o-toro, and in dark flesh cuts. The flesh quality of cultured or cultured fasted PBTs has the advantage of having a higher total amount of essential FAs than that of wild PBT.     

山西沁河乌苏里拟鲿形态、分子鉴定及与黑龙江群体比较

研究山西沁河水系野生乌苏里拟鲿群体、黑龙江水系野生和养殖乌苏里拟鲿群体的形态学区分,为沁河水系本土拟鲿的增殖放流提供形态学判别依据,以利于优良经济鱼类种质资源保护与合理利用。沁河拟鲿采集于山西沁河安泽段(35.91°N,112.33°E),黑龙江野生拟鲿采集于黑龙江抚远江段(48.37°N,134.25°E)、养殖拟鲿采集于抚远当地水库(48.30°N,134.27°E)养殖网箱,从形态学和分子生物学途径对山西沁河野生种群进行种属鉴定,运用方差分析和聚类分析以及判别分析研究其形态学差异。(1)15个形态学指标和其他分类性状的形态学分析、线粒体DNA的CO I、Cyt b基因以及D-Loop区的序列比对结果均表明,沁河捕获的样本鱼为乌苏里拟鲿;(2)形态学差异分析表明山西沁河野生乌苏里拟鲿与黑龙江野生及养殖乌苏里拟鲿的形态差异均较大,尤其是眼径/头长达到亚种分化水平;(3)聚类分析表明,山西沁河野生群体单独成为1支,黑龙江野生群体和黑龙江养殖群体聚为另1支;(4)筛选出4个判别贡献率较大的形态学指标,建立了3个群体的判别函数,对山西乌苏里拟鲿群体综合判别率为84.6%,逐步判别分析显示沁河野生群体与黑龙江2个群体组中心相距较远,测量值分布独立于2群之外的区域。为避免人工放流过程中的基因污染,需要放流本水域的群体子代,以保护当地特色的种质资源;建立准确率高的判别函数将有助于简便地分析放流种类是否为该水系种群繁育的后代。     

Comparison of Collagen Distribution and Muscle Structure Between Cultured Amberjack (Seriola dumerili) and Cultured Yellowtail (Seriola quinqueradiata)

ABSTRACT

The collagen distribution in cultured specimens of amberjack and yellowtail were assessed by histochemical observation in relation to the meat texture of the fish. Major structural alteration was observed in the level of pericellular connective tissue of yellowtail that had higher muscle lipid content; these changes are likely to be associated with the large-scale changes in muscle firmness resulting from the weakening of the cellular binding force. However, lipid deposition was limited to the myocommata in amberjack muscle; lipid deposition was not observed in the pericellular connective tissue, which is the likely reason why amberjack maintained firmer meat texture.     

野生与养殖黄颡鱼鱼卵的营养成分比较

以贵州省铜仁锦江河漾头河段野生黄颡鱼鱼卵和同一区域内养殖黄颡鱼鱼卵为研究对象,采用常规生化方法测定了野生与养殖黄颡鱼鱼卵氨基酸组成和含量,采用气相色谱技术检测了野生与养殖黄颡鱼鱼卵脂肪酸组成和含量。氨基酸测定结果表明,野生黄颡鱼鱼卵的氨基酸总量、必需氨基酸总量、鲜味氨基酸总量显著低于养殖黄颡鱼鱼卵(P0.05),第一限制性氨基酸均为甲硫氨酸+半胱氨酸,必需氨基酸指数分别为55.60和59.12。脂肪酸测定结果表明,野生黄颡鱼鱼卵的饱和脂肪酸总量极显著高于养殖黄颡鱼鱼卵(P0.01),单不饱和脂肪酸总量二者差异不显著(P0.05),多不饱和脂肪酸总量极显著低于养殖黄颡鱼鱼卵(P0.01),但野生黄颡鱼鱼卵的二十碳五烯酸和二十二碳六烯酸的总量极显著高于养殖黄颡鱼鱼卵(P0.01),野生黄颡鱼鱼卵的n-3系列的多不饱和脂肪酸总量与n-6系列不饱和脂肪酸总量的比值(1.57)低于养殖黄颡鱼鱼卵(1.80)。     

池塘养殖牙鲆肠道和环境菌群结构对益生菌制剂的响应

为研究益生菌制剂对池塘养殖牙鲆(Paralichthys olivaceus)肠道及环境菌群结构的调控效果,采用高通量测序技术和生物信息学分析手段构建牙鲆肠道、养殖水体、饵料和池塘底泥的16S rDNA基因测序文库,分析不同样品中菌群组成和多样性在益生菌制剂调控过程中的变化趋势.结果显示,添加益生菌制剂后,池塘底泥和牙...     

Genetic Variation in Wild and Cultured Populations of the Freshwater Prawn,Macrobrachium nipponense,in China

Genetic diversities of five domestic and five wild populations of the freshwater prawn, Macrobrachium nipponense, in Jiangsu Province, China, were assessed by amplified fragment length polymorphism analysis. A total of 267 unambiguous polymorphic bands were detected from 300 individuals. The percentage of polymorphic bands varied from 33.64 to 55.14% in the 10 populations. The Nei genetic diversities of the wild populations and their domestic counterparts after several generations were 0.185 ± 0.024 and 0.164 ± 0.013, respectively, showing a decrease in genetic diversity in domestic populations. The largest genetic differentiation exists among the populations from different geographical locations, whereas there was less differentiation between the wild and domestic population in the same site. The cultured population in the north of Jiangsu Province where the large individuals of the prawns were harvested twice a year in spring and autumn for 4 yr almost had no change of genetic diversity (P > 0.05); whereas the cultured population in the south of Jiangsu where the large individuals were harvested all the year had a significantly reduced genetic diversity (P < 0.05). Therefore, we deduced that the aquaculture model in the north of Jiangsu should be better than that in the south. The results may be helpful to genetic enhancement and conservation programs of this species.     

Risk analysis of non-native three-spot cichlid,Amphilophus trimaculatus, in the River Cauvery (India)

The three-spot cichlid Amphilophus trimaculatus (Günther) is an ornamental fish known to be invasive but has not been assessed for India. The present study confirmed this non-native species’ identity using conventional and molecular methods, as well as its occurrence in the River Cauvery, the first for this species in a lotic environment outside its native range. Gut content analysis indicated a diet of predominantly insects. The river's water quality and habitat were conducive for the species’ growth and reproduction. Using the Aquatic Species Invasiveness Screening Kit, A. trimaculatus was ranked as posing a “high” risk of being invasive in the River Cauvery, with climate match analysis showing 58% similarity with the species’ native range. Vector and pathway analysis found that A. trimaculatus was introduced to India via the aquarium trade, although consignment origin remains unknown, and the most likely means of entry into the river and its tributaries was the species’ escaping from holding facilities. Subsequent dispersal and impact of the species on native fauna are discussed. The study's outcomes demonstrate the importance of using risk analysis protocols to inform management of non-native species in India, with suggestions provided for immediate and long-term measures for the species’ management.     

Morphological Traits of Wild and Selected Strains of Cultured Undaria pinnatifida from Galicia (NW Spain)

Wakame, Undaria pinnatifida, is one of the most popular seaweeds used for human consumption in the world. Wakame quality is mainly valued on the basis of its morphological features. Continual inbreeding and directional selection have traditionally been used with economic seaweeds to obtain elite strains with high‐quality forms. In this study, we compared the morphological traits of cultured sporophytes originating from wild and selected strains of U. pinnatifida in Galicia (NW Spain). Seedlings (young sporophytes) of the two strains were cultured at a sheltered site in a coastal bay of Galicia under the same environmental conditions. Sixteen different morphological measurements were taken on cultured sporophytes. We found that the sporophytes of both wild and selected strains were significantly similar in all studied morphological characters. These results suggest that the morphology of cultured strains of U. pinnatifida from Galicia is due to environmental conditions and that specific morphological traits are dependent on the cultivation environment. Consequently, the morphological traits of Galician U. pinnatifida populations are not an important factor in selective breeding for enhanced wakame quality, and hence, for the establishment of a germplasm bank (e.g., gametophyte stocks).     

人工养殖与野生鳙鱼肌肉营养成分的比较分析

本试验分析测定了贵州省人工养殖鳙鱼与贵州省红枫湖水库野生鳙鱼的含肉率及其肌肉的生化成分,比较分析了它们的含肉率、水分、粗蛋白、粗脂肪、灰分以及氨基酸。结果表明:人工养殖鳙鱼和野生鳙鱼含肉率、粗蛋白、粗脂肪、水分、灰分含量分别为57.73%和52.73%;18.06%和17.71%;0.70%和0.67%;80.03%和80.00%;1.21%和1.62%,肌肉中17种氨基酸(除色氨酸)总含量分别为14.642%和14.979%,其中7种必需氨基酸(除色氨酸)含量分别为5.957%和5.554%,必需氨基酸占总氨基酸的比值分别为40.684%和37.785%,4种鲜味氨基酸总量分别为5.266%和6.291%,占总氨基酸含量分别为35.965%和41.999%,必需氨基酸的指数分别为67.4和68.4;对鱼肉进行氨基酸评价,蛋氨酸、胱氨酸和缬氨酸为人工养殖鳙鱼的限制性氨基酸;而蛋氨酸、胱氨酸和亮氨酸为野生鳙鱼的限制性氨基酸。     

黄鳝体内睾酮、雌二醇和炔诺酮含量的检测分析

检测并分析了黄鳝体内睾酮、雌二醇和炔诺酮的含量。结果显示，野生和人工饲养的黄鳝，其血清中睾酮、雌二醇的平均值为0．055ng／ml和22．43pg/ml，野生黄鳝中睾酮、雌二醇的含量普遍高于人工饲养的黄鳝，Student′↑s t检验差异显著。在野生及人工饲养的黄鳝体内均未检出炔诺酮。饲养试验的结果表明，如果黄鳝摄食了添加一定浓度炔诺酮的饲料，能检出其体内炔诺酮的残留。     

Digestive protease characterization, localization and adaptation in blacklip abalone (Haliotis rubra Leach)

Digestive protease in blacklip abalone (Haliotis rubra Leach) from whole gut extracts was found to have dual pH optima at pH 3 and 10 and an optimum temperature of 45 °C. Over the biologically relevant range of pH (5–8), protease activity dropped to a minimum at pH 5 (53% of the maximal rate at pH 3) rising gradually and continuously up to (and beyond) pH 8. Over the biologically relevant range of temperatures (9–24 °C), protease activity increased continuously with activity at 24 °C being 75% higher than activity at 9 °C. Protease digestion was relatively uniform in gut extracts from sections containing gut contents. Digestion thus appears to be significantly extracellular (in the lumen of the gut). Analysis of gut sections washed free of food matter suggests the anatomical origin of protease from activity of gut regions in the order: digestive gland » salivary gland ≈ stomach > crop > intestine > upper oesophagus. Whole gut protease levels did not alter in response to a high protein artificial diet.     

Cryopreservation of sperm in farmed blacklip abalone (Haliotis rubra Leach, 1814)

This study developed a technique of sperm cryopreservation using liquid nitrogen (LN) vapour in farmed blacklip abalone Haliotis rubra through evaluating the following five key factors: (1) cryoprotectant agent (CPA) toxicity; (2) cooling temperature; (3) thawing temperature; (4) sperm to egg ratio and (5) sugar addition, using sperm motility or fertilization rate as quality assessment indicators. The results demonstrated that 6% dimethyl sulfoxide (DMSO) was the best single CPA for sperm cryopreservation in this species. The highest post‐thaw sperm motility was achieved when sperm were exposed to LN vapour for 10 min at 5.2 cm above the LN surface and thawed at 60°C and recovered at 16°C in seawater baths. Post‐thaw sperm motility was found to be significantly higher when 6% DMSO was used in combination with 1% or 2% glucose than 6% DMSO alone. Further evaluation of fertilization rate between these CPAs showed that 6% DMSO+2% glucose achieved the highest fertilization rate of 70% at a sperm to egg ratio of 10 000:1.