褐点石斑鱼的核型研究

采用胸腔活体注射PHA和秋水仙素溶液,取头肾细胞,低渗处理,空气干燥法制片,对染色体进行G iem sa染色来研究褐点石斑鱼的核型。试验结果表明,禢点石斑鱼的核型为2n=48,2 sm 46 t,NF=50;其核型特点符合典型的高位类群鱼类核型特征。     

点带石斑鱼与褐点石斑鱼4种同工酶的比较研究

采用聚丙烯酰胺凝胶垂直梯度凝胶电泳法,对点带石斑鱼与褐点石斑鱼7种组织中的4种同工酶(EST、LDH、MDH、SOD)的组织特异性进行比较研究。试验结果表明:2种石斑鱼的4种同工酶均具有明显的组织特异性。2种石斑鱼同一组织间MDH酶谱没有差别;LDH酶谱相似,只在迁移率上略有差异;EST、SOD酶谱间存在不同程度的种间差异,可作为鉴定点带石斑鱼与褐点石斑鱼的遗传标记。     

棕点石斑鱼的肌肉营养成分分析

试验结果表明,棕点石斑鱼的含肉率为77.3%,肌肉中粗蛋白、粗脂肪、粗灰分和水分的含量分别为18.8%、2.2%、1.16%和77.1%;18种氨基酸总量为18.22%(占鲜样),其中人体必需的8种氨基酸含量为6.88%,占氨基酸总量的37.36%,4种鲜味氨基酸含量为7.11%.其氨基酸构成比例符合FAO/WHO标准.必需氨基酸指数(EAAI)为514.DHA和EPA含量丰富,占脂肪酸总量的28.2%.     

Immunostimulating influence of herbal biomedicines on nonspecific immunity in Grouper Epinephelus tauvina juvenile against Vibrio harveyi infection

Herbals such as Cynodon dactylon, Piper longum, Phyllanthus niruri, Tridax procumbens, and Zingiber officinalis were extracted with acetone, benzene, butanol, and petroleum ether and screened against the pathogen Vibrio harveyi isolated from the infected Grouper Epinephalus tauvina. Among the different solvent extractions screening to V. harveyi, petroleum ether extracts were suppressed significantly (P < 0.05). Equal proportions of the all-plant extracts were mixed with the artificial feeds at concentrations of 100, 200, 400, and 800 mg kg⁻¹ of diet and fed to grouper juveniles of 20 ± 2 g average weight for a period of 60 days. Every 20 days, fish juveniles were challenged with V. harveyi and the immune response was studied. The herbal diets significantly (P < 0.05) increased the survival, growth, and immune responses compared to the control group. The herbal diets were significantly improved (P < 0.01) in immune parameters such as phagocytic activity and albumin–globulin (A–G) ratio. Among the different concentrations of the herbals in the diet, the 400 mg kg⁻¹ diet was the most effective in the experiment.     

Investigation of outbreaks of a novel disease, 'Sleepy Grouper Disease', affecting the brown-spotted grouper, Epinephelus tauvina Forskal

Abstract. A novel disease affecting the brown-spotted grouper, Epinephelus tauvina Forskal, described here as Sleepy Grouper Disease¹ (SGD), resulted in significant economic losses in some Singaporean marine net-cage farms from April to August 1992. Investigations suggested that the aetiological agent was a virus, probably introduced with imported groupers. The virus was provisionally identified as an iridovirus on morphological evidence. The disease caused extreme lethargy in affected fish with few visible external signs. Mortalities either occurred gradually over the week from onset of clinical signs, or over a shorter period and in large numbers if fish were stressed. Consistent tissue changes were seen by light microscopy in the spleen, heart and kidney of affected fish. Electron microscopy showed viral particles associated with damage to cell organelles. In an experimental infection, apparently healthy fish cohabiting with an infected fish developed similar lesions and died. The significance of SGD in grouper culture is discussed.     

斜带石斑鱼溶藻弧菌病的研究

从患病的斜带石斑鱼肝和肾组织分离的两株病原菌,进行纯化培养、人工感染、VITEK-AMS-32自动微生物分析鉴定及药敏试验,经形态和生理生化测定,确定为溶藻弧菌(Vibrioalginolyticus)。组织病理变化主要表现为鳃、肝和肾细胞变性、坏死,病变组织炎性细胞浸润,呈变质性炎症。     

Salinity and temperature tolerance of brown-marbled grouper Epinephelus fuscoguttatus

Grouper have to face varied environmental stressors as a result of drastic changes to water conditions during the storm season. We aimed to test the response of brown-marbled grouper to drastic and gradual changes in temperature and salinity to understand the grouper’s basic stress response. The results can improve the culture of grouper. Brown-marbled grouper, Epinephelus fuscoguttatus (6.2 ± 0.8 g) were examined for temperature and salinity tolerances at nine different environmental regimes (10, 20, and 33 ‰ combined with 20, 26 and 32 °C), in which the fish were subjected to both gradual and sudden changes in temperature and salinity. The critical thermal maximum (50 % CT_MAX) and the upper incipient lethal temperature (UILT) were in the ranges of 35.9–38.3 and 32.7–36.5 °C, respectively. The critical thermal minimum (50 % CT_MIN) and the lower incipient lethal temperature (LILT) were in the ranges of 9.8–12.2 and 14.9–22.3 °C, respectively. The critical salinity maximum (50 % CS_MAX) and the upper incipient lethal salinity (UILS) were in the ranges of 67.0–75.5 and 54.2–64.8 ‰, respectively. Fish at temperature of 20 °C and a salinity of 33 ‰ tolerated temperatures as low as 10 °C when the temperature was gradually decreased. Fish acclimated at salinities of 10–33 ‰ and a temperature of 32 °C tolerated salinities of as high as 75–79 ‰. All fish survived from accumulating salinity after acute transfer to 20, 10, 5, and 3 ‰. But all fish died while transferred to 0 ‰. Relationships among the UILT, LILT, 50 % CT_MAX, 50 % CT_MIN, UILS, 50 % CS_MAX, salinity, and temperature were examined. The grouper’s temperature and salinity tolerance elevated by increasing acclimation temperature and salinity. On the contrary, the grouper’s temperature and salinity tolerance degraded by decreasing acclimation temperature and salinity. The tolerance of temperature and salinity on grouper in gradual changes were higher than in drastic changes.     

六带石斑鱼染色体核型和银染研究

以六带石斑鱼为材料,利用腹腔注射法体内注射植物血球凝集素和秋水仙碱获得大量处于分裂中期的头肾细胞,头肾细胞经低渗处理、卡诺氏液固定后,常规自然晾干法制作成染色体标本后,进行染色体核型分析和银染研究。结果显示,六带石斑鱼的二倍体染色体数目为2n=48,核型为2n=2st+46t,NF=48;Ag-NORs仅有一对位于第24对染色体即亚端部着丝点染色体的短臂上。     

Preliminary Studies on Stocking Density and Production of Hamoor Epinephelus tauvina in PVC-Lined Raceways

The results of two stocking density trials on the nursery and grow-out stages of Epinephelus tauvina (Family: Serranidae), in PVC-lined raceways are presented.
At the nursery stage, fry of 17.1 g initial mean weight showed no significant differences in growth rate, survival rate and condition factor when stocked at densities of 200 and 400 fish/m³ over a period of 52 days. Fish grew to mean weights of 61.7 and 63.7 g, giving growth rates of 0.86 and 0.90 g/fish/day and final biomasses of 12.1 and 2S.2 kg/m³ for densities of 200 and 400 fish/m³, respectively. Survival rates were excellent for both treatments at 98percnt; or greater. Food conversion efficiency was slightly improved at the higher density.
At the grow-out stage, E. tauvina of mean weights ranging from 150-170 g cultured for a period of 215 days grew better at a density of 5 fish/m³ than at densities of 20 and 60 fish/m³ (final size: 770, 560 and 450 g with growth rates of 2.8, 1.8 and 1.4 g/fish/day, respectively). Survival rates were higher at the two lower densities. Overall, total biomass increased with stocking density (3.9, 11.1 and 23.4 kg/m³, for 5, 20 and 60 fish/m³, respectively). These results indicate that hamoor has potential to be successfully cultured in raceways.     

Preliminary observations of chilled and deep-frozen storage of grouper (Epinephelus tauvina) sperm

Trials of chilled (5–10° C) and cryogenic storage of grouper sperm revealed that sperm suspended in two different solutions containing 10% dimethyl sulfoxide (DMSO) were active after 2 days of chilled and deep-frozen storage, whereas those suspended in the same solutions containing 10% glycerol were not. Sperm suspended in the 10% DMSO sulutions were more active after chilled storage than were those in undiluted milt under the same conditions.     

Dietary manganese requirement of juvenile hybrid grouper,Epinephelus lanceolatus × E. fuscoguttatus

An 8‐week feeding trial was conducted to estimate the optimum dietary manganese (Mn) requirement for juvenile hybrid grouper, Epinephelus lanceolatus × E. fuscoguttatus. The basal diet was formulated to contain 520 g/kg crude protein from casein and fishmeal. Manganese methionine was added to the basal diet at 0 (control group), 2.5, 5, 10, 20 and 40 mg Mn/kg diet providing 7.48, 10.34, 13.76, 19.72, 31.00 and 53.91 mg Mn/kg diet, respectively. Each diet was randomly fed to triplicate groups of juveniles, and each tank was stocked with 20 fish (initial weight, 60.06 ± 0.68 g). The manganese content in rearing water was monitored and kept below 0.01 mg/L. Results showed that the weight gain ratio (WGR), protein efficiency ratio (PER), specific growth rate (SGR), Mn contents in whole body, liver and vertebra, and activities of hepatic Mn superoxide dismutase (Mn‐SOD), total SOD (T‐SOD) and glutathione peroxidase (GSH‐PX) were significantly improved by dietary Mn supplementation (p < .05). However, dietary Mn did not affect arginase (DArg) activity. The highest feed conversion ratio (FCR) was observed in fish fed the basal diet (p < .05). No significant differences were found on the Cu and Zn contents in whole body by supplementing dietary Mn. Supplemented Mn in diets had significantly effect on liver and vertebral trace element deposition (p < .05). Fish fed the basal diet had the highest Fe and Zn contents in vertebra (p < .05). There were no significant differences on hepatic pyruvate decarboxylase (PDC) activity with supplemented Mn levels below 13.76 mg/kg. As biomarker of oxidative stress, malondialdehyde (MDA) content in liver was significantly higher in fish fed the basal diet (p < .05). Using the broken‐line models based on SGR, dietary Mn requirement of the juvenile hybrid grouper was estimated to be 12.70 mg/kg diet.     

Isolation,molecular characterization and antimicrobial susceptibility of Aeromonas spp. obtained from Tiger Grouper (Epinephelus fuscoguttatus) and Marble Goby (Oxyeleotris marmoratus) fish in Sabah,Malaysia

Aeromonads are ubiquitous in aquatic environments and have been implicated in fish and human infections. In this study, we isolated, studied antimicrobial susceptibility patterns and screened the existence of 15 virulence genes in aeromonads from two famously consumed fish species—seven marine Tiger Grouper (Epinephelus fuscoguttatus) and eight freshwater Marble Goby (Oxyeleotris marmoratus) from the aquaculture hatchery in Sabah, Malaysia. A total of 30 aeromonads (17 A. caviae, 9 A. rivuli, 4 A. dhakensis) were identified using PCR targeting GCAT gene, rpoD‐restriction fragment length polymorphism and multi‐locus phylogenetic analysis. All 30 strains were resistant to amoxicillin and cephalothin and five strains were multidrug‐resistant. Nine virulence genes (lip, ela, eno, fla, aerA, hylA, dam, alt and ser) present in A. dhakensis, suggesting the virulence potential of this species as a fish pathogen. This study offers as a baseline for future studies in monitoring and managing these two fish in aquaculture industry.     

九种药物对斜带石斑鱼受精卵孵化率的影响

以斜带石斑鱼受精卵为试验对象,采用药物浸泡方法,研究了盐酸吗啉胍、利巴韦林、阿昔洛韦、二溴海因、溴氯海因、三氯异氰尿酸、10%的聚维酮碘、37%的甲醛、次氯酸钠等9种药物对斜带石斑鱼受精卵孵化率的影响。试验数据通过SPSS Inc软件进行了单因素方差分析及线性回归分析,研究结果表明,抗病毒药物盐酸吗啉胍、利巴韦林、阿昔洛韦对斜带石斑鱼受精卵孵化影响无差别,三者药物浓度与孵化率无线性相关;6种常用化学消毒剂毒性依次为二溴海因次氯酸钠三氯异氰尿酸溴氯海因甲醛聚维酮碘,石斑鱼受精卵孵化率随着6种常用化学消毒剂质量浓度增加而下降,且药物质量浓度与孵化率呈线性负相关。根据试验结果,建议斜带石斑鱼育苗生产上药物消毒受精卵:盐酸吗啉胍、利巴韦林、阿昔洛韦生产上用药质量浓度为1～3mg/L,10%的聚维酮碘生产上用药质量浓度为20～100mg/L,37%的甲醛生产上用药质量浓度为20mg/L,二溴海因、溴氯海因、三氯异氰尿酸、次氯酸钠生产上慎用。     

鱼源芽孢杆菌在石斑鱼稚鱼育苗中的应用研究

利用芽孢杆菌SE5和DE5单独及联合强化桡足类,研究SE5和DE5对斜带石斑鱼稚鱼生长、存活率、水质及水体和稚鱼体内细菌总数和弧菌数量的影响。试验结果表明,饲养14d时,SE5组和DE5组体长显著高于对照组,混合组体长和体质量显著高于对照组。饲养28d时,SE5组和DE5组体长和体质量均高于对照组,混合组体长和体质量显著高于对照组。饲养28d时,SE5组和DE5组存活率显著高于对照组。14d时SE5组和混合组水体NH3-N显著低于对照组,28d时各组NH3-N均低于对照组。14d时,混合组水体NO2-N显著高于对照组,28d时各试验组NO2-N均显著高于对照组。试验结束时(28d),各试验组水体细菌总数均高于对照组,SE5组和DE5组水体弧菌数量高于对照组;DE5组和混合组活饵细菌总数高于对照组,各试验组活饵弧菌数量高于对照组,其中混合组显著高于对照组;各试验组稚鱼体内细菌总数高于对照组,其中DE5组显著高于对照组。DE5组稚鱼体内弧菌数量显著高于对照组,SE5组高于对照组。     

Natural spawning,embryonic and larval development of F2 hybrid grouper,tiger grouper Epinephelus fuscoguttatus × giant grouper E. lanceolatus

This study aims to reveal the first report of the natural spawning of F1 hybrid grouper (TGGG), a crossbreed between the tiger grouper, Epinephelus fuscoguttatus × giant grouper, E. lanceolatus, since its first production in 2006. This marks the completion of its full cycle after a 10-year period. In order to establish a seed rearing protocol for a novel F2 hybrid TGGG, natural spawning, embryonic and larval developments were thoroughly observed. Five batches of natural spawning were recorded with an average of 1.50–15.3 kg eggs collected, while fertilization and hatching rates were recorded at 85.3–97.6%, and 63.0–98.3%, respectively. F2 larvae hatched out at 17:50 hours with an average body size of 1.74 ± 0.01 mm, and a yolk sac volume of 0.85 ± 0.197 mm3. The first feeding was initiated 3 days after hatching, which coincided with the onset of functional feeding apparatus and active swimming behavior. Larval dorsal and pelvic spines were formed at 6 days AH coupled with dynamic feeding activity, as more food was found in the digestive tract. Meanwhile, the F2 hybrid grouper shifted habitat from pelagic to benthic as early as 25 days AH, and entered a juvenile stage at 35 days AH, attaining a skin coloration similar to that of the F1 juvenile. This study concluded that naturally spawned eggs of F2 hybrid TGGG were exceptionally high in quality, although larvae were small and fragile, and performed vigorous feeding activities and cannibalistic behavior. Thus, these findings can serve as primary data to further develop the optimal rearing protocol to enhance the overall rearing performance.     

棕点石斑鱼Piscidin样肽基因的克隆及其成熟肽的原核表达

以简并引物通过RT-PCR从重要经济海水鱼类棕点石斑鱼Epinephelus fuscoguttatus白细胞中扩增出一条388bp具有完整编码框的cDNA序列。Blast分析初步显示,该序列属于鱼类抗菌肽Piscidin家族的一员,将其命名为棕点石斑鱼Piscidin样肽(GU592793),推导氨基酸序列具有界定鱼类Piscidin的以下共同特征:(1)预测的信号肽序列与其他Piscidin的同源性较高,在60%~95%之间;(2)推测的成熟肽N端6个氨基酸残基富含Phe、Ile及His;(3)成熟肽第8个和第13个氨基酸位点均为Gly。NJ进化树分析表明,该cDNA推导的氨基酸序列与赤点石斑鱼Epinephelusakaarapiscidin-like peptide(ACE78290)、斜带石斑鱼Epinephelus coioidesPiscidin-like peptide(ACE78291)以高达81%的支持率聚为一支。也表明本研究成功克隆到棕点石斑鱼首条PiscidincDNA序列。推测的成熟肽为两亲性阳离子肽,等电点12.48,Schiffer-Edmunson预测其二级结构呈α螺旋构型。将...     

青石斑鱼人工繁育技术研究

平均体重为1.8kg的5－6龄育石斑鱼亲鱼，经强化培育，雄性亲鱼的促熟培育，性腺促熟，人工催产等措施，获受精卵320万粒，受精卵的卵化时间为26h，卵化率为80．7％，仔稚鱼的饵料系列为：牡蛎受精卵或担轮幼虫，轮虫，卤虫，桡足类；经41d培育，育出平均全长为3.79cm的幼鱼19万尾，培育成活率为7．3％，通过试验取得了一套可行的青石斑鱼人工繁育技术。     

闽南地区养殖石斑鱼病毒性神经坏死病初步研究

应用流行病学调查方法。对发生在福建南部海区网箱养殖石斑鱼的暴发性传染病进行了初步研究。应用PCR和RT-PCR技术。检测石斑鱼常见的病毒性神经坏死病病毒、真鲷虹彩病毒，结果各发病渔场均检出病毒性神经坏死病病毒；病原菌分离未发现强致病性细菌；寄生虫检查发现腹腔普遍有一种微孢子虫感染形成的孢囊。临床症状主要表现为游动失常、厌食、鳔肿大、肾脏坏死、糜烂。表明病毒性神经坏死病病毒感染是导致石斑鱼大批死亡的主要原因。