紫红笛鲷血细胞发生研究

将体质量510~620 g的紫红笛鲷用间氨基苯甲酸乙酯甲磺酸盐麻醉后解剖,取出头肾、体肾、肝脏、脾脏,用干净的刀片居中横切、纵切,印片和涂片用Wright-Giemsa染液染色10 min,观察头肾、体肾、脾脏、肝脏4个组织印片以及外周血涂片。试验结果显示,头肾、体肾、脾脏是其造血器官。头肾能发育生成各类型血细胞,体肾能生成红细胞、淋巴细胞、粒细胞和单核细胞,脾脏能生成淋巴细胞。肝脏中未发现幼稚型血细胞。红细胞发育经过原红细胞、早幼红细胞、中幼红细胞、晚幼红细胞和红细胞5个阶段;原粒细胞发育至早幼粒细胞后,分化为嗜碱性中幼粒细胞、嗜酸性中幼粒细胞和中性中幼粒细胞,最后发育成嗜碱性粒细胞、嗜酸性粒细胞和中性粒细胞;淋巴细胞和单核细胞发育经过原始、幼稚和成熟3个阶段。血细胞在发育过程中,胞体逐渐变小,细胞核逐渐变小,染色质由疏松到致密;粒细胞中,颗粒由少到多。     

消化酶活力在千年笛鲷幼鱼不同消化器官中的比较研究

测定和比较了千年笛鲷(Lutjanussebae)幼鱼不同消化器官的消化酶活性。结果表明,蛋白酶比活力为:肠>胃>肝胰脏(P<0·01);淀粉酶比活力为:肠>肝胰脏>胃(P<0·01);脂肪酶比活力为:肠>肝胰脏>胃,胃和肝胰脏间差异不显著(P>0·05),但二者和肠之间差异极显著(P<0·01)。千年笛鲷幼鱼肠道对食物的整体消化能力始终较强,肝胰脏和胃是消化食物的辅助器官。     

红笛鲷和卵形鲳鲹鳃的扫描电镜观察与功能探讨

对两种鲈形目鱼类红笛鲷Lutjanus erythopterus和卵形鲳(鱼参) Trachinotus ovatus的鳃结构进行扫描电镜观察。结果表明,红笛鲷和卵形鲳(鱼参)鳃的表面结构和微细结构与其他硬骨鱼类基本相似,鳃丝表面都具有规则或不规则分布的环形微嵴、沟、坑、孔等结构。红笛鲷的中部鳃丝表面一部分较为平坦,基部鳃丝表面则凹凸不平。红笛鲷的鳃小片高度要较卵形鲳(鱼参)鳃小片高。红笛鲷和卵形鲳(鱼参)鳃上皮的几种细胞的形态结构及数量分布存在细微的差异。红笛鲷鳃上的扁平上皮细胞界限清楚,而卵形鲳(鱼参)鳃上扁平上皮细胞表面遍布不规则的微嵴,细胞界限模糊。红笛鲷鳃丝表面的氯细胞数量多于卵形鲳(鱼参),这可能与两种鱼对生活环境、生活习性的长期演变相关。     

溶藻弧菌鞭毛蛋白flaC基因DNA疫苗对红笛鲷的免疫保护研究

为研究溶藻弧菌鞭毛蛋白flaC基因DNA疫苗对红笛鲷的免疫保护作用,实验构建了重组真核表达质粒pcDNA-flaC并将该质粒肌肉注射红笛鲷,采用PCR、RT-PCR、ELISA和攻毒试验等方法检测了该真核表达质粒在红笛鲷组织内的分布、表达和对红笛鲷的免疫保护.PCR结果显示,免疫接种7和28 d,注射点周围肌肉、鳃、肾脏、肝脏和脾脏都存在质粒分布;RT-PCR结果显示,免疫接种后第7天、14天和28天,红笛鲷不同组织内均有目的基因表达.ELISA结果表明,鱼血清内产生了抗FlaC蛋白的抗体,表明DNA疫苗免疫后鱼体表达了目的蛋白,并诱导产生了相应抗体.攻毒实验表明,免疫后的红笛鲷能较好地抵抗致病性溶藻弧菌的感染.结果表明,质粒pcDNA-flaC可能是抵抗溶藻弧菌感染的有效的疫苗候选物.     

Evidence of Exposure to Spotted Fever Group Rickettsiae among Arizona Dogs Outside a Previously Documented Outbreak Area

Since 2003, two communities in eastern Arizona have experienced a sustained outbreak of Rocky Mountain spotted fever (RMSF), caused by Rickettsia rickettsii, associated with transmission by Rhipicephalus sanguineus, the brown dog tick; 70 human cases, including eight deaths, were reported from these communities during 2003 through 2008. In both of the affected communities, antibodies to spotted fever group rickettsiae (SFGR) were present in dogs before the notice of the first human cases, suggesting that dogs may serve as useful sentinels for human risk of RMSF in this region. During 2005 and 2006, an exploratory serosurvey was conducted among stray and relinquished dogs presenting to animal control facilities in eastern Arizona located outside the area where human cases had been reported. Antibodies to SFGR were detected in 5.7% (14 of 247) dogs assessed outside the RMSF outbreak area. Animal shelters located in counties that either included or shared large borders with the outbreak area were significantly more likely to have seropositive dogs than facilities in more geographically separated counties (P = 0.01). In addition, stray dogs were significantly more likely to be antibody‐positive than relinquished animals (P = 0.01), suggesting that control of stray dog populations should be considered as a means of limiting SFGR transmission in this region. The findings from this study may be extrapolated to suggest that the current risk for human RMSF infection may extend beyond the noted outbreak area. Heightened surveillance for human disease is needed in the region.     

血红栓菌培养特性1）

对血红栓菌生物学特性、驯化栽培和液体深层发酵培养进行了研究。通过单因子和正交试验的方法,得出血红栓菌固体基质上最佳培养条件：温度35℃、初始pH值5、以蔗糖为碳源,以酵母粉为氮源,并驯化栽培出了子实体;优化后血红栓菌摇瓶发酵条件：最优培养基为54．46 g/L蔗糖,9．64 g/L酵母粉,4．40 g/L磷酸二氢钾;最优培养条件为温度20℃,500 mL三角瓶装液量200 mL,初始pH值为5,摇床转速180 r/min,接种量10％,培养11 d,达到最大产量（24．18 g/L）。发酵罐培养以54．46 g/L蔗糖,9．64 g/L酵母粉,4．40 g/L磷酸二氢钾为培养基,初始pH值为5,装液量为10 L罐体装6 L,在温度20℃,搅拌速度380 r/min,10％接种量的培养条件下,培养132 h达到最大值16．8 g/L。     

Distribution and feeding habits of juvenile and young John's snapper Lutjanus johnii in the Matang mangrove estuary, west coast of Peninsular Malaysia

ABSTRACT:   The aim of the present paper was to provide some information on the distribution pattern and feeding habits of juvenile and young Lutjanus johnii in the Matang mangrove estuary on the west coast of Peninsular Malaysia. Sampling was carried out at five sites using otter trawl nets from October 1998 to January 2000. Ninety-three individuals of juvenile and young L. johnii were collected during the research period. The range in total length varied from 3.4 to 21.1 cm, and the gonads of all fish were at the immature stage. Fish were caught at the river mouth and neighboring sites in Matang at a water depth of 1.6–7.5 m, salinity of 12.4–28.3, and temperature of 27.3–31.6°C. Individuals fed mainly on Natantia and Mysidacea, although the type of food varied with size. Large-sized individuals fed mainly on Natantia, and small-sized individuals on Mysidacea.     

Stock assessment on fishery-dependent data: Effect of data quality and parametrisation for a red snapper fishery

Data availability, and unreported and unregulated fishing are significant obstacles to evaluating stock status, especially in tropical areas. Limitations in data quantity and quality can lead to model misspecification and erroneous data treatments, potentially causing important changes in model outputs and subsequent management implications. Red snapper Lutjanus purpureus (Poey) in French Guiana provides an example of a stock with a long-time series of fishery-dependent data subject to large uncertainty. A flexible catch-at-age model (Stock Synthesis) was applied to the available data and compared to an historically applied assessment approach. Inter-model variability based on different model specifications and data treatments were compared to identify better the status of the resource. Results showed that a major source of uncertainty in the model was the inclusion of a catch-per-unit-effort abundance index with questionable ability to track abundance. The Stock Synthesis model provided a more flexible and viable method than the virtual population analysis approach. Despite large uncertainty, models depicted a similar trend with a notable stock depletion in the late 1990s but with two distinct biomass trends in more recent years depending on the treatment. To reduce uncertainty and preserve this important economic resource, new data collection programmes and management policies are needed.     

What are the consequences of infection by the introduced parasite Philometroides sanguineus for threatened crucian carp Carassius carassius populations in England?

Abstract – Nonnative parasites have the potential to detrimentally affect naïve hosts, resulting in negative consequences for their growth, condition and energetics. Here, the effect of the introduced parasitic nematode Philometroides sanguineus on crucian carp Carassius carassius populations in England was investigated. Populations of C. carassius populations are increasingly spatially restricted in England and under increasing threat from habitat loss and hybridisation. Parasite prevalence across 6 infected populations was <27% and, generally, there was no significant relationship between levels of infection and fish length and age. Parasite abundance ranged between 1 and 8 nematodes and was not significantly related to fish length and age. Comparison of the growth, body weight and condition, and energy reserves between infected and noninfected C. carassius revealed infection did not incur significant detrimental impacts on these parameters. Whilst this suggests that infection had only minimal impacts on the examined host fish, this may have been a consequence of a low proportion of fish <100 mm in samples (i.e., size‐selective effects) and some tests did suffer from low statistical power because of, for example, unbalanced sample sizes. It does, however, suggest that P. sanguineus may not be a major threat to the status of these C. carassius populations and infection by introduced parasites may not always incur significant impacts in naïve fishes.