Microbial community of Pacific abalone (Haliotis discus hannai) juveniles during a disease outbreak in South China

A mass mortality of farmed juvenile abalones (Haliotis discus hannai) occurred in South China in December of 2012. Combined traditional culturing with terminal restriction fragment length polymorphism (T‐RFLP) methods, microbial communities associated with juvenile abalones were investigated under different survival conditions, including healthy (HA) and moribund (HM) abalones in the healthy pond with low mortalities, and healthy (DA) and moribund (DM) abalones in the diseased pond with a high mortality rate. The results indicated that both HA and DM exhibited greater microbial diversity and evenness. Moreover, the number of bacterial colony forming units (CFUs) from HA and DM were higher than other samples from the same pond. HA and DA samples harboured absolutely dominant T‐RFs with 504 bp (76.2% of total T‐RFs) and 436 bp (63.2%) respectively. Nesterenkonia sandarakina, Staphylococcus haemolyticus and Agarivorans albus were the dominate isolates in HA samples, but no Vibrio genus was isolated even on vibrio‐specific medium. Reversely, in the DM samples, up to 94% of the total bacterial CFUs were composed of the family Vibrionaceae, represented by Photobacterium swingsii (44%) and Vibrio shilonii (45%). Also, Vibrio was the only cultivated genus from the HM group. Of these Vibrio species, V. atlanticus were detected in HM, DA and DM samples and could generate the T‐RF 504 bp. The microbial composition and diversity of juvenile abalones in different surviving states provided insights into the stability and dynamics of microbial communities during disease outbreak which could be helpful to predict and to control disease in the future.     

Effects of diets on the growth performance and shell pigmentation of Pacific abalone

This study investigated the effects of natural and artificial diets on growth performance and shell pigmentation of cultured abalone. A 7‐month feeding trial was conducted on 12 000 Pacific abalones (Haliotis discus hannai) with four diets including two extruder‐processed test diets (with & without addition of oleopaprika carotenoids), Pacific dulse (Palmaria mollis) and a combination of Pacific dulse and a test diet. The results showed that the two test diets resulted in higher survival of abalone, but with a lower growth rates when compared with Pacific dulse alone (P < 0.05). The combination diet achieved the highest survival and growth rates. The Pacific dulse resulted in abalone with dark‐brown shells, which are preferred by Asian markets. The test diets led to 52% and 55% of the animals with pink coloured shells and the supplementation of oleopaprika did not affect shell pigmentation. The aqueous acidic extracts from both dark‐brown and pink shells showed blue colour; HPLC‐MS chromatography revealed that the pigments in the extracts were consistent with a biliverdin and a cysteine‐biliverdin. These results are valuable for the development of abalone feed and the control of abalone shell colouration.     

Field and laboratory pilot rearing experiments with early ontogenic stages of Concholepas concholepas (Gastropoda: Muricidae)

The carnivorous gastropod Concholepas concholepas, known in Chile as “loco”, is a species present only along the Chilean coast line and in central-southern Perú showing high economic and ecological importance. Its fishery, which in the past decades has ranged between 828 (2001) and 24,828 (1980) metric tons per year [SERNAP, 2005. Servicio Nacional de Pesca: Anuarios estadísticos. (http://www.sernap.cl/paginas/publicaciones/anuarios/index_anuario.php)], is based exclusively on the exploitation of wild stocks. So far, there has been limited interest in tackling the biological and technical feasibility of cultivation of C. concholepas. Hence, the knowledge about its early ontogenetic stages (i.e., larval, early postmetamorphic and small juvenile) cultivation is still deficient. In this study we investigated, under laboratory and field conditions, C. concholepas survivorship, growth rates, feeding rates and the onset of sexual reproduction. Competent loco's larvae were collected in the field and metamorphosed in the laboratory to assess growth rates and survivorship during the first six months of postmetamorphic life. Moreover, using small juvenile C. concholepas of ca. 20 mm of peristomal length, collected in the field, we monitored for the body size and live weight traits in laboratory and field rearing conditions. The feeding of the early postmetamorphics and small juveniles was exclusively based in mono diets of the mussel Semimytilus algosus. The rearing of small juveniles was conducted in two consecutive phases, using two specially designed rearing apparatus. The biochemical content of our laboratory cultivated specimens was compared with values obtained from specimens collected in natural habitats. Their rapid growth and good survivorship makes this species suitable for rearing of cocktail-size specimens (50–60 mm) in less than a year. According to the growing rates reported in this study the legal commercial size of C. concholepas: 100 mm of PL would be reached under field and laboratory conditions in 1.65 and 2.64 years respectively. Moreover, it was found that in our rearing conditions C. concholepas reach sexual maturity in less than a year of benthic life. In summary, considering the findings about C. concholepas high growth rates, and low mortalities, we suggest that our rearing methodologies may be scaled up and implemented for the commercial aquaculture of this unique and valuable muricid.     

福建大连1号杂交鲍肠道及养殖水体中细菌产酶能力的分析

从大连1号杂交鲍养殖水体及肠道中分离出18株弧菌和32株异养型细菌,对其进行革兰氏染色及产胞外酶能力的分析。结果表明,养殖水体中分离出的14株弧菌和22株异养细菌,共有22株(61.1%)具有分泌脂肪酶、卵磷脂酶、明胶酶、蛋白酶、淀粉酶或溶血毒素的能力;鲍肠道分离出的4株弧菌和10株异养细菌,共有9株(64.3%)具有此产酶能力。但总体上,从水体中分离出的菌株的产酶能力要强于从鲍肠道中分离出的菌株,且数量更多,尤其是水体中异养细菌。在所有的50株菌株中,有2株(4%)具有产3种酶(脂肪酶、卵磷脂酶和溶血素)的能力;有9(18%)株具有产2种酶的能力。产酶菌株大部分为革兰氏阴性。本次试验对鲍肠道及养殖水体中菌株产酶能力进行了分析,为大连1号杂交鲍在南方的健康养殖提供科学依据。     

九孔鲍育苗池附着基上底栖微藻群落及其多样性

2006年9月14至10月26日对福建省漳浦县下蔡九孔鲍(Haliotis diversicolor supertexta)育苗池进行定点采样。检测结果共鉴定底栖微藻24属62种,其中硅藻21属59种,绿藻、蓝藻和褐藻各1种。附着基上底栖微藻的优势种有12种,全部为硅藻,如盾卵形藻微小变种(Cocconeis scutellum var.parva)、小形舟形藻(Navicula parva)、咖啡双眉藻(Amphora coffeaeformis)、琴式菱形藻(Nitzschia panduriformis)等。优势种的优势度突出。常见种有25种,少见种有27种。优势种和常见种多是能够适应底栖环境的种类。附着基上底栖微藻种类及多样性指数育苗早期波动大,后期逐渐稳定,底栖微藻多样性指数平均为0.980～1.959,结果表明,底栖微藻群落结构的演变与鲍幼体摄食活动有很大的相关性。     

孔石莼对养鲍污水的静态净化研究

鱼类代谢产物是养殖水体的主要污染源,但同时也是能被水生植物利用的高能、优质的营养物质（Ｎ和Ｐ）。该文研究了孔石莼对养鲍污水的静态净化过程,分析了孔石莼滤池中水质的变化规律。结果表明,孔石莼能同时吸收水中的三氮和磷酸盐,尤其对氨氮有极强的吸收作用,但对有机物的去除不明显。建立了静态条件下对氨氮的净化模型。用孔石莼净化养殖污水具有净水、节能和收获饵料的综合效果。     

皱纹盘鲍酶促溶性胶原蛋白的性质研究及抗体制备

针对加工副产物鲍鱼外套膜利用率低的现象,对鲍鱼腹足和外套膜胶原蛋白相关性质进行比较研究,以期为鲍鱼的综合加工提供一定的理论依据。本研究以皱纹盘鲍为原料分别提取得到腹足酶促溶性胶原蛋白(pepsin-soluble collagen of abalone adductor,PSC1)和外套膜酶促溶性胶原蛋白(pepsin-soluble collagen of abalone mantle,PSC2),对PSC1和PSC2相关特性进行比较分析,并利用PSC1制备得到兔抗鲍鱼胶原蛋白多克隆抗体。SDS-PAGE显示,PSC1和PSC2分子组成均为(α1)3,且α1的分子量为140 ku,与水产无脊椎动物Ⅰ型胶原蛋白特征相似。对PSC1进行肽指纹图谱分析,获得6个肽段、含75个氨基酸残基,与盘鲍螺的胶原蛋白前肽α链和欧洲鲍螺的纤维状胶原一致性分别达100%和88%,证明纯化的PSC1为胶原蛋白。氨基酸组成分析表明,PSC1和PSC2的组成基本一致,但脯氨酸和羟脯氨酸含量均低于牛酸溶性胶原蛋白。圆二色谱分析结果显示,PSC1和PSC2溶液均在220和197 nm分别有一正、负峰,具有典型胶原蛋白三股螺旋结构特征。FTIR光谱分析结果提示PSC1和PSC2具有相似的三螺旋结构。利用兔抗皱纹盘鲍PSC1多克隆抗体对皱纹盘鲍、尼罗罗非鱼、鲤和仿刺参胶原蛋白进行免疫印迹分析发现,该抗体只与皱纹盘鲍PSC1和PSC2的α、β和γ链产生反应,表明该抗体具有良好的特异性。     

鲍科染色体研究进展

正鲍科动物简称鲍或鲍鱼,隶属于软体动物门、原始腹足目,是重要的海生单壳经济贝类。鲍现存56种,除北冰洋外,世界大部分海域都有分布,目前能够进行规模化捕捞和养殖的种类有20余种。随着鲍养殖业的兴起和快速发展,对鲍的各项研究也逐渐开展,主要涉及遗传育种、养殖技术、生态、分子和细胞学方面的研究[1-8]。细胞遗传学是遗传育种研究的基础,其中染色体研究是细胞遗传     

刺参南方度夏试验

选择刺参南方池塘养殖收获时的小规格个体,采用鲍鱼养殖池流水度夏,时间超过6个月。2年刺参度夏存活率分别为70.6%和89.1%;失重率为56.1%和61.8%。度夏后刺参再养殖约150天,成活率分别为94.9%和81.1%;增长率为10.5倍和13.6倍。