多肽菌素在长牡蛎人工育苗生产中的应用

多肽菌素作为一类具有抗菌活性的生物短肽,是一种可以替代抗生素的生物肽。为了推广多肽菌素在水产养殖中的应用,本研究以长牡蛎(Crassostreagigas)人工育苗为基础,以添加2×10_(–6) mol/L青霉素钠为对照组,以添加5个不同浓度(2×10_(–6)、4×10_(–6)、6×10_(–6)、8×10_(–6)、10×10_(–6) mol/L)多肽菌素为实验组,研究多肽菌素在长牡蛎人工育苗生产中的应用。结果显示:(1)在长牡蛎种贝培育方面,培育前8天各组差异不显著(P 0.05),培育后期添加6×10_(–6) mol/L多肽菌素组存活率均最高,对照组最低,且培育至32天时该实验组均显著高于其他组(P0.05)。(2)在长牡蛎幼虫培育方面,幼虫壳高日增长量在添加6×10_(–6) mol/L多肽菌素组中最大,为11.57μm/d,而对照组仅为9.61μm/d;幼虫存活率方面对照组始终最低,而添加6×10_(–6) mol/L与8×10_(–6) mol/L多肽菌素组均保持较高存活率,显著高于对照组(P 0.05)。(3)在长牡蛎幼虫附着变态方面,添加6×10_(–6) mol/L多肽菌素组附着率最高、附着时间最短,且均与对照组差异显著(P0.05)。(4)在长牡蛎稚贝培育方面,稚贝壳长日增长量实验组均高于对照组,且随添加浓度的上升,日增长量也随之增加;稚贝存活率在添加6×10_(–6) mol/L多肽菌素组达到最高,与对照组差异显著(P0.05)。结果表明,使用多肽菌素与使用青霉素钠相比,多肽菌素显著提高了整个牡蛎培育过程中的存活率、生长速度、及附着变态率,这也为多肽菌素在贝类育苗生产中的推广提供了基础依据。     

海洋酸化、暖化对两种鹿角珊瑚幼虫附着及幼体存活的影响

大气CO₂浓度持续升高导致海洋酸化和暖化影响着造礁石珊瑚和珊瑚礁生态系统。为探明造礁石珊瑚早期生活史对海洋酸化和暖化的生理学响应,本文研究了温度（约28°C, 约30°C）和pCO₂（约570 μatm, 约1 300 μatm）以及两者协同作用对简单鹿角珊瑚（Acropora austera）和中间鹿角珊瑚（A. intermedia）早期生活史的影响。实验结果表明,升温（+约2.5°C）和酸化（约1 300 μatm）对两种鹿角珊瑚幼虫的附着率和死亡率均无显著影响。酸化显著降低了简单鹿角珊瑚幼体存活率（25.87%）,但并不显著影响中间鹿角珊瑚幼体的存活率;升温对两种鹿角珊瑚幼体存活率无显著影响。升温（+约2.5°C）、酸化（约1 300 μatm）对简单、中间鹿角珊瑚幼虫的存活和附着过程的影响较小,但是酸化对简单鹿角珊瑚幼体存活的影响高于暖化。本文结果表明,珊瑚补充过程对海洋酸化和暖化的响应可能具有种类特异性,气候变化将逐渐改变造礁石珊瑚的群落结构。     

Toxic effects of several phthalate esters on the embryos and larvae of abalone Haliotis diversicolor supertexta

As the most widely used plasticizers in the world, phthalate esters (PAEs) are potential endocrine disruption compounds (EDCs). In the present study, the toxicity of dimethyl phthalate (DMP),diethyl phthalate (DEP), dibutyl phthalate (DBP), di (2-ethylhexyl) phthalate (DEHP) on embryogenesis and larvae development of the marine univalve Haliotis diversicolor supertexta was examined in laboratory. The results show that the malformation of embryos appeared during the experiment, such as embryos died or lysed, small transparent flocculent rings studded on the periphery of the embryo, and the larvae could failed to hatch. In embryo toxic test, embryos incubated at the highest concentration of DMP,DEP and DBP solutions showed significantly high abnormal rate compared with the control, while DEHP solutions displayed no significant difference. In larval toxic test, in all concentrations of DMP, DEP and DBP solutions, larval settlement rates were low significantly than that of the control. Similarly, DEHP solutions show nearly no effect on the larval settlement. The order of toxicity on embryos and larvae is DBP>DEP>DMP>DEHP. Being a simple and easy stimulation to indoor spawn, sensitive to environmental factors, and short culture time, the embryos of 1-1. diversicolor supertexta can be used to indicate toxicity of the PAEs.     

关于南珠产业可持续发展的思考

基于南珠产业的特色、优势、现状,针对其目前存在养殖环境恶化,珍珠贝生长慢、病害多、死亡大,珍珠单产低、质量差、品种单一、市场竞争力不强,产业效益下降、发展后劲不足等问题;提出实现南珠产业可持续健康发展的相应对策:进行科学规划,加强容量管理;加速良种选育与新品种开发;加强技术培训,推广规范化养殖;革新加工技术,提升市场竞争力;加大监管力度,规范市场秩序,扶强龙头企业;促进南珠产业向集约化、组织化方向发展。     

Distribution of whitemouth croaker (Micropogonias furnieri, Desmarest 1823) larvae in the Río de la Plata estuarine front

Whitemouth croaker (Micropogonias furnieri) larvae obtained and hydrographic data collected in the Rio de la Plata estuary (35°S–56°W) between 1987 and 2000 were used to explore the early life stages spatial and temporal distribution patterns and their relation to oceanographic features. The spatial distribution, restricted to a band in the inner part of the estuary, coincided with the bottom salinity front and the maximum turbidity zone (MTZ, turbidity front). Larvae were present during the warmest months (October through May) within a range of 14–24.5 °C temperature and 0.9–33 salinity. A vertically stratified sampling performed in the region where the largest abundance was found (December 2005 and March 2006) was used to test the hypothesis that larvae retention occurs in the bottom salinity front.The vertically stratified sampling showed larvae throughout the water column with high predominance in the river–estuary transition zone. A positive correlation between abundance and the bottom salinity horizontal gradient was found. The size analysis showed that the largest individuals (>10 mm SL), probably undergoing the settlement process, inhabited near the bottom and that the smallest (<10 mm SL) were present in the whole water column. Length distribution along the front showed no trend.Results support the estuarine retention hypothesis of previous studies on whitemouth croaker gravid females, eggs distribution and outcomes from a numerical simulation model. Retention in the salinity front/MTZ would allow larvae to benefit from food accumulation in the region, the high turbidity level provide shelter against predators and retention in the estuary secure closeness to the main nursery ground.     

盐度对近江牡蛎幼虫生长及存活的影响

采用室内培育手段,研究了盐度对近江牡蛎(Crassostrea rivularis)幼虫生长及存活的影响。将人工授精孵育的面盘幼虫分别置于盐度依次为16,25,30的砂滤海水中培育至眼点幼虫。每隔一天检测各盐度组幼虫的壳长、壳高和存活数量。结果表明,16盐度组的幼虫生长最快,25盐度组次之,30盐度组最慢。从受精后第14天开始,16盐度组幼虫的生长显著快于30盐度组(P<0.05)。在整个浮游幼虫阶段,高盐度组幼虫的存活率低于低盐度组,其中30盐度组的存活率最低。16和25盐度组在幼虫出现眼点之前均出现大量死亡现象,而30盐度组并没有出现大量死亡现象。上述结果说明,近江牡蛎幼虫经过高盐驯化,对高盐环境的抗性具有一定的提高。     

Larval fish assemblages,environment and circulation in a semienclosed sea (Gulf of California,Mexico)

Fish larvae and hydrographic data collected in the Gulf of California (GC) in December 2002 are used to describe larval fish assemblages (LFAs) and to explore their relationships with environmental variables (temperature, salinity, dissolved oxygen, fluorescence maximum, ?$?$ and superficial chlorophyll a). The Bray–Curtis dissimilarity index defined three LFAs, distributed in areas with distinctly different environmental conditions. The affinity of most of the species with the environmental characteristics of their areas of distribution could be interpreted as an indication that spawning occurred inside those areas. Particle tracking in current fields from a 3D numerical model and connectivity matrices are used to assess larval retention in the LFA areas. The technique is well suited for seas like the GC that have well-defined circulation patterns. On time scales around 30 days, retention (from 56% to 73% of the particles) occurred (1) for the North LFA in the Upper GC, (2) for the Channel-Center LFA in the anticyclone over the Northern GC and in Ballenas Channel, and (3) for the South LFA in the eddy over San Pedro Mártir basin and in the shallow zone off the peninsula. Therefore, the Lagrangian analysis revealed that the observed LFAs have a permanency long enough to allow fish larvae to remain in a favorable environment until they develop motility. The main particle export path (less than 26% of the particles) was from the North to the South LFA, following the anticyclonic main flow and coinciding with the gradient in species number and larval abundance.     

似刺鳊鮈发育过程中同工酶变化及组织分布特征分析

运用高pH不连续聚丙烯酰胺凝胶(PAGE)电泳技术分析了似刺鳊鮈胚胎、仔鱼发育过程中5种同工酶变化,并对成鱼的9种组织同工酶分布特征进行了检测。结果发现:除醇脱氢酶(ADH)外,其他4种酶(EST、LDH、MDH、SOD)在发育过程中均被检出,且呈现明显的阶段性特征;在成鱼的4种同工酶也存在明显的组织特异性。4种酶共检测到9个基因位点。     

湛江市草莓栽培的气象条件分析

根据 1970～ 1990年湛江市气象资料 ,对湛江市草莓栽培有利和不利的气象条件作了分析研究 ,为湛江选育草莓品种、采用适当的栽培技术措施和种植制度提供依据。     

长江口及其邻近水域鱼卵、仔鱼的种项组成与分布特征

鱼卵、仔鱼作为海洋生物的被捕食者、捕食者,不仅种类多,而且数量大,常是研究海洋生态系统重要的组成部分.通过对鱼卵、仔鱼的调查研究,可了解和掌握鱼类产卵场和产卵期,确定中心渔场的位置和寻找产卵鱼群,鱼卵仔鱼尚决定着资源的补充,从而为资源量的估算提供理论基础.