漠斑牙鲆淡化养殖中的疾病及其防治

2004年，笔者从事漠斑牙鲆淡化技术研究和漠斑牙鲆微咸水养殖技术研究(养殖水体盐度2‰～3‰)，对漠斑牙鲆在工厂化养殖中发生的疾病及其防治措施进行了初步研究，现总结如下：     

淡水闭合循环养殖条件下养殖密度和个体大小对漠斑牙鲆(Paralichthys lethostigma)幼鱼生长的影响

以新疆伊犁河生态渔业中心漠斑牙鲆循环水养殖系统为实验平台，在生产规模上研究了闭合循环淡水养殖条件下养殖密度和个体大小对漠斑牙鲆幼鱼生长的影响。结果表明：漠斑牙鲆池底覆盖率低于34％时，养殖密度对漠斑牙鲆生长的影响不显著（P〉0．05）；养殖密度对个体大小的分化具有显著影响（P〈0．05），加强养殖管理可以降低该影响；漠斑牙鲆全长120mm时，性别分化基本完成，雄鱼规格和生长速度明显低于雌鱼。     

漠斑牙鲆人工育苗过程中的生物饵料问题

<正>漠斑牙鲆(Paralichthys lethost igma),又称美国漠斑牙鲆、南方鲆、太平洋漠斑牙鲆,隶属鲽形目、鲆科、牙鲆亚科、牙鲆属。漠斑牙鲆属底栖鱼类,主要分布在美国的大西洋沿海地区和墨西哥湾。漠斑牙鲆肉质细嫩鲜美,具有生长速度快,抗逆性强,广温、广盐等优良生物学特性,适合于池塘养殖、网箱养殖和工厂化养殖等多种养殖方式,在肉质和生长速度及对环境的适应性等方面均优于褐牙鲆,被公认为是一种优良的养殖品种。     

“漠斑牙鲆子二代苗种繁育与养殖技术研究”通过鉴定

日前，由莱州市大华水产有限公司进行的“漠斑牙鲆子二代苗种繁育与养殖技术研究”通过了省科技厅组织的专家鉴定。该公司在2002年以来进行漠斑牙鲆引进与苗种规模化生产研究和漠斑牙鲆养殖研究的基础上，于2004年以来开展漠斑牙鲆子二代苗种繁育与养殖技术研究，通过4年多的试验研究和生产实践，建立了漠斑牙鲆子二代苗种人工繁育、养殖工艺技术和养殖模式，实现了亲鱼自然产卵，验证了漠斑牙鲆适合于池塘养殖、工厂化养殖和网箱养殖。共培育出性状优良的漠斑牙鲆子一代亲鱼200尾，繁育子二代苗种94．3万尾，延续了子一代鱼的优良性状。试验养殖，池塘养殖成活率达到90％，每667m^2产量达到276．8kg；工厂化养殖成活率达到95％，单产达到每平方米11．7kg；网箱养殖成活率达到86．9％，单产达到每平方米10．4kg。养殖效益显著。     

漠斑牙鲆苗种培育过程中几个关键问题初探

2006年课题组承担了福建省科技厅下达的漠斑牙鲆人工育苗和土池健康养殖技术和厦门市科技局下达的美国漠斑牙鲆工厂化育苗技术研究课题,并相继开展了漠斑牙鲆人工育苗和早期生物学等相关研究,初步建立了一套适于漠斑牙鲆育苗的生产工艺,为开展漠斑牙鲆大规模工厂化苗种生产提供了依据。     

我国漠斑牙鲆养殖研究现状及展望

漠斑牙鲆Paralichthys lethostigma是一种广温广盐的海水鱼,可以在淡水中进行养殖。文章综述了我国自2001年引进漠斑牙鲆以来的研究现状,对比了国内外的研究方向,对漠斑牙鲆的广温广盐特性进行重点阐述,指出今后推广养殖过程中需要注意的问题,提出了一些参考建议,并对其在我国的养殖前景进行了展望。     

漠斑牙鲆内陆淡水池塘网箱养殖试验

通过内陆淡水池塘网箱养殖漠斑牙鲆试验,探索出内陆淡水池塘漠斑牙鲆网箱养殖的模式,总结出养殖过程中应采取的技术措施,25m2网箱总产漠斑牙鲆102.9kg,平均单产4.12kg/m2,漠斑牙鲆平均规格为306.25g/尾,成活率达84%,使池塘产量比往年养殖产量增加5.94%。     

池塘网箱漠斑牙鲆套养项目通过专家鉴定

近日,由河口区海洋与渔业局承担的《半咸水南美白对虾养殖池塘高效综合利用———网箱漠斑牙鲆养殖技术试验》科研项目,通过专家鉴定,该项目综合研究达到国内领先水平。项目实施两年,共开发推广南美白对虾与漠斑牙鲆套养面积250亩,漠斑牙鲆养殖网箱(3m×3m)100个,鱼虾总产84.3t,漠斑牙鲆网箱平均单产11.2kg/m2,实现产值379.6万元,效益215.7万元,辐射带动养殖面积1 000亩,实现产值1 500万元,经济和社会效益显著。项目根据黄河三角洲地区荒碱地资源优势和养殖现状,首次在国内利用半咸水南美白对虾养殖池塘进行网箱漠斑牙鲆养殖,取得成功,并总…     

碧流河水库漠斑牙鲆养殖技术总结

漠斑牙鲆属于广温广盐性鱼类,在淡水、微咸水、半咸水、海水至高盐水中都能适应,南北方沿海地区以及内陆都能养殖。碧流河水库先后于2007年和2008年对该鱼进行了试养,成果较为显著。下面将漠斑牙鲆养殖经验、技术进行总结如下。一、养殖设施碧流河水库运用圆形孵化池进行漠斑牙鲆的养殖试验。     

淡水池塘网箱养殖漠斑牙鲆试验报告

通过对漠斑牙鲆淡水池塘网箱养殖试验,掌握了该品种的生活习性,探索出漠斑牙鲆内陆地区淡水养殖模式,总结出养殖过程中应采取的技术措施。25m~2网箱总产漠斑牙鲆102．9 kg,平均单产4．12 kg/m~2,平均规格为306．25 g/尾,成活率达84%。     

Advance in the Culture Research of Small-Eye Flounder,Paralichthys microps,and Chilean Flounder,P. adspersus,in Chile

ABSTRACT

Over 71% of the aquaculture production of Chile is based on salmonids, and given the recents problems in the world salmon industry, it is necessary to investigate the culture of new species as a vital priority to maintain an industry of great social and economic impact for Chile. Small-eye flounder, Paralichthys microps, and chilean flounder P. adspersus, are native, high-value flatfish present off the coasts of Perú and Chile, that are commonly exploted by artisanal fishermen. Since 1986 both species have been objects of research studies for culture based on techniques developed for Japanese flounder. This paper is a review of current knowledge of this species and to identify research needs for the near future. Natural spawning of small-eye flounder and chilean flounder broodstock in captivity is already possible, but the manipulation of spawning using photoperiod and hormonal inducement, as well as the role of broodstock nutrition in egg and larval quality, needs to be explored. Successful incubation and larval culture protocol for both species have been developed, with larval survival over 24% from certain egg batches. Nutritional characterization and requirements for chilean flounder eggs and larvae during the culture period, optimal temperature, density, light intensity and green-water culture, are all subjects of ongoing research. Efforts to improve early culture protocol continues with emphasis on causes of larval mortality, early use of dry feed, microbial ecology of culture tanks and water quality. Weaning from live to formulated diets has been investigated, demonstrating survival of 30-50%. Presently only about 1-5% of hatchery raised flounder show a pigment disorder. Research on formulated diets and the weaning process are under way to ameliorate these results. Juveniles are being grown experimental in tanks and net pens systems and their performance (growth, survival, health) in both systems is being evaluated. Chilean flounder require approximately 2.8 years to reach 1 kg. Effort is also focusing on improving juvenile growing protocol, including recirculation systems, culture environment and diet formulation. Much future research will be required to attain optimal production of the species, such as species-specific nutritional requirements, optimum stocking density, disease and health management and growing protocols with new systems (shallow raceway). At present there is enough known about chilean flounder to begin a pilot-stage that will be the key for future development of its culture.     

Can bycatch in a flatfish gillnet fishery be reduced with rectangular mesh?

Gillnets fished in North Carolina, USA, estuaries have high rates of bycatch relative to the target catch of southern flounder, Paralichthys lethostigma Jordan & Gilbert. This study tested whether rectangular‐mesh gillnets would maintain catch rates of southern flounder and reduce fish bycatch relative to conventional diamond‐mesh gillnets in two North Carolina estuaries. In the Neuse River estuary, catch rates of legal southern flounder were not different between the two mesh shapes, but the bycatch of red drum, Sciaenops ocellatus (Linnaeus) and other fish species was reduced with rectangular‐mesh net. In the Newport River estuary, southern flounder and red drum catches were reduced in rectangular‐mesh net, but the decrease was greater for red drum. Catches of sublegal southern flounder were reduced in the rectangular‐mesh net in both estuaries. Reduced catch rates of sublegal southern flounder and bycatch species suggest rectangular mesh may help manage stocks of estuarine fish species in areas where gillnets are used to target flatfishes.     

漠斑牙鲆仔鱼、稚鱼和幼鱼对低盐度的耐受力和淡水驯化技术的研究

研究了漠斑牙鲆仔鱼、稚鱼和幼鱼对低盐度的耐受力和漠斑牙鲆的淡水驯化技术。初孵仔鱼在盐度为5的水中最多存活5d,5d以后全部死亡。30日龄稚鱼在4h10min淡水组全部死亡,对淡水的耐受力较低,而盐度为5～25的各组72h的存活率都在95.00%以上。90日龄幼鱼经缓慢淡水驯化9d后存活率可达98%以上,对漠斑牙鲆幼鱼进行淡水驯化的最佳年龄为90日龄。淡水驯化影响幼鱼初期的摄食,以后则逐渐趋于正常;急性淡水驯化对幼鱼的伤害比缓慢淡水驯化大;漠斑牙鲆对低盐的耐受力随生长和发育逐渐增加,年龄是影响幼鱼对低盐度耐受力的主要因素。     

Nitrite Toxicity and Methemoglobin Changes in Southern Flounder,Paralichthys lethostigma,in Brackish Water

This study was performed to estimate the nitrite toxicity to southern flounder, Paralichthys lethostigma, in brackish water (7.5 ppt of salinity). For a LC₅₀ test, 20 fingerlings (5.7 ± 0.4 cm) in each aquarium (15 L) were exposed to the concentrations of 0, 1, 5, 10, 15, 30, 60, 120, and 240 mg NO₂^?‐N/L in duplication for 10 d. Median lethal concentration at 96 h (96‐h LC₅₀) was calculated as 81.6 mg NO₂^?‐N/L. For a verification test, young flounder (164.2 ± 9.1 g) were exposed to a simulated culture condition in recirculating systems (1000 L). Sodium nitrite was not added to control system, whereas it was added to Treatment system 1 (TS 1) and Treatment system 2 (TS 2) to maintain nitrite concentrations of 20 and 30 mg NO₂^?‐N/L, respectively. The plasma nitrite concentrations of the young flounder in TS 1 and TS 2 were 4.5 and 6.6 mg NO₂^?‐N/L, respectively, after 2 wk. At this time, the methemoglobin percentages in TS 1 and TS 2 reached 85.8 and 89.7%, and survival rates were 37.5 and 25.0%, respectively. The results of these tests indicate that southern flounder do not concentrate nitrite in blood from the environment, but they seem to be more sensitive to nitrite compared with other species that do not concentrate nitrite.     

乳酸菌对牙鲆稚鱼养殖水体和肠道菌群的影响

在牙鲆稚鱼中投喂添加由单一鼠李糖乳杆菌P15制备的微生态制剂和黄霉素,在60d的投喂期内,采用平板计数法检测好氧性异养菌的总数、总弧菌数和乳酸菌的数量。结果表明,在投喂菌液和冻干菌粉后,养殖水体和牙鲆肠道的乳酸菌数均呈上升趋势,在30d后乳酸菌数量达到稳定并在肠道内定植。同时,由于乳酸菌的抑制作用,弧菌的数量下降,以肠道中的弧菌最明显。乳酸菌对养殖水体和牙鲆肠道的好氧性异养菌没任何影响。乳酸菌对养殖水体和肠道菌群的影响与抗生素具有相近的效果,表明乳酸菌作为饲料添加剂可以取代抗生素应用在牙鲆的养殖中。     

牙鲆的养殖与饲料

介绍了牙鲆亲鱼、苗种及养成各阶段的养殖方式、养殖条件发展情况，讨论了微颗粒饲料、硬颗粒饲料、膨化颗粒饲料、软湿颗粒饲料、鲜杂鱼生鲜料、粉末饲料等多种饲料在牙鲆的全养殖过程的应用情况，总结了牙鲆配合饲料及营养研究的进展情况，列出了行业标准中的牙鲆饲料的营养要求。     

Effects of Light Intensity and Salinity on Growth, Survival, and Whole-Body Osmolality of Larval Southern Flounder Paralichthys lethostigma

The southern flounder Paralichthys lethosligma is a high‐valued flatfish found in estuarine and shelf waters of the south Atlantic and Gulf coasts of the United States. Wide temperature and salinity tolerances exhibited by juveniles and adults make it a versatile new candidate for commercial culture, and studies are underway in the southeastern U.S. to develop hatchery methods for this species. The objectives of this study were to establish illumination and salinity conditions that optimize growth and survival of larval southern flounder reared through the yolk‐sac and first feeding stages to 15‐d post‐hatching (15 dph). Early embryos were stocked into black 15‐L tanks under light intensities of 5, 50, 100, and 1,000 Ix and at salinities of 24 and 34 ppt in a 4 ± 2 factorial design. Significant (P 0.05) effects of both light intensity and salinity on growth and survival were obtained, with no interaction between these effects. On 11 dph and 15 dph, growth was generally maximized at the intermediate light intensities (50 and 100 Ix) and minimized at the extremes (5 and 1,000 Ix). By 15 dph, growth was higher at 34 ppt than at 24 ppt. Survival to 15 dph showed trends similar to those of growth. Survival was higher at 100 Ix (avg. = 46%, range = 41–54%) than at 5 Ix (avg. = 11%, range = 6–17%) and higher at 34 ppt (avg. = 43%, range = 3145%) than at 24 ppt (avg. = 17%, range = 8–38%). Whole‐body osmolality (mOsmol/kg) was significantly lower in larvae reared at 24 ppt (avg. = 304, range = 285–325) through 11 dph than in larvae reared at 34 ppt (avg. = 343, range = 296–405). Larvae reared under the extreme light intensity treatments (5 and 1,000 Ix) at 34 ppt appeared to exhibit osmoregulatory stress, particularly on 11 dph, when a marked increase in whole‐body osmolality was observed. The mid‐intensity treatments (50 and 100 Ix) at 34 ppt optimized growth and survival of larval southern flounder in this study; and elicited the most stable osmotic response. These conditions appear to be consistent with those that southern flounder larvae encounter in nature during this early developmental period.     

容器颜色对漠斑牙鲆白化率和成活率的影响

本文就培养容器的颜色对漠斑牙鲆稚鱼的白化率和生长率的影响进行初步研究。结果表明:用深蓝色和黑色等深色容器培养的稚鱼白化率显著低于白色和黄色等浅色容器(p<0.05),黑色、深蓝色、黄色和白色4个组别(N=100)的白化率分别为20.8%、14.4%、57.6%和86.6%;白色最高为86.6%,深蓝色最低为14.4%;而用不同颜色的容器培养漠斑牙鲆的稚幼鱼,对其成活率影响不大(p>0.05),黑色、深蓝色、黄色和白色4个组别的成活率分别为96.0%、90.0%、82.5%、93.0%;白化稚幼鱼的生长发育并无异常。     

牙鲆无水保活技术

选用２龄人工养殖牙鲆,采用生态冰温学原理,研究了牙鲆的临界温度、无水保活技术工艺、影响无水保活时间的因子。结果表明：人工养殖牙鲆的临界温度为－０．７～０℃;温度、暂养时间、梯度降温速率、氧气的供应是影响牙鲆无水保活时间的主要因子;采用低温法,牙鲆无水保活５２ｈ,成活率１００％;６０ｈ,成活率９０％;低温法明显优于ＴＭＳ麻醉法。