牙鲆身体纵轴生长相关性状QTL定位

以经紫外线灭活的真鲷(Pagrosomus major)精子作为异源精子,诱导牙鲆(Paralichthys olivaceus)卵子进行有丝分裂雌核发育,通过静水压方法获得165个双单倍体作为实验材料.测量牙鲆身体纵轴6个生长相关性状(体长、头长、背鳍基长、腹鳍基长、尾柄长和尾长),并用SPSS 19.0对其进行正态分布及相关性分析.运用MapQTL4.0中多座位QTL 模型(MQM)对控制6个性状的QTL进行定位及遗传效应分析.结果表明,所检测6个性状均符合正态分布,并且相互之间呈极显著相关(P<0.01).在全部24个连锁群上检测到22个控制相关性状的QTL,分布在10个连锁群上.其中与体长相关的QTL有4个,头长相关的QTL为3个,控制背鳍基长的QTL为4个,与腹鳍基长相关的QTL为3个,与尾柄长相关QTL 7个,控制尾长的QTL仅有1个.各QTLs的LOD 值在2.01~3.68之间,可解释3.7%~12.6%的表型变异.控制体长和尾长的 QTL存在共定位,控制体长的 QTL 还与控制背鳍基长及腹鳍基长的QTL存在共定位.本研究结果可为今后进一步辅助育种和改良性状提供参考.     

Cryopreservation of summer flounder,Paralichthys dentatus L., sperm

The summer flounder, Paralichthys dentatus L., is a high‐value species and considerable research has been conducted to determine practices conducive for its culture. As milt can be limited in this species, experiments were conducted to develop a practical sperm cryopreservation protocol for hatchery use. Two dilution ratios (1:2 and 1:4; sperm:extender), 2 diluents (saline and sucrose‐based), 2 cryoprotectants (10% DMSO and 12% glycerol) and 3 freezing rates (?5, ?10 and ?15°C min^?1) were evaluated using differential staining to assess post‐thaw sperm survival. Seven combinations of the factors examined reduced post‐thaw viability by less than 30%. The average viability of sperm from fresh, pooled flounder milt (67.2 ± 2.9%) was not different from that of thawed milt diluted 1:4 with sucrose diluent (10% DMSO) frozen at ?5°C min^?1 (38.4 ± 7.7%) and fertilization and hatch success were not different in trials using fresh or thawed, cryopreserved sperm. From these experiments a practical sperm cryopreservation method was developed, but further refinement of the freezing protocol is necessary to optimize results.     

T型标志牌标记牙鲆苗种

摘要以牙鲆为实验对象,研究了4种不同规格的T型标志牌（T-A、T-B、T-C和T-D）对全长5、7、9和11cm苗种的标记效果,确立了适宜标志的牙鲆苗种规格,筛选了适宜于不同规格牙鲆苗种标记用的T型标志牌。全长5cm的苗种不宜使用这4种规格的标志牌标记;T-A和T-B标志牌适宜于全长7～11cm的牙鲆苗种,标记后脱牌率为2％～8％,存活率为90％～100％;T-C标志牌适宜于标记全长11cm的苗种,成活率为94％,脱牌率为5％,对全长7～9cm苗种的标志效果不佳,成活率为85％～87％,脱牌率为9％～11％;T-D标志牌不适宜于全长11cm以下牙鲆苗种的标记,脱牌率为11％～26％,成活率为51％～89％。2011～2012年,利用T-B标志牌在北戴河开展了牙鲆大规模标志放流试验,取得了良好的标记效果。     

不同牙鲆群体遗传力和育种值分析

以牙鲆(Paralichthys olivaceus)抗病群体(RS)、RS(♂)与从日本引进的日本群体(♀)交配建立的群体(RJ)、日本群体(♂)与RS(♀)交配建立的群体(JR)、以及韩国群体(KS)为基础群体, 通过随机交配建立牙鲆家系, 研究了4个群体作为亲本的育种性能。待所建立的家系生长至19月龄左右时, 测量家系生长性状, 包括全长和体质量, 测量所得数据用SPSS及DMU软件中的REML算法和BLUP方法进行分析。结果显示, 从表型参数可以看出KS(♂)×RJ(♀)杂交后代表现出明显的生长优势。19月龄牙鲆全长和体质量的遗传力分别为0.301、0.295, 都属于中等遗传力。因此, 牙鲆群体具有较好的遗传改良潜力。全长、体质量育种值与其表型值的相关系数分别为0.838和0.827, 且呈极显著相关(P<0.01), 表明个体育种值的预测结果具有较高的准确性。对父母本分别进行育种值比较可知, 父本中KS的育种值最高, 母本中RJ的育种值最高, 因此选用KS(♂)和RJ(♀)杂交可培育出生长迅速的牙鲆新品种。本研究通过比较4个资源群体牙鲆生长性状的育种性能, 并以此作为筛选优良亲本群体的重要依据, 旨在为牙鲆新品种的成功选育奠定理论基础, 同时为牙鲆的进一步遗传改良提供重要的科学依据。

     

Development of California Halibut,Paralichthys californicus,Culture

Abstract

In contrast to freshwater aquaculture and the culture of anadromous species such as salmon, marine fish culture is in its infancy. The small larval size of many marine species presents significant challenges to culture, however, these highly valuable fish offer considerable promise for aquaculture. A particularly attractive group for marine aquaculture is the flatfish. The California halibut, Paralichthys californicus, with a range in nature from Washington State south to Baja California Sur, Mexico is one such species.

With the goal of enhancing the fishery for this species, a hatchery program was developed over a decade ago. The hatchery at Redondo Beach, California, maintains a group of adults that routinely spawn throughout most of each year. Further development of routine culture and juvenile growout techniques ultimately aimed at commercial aquaculture was initiated last year with support from the California Sea Grant College Program.

Profitable commercial ventures culturing various flatfish species already exist in other parts of the world, but development of a flatfish culture industry in California confronts unique challenges. Two challenges in particular are the relatively high cost of energy and stringent environmental regulations. To meet these challenges, a culture system built around recirculation technology is being developed that would allow for an energy-efficient industrial-like approach to the culture of California halibut while minimizing environmental impacts.     

Development of Aquaculture Methods for Southern Flounder,Paralichthys lethostigma

ABSTRACT

A detailed spawning and larval rearing protocol for the production of southern flounder, Paralichthys lethostigma, is presented. The protocol is based on the results of spawning, larval culture and fingerling production trials with the southern flounder, which were completed during 1998 and 1999. Seventy-six brood fish (0.1-3.8 kg) were collected from the wild, acclimated to captivity, and stocked in matura tion tanks. Sex ratio (male:female) was 1.1:1. Males (0.1-1.0 kg; mean = 0.5 kg±0.30 SD) were significantly smaller (P > 000.1) than females (0.5-3.8 kg; mean =1.8 kg±0.75 SD). Spermatogenesis was achieved using temperature manipulation during a 3-month period. Vitellogenesis was nearly completed when most females were caught, and final ovulation was accomplished using gonadotropin releasing hormone-analogue (GnRH-a) implants and human chorionic gonadotropin (HCG). Eggs were obtained from both tank and strip spawnings. At 24-26°C, fertilized eggs hatched within 24-28 hours. Weaning to artificial diets was completed after 5 weeks, when metamorphosis was completed. Epizootics of Vibriosis and Amyloodinium ocellatum caused massive mortalities. Average survival rate from eggs to fully metamorphosed fingerlings was 30%, ranging from 5-40%. A total of 14,562 juveniles measuring 5 cm were produced in these experimental trials. Approximately 25% of the fingerlings exhibited pigment abnormalities known as hypomelanosis or pseudo-albinism on the dark side and hypermelanosis or ambicoloration on the blind side. Reversed asymmetry was observed in 5% of the fingerlings and a few individuals (0.02%) exhibited no ocular migration at all. A large size variation was observed during early larval development stages, with larger individuals growing faster through post-larval, juvenile, and adult stages. Results suggest that hatchery production of southern flounder fingerlings should rely on early culling of runts.     

牙鲆在低温无水保活过程中的生化变化

牙鲆（Ｐａｒａｌｉｃｈｔｈｙｓｏｌｉｖａｃｅｕｓ）属于鲽形目,鲆科,牙鲆属。近几年,随着海水鱼类养殖业的发展,牙鲆的养殖产量有了明显增加。以日本为代表的国外渔业发达国家相继开发了机械充氧高密度运输技术,最近几年又将生态冰温技术开发应用于部分海产动物的无水干运,并对日本对虾无水活运中的生化变化进行了研究［古庄真喜１９８９］。在我国,海水动物活运技术也得到了提高,殷邦忠等［１９９４、１９９６］采用低温法无水活运菲律宾蛤仔、魁蚶获得了成功。但到目前为止,国内外关于牙鲆低温无水保活过程中生化变化的研究未…     

恩诺沙星在大菱鲆(Scophthalmus maximus)、牙鲆(Paralichthys olivaceus)和半滑舌鳎(Cynoglossus semilaevis)体内的残留消除规律

本研究比较了在20℃水温条件下恩诺沙星(Enrofloxacin)在3种主要养殖鲆鲽鱼[大菱鲆(Scophthalmus maximus)、牙鲆(Paralichthys olivaceus)和半滑舌鳎(Cynoglossus semilaevis)]体内的残留消除规律。选择体重为300–400 g 的健康2龄大菱鲆、牙鲆和半滑舌鳎,以10 mg/kg 的剂量连续3 d 通过灌胃的方式分别给予恩诺沙星后,于1、3、6、10、15、20、25、30、35、40 d 采集血浆、肝、鳃、肌肉和肾组织。利用高效液相色谱法检测血浆和各组织中的恩诺沙星浓度,拟合恩诺沙星在3种鲆鲽鱼体内的消除曲线,计算消除半衰期。结果显示,3种鲆鲽鱼的组织中,恩诺沙星在肾中残留浓度最高,其消除速度依次为牙鲆>大菱鲆>半滑舌鳎,其消除半衰期分别为3.75、6.54、7.37 d;恩诺沙星在大菱鲆、牙鲆和半滑舌鳎血浆中的消除比其代谢产物环丙沙星慢;综合比较恩诺沙星在3种鲆鲽鱼血浆和大多数组织中的消除规律,均呈现出牙鲆体内消除最快,大菱鲆次之,半滑舌鳎最慢的趋势。依据我国无公害水产品中恩诺沙星最高残留限量为50μg/kg 的标准,建议在20℃水温条件下使用恩诺沙星防治鲆鲽鱼细菌性疾病时的休药期为：大菱鲆44 d、牙鲆33 d、半滑舌鳎47 d 以上。     

牙鲆在保藏过程中影响ATP关联化合物降解的因素

为了深入了解牙鲆体内ATP关联化合物的变化,尤其是肌苷酸(IMP)降解这一限速步骤,利用高效液相色谱法(high efficiency liquid chromatography,HPLC)测定不同保藏条件下牙鲆体内ATP关联化合物和K值变化,并探讨了影响其变化的因素。结果显示,0°C保藏条件下牙鲆体内ATP在1 d内迅速降解,产生IMP作为初期的主要积累物质,蓄积一段时间(10 d)后迅速降解为次黄嘌呤(Hx),IMP的降解过程呈现二相性;鱼肉制成鱼糜形态保藏,ATP 0 d时几乎降解完全,但IMP的降解过程仍旧呈现二相性;加入抗菌素的鱼肉中微生物的生长得到有效抑制,此时IMP降解缓慢并且呈线性下降,原本的蓄积过程消失,K值的增长速率也随之减慢;加入Tritonx-100破坏细胞膜结构发现,牙鲆体内IMP的降解速率加快,同时K值的增长速率也随之加快。结果表明,牙鲆的保藏形态影响ATP的降解速率,但几乎不影响其他关联产物的降解变化;保藏后期外源微生物产生的酶与内源酶的叠加作用是导致保藏后期IMP加速降解、从而呈现二相性的原因,微生物是影响ATP关联化合物降解的关键因素;表面活性剂通过改变细胞膜结构也能够影响IMP的降解过程。     

浸泡免疫迟钝爱德华氏菌疫苗诱导牙鲆黏液细胞的动态变化

为探明鱼类黏膜相关淋巴组织中黏液细胞对疫苗免疫的应答特性,本研究利用组织学和组织化学技术,研究了浸泡免疫灭活迟钝爱德华氏菌前后牙鲆皮肤、鳃、前肠、中肠和后肠中黏液细胞数量和特性的时序变化。苏木精-曙红(HE)、阿尔新蓝-过碘酸雪夫氏(AB-PAS)染色结果显示,免疫前皮肤主要分布含中性黏多糖的Ⅰ型黏液细胞以及含中性黏多糖和少量酸性黏多糖的Ⅲ型黏液细胞,鳃中可观察到Ⅰ、Ⅲ型以及含酸性黏多糖和少量中性黏多糖的Ⅳ型黏液细胞,前肠中主要分布Ⅰ型黏液细胞,中肠、后肠上皮中可观察到Ⅰ、Ⅲ、Ⅳ型和含酸性黏多糖的Ⅱ型黏液细胞。免疫后,牙鲆黏膜免疫相关淋巴组织中黏液细胞总量随时间呈现先增多后减少趋势,后肠在第5天达到峰值,其他于第3天达到峰值;免疫后各组织中Ⅰ型黏液细胞数量减少,含酸性黏多糖成分的Ⅱ、Ⅲ及Ⅳ型黏液细胞数量显著增多,表明疫苗免疫诱导黏液细胞成分由中性黏多糖向酸性黏多糖转变。p H 2.5和p H 1.0条件下AB染色结果显示,免疫后黏膜相关淋巴组织中酸性黏液细胞数量增多,且多数为硫酸化酸性黏液细胞。本研究结果为鱼类黏液的免疫防御功能及黏液细胞在鱼类黏膜免疫中的作用提供了理论依据。