混养海湾扇贝对刺参池塘养殖环境的影响

为建立参贝混养的生态养殖模式,研究了海湾扇贝在池塘中与刺参混养,对养殖环境的影响。通过参贝混养与海参单养池的比较研究表明:参贝混养池的水质指标:氨态氮、亚硝酸盐等明显低于海参单养池;扇贝的滤食作用改善了水的透明度,参贝混养池明显高于海参单养池。参贝混养池中浮游生物的种类和数量优于单养池,海参喜食的底栖硅藻的生物量较多;浮游动物的种类较少,规格也较小。为池塘参贝生态养殖提供了参考依据。     

扇贝亲贝配合饲料的研究

“配合饲料”以植物蛋白质和碳水化合物为主，加以适量各种添加剂，经科学调配混合组成。蛋白质含量２５－２６％，脂肪８４－１２９％，碳水化合物４３－５６％，并含有扇贝亲贝性腺成熟必需的微量元素和其他促进性腺成长发育的重要成分。经饲喂试验表明：亲贝性腺指数提高２０－３０％，亲贝成活率９８％，比对照提高２６％，亲贝产出优质精、卵，受精卵的孵化率９３％，饲料成本降低５０％，是一种完全可以代替单胞藻喂养扇贝亲贝的优良配合饲料。     

磁化水蓄养海湾扇贝亲贝试验

试验表明，与对照组比，磁化水中氨氮含量及化学耗量降低，溶解氧增加，用磁化水蓄养海湾扇贝亲贝，性腺发育好，卵质优，平均每个亲贝产卵量１１７万粒，Ｄ型幼虫率８９％，亲贝成活率９６％，亲贝成活率９６％，分别比对照组提高１５．８％、２７％、７％。     

海湾扇贝秋季全人工育苗技术

一、亲贝培育 (一)亲贝来源 1993年9月28日,从平潭县竹屿港养殖区中,挑选壳高5cm以上的优质扇贝亲贝1000个,蓄养在1700m~2室外虾池中,进行强化培养。 (二)亲贝培养 培养海湾扇贝,主要抓住生物饵料的培养和水质条件的控制等管理措施。 1.培养饵料: 由于培养池饵料生物的丰欠至关重要。为此,要采取定期施肥繁殖单细胞藻类,促进其密度达到10—30万个/ml。 2、控制水质:     

栉孔扇贝亲贝室外饲养试验

在室外塑料大棚中以自然（接种）繁殖方法，使饵料生物的总密度超过６万个细胞／ｍｌ；饲养栉孔扇贝亲贝３０天，亲贝的成活率在９６％以上，性腺成熟并产卵，亲贝的各项生物指标均明显好于自然海区。     

虾夷扇贝控温育苗高产技术研究

净化海水，控制水质理化因子，选择合格亲贝，搞好亲贝控温促熟和产卵孵化，并采取换水充气，倒池施药，兼用光合细菌等措施培育虾夷扇贝幼虫。结果：单位水体平均虾夷扇贝出库苗760万粒／m3。     

关于养殖品种越冬技术之二海湾扇贝亲贝浅海越冬需注意的几个问题

近两年山东省日照市东港区任家台村凭借地处鲁东南冬暖夏凉优越的地理位置和水质清新的自然条件，逐步成为海湾扇贝亲贝浅海越冬的重要基地，每年为各育苗场过渡大量的亲贝，效果非常理想。但也有个别的单位因经验不足等原因造成了不必要的损失，现将近两年的经验总结如下供育苗单位参考。 １．亲贝的选择 海湾扇贝亲贝的选择直接关系到浅海越冬成活率和育苗效果。海湾扇贝亲贝应来自无污染养殖海区、个体较大且均匀、无杂贝藻等附着物。养殖海区污染则亲贝性腺发育不良，个体差异大则性腺发育不同步，杂贝藻过多则洗刷时宜造成机械损伤。 …     

利用地下海水进行海湾扇贝越冬的效果研究

把5cm以上海湾扇贝亲贝按43-50个／m^3密度吊养于水泥沉淀池,利用附近井水调温：使池水温度达4℃以上。越冬两个半月,成活率84％以上,而自然海区越冬贝成活率仅70％．升温促熟后．亲贝产卵孵化率60％以上,而自然海区越冬贝仅为15．1％。地下海水越冬贝的单位水体出苗量为505万粒／m^3和544万粒／m^3,而自然海区越冬贝出苗量仅有209万粒／m^3．证明利用地下海水调温,在沉淀池进行海湾扇贝亲贝越冬,效果明显,完全可行．     

海螺酶酶解紫菜投喂扇贝亲贝的研究

用海螺酶将紫菜叶状体酶解分离成单细胞活饵料，用于扇贝亲贝饲养促熟，之前未见报道。本研究结果，加速了亲贝性腺发育和成熟，性腺指数呈上升趋势，排卵量大，孵化率高，亲贝死亡率明显下降。     

海湾扇贝人工育苗中几个常见问题的探讨

对海湾扇贝人工育苗中常见的亲贝死亡、孵化率低、“面盘解体”等问题提出一些看法 ,认为通过选择亲贝 ,提高亲贝培养的成熟度 ,加强水质控制等措施 ,可避免或减少育苗过程中以上问题所造成的损失     

中国对虾与海湾扇贝投饵混养的实验研究

用放在海水池塘中的8个陆基围隔(5.0m×5.0m×1.8m),研究中国对虾(Penaeuschinensis)与不同密度海湾扇贝(Argopectenirradians)投饵混养的放养方式、生产力和极限放养量.对虾体长(2.85±0.16)cm,扇贝壳长(1.10±0.12)cm,放养密度分别为6.0尾/m2和0,1.5,4.5,7.5粒/m2,用投饵和施肥(鸡粪和化肥)饲养.结果表明,扇贝密度为0和1.5粒/m2时,对虾的成活率无显著差异.混养(扇贝1.5粒/m2)时对虾的出塘体长、体重和产量分别比单养高2.5%,3.8%和6.5%;当扇贝密度高于1.5粒/m2时,对虾的平均体长、体重和产量随扇贝密度的增加而显著减少(P＜0.05).扇贝密度为1.5和7.5粒/m2时,其产量由470kg/hm2增至1236kg/hm2;当扇贝密度高时,去壳后湿重占体重的百分数从(42.84±3.44)%降至(37.88±4.26)%.扇贝的极限放养量为600～800kg/hm2,适宜放养密度为1.0～1.5粒/m2.     

Antibrowning of the Adductor Muscles of Bay Scallop by Glutathione During Hot Air Drying

ABSTRACT

Browning in the adductor muscle of bay scallop (Argopecten irradians) tends to occur during hot air drying due to polyphenoloxidase (PPO) and Maillard reaction and decreases the sensory quality and commercial value of bay scallop adductor muscles (BSAM). In the present study, the effects of glutathione on the browning inhibition of BSAM were evaluated. The PPO activity in BSAM was inhibited by 97.8 with 0.08% glutathione. The browning of BSAM pretreated with glutathione was evaluated during hot air drying. Compared with the control, BSAM pretreated with glutathione resulted in less drying time and browning during hot air drying. The results indicate that pretreatment with glutathione may be a promising method of BSAM browning inhibition during hot air drying.     

Chlamydiosis: a newly reported serious disease of larval and postmetamorphic bay scallops, Argopecten irradians (Lamarck)

Abstract. Diseases of bivalve molluscs characterized by the presence of prokaryotic intra-cytoplasmic inclusion bodies in epithelial cells are reviewed. The paper reports the history, clinical and pathological findings during hatchery epizootics of chlamydiosis in larval and postmetamorphic bay scallops, Argopecten irradians (Lamarck), and enzootic infection in wild, captive and cultured adult and juvenile bay scallops during a 15-year period (1972–1987) of surveillance for scallop diseases in the northeastern Atlantic coastal region of the United States. The disease was found in 44·4% of adult bay scallop laboratory accessions as an endemic disease without overt clinical signs or mortalities, and as a highly fatal epizootic disease with a rapid course in 20% of hatchery-reared larval and postmetamorphic bay scallop accessions. The pathogenesis and development of the chlamydial agent during hatchery epizootics are described. The importance of the congenital 'childhood' diseases of larval bay scallops and other species of bivalve molluscs is discussed.     

Possible cytotoxic effects of the dinoflagellate, Gyrodinium aureolum, on juvenile bivalve molluscs

Juveniles of eight commercially important species of bivalve molluscs (Spisula solidissima, Argopecten irradians, Crassostrea virginica, Mytilus edulis, Mya arenaria, Ostrea edulis, Mercenaria mercenaria, Placopecten magellanicus) were exposed in the laboratory to the commonly occurring dinoflagellate, Gyrodinium aureolum. Histological analyses of gut tissues indicated that the impact of G. aureolum on the shellfish was species-specific. High rates of mortality were noted in the bay scallop, A. irradians, but not in other molluscan species. There were no pathological differences between control animals and animals fed G. aureolum in S. solidissima, M. arenaria, or M. mercenaria. The most severely affected molluscs were C. virginica and A. irradians. C. virginica did not exhibit differences in digestive gland parameters between control and experimental animals; however, several animals did show significant mantle and gill lesions. Bay scallops exhibited decreased height of absorptive cells and increased lumen diameter after exposure to Gyrodinium suggesting, at least, poor food quality of Gyrodinium. Evidence of toxic effects was not identified in the digestive gland. Several bay scallops also showed variable amounts of inflammation in the kidney associated with protozoal infestations and variable amounts of predominately rod-shaped bacteria within the urinary space. Aquaculturists, especially of scallop species, should monitor for the presence of G. aureolum. Given its large size (25-30 m), G. aureolum could be filtered from incoming water to hatcheries, thus avoiding mass mortalities of spat and juvenile scallops.     

我国海湾扇贝养殖现状、问题与发展对策

据统计，到１９９８年我国海湾扇贝养殖面积发展到近７０００ｈｍ＾２，养殖产量约３０万ｔ。特别是自１９９７年栉孔扇贝养殖出现大面积死亡以来，海湾扇贝养殖面积不断扩大。但在１９９９年贝苗中间暂养阶段发生了大量死亡，造成养殖苗种严重不足，使养殖面积减少约２／３，经济损失惨重。作者就海湾扇贝养殖中存在的问题进行了分析，并对今后的发展提出了一些设想。     

Scope for growth of Texas Bay scallop Argopecten irradians amplicostatus

Bivalves have exceptional potential as sentinel organisms because their sedentary benthic lifestyle and ability to pump large volumes of water in short periods of time results in bioaccumulation of pollutants and toxins present in the water column. Scope for Growth (SFG) is an instantaneous measure of production that ranges from maximum positive values under optimal conditions to negative valves when the organism is stressed and utilizing its body reserves for maintenance. We determined baseline SFG for the Texas bay scallop Argopecten irradians amplicostatus so that this species might be used to determine sublethal effects of toxins, contaminants, or other environmental stressors in light of recent harmful algal bloom events in the Gulf of Mexico. We also quantified the effects of different diets (phytoplankton, zooplankton, mixed phytoplankton/zooplankton) on Texas bay scallop SFG. SFG of starved animals was negative, indicating that body reserves were used for maintenance. SFG varied significantly (P < 0.001) by diet, with rotifers yielding the highest value (mean = 14.88 Joules hr^?1g dry weight, SE = 0.72). We determined that the Texas bay scallop has presently unrecognized potential as sentinel organisms to define effects of various environmental and anthropogenic perturbations.     

Genetic linkage map of bay scallop, Argopecten irradians irradians (Lamarck 1819)

The bay scallop (Argopecten irradians irradians Lamarck 1819) has become one of the most important aquaculture species in China. Genetic improvement of cultured bay scallop can benefit greatly from a better understanding of its genome. In this study, we developed amplified fragment length polymorphisms (AFLPs) and simple sequence repeat markers from expressed sequence tags (EST‐SSRs) for linkage analysis in bay scallop. Segregation of 390 AFLP and eight SSR markers was analysed in a mapping population of 97 progeny. Of the AFLP markers analysed, 326 segregated in the expected 1:1 Mendelian ratio, while the remaining 74 (or 19.0%) showed significant deviation, with 33 (44.6%) being deficient in heterozygotes (A/a). Among the eight polymorphic EST‐SSR loci, one marker (12.5%) was found skewing from its expected Mendelian ratios. Eighteen per cent of the markers segregating from female parent were distorted compared with 21% of the markers segregating from male parent. The female map included 147 markers in 17 linkage groups (LGs) and covered 1892.4 cM of the genome. In the male map, totally 146 AFLP and SSR markers were grouped in 18 LGs spanning 1937.1 cM. The average inter‐marker spacing in female and male map was 12.9 and 13.3 cM respectively. The AFLP and SSR markers were distributed evenly throughout the genome except for a few large gaps over 20 cM. Although preliminary, the genetic maps presented here provide a starting point for the mapping of the bay scallop genome.     

Crosses between two subspecies of bay scallop Argopecten irradians and heterosis for yield traits at harvest

In order to improve the yield of bay scallop Argopecten irradians by exploiting geographic subspecies heterosis, crosses between and within two subspecies, the northern A. i. irradians (Lamarck) and the southern A. i. concentricus (Say), were created and the offspring were cultured under the same environmental conditions. The two parental populations were collected from Bohai Bay in northern China and Beibu Bay in southern China, which were distinct in particular shell colours. The results indicated that the shell colour of bay scallop was inheritable and could be used as a morphological mark to distinguish hybrid and purebred individuals. At harvest, hybrid offspring always produced a significantly higher yield than purebred offspring. Positive heterosis was achieved for shell length, shell height, shell width, total weight and adductor weight, which was 5.02, 5.22, 3.88, 7.53 and 9.47 respectively. Hybrid gain was 10.86% for shell length, 10.48% for shell height, 9.77% for shell width, 34.90% for total weight and 41.69% for adductor weight, respectively, and all were significantly >5%. The present study reveals that it is effective for improving yield by hybridization between different geographic subspecies in the bay scallop.     

Chlamydia-like organisms in the digestive diverticula of the bay scallop, Argopecten irradians (Lmk)

Abstract. The morphology of a chlamydia-like organism from the digestive diverticula of the bay scallop, Argopecten irradians (Lmk), is described. This organism was found in about 40% of bay scallops introduced to the quarantine unit at Ellerslie, Prince Edward Island, Canada and also in about 40% of the F₁ and F₂ generations. Procaryote infections were also found in the northern quahog, Mercenaria mercenaria (L.), the soft-shelled clam, Mya arenaria L., and the Atlantic deepsea scallop, Placopecten magellanicus (Gmelin).     

Suspension-feeding aquaculture systems: Effects of phytoplankton concentration and temperature on growth of the bay scallop

The growth rate of the bay scallop Argopecten irradians was studied in relation to temperature and phytoplankton concentration. Results suggest that normal variations in phytoplankton concentration do not influence the growth rate of scallops in their natural habitat. Increasing the concentration of phytoplankton above natural levels did not result in increased growth rates while decreasing the phytoplankton concentration resulted in a decrease in growth rate of the scallops. Under extremely low phytoplankton concentrations, such as those that characterize ‘clean water’ effluent from a culture system, the animals ceased growing. A mathematical model of scallop growth rate as a function of phytoplankton concentration is proposed as a tool for comparing the functioning of different suspension feeders in aquaculture systems.