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1.
The experimental results showed that: 1) The embryonic development of bay scallop is inhibited at a dissolved oxygen range of 1.38–3.64×10−3 at 23°C, and completely blocked below the lower limit. 2) The tolerance of larvae to anoxia increased with larval sizes and was related to their oxygen debt. 3) The scallop larvae exhibited specific behavioral responses to oxygen deficiency, which finally led to velum disintegration and larval death. The possible relationship between environmental oxygen deficiency and the disease of disintegration of the larval velum is also discussed. In this study, considerable oxygen debt was found in bay scallop larvae, which was greater in small animals. Based on the works of previous authors, a new concept is proposed for the estimation of oxygen debt, namely, the compensatory rate of oxygen debt (CROD). This can be used in intra—or interspecific comparison of oxygen debt. The results can be helpful in the management of water quality and for the prevention of larval diseases encountered in scallop culture. Contribution No. 2167 from the Institute of Oceanology, Chinese Academy of Sciences.  相似文献   

2.
3.
The 48-h straight-hinge larvae ofArgopecten irradians were exposed for 9 days to various concentrations of zinc in seawater. The growth rate of larvae in the 50 ppb Zn mediums was 77% that of the controls, and nearly zero in the 200 ppb Zn mediums. A progressive decrease in growth and increase in larval deformity and mortality was observed with increasing zinc concentrations from 50 to 200 ppb. 50 and 100 ppb Zn resulted in delayed development of eye spot and metamorphosis and reduced numbers of larvae at both stages. All larvae subjected to higher zinc concentrations died before attaining the eye-spot stage. The zinc concentrations which caused 50% reduction in growth (G C50) and 50% mortality (LC50) were 109 and 120 ppb respectively. Growing in the medium with 100 ppb Zn, the larvae fed withIsochrysis galbana cultured in a medium with 100 ppb Zn showed more suppressed growth and development than those fed with normal food. It is suggested that zinc contaminated food has strong influence on the bay scallop larvae. Contribution No. 1616 from the Institute of Oceanology, Academia Sinica.  相似文献   

4.
DAX1, a member of nuclear receptor superfamily, has a function in the sex determination and gonadal differentiation of several vertebrate species. However, little information about DAX1 of invertebrates is available. Here we cloned a homolog of scallop (Chlamys farreri Jones and Preston 1904) dax1, Cf-dax1, and determined its expression characteristics at mRNA and protein levels. The cDNA sequence of Cf-dax1 was 2093 bp in length, including 1404 bp open reading frame (ORF) encoding 467 amino acids. Unlike those of vertebrates, no conserved LXXLL-related motif was found in the putative DNA binding region of Cf-DAX1. Fluorescence in situ hybridization showed that Cf-dax1 located on the short arm of a pair of subtelocentric chromosomes. Tissue distribution analysis using semi-quantitative RT-PCR revealed that Cf-dax1 expressed widely in adult scallop tissues, with the highest expression level found in adductor muscle, moderate level in mantle, gill and testis, and low level in kidney, ovary and hepatopancreas. The result of quantitative real-time PCR indicated that the expression of Cf-dax1 was significantly higher (P<0.05) in testis than in ovary at the same stage, showing a sex-dimorphic expression pattern. Furthermore, immunohistochemical detection found that Cf-DAX1 mainly located in spermatogonia and spermatocytes of testis and in oogonia and oocytes of ovary, implying that DAX1 may involve in gametogenesis of bivalves.  相似文献   

5.
We used Illumina high-throughput sequencing of PCR-amplified V3-V4 16 S rRNA gene regions to characterize bacterial communities associated with the adductor muscles, gills, gonads and intestines of the Yesso scallop(Patinopecten yessoensis) from waters around Zhangzidao, Dalian, China. Overall, 421,276 optimized reads were classified as 25 described bacterial phyla and 308 genera. Firmicutes, Proteobacteria, Tenericutes, Bacteroidetes, Chlamydiae and Spirochaetae accounted for 97% of the total reads in the four organs. The bacterial 16 S rDNA sequences assigned to Firmicutes and Proteobacteria were abundant in the adductor muscles, gills and gonads; while reads from Tenericutes were dominant in the intestines, followed by those from Firmicutes, Chlamydiae, Proteobacteria and Bacteroidetes. At the genus level, the dominant genera in the adductor muscles, gills and gonads appeared to be Bacillus, Enterococcus and Lactococcus, whereas Mycoplasma was dominant in the intestines. The relative abundances of Bacillus, Enterococcus, Lactococcus, Alkaliphilus, Raoultella, Paenibacillus and Oceanobacillus were significantly lower in the intestine than in the other three organs. Cluster analysis and principal coordinates analysis of the operational taxonomy units profile revealed significant differences in the bacterial community structure between the intestine and the other three organs. Taken together, these results suggest that scallops have intestine-specific bacterial communities and the adductor muscles, gills and gonads harbor similar communities. The difference in the bacterial community between organs may relate to unique habitats, surroundings, diet and their respective physiological functions.  相似文献   

6.
This study describes the complete diaUel hybridization between newly introduced bay scallop stock (W) from Canada and local commercial stock (D) grown under laboratory conditions, in China. Larval survival and growth during all life stages (larvae, spat, and adult) were compared among hybrid (DW, WD) and purebred (DD, WW) populations. Significant heterosis was detected for survival during the larval stage (〉 1% of the mid-parent values). The mean heterosis (Hm) varied in growth throughout the life span. More than 50% of the Hm values were positive and negative in the DW and WD groups, respectively. The influence of maternal effects and mating types (intrapopulation vs. interpopulation crosses) on growth for all life stages was not consistent. Larval survival did not differ significantly (P〉0.05) with maternal effect or mating type. In the harvest stage, shell length (SL), shell height (SH), shell width (SW), and total weight (TW) were larger in the hybrid compared with the inbred groups. Positive Hm values were observed in SL (1.5%), SW (5.8%), and TW (12.3%), and were more significant in the DW groups (6.1%, 4.5%, 6.8%, and 27.2%). These results suggest that hybridization between two geographic populations is a good tool for improving bay scallop growth. However, unstable heterosis between the two populations requires further study.  相似文献   

7.
Two Large-insert genomic bacterial artificial chromosome (BAC) libraries of Zhikong scallop Chlamys farreri were constructed to promote our genetic and genomic research. High-quality megabase-sized DNA was isolated from the adductor muscle of the scallop and partially digested by BamH I and Mbo I, respectively. The BamH I library consisted of 53 760 clones while the Mbo I library consisted of 7 680clones. Approximately 96 % of the clones in BamH I library contained nuclear DNA inserts in average size of 100 kb, providing a coverage of 5.3 haploid genome equivalents. Similarly, the Mbo I library with an average insert of 145 kb and no insert-empty clones, thus providing a genome coverage of 1.1 haploid genome equivalents.  相似文献   

8.
The dried shellfish products with rich nutrients and low-calorie content are favorite food in China, especially in coastal areas. However, the species of dried shellfish products in the market are usually unknown, as the taxonomic features were removed during the production process. This study described the application of DNA barcoding technique to the identification of 100 dried shellfish(scallop, squid, octopus and cuttlefish) products in markets. Samples were authenticated by comparing mitochondrial cytochrome oxidase subunit I(COI) gene and 16 S ribosomal RNA(16 S rRNA) gene sequences with public reference taxonomic databases. The results showed that all the 100 products can be identified at species level. Sixty four scallop adductor products were processed using the bay scallop, Argopecten irradians, and one was from Portuguese oyster, Crassostrea angulata. All the 27 squid, 2 cuttlefish and 6 octopus products were produced by the Jumbo flying squid, Dosidicus gigas. The neighbour-joining tree is in agreement with the results of DNA barcoding analysis. The 64 scallop samples formed one A. irradians cluster, leaving Sca65 clustered with the reference oyster sequence C. angulata(MH997922). All the 35 cephalopod(squid, octopus and cuttlefish) samples formed a D. gigas cluster. This investigation revealed a low variety of dried shellfish products sold on the market, and highlighted the high rate of mislabeling and species substitution. Our present work provides a practical method for tracing and authenticating shellfish products.  相似文献   

9.
Bacterial community presumably plays an essential role in inhibiting pathogen colonization and maintaining the health of scallop larvae, but limiting data are available for Yesso scallop(Patinopecten yessoensisis Jay, 1857) larval development stages. The aim of this study was to characterize and compare the bacterial communities associating with Yesso scallop larval development at fertilized egg S1, trochophora S2, D-shaped larvae S3, umbo larvae S4, and juvenile scallop S5 stages by Illumina high-throughput sequencing. Genomic DNA was extracted from the larvae and their associating bactera, and a gene segment covering V3-V4 region of 16 S r RNA gene was amplified and sequenced using an Illumina Miseq sequencer. Overall, 106760 qualified sequences with an average length of 449 bp were obtained. Sequences were compared with those retrieved from 16 S r RNA gene databases, and 4 phyla, 7 classes, 15 orders, 21 families, 31 genera were identified. Proteobacteria was predominant phylum, accounting for more than 99%, at all 5 larval development stages. At genus level, Pseudomonas was dominant at stages S1(80.60%), S2(87.77%) and S5(68.71%), followed by Photobacterium(17.06%) and Aeromonas(1.64%) at stage S1, Serratia(6.94%), Stenotrophomonas(3.08%) and Acinetobacter(1.2%) at stage S2, Shewanella(25.95%) and Pseudoalteromonas(4.57%) at stage S5. Moreover, genus Pseudoalteromonas became dominant at stages S3(44.85%) and S4(56.02%), followed by Photobacterium(29.82%), Pseudomonas(11.86%), Aliivibrio(8.60%) and Shewanella(3.39%) at stage S3, Pseudomonas(18.16%), Aliivibrio(14.29%), Shewanella(4.11%), Psychromonas(4.04%) and Psychrobacter(1.81%) at stage S4. From the results, we concluded that the bacterial community changed significantly at different development stages of Yesso Scallop larvae.  相似文献   

10.
In order to improve production and breed new broods of bay scallopArgopecten irradians irradians, different-colored orange, purple and white lines were established by two mating methods of self-fertilization and mass spawning at a commercial scallop hatchery in spring, 2002. And then larval growth and survival of different lines was compared to test whether there is a relationship between shell color and growth and survival at early developmental stage. Both growth and survival have no significant differences among different experimental larvae of self-fertilization or mass spawning. Results are as following in the order of orange, purple and white shell stock. For the self-fertilization, growth rates of larvae were 6.174, 6.412, and 6.599 μm/d, respectively. Survival rates of larvae at Day 3 were 74.41%, 76.86%, and 82.05%; Day 6 were 49.14%, 65.63%, and 52.79%; and Day 9 were 25.06%, 20.80%, and 26.47%, respectively. For the mass spawning, the growth rates were 7.836, 7.941, and 7.878 μm/d, respectively. Survival rates at Day 3 were 93.05%, 91.95%, and 92.50%; Day 6 were 79.17%, 78.05%, and 82.50%; and Day 9 were 34.72%, 36.67%, and 38.33%, respectively. The absence of any relationship between shell color and growth and survival at the larval stage may be resulted from their common genetic basis. This work was financially supported by Project of Scientific Innovation, Chinese Academy of Sciences (ZKCX2-211).  相似文献   

11.
INTRODUCTIONKnowledgeofgametogenesisinvaluablemarineanimalsisveryimportanttocommercialfish ery.Gametogenesisinbivalveswasextensivelystudiedatdifferentlevels (Dohmen ,1 983 ;DorangeandLePennec ,1 989a,b) .Scallopsandothermarinebivalveshavesimilarreproductivecycle…  相似文献   

12.
Gao  Jian  Dong  Yuelei  Zhou  Xiaoyu  Cui  Lei    Songhui 《中国海洋湖沼学报》2022,40(6):2189-2201
Journal of Oceanology and Limnology - A large-scale algal bloom, caused by Aureococcus anophagefferens, has plagued the coastal embayment of Qinhuangdao, China since 2009. The bay scallop...  相似文献   

13.
进行了施氏獭蛤(Lutraria sieboldii Reeve)的人工育苗、幼虫发育及行为观察实验。结果显示:在施氏獭蛤幼虫发育过程中,壳顶后期幼虫只有鳃丝及足出现,而没有眼点出现,发达的足和鳃丝是幼虫变态的标志;幼虫变态期明显的分为3~5d的爬行期和3~5d的附着期;爬行期幼虫有单条水管形成,附着期幼虫只有一条分叉的足丝,水管为单管型;底栖稚贝期开始形成两条水管,底栖稚贝早期的幼虫不具备潜沙能力,只进行爬行活动,随着水管的快速发育,幼虫逐渐具备潜沙能力,幼虫壳长达2500μm、水管长达6000μm以上时,最终具备和成体一样的完全潜沙能力。  相似文献   

14.
The effects of different dietary lipid content on the growth and lipase activity of Eriocheir sinensis larvae were studied in the paper. The results showed that the survival, metamorphic rate and weight gain of E. sinensis larvae at different stages of growth all varied significantly with lipid content (P<0.05). Further, the survival and metamorphosis rates were the highest during the larval phases Z3 to Z4, and the weight gain was the highest during the larval phases Z5 to M. During the first 20 h after metamorphosis of every larval stage, the lipase activity increased over time at Z1, Z2, Z3 and M and declined at Z4 and Z5, and was influenced significantly by lipid content (P<0.05). In addition, lipase activity at each larval stage began to respond to dietary lipid contents 4 h after the larvae were fed, and tended to be stable after 12 h. The diets with higher lipase activity and lower lipid content were selected to give the suitable recipe of lipid requirements at each larval stage. It was concluded that the suitable lipid requirements at Z1, Z2, Z3, Z4, Z5 and M were 6%, 4%, 6%, 8%, 8% and 10%, respectively.  相似文献   

15.
Histological characteristics of gametogenesis of two kinds of scallops, gonochoric Chinese scallop, Chlamys farreri and hermaphroditic bay scallop, Argopecten irradians were investigated in this study. Spermatogenesis in C. farreri has different developmental stages: spermatogonia, primary spermatocyte, second spermatocyte, spermatid and spermatozoon. A large number of same developmental stage spermatic cells converge at a definite area of the testis. Premeiotic, previtellogenic and vitellogenic oocytes can be found during oogenesis in C. farreri, where oocyte distribution is obviously irregular. The A. irradians gonad consists of two different parts in one individual: one part functions as testis, the other as ovary. Between these two parts is a special appearance area, where a large number of spermatic cells are bound with two layers of acellular substance with many oocytes in it.  相似文献   

16.
We evaluated the effect of pH on larval development in larval Pacific oyster(Crassostrea gigas) and blood cockle(Arca inflata Reeve).The larvae were reared at pH 8.2(control),7.9,7.6,or 7.3beginning 30 min or 24 h post fertilization.Exposure to lower pH during early embryonic development inhibited larval shell formation in both species.Compared with the control,larvae took longer to reach the D-veliger stage when reared under pH 7.6 and 7.3.Exposure to lower pH immediately after fertilization resulted in significantly delayed shell formation in the Pacific oyster larvae at pH 7.3 and blood cockle larvae at pH 7.6 and 7.3.However,when exposure was delayed until 24 h post fertilization,shell formation was only inhibited in blood cockle larvae reared at pH 7.3.Thus,the early embryonic stages were more sensitive to acidified conditions.Our results suggest that ocean acidification will have an adverse effect on embryonic development in bivalves.Although the effects appear subtle,they may accumulate and lead to subsequent issues during later larval development.  相似文献   

17.
Bacterial community presumably plays an essential role in inhibiting pathogen colonization and maintaining the health of scallop larvae, but limiting data are available for Yesso scallop (Patinopecten yessoensisis Jay, 1857) larval development stages. The aim of this study was to characterize and compare the bacterial communities associating with Yesso scallop larval development at fertilized egg S1, trochophora S2, D-shaped larvae S3, umbo larvae S4, and juvenile scallop S5 stages by Illumina high-throughput sequencing. Genomic DNA was extracted from the larvae and their associating bactera, and a gene segment covering V3-V4 region of 16S rRNA gene was amplified and sequenced using an Illumina Miseq sequencer. Overall, 106760 qualified sequences with an average length of 449 bp were obtained. Sequences were compared with those retrieved from 16S rRNA gene databases, and 4 phyla, 7 classes, 15 orders, 21 families, 31 genera were identified. Proteobacteria was predominant phylum, accounting for more than 99%, at all 5 larval development stages. At genus level, Pseudomonas was dominant at stages S1 (80.60%), S2 (87.77%) and S5 (68.71%), followed by Photobacterium (17.06%) and Aeromonas (1.64%) at stage S1, Serratia (6.94%), Stenotrophomonas (3.08%) and Acinetobacter (1.2%) at stage S2, Shewanella (25.95%) and Pseudoalteromonas (4.57%) at stage S5. Moreover, genus Pseudoalteromonas became dominant at stages S3 (44.85%) and S4 (56.02%), followed by Photobacterium (29.82%), Pseudomonas (11.86%), Aliivibrio (8.60%) and Shewanella (3.39%) at stage S3, Pseudomonas (18.16%), Aliivibrio (14.29%), Shewanella (4.11%), Psychromonas (4.04%) and Psychrobacter (1.81%) at stage S4. From the results, we concluded that the bacterial community changed significantly at different development stages of Yesso Scallop larvae.  相似文献   

18.
We evaluated the effect of pH on larval development in larval Pacific oyster (Crassostrea gigas) and blood cockle (Arca inflata Reeve). The larvae were reared at pH 8.2 (control), 7.9, 7.6, or 7.3 beginning 30 min or 24 h post fertilization. Exposure to lower pH during early embryonic development inhibited larval shell formation in both species. Compared with the control, larvae took longer to reach the D-veliger stage when reared under pH 7.6 and 7.3. Exposure to lower pH immediately after fertilization resulted in significantly delayed shell formation in the Pacific oyster larvae at pH 7.3 and blood cockle larvae at pH 7.6 and 7.3. However, when exposure was delayed until 24 h post fertilization, shell formation was only inhibited in blood cockle larvae reared at pH 7.3. Thus, the early embryonic stages were more sensitive to acidified conditions. Our results suggest that ocean acidification will have an adverse effect on embryonic development in bivalves. Although the effects appear subtle, they may accumulate and lead to subsequent issues during later larval development.  相似文献   

19.
Surveys were conducted in five voyages in Haizhou Bay and its adjacent coastal area from March to December 2011 during full moon spring tides. The ichthyoplankton assemblages and the environmental factors that affect their spatial and seasonal patterns were determined. Totally 35 and 12 fish egg and larvae taxa were identified, respectively. Over the past several decades, the egg and larval species composition has significantly changed in Haizhou Bay and its adjacent waters, most likely corresponding with the alteration of fishery resources, which are strongly affected by anthropogenic activities and climate change. The Bray-Curtis dissimilarity index identified four assemblages: near-shore bay assemblage, middle bay assemblage and two closely related assemblages(near-shore/middle bay assemblage and middle/edge of bay assemblage). The primary species of each assemblage principally reflected the spawning strategies of adult fish. The near-shore bay assemblage generally occurred in near-shore bay, with depths measuring 20 m, and the middle bay assemblage generally occurred in the middle of bay, with depths measuring 20 to 40 m. Spatial and seasonal variations in ichthyoplankton in each assemblage were determined by interactions between biological behavioral traits and oceanographic features, particularly the variation of local conditions within the constraint of a general reproductive strategy. The results of Spearman's rank correlation analysis indicated that both fish egg and larval abundance were positively correlated with depth, which is critical to the oceanographic features in Haizhou Bay.  相似文献   

20.
Wang  Xiaobing  Bai  Yang  Huang  Bo 《中国海洋湖沼学报》2010,28(6):1261-1265
Journal of Oceanology and Limnology - Low larval survival, poor settlement, and abnormal metamorphosis are major problems in seed production of donkey-ear abalone Haliotis asinina. We examined the...  相似文献   

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