Divergent selection for shell length in two stocks of small abalone Haliotis diversicolor

To determine whether genetic improvement can be attained through a selective breeding programme, divergent selection for shell length was applied to two stocks of Haliotis diversicolor. Stock A was descended from the cross between males from a Japanese wild population and females from a Taiwan aquacultured population and Stock B was from the Taiwan cultured population, which had been successively cultured in mainland China for about 10 generations. The 10% largest and 10% smallest abalones for each of these two stocks were selected as parents for the large‐selected and small‐selected lines respectively. Equal numbers of abalone were randomly chosen from the two stocks to serve as parents for the control lines before the selection. The selected and control lines were reared under the same conditions at early juvenile, later juvenile and grow‐out stages. Stock A showed a significantly higher response to selection and realized heritability than Stock B (P<0.01). The large‐selected line of Stock A and Stock B grew 12.79% and 4.58% faster than their control lines on shell length respectively. The average realized heritability for shell length was 0.441±0.064 for Stock A and 0.113±0.013 for Stock B. Responses to selection were different at different ages in each stock and the body weights of the selected lines were significantly different from the control lines in both stocks at the grow‐out stage. Asymmetric responses to selection in the two directions were also observed in both stocks. Differences in response to selection and realized heritability between the two stocks are presumably due to genetic variability.     

高锰酸钾及甲醛对九孔鲍受精卵及面盘幼虫的毒性试验

用不同浓度高锰酸钾溶液及甲醛对九孔鲍受精卵和面盘幼虫进行毒性试验。结果表明:高锰酸钾对九孔鲍受精卵的6hLC50、12hLC50分别为:2.66×10-6,2.03×10-6,;对九孔鲍面盘幼虫的24hLC50、48hLC50和安全浓度分别为:4.34×10-6,2.82×10-6,0.357×10-6,甲醛对九孔鲍面盘幼虫的24hLC50、48hLC50和安全浓度分别为:38.5×10-6,31.05×10-6,6.05×10-6。     

杂色鲍对底泥悬浮物胁迫的生理响应

研究了不同浓度的底泥悬浮物(100、200、300、400 mg/L)对杂色鲍Haliotis divericolor的急性毒性以及对其血清中一氧化氮(NO)、一氧化氮合酶(NOS)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)的影响。分别在处理后24、48、72、96 h从杂色鲍足部取血,测定其血清中NO含量和NOS、SOD、CAT活性,并记录了24、48、72、96 h时杂色鲍的存活情况。结果表明:在处理后96 h内,对照组和试验组的杂色鲍均未出现死亡,但300 mg/L和400 mg/L试验组鲍的活性明显下降;用悬浮物处理后,杂色鲍血清中NO含量及NOS活力显著高于对照组(P<0.05),且NOS活性的最大值出现的较NO最大值早;试验组SOD活性和CAT活性在24 h后显著低于对照组(P<0.05)。表明底泥悬浮物浓度对杂色鲍的生理生化存在一定影响。     

Identification of juvenile abalone <Emphasis Type="Italic">Haliotis diversicolor</Emphasis> based on number of open and sealed respiratory pores

ABSTRACT:   Changes in the number of respiratory pores (open pores) and their imprints (sealed pores) in post-larvae and juveniles were observed and compared for four abalone species Haliotis diversicolor , H. discus discus , H. madaka , and H. gigantea . The first open pore was evident at a shell length (SL) of 1.5 mm in H. diversicolor , 1.9–2.0 mm SL in H. discus discus , and 2.3–2.4 mm SL in H. madaka and H. gigantea . The number of open pores in H. diversicolor gradually increased with growth, with four to five pores at 2.5–18.0 mm SL and five to six pores at 18.0–27.0 mm SL. The other three species maintained four to five open pores after they reached 3.4–4.5 mm SL. The total number of open and sealed pores (TNP) was greater in H. diversicolor than in the other species at the same SL. Juvenile H. diversicolor were identified among field-caught abalone by the difference in the relationship between SL and TNP (SL–TNP relationship) and also by the monoclonal antibody reaction method. The results of the two methods were in perfect agreement, indicating that our method using the SL–TNP relationship is reliable for the identification of H. diversicolor .     

金属蛋白酶组织抑制剂在皱纹盘鲍抗弧菌免疫中的作用

由弧菌感染引起的疾病是影响鲍存活率的主要因素,实验以皱纹盘鲍为研究对象,探讨金属蛋白酶组织抑制剂(tissue inhibitor of metalloproteinase,TIMP)在皱纹盘鲍抗弧菌免疫中的功能及其与基质金属蛋白酶1 (matrix metalloproteinase 1,MMP-1)的相互作用关系....     

Influence of 18:2n‐6/20:5n‐3 ratio in diets on growth and fatty acid composition of juvenile abalone,Haliotis discus hannai Ino

A 120‐day feeding trial was conducted to examine the effects of the ratio of dietary linoleic acid (LA, 18:2n‐6) to eicosapentaenoic acid (EPA, 20:5n‐3) on the growth and fatty acid composition of juvenile Haliotis discus hannai (initial shell length 10.23 ± 1.48 mm; initial body weight 0.13 ± 0.05 g) in a recirculation water system. Five semipurified diets with 35 g kg^?1 total lipid were formulated to contain graded LA/EPA ratios (1 : 0, 0.75 : 0.25, 0.5 : 0.5, 0.25 : 0.75, and 0 : 1, respectively). Twenty‐five juveniles were stocked in a rearing unit, a plastic basket (20 × 20 × 10 cm), as a replicate, and there were three replicates for each dietary treatment. The results showed that abalone survival rates were generally high (90.1–98.3%) and independent of the dietary treatments. However, abalone growth was significantly affected by LA/EPA ratio (P < 0.05). The LA/EPA ratio of 0.25 : 0.75 (Diet 4) produced the highest weight gain rate (WGR, 416.3%), closely followed by the ratio of 0 : 1 (Diet 5, 412.9%), the ratio of 0.5 : 0.5 (Diet 3, 399.7%) and the ratio of 0.75 : 0.25 (Diet 2, 372.1%), but no significant differences were observed among these treatments. The abalone fed the diet without 20:5n‐3 (Diet 1) had the lowest WGR (Diet 1, 363.8%), which was significantly lower than that of Diet 4. Fatty acid profiles in abalone body reflected those of dietary lipids, especially for the polyunsaturated fatty acids. The contents of arachidonic acid (AA; 20:4n‐6) in abalone tissues were positively correlated with dietary level of 18:2n‐6 (P < 0.05). Similar correlation was also observed between the level of docosahexaenoic acid (DHA, 22:6n‐3) in abalone tissues and the level of dietary EPA. It is suggested that abalone, H. discus hannai, have the capacity to synthesize 20:4n‐6 from 18:2n‐6, and maybe 22:6n‐3 from 20:5n‐3.     

Highly efficient induction of triploid Pacific abalone <Emphasis Type="Italic">Haliotis discus hannai</Emphasis> by caffeine treatment

ABSTRACT:   In order to develop a highly efficient method for mass production of triploid Pacific abalone Haliotis discus hannai , caffeine treatment that is safe and inexpensive was optimized. To suppress the first meiotic division, fertilized eggs were exposed to either a 10- or 15-mM caffeine solution for 24 min beginning at 12 min after fertilization. In most treated batches, the rates of cleaved eggs showed no significant difference from the control batches. However, in most treated batches, the rates of occurrence of normal larvae and the survival rates of the early juveniles were significantly lower than those of the controls. The triploid rates at 6 days to 11 months after settlement in all the treated batches were extremely high (91–100%). There was no significant difference in the mean triploid rates between 10- and 15-mM caffeine treatments. These results suggest that both treatment conditions were conducive to triploid abalone production. One live 2n/3n mosaic specimen was found in the treated batches. However, since the frequency of mosaic was extremely low, the mosaicism would probably not have an adverse effect on the stable production of triploid abalones.     

皱纹盘鲍消化道粘液细胞的类型与分布

采用阿新兰—过碘酸雪夫氏反应 (AB -PAS)染色方法显微观察和分析了皱纹盘鲍成贝消化道粘液细胞的类型与分布。据所显示颜色的不同 ,将粘液细胞分为Ⅰ—Ⅳ 4种类型 :分别呈红色、蓝色、紫红色和蓝紫色。口区唇上皮分布有大量粘液细胞 ,以Ⅱ型为主 ,另有少量Ⅳ型 ,主要为杯形并多为大型细胞。口球上皮及齿舌囊上皮粘液细胞分布密度高 ,以Ⅱ型为主 ,Ⅳ型次之。食道前段上皮有大量粘液细胞分布 ,中段和后段粘液细胞逐步减少 ,主要为Ⅱ型。肠各段上皮均有粘液细胞分布 ,但下行肠道比上行肠的粘液细胞相对多些 ,也以Ⅱ型为主 ,多为杯形和近圆形。直肠内、外上皮均有大量Ⅱ型粘液细胞分布 ,近圆形的较多。在嗉囊、胃盲囊和胃未见明显着色的粘液细胞     

盐度和胁迫时间对九孔鲍α-淀粉酶基因表达量的联合效应分析

采用中心复合设计和响应曲面法研究了盐度和胁迫时间对九孔鲍(Haliotis diversicolor supertexta)?-淀粉酶基因表达量影响的联合效应,旨在为九孔鲍盐度驯化及海区推广提供指导。实验设定盐度范围为22~40,时间范围为0~72 h,建立了盐度、胁迫时间与?-淀粉酶基因表达量之间关系的定量模型,并通过分析明确了盐度和胁迫时间的最优组合。结果表明,盐度对九孔鲍?-淀粉酶基因表达量影响的一次效应不显著(P0.05),而二次效应极显著(P0.01),说明盐度与九孔鲍?-淀粉酶基因表达量之间为非线性关系。随盐度升高,淀粉酶基因表达量呈先上升后下降的变化趋势,当盐度为31时淀粉酶基因表达量最大,此时九孔鲍消化能力最强。胁迫时间对淀粉酶基因表达量影响的一次效应显著(P0.05),二次效应不显著(P0.05),表明胁迫时间与九孔鲍?-淀粉酶基因表达量之间呈线性关系,即随着胁迫时间的延长,淀粉酶基因从开始低水平表达逐渐升高并恢复至正常表达水平。盐度和胁迫时间之间不存在交互作用。对实验结果建立模型可知,?-淀粉酶基因表达回归模型达极显著水平(P0.05),且失拟项不显著(P0.05),表明实验拟合出的方程有效。回归方程的决定系数为80.05%,校正系数65.80%,预测系数50.18%,表明方程拟合度较好,模型选择较为恰当,可以为不同盐度和胁迫时间诱导下的淀粉酶基因表达量变化提供参考依据。     

鲍消化道及其养殖水体异养菌的耐药性研究

采用纸片扩散法对分离自福建省皱纹盘鲍(Haliotis discus hannai)消化道及其养殖水体中的284株异养细菌(其中消化道菌131株,水体菌153株)进行药物敏感测试,以期了解其耐药性概况。结果显示,皱纹盘鲍消化道与养殖水体异养菌对多种抗菌药物的耐药率差异不明显,大部分菌株对青霉素、卡那霉素、庆大霉素、利福平产生耐药性,耐药率最高达83.95%,而对诺氟沙星、恩诺沙星、氯霉素耐药率较低,受试的水体异养菌对诺氟沙星耐药率为0;不同来源菌株的多重耐药(multiple antibiotic resistance,MAR)现象普遍,消化道及其养殖水体异养菌的多重耐药率均值分别为59.15%和51.31%。该研究同时发现相同分离源的菌株对青霉素、卡那霉素、庆大霉素和利福平的耐药率呈现一定的季节波动规律,消化道异养菌于9月耐药率最低,而水体异养菌耐药率在6月最低。结果表明,皱纹盘鲍消化道及水体异养菌的多重耐药率较高,耐药状况较严重。