牙鲆群体生化遗传学研究— — Ⅱ．等位酶的生化遗传分析

应用聚丙烯酰胺凝胶电泳技术对牙鲆[Paralichthys olivaceus(T.et S.)]养殖群体进行10种等位酶的电泳检测和谱带遗传分析,确定了21个等位酶位点和25个等位基因,单态位点有Est-2、Est-3、Aat-2、Sod-1、Sod-2、Ldh-1、Mdh-1、Me-1、Adh-2、Sdh-2、Sdh-3、Idh-1、Idh-2、Amy-1、Amy-2和Amy-3,而这些位点仅有1个等位基因。仅有Aat-l、Sdh-1、Adh-l、Est-1和Est-4(P_(0.99)标准)5个位点是多态的,多态位点的百分数为23.81％,而这些位点有2个等位基因。揭示了牙鲆群体等位酶位点及其等位基因带谱的变异式样,为牙鲆遗传育种及遗传结构的研究提供一批等位酶位点及其等位基因参考图谱。     

漠斑牙鲆染色体组型研究

以体长6cm左右的漠斑牙鲆幼鱼为材料,采用秋水仙素浸泡的方法,取鳃和鳍经低渗处理,空气干燥制片法制作染色体标本,最后经Giemsa染液染色进行核型分析。结果表明,漠斑牙鲆的染色体核型为2n=48,48t,染色体臂数为NF=48,未发现有多倍体的现象,也未发现性染色体和随体。     

温度、盐度对褐牙鲆（♀）×犬齿牙鲆（♂）杂交子一代胚胎发育和仔鱼存活的影响

探讨了温度、盐度对褐牙鲆（♀）×犬齿牙鲆（♂）杂交子一代（杂交F1）胚胎和初孵仔鱼发育的影响。结果表明，杂交F1受精卵孵化适宜温度范围和最适温度分别为15～21℃和18℃，在适宜温度范围内胚胎发育时间随温度的升高而缩短，二者符合乘幂函数关系式N=115．99T^-0.768.8（R^2=0．9769）。胚胎发育的生物学零度和有效积温分别是7．54℃和540．1℃·h，积算温度（A）与试验水温间呈乘幂函数相关，表达式：A=1328．1T^-0.3149。（R^2=0．9624）。胚胎发育的最低盐度界限为10，孵化的适宜盐度范围和最适盐度范围分别为10～45、25～35；初孵仔鱼生存发育的适宜盐度范围、最适盐唐范围分别为10～40和10～20。     

漠斑牙鲆人工繁育技术研究

本文研究了漠斑牙鲆亲鱼培育、产卵、受精卵孵化,仔稚鱼饵料系列的选择以及营养强化,并进行了人工授精试验,完善了漠斑牙鲆人工繁育技术工艺.结果表明:16～18 ℃为漠斑牙鲆最佳自然产卵水温;18～19 ℃水温下仔稚鱼的成活率较高.     

Quantitative genetic parameters for growth-related and morphometric traits of hatchery-produced Japanese flounder Paralichthys olivaceus in the wild

To understand quantitative genetic characteristics of hatchery‐produced Japanese flounder in the wild, heritability and genetic correlation of growth‐related and morphometric traits were examined in yearling released individuals at a coastal region in northeast Japan. Quantitative genetic parameters were estimated with restricted maximum likelihood following reconstruction of pedigree by a likelihood method using seven microsatellite loci. Estimates of heritability were 0.65 and 0.51 for growth‐related traits (body length and the proportion of body length to body depth) and 0.45–0.62 for morphometric traits (vertebral count and dorsal and anal fin ray counts). Genetic correlation was significantly positive (0.61) between dorsal and anal fin ray counts, indicating the possibility of pleiotropic genes or gametic phase disequilibrium for these traits. All the estimates of heritability and genetic correlation in the released individuals were close to those of hatchery‐reared juveniles, suggesting that yearling released individuals had similar quantitative genetic characteristics of growth and morphometric traits in the wild to hatchery‐reared juveniles.     

牙鲆病原迟钝爱德华氏菌的药物敏感性测定与分析

对分离并经鉴定的牙鲆病原迟钝爱德华氏菌进行了常用抗菌类药物的敏感性测定,结果表明供试的35株迟钝爱德华氏菌,均对所测定的37种抗菌类药物中的头孢唑啉等20种药物高度敏感、对青霉素G等5种药物耐药、对氨苄青霉素等12种药物表现在株间存在差异。     

Energy budget of the Japanese flounder Paralichthys olivaceus (Temminck & Schlegel) larvae fed HUFA-enriched and non-enriched Artemia nauplii

The energy budget of the Japanese flounder Paralichthys olivaceus (Temminck & Schlegel) larvae fed enriched (EA) and non‐enriched (NEA) Artemia nauplii was determined by equating energy intake (EI) with the summation of energy channelled to faeces (F), metabolism (M), excretion (U) and growth (G). Larvae (21 days post hatching, 2.2 mg mean wet wt) were reared in six 80‐L circular tanks with three replicates of 160 larvae per tank and fed EA and NEA for 20 days. EI was calculated from the energy content of consumed nauplii, M from the summation of energy for routine, feeding and active metabolisms, U from ammonia excretion and G from energy gained based on weight gain, while F was the difference between EI and the total of other components. The heat increment of larvae was calculated from the difference of O₂ consumption at post‐prandial and routine conditions. Except for G and F, variables were correlated to the dry body weight (W) of larvae in a power function: Y=aW^b. Coefficients a and b were estimated by regression after a logarithmic transformation of the raw data. Overall, growth and survival rates of the larvae fed EA were higher than those fed NEA. For a larval flounder growing from 2 to 20 mg wet wt, the ingested energy was partitioned as follows: 22.8% to faecal loss, 38.3% to metabolism, 1.5% to urinary loss and 37.4% to growth for the EA group, whereas 35.4% to faecal loss, 28.4% to metabolism, 1.3% to urinary loss and 34.9% to growth for the NEA group. Gross conversion and assimilation efficiencies were higher, but the net conversion efficiency was lower in EA‐fed larvae than NEA‐fed larvae. This study suggests that the higher growth and survival rates of the EA‐fed group compared with the NEA‐fed group were attributed to their higher intake of essential fatty acids, higher metabolism and lower energy loss of faeces.     

牙鲆疾病的诊断及防治（一）

结合养殖实践，参考日本９０年代最新研究成果，对牙鲆的各种病毒性，细菌性疾病的病原体、症状及防治方法了作了详细报道。     

Influence of California halibut (Paralichthys californicus) on the vertical distribution of dissolved oxygen in a raceway and a circular tank at two depths

The design and operation of aquaculture tanks should minimize stagnant areas especially in the immediate vicinity of the fish. In tanks with pelagic fish, mixing caused by the water flow and by fish swimming is sufficient to maintain dissolved oxygen and metabolite concentrations in the immediate vicinity of the fish that are similar to those in the main water body. Given the behavior of sedentary benthic species, such as the California halibut (Paralichthys californicus), and their tendency to remain motionless on the bottom of aquaculture tanks, often in layers that are several fish deep, water quality may stratify with the worse conditions occurring in the area where they fish are lying. The purpose of this study was to evaluate the influence that California halibut (450 g average weight) may have on the vertical profile of oxygen concentration in a raceway (239 cm long, 28 cm wide) and a circular tank (92 cm diameter) operated at two water depths (10 and 20 cm). Oxygen was measured at each centimeter of the vertical profile both in an area with fish and without fish to assess their influence.

Results showed a lower oxygen concentration in the near-bottom region of the raceway and circular tanks. The phenomenon was most pronounced in the raceway operated at a 20 cm depth, but was also observed in the circular tank operated at 20 cm and in the raceway at 10 cm.

Measurements were also taken in samples collected just in front of or directly from a fish's mouth. A zone of depressed oxygen concentration in the immediate vicinity of the fish was documented, with oxygen concentrations as low as 50% of the measured tank effluent concentration. The magnitude of the depression was greater in raceways than in circular tanks and in 20 cm water depth than in 10 cm depth. The fish remained sedentary in these zones of depressed oxygen concentration for extended periods of time and frequently exhibited hyperventilation. The oxygen concentrations in the vicinity of the fish were consistently lower than the concentrations measured in the tank effluent. Therefore, effluent measurements did not provide an accurate representation of conditions to which the fish were exposed.