Construction of a genetic linkage map for silver carp (Hypophthalmichthys molitrix)

For silver carp (Hypophthalmichthys molitrix), a combined microsatellite (or simple sequence repeat) and amplified fragment length polymorphism (AFLP) sex average linkage map was constructed. A total of 483 markers (245 microsatellites and 238 AFLPs) were assigned to 33 linkage groups. The map spanned 1352.2 cM, covering 86.4% of the estimated genome size of silver carp. The maximum and average spaces between 420 loci were 21.5 cM and 3.2 cM, respectively. The length of linkage groups ranged from 3.6 cM to 98.5 cM with an average of 41.0 cM. The number of markers per group varied from 2 to 44 with an average of 14.6. The AFLP markers significantly improved the integrity of microsatellite-based linkage groups and increased the genome coverage and marker evenness. A genome-wide recombination suppression was observed in male. In an extreme case, six microsatellites co-segregated in male, but spanned a 45.1 cM region in female.     

鱼类染色体G—显带的Brd U—BSG方法及白鲢G—带模式图的初步建立

本文报道了一种显示鱼类染色体G-带的BrdU-BsG方法。采用肾细胞短期培养,收获前12小时加入BrdU,使终浓度为10μg/ml。制片经HCl、Ba(OH)_2处理,4×SSC温育。Giemsa染色,显示出白鲢的G-带。其带纹细致清晰,一个细胞的单倍染色体上显示带纹达200条以上,是目前已报道的鱼类多重带中带纹最多的,且反差明显,带纹有特征性,结果较稳定。根据实验结果初步建立了白鲢的G-带模式图。     

The nutrition of stomachless phytoplanktivorous fish in comparison with Tilapia

The contents of alimentary tracts of stomachless phytoplanktivorous fish, including silvercarp (Hypophthalmichthys molitrix), Esomus danrica thermoicos, and Amblypharyngodon meletinus were investigated microscopically and compared with those of Tilapia (Oreochromis mossambicus, a fish with stomach).The predominance of detritus in the food and the low efficiency with which phytoplankton is utilized prove, that stomachless fish are not primarily herbivorous. The possibility of omnivorous feeding as an alternative is discussed. These results may contribute to our understanding of the role of filterfeeders in aquaculture and ecosystems.     

长江鲢、鳙个体发育过程中的表型变化

采用多元分析方法,对采自长江老江河国家级四大家鱼原种场255尾1—5龄鲢、鳙的30项形态度量数据进行了分析。聚类分析显示,鲢可明显地聚成欧氏距离相对较远的1龄组和2—5龄组,鳙也可聚成欧氏距离较远的1、2龄组与3—5龄组。判别分析显示,144尾鲢个体对所聚类的两个组别的判别准确率高达98.0%,111尾鳙个体对所聚类的两个组别的判别准确率也达90.7%。这表明,在幼体向成体的发育过程中,鲢和鳙在形态上均存在着两个具有显著差异阶段。单因素方差分析显示,鲢两个组别之间有18个参数差异极显著,4个差异显著,其中10个显著或极显著地变小,12个显著或极显著地变大。鳙两个组别间有极显著和显著差异的参数分别有14个和3个,其中极显著或显著差异变小和变大的分别有12个和5个。这表明在鲢、鳙个体发育过程中,分别有73.3%和56.7%的特征参数具有生长异速现象。因此,在根据形态鉴别物种、分析种群差异、确立种质标准和作生长退算时,均应考虑所选用特征的生长异速现象。     

Cross‐species amplification in silver carp and bighead carp with microsatellite primers of common carp

About a third of microsatellite primers designed for common carp (Cyprinus carpio) was successfully amplified in silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis). These markers, inherited in Mendelian mode, are of potential applications in cypinid genetics.     

白鲢鳃部血管的研究

本文用甲基丙烯酸甲脂铸型技术,配合扫描电镜,研究白鲢鳃部血管的分布。鳃区具有双血液循环,动脉—动脉循环,主司血液与水体间气体交换;动脉—静脉循环主司鳃区营养交换。入鳃丝动脉上具有膨大的“血泡”结构,可能起“鳃心”作用,当鳃丝内收时将血液输送入入鳃动脉。伪鳃鳃小片彼此排列紧密,这种结构似不利于气体交换,可能没有什么呼吸功能。     

First U.K. recording in the wild of the bighead carp Hypophthalmichthys nobilis

Five specimens of bighead carp Hypophthalmichthys nobilis were captured from a lake in eastern England in January 2006, their first confirmed recording in the wild in the U.K. They varied in fork lengths from 746 to 796 mm and mass from 10·0 to 13·5 kg. All the fish were age 9 years and were slow growing compared to populations elsewhere in their expanded range.     

鲢鳙对鱼粪消化利用的研究

以鱼粪代表天然水体中有机碎屑,研究鲢、鳙对鱼粪的消化利用,并评价有机碎屑在鲢、鳙营养中的作用。在实验室条件下(水温30℃,溶氧6毫克/升以上,pH7—8,光照度2800lx),收集鲢、鳙摄食微囊藻后排出的粪作为试验用饲料。在限制摄食量的条件下,测定鱼对鱼粪的消化率及研究鱼粪对鲢、鳙生长的影响。研究结果是:(1)鲢、鳙对鱼粪中干物质消化率分别为58.54±9.53％及68.57±8.98％。其中蛋白质消化率分别为74.49±7.96％及80.41±9.02％,脂肪消化率分别为90.23±15.33％及84.24±6.96％,碳水化合物分别为49.14±20.67％及60.36±11.29％;(2)经10天饲养,鲢、鳙体重增重率分别为6.25±3.46％及7.80±3.18％。根据鱼粪的营养价值及鲢、鳙对鱼粪的能量转化率,表明鲢、鳙鱼粪在鲢、鳙营养中起着一定作用。     

Richness and diversity of helminth parasite communities in the common carp and in three more recently introduced carp species

It can be predicted that common carp Cyprinus carpio , as an introduced species, would harbour poor helminth infra-communities but that these would nevertheless be richer than those in three other species of carps introduced into Europe in recent decades. These predictions were tested by comparing the helminth infra-communities of common carp, Ctenopharyngodon idella, Hypophthalmichthys molitrix and Aristichthys nobilis reared under similar conditions in a fish farm. Data were presented on species richness of total helminth infra-communities, and on richness and diversity of gill, eye and intestinal infra-communities separately. These confirmed that common carp helminth infra-communities were poor and that they were no richer than those of the three other species of carp. This situation in the farm was considered to be representative of the situation in natural habitats in Europe. It is suggested that the poor infra-communities in common carp reflect the facts that their helminth communities are composed mainly of specialists, that they are not readily susceptible to invasion by specialists of other fish hosts and that, as introduced species, they have not had sufficient time to acquire many generalist helminths from native species of fish. The difference in time between the introduction of common carp into Europe centuries ago and the introduction of the other three species of carps decades ago is not sufficient to produce any significant differences in the richness and diversity of their helminth infra-communities.     

二龄鲢和鳙血液的比较研究

以１１５尾二龄链和９１尾二龄鳙为材料,测定了血液中红细胞数,白细胞数、血红蛋白值、红细胞脆性植、比积及比重,红细胞沉降率,白细胞分数计数值及各型血细胞大小等正常值。结果显示：红细胞和白细胞值,比积值及淋巴细胞所占百分比值均是鲢高于鳙,而红细胞沉降率和中性粒细胞却是鳙高于链,在鲢上,其血液指标植也存在雌雄差异,上述血液指标值也存在周年变化。