黑龙江流域两种细鳞鲑的形态学比较及其分类地位初探

对比研究了分布于我国黑龙江流域具钝吻和尖吻两种形态特征的细鳞鲑,其主要形态学性状的显著差异达到种间分化水平.细鳞鲑属Brachymystax在中国应有两个种,分别为图们江细鳞鲑B.tumensis(具钝吻特征)和细鳞鲑B.lenok(具尖吻特征).  

阿根廷滑柔鱼两个群体间耳石和角质颚的形态差异

头足类硬组织具有稳定的形态特征、良好的信息储存以及抗腐蚀性等特点。根据2007年2—5月和2010年1—3月我国鱿钓船采集的阿根廷滑柔鱼样品,提取出625对耳石和787对角质颚,测量耳石10个形态数据和角质颚12个形态数据,通过除以胴长(Mantle Length,ML)校正后,对南巴塔哥尼亚群体(South Patagonic Stock,SPS)和布宜诺斯艾利斯-巴塔哥尼亚群体(Bonaerensis-Northpatagonic Stock,BNS)形态差异进行分析,并建立不同群体的判别函数。结果表明,BNS群体耳石和角质颚外形参数雌性大于雄性,而SPS群体则为雄性大于雌性。均数差异性检验认为,同一群体不同性别的耳石总长(Total StatolithLength,TSL)、最大宽度(Maximum Width,MW)、侧区长(Lateral Dome Length,LDL)、翼区长(Wing Length,WL)、翼区宽(WingWidth,WW)存在显著差异(P<0.05),同性别不同群体的MW、背侧区长(Dorsal Lateral Length,DLL)、吻侧区长(RostrumLateral Length,RLL)和WW存在显著差异(P<0.05)。而同一群体不同性别间角质颚的上头盖长(Upper Hood length,UHL)、上脊突长(Upper Crest length,UCL)、上喙长(Upper Rostrum length,URL)、上喙宽(Upper rostrum width,URW)、上侧壁长(UpperLateral wall length,ULWL)、下喙长(Lower Rostrum length,LRL)存在显著差异(P<0.01),同一性别不同群体角质颚的下头盖长(Lower Hood length,LHL)、下脊突长(Lower crest length,LCL)、LRL、下喙宽(Lower Rostrum width,LRW)、下侧壁长(LowerLateral wall length,LLWL)、下翼长(Lower Wing length,LWL)存在显著差异(P<0.01)。耳石形态参数经主成分分析,认为BNS群体雌雄的主成分因子主要集中在TSL/ML、DLL/ML、RW/ML和MW/ML,SPS群体主要集中于TSL/ML、RW/ML、WW/ML和DDL/ML;角质颚形态参数经主成分分析,认为BNS群体主成分因子主要集中在UHL/ML、UCL/ML、ULWL/ML和LRW/ML,SPS群体主要集中在UHL/ML、UCL/ML、ULWL/ML、URL/ML、LWL/ML和LRL/ML。利用角质颚和耳石对两群体样本分性别建立了判别函数,判别正确率均高于60%,所划分群体在部分形态指标上差异明显,具有一定的可信度。今后应加强样本采集个体大小和时间跨度,以更好的分析其群体变化规律。  

组培广藿香形态特征及挥发油成分分析

对原产于广州石牌和海南的两个广藿香(Pogostemon cablin)栽培品种进行组织培养并获得了再生植株.用GC法对广藿香再生植株的挥发油成分进行分析研究.结果表明,广藿香两个品种的再生植株生长2～3个月后形态上有明显的差异.生长3个月的再生植株中,原产于广州石牌的广藿香挥发油含量为1.4%,低于原产于海南的广藿香(2.9%);而挥发油的成分中,广州石牌广藿香的广藿香酮含量为375.76 mg ml1,显著高于海南广藿香(7.82 mg ml1).这说明组织培养获得的再生植株保持了其原植物在形态、挥发油含量和成分上的差异性,为广藿香的品种分类提供了实验依据.  

Two morphological types in the reproductive stock of three-spined stickleback,Gasterosteus aculeatus,in Lake Harutori,Hokkaido Island

Synopsis Two morphological types of the trachurus form (completely plated morph) of three-spined stickleback, Gasterosteus aculeatus, are found in Lake Harutori, Kushiro, east district of Hokkaido Island. For convenience, the two forms are referred to as ‘large type’ and ‘small type’ on the basis of body length (discrimination at 70 mm in length). The two types were examined for morphometric, meristic and reproductive characteristics. They differ in body length, the number of lateral plates, means of the 2nd dorsal spine length/body length and of the pelvic spine length/body length, the relationship between body length and head length, between body length and gonad weight, between body weight and gonad weight, and between body length and ovarian egg number; significant differences were present for each sex. These two types were compared with the anadromous stickleback migrating into the freshwater area near Lake Harutori to breed. The anadromous fish was morphologically much more similar to the large type than the small type. It is suggested that the large type is also an anadromous form and the small type is the permanent freshwater resident.  

两种鼢鼠内脏器官形态差异及其分类学意义

分子生物学研究表明,甘肃鼢鼠(Eospalaxcansus)和高原鼢鼠(Eospalax baileyi)是啮齿目(Rodentia),鼹形鼠科(Spalacidae),鼢鼠亚科(Myospalactinae),中华鼢鼠属(Eospalax)的两个  

Comparison of genetic and morphological methods to detect the presence of American lobsters, <Emphasis Type="Italic">Homarus americanus</Emphasis> H. Milne Edwards, 1837 (Astacidea: Nephropidae) in Norwegian waters

American lobsters (Homarus americanus H. Milne Edwards, 1837) are imported live to Europe and should according regulations be kept in land-based tanks until sold. In spite of the strict regulations aimed specifically at preventing the introduction of this species into the NE Atlantic, several specimens of H. americanus have been captured in the wild, especially in Oslofjord, Norway since 1999. One of the great concerns is interbreeding between the introduced American species and the local European lobster, H. gammarus (Linnaeus, 1758). For this reason an awareness campaign was launched in 2000 focusing on morphologically “unusual” lobsters caught in local waters. Morphological characters have been based on colour and sub-ventral spines on the rostrum. Two samples of H. americanus were used for comparisons, as well as samples of European lobster from Oslofjord collected in 1992. Previous genetic analyses (allozymes, mtDNA and microsatellite DNA) have demonstrated that the American lobster is distinct from its European counterpart, with several additional alleles at many loci in addition to different allelic frequency distribution of alleles of “shared” alleles. During the present study, thirteen microsatellite loci were tested in the initial screening, and the three most discriminating loci (Hgam98, Hgam197b and Hgam47b) were used in a detailed comparison between the two species. A total of 45 unusual lobsters were reported captured from Ålesund (west) to Oslofjord (southeast) from 2001 to 2005 and these were analysed for the three microsatellite loci. Nine specimens were identified as American lobsters. Comparisons between morphological and genetic characteristics revealed that morphological differences are not reliable in discrimination the two species, or to identify hybrids. Further, some loci display almost no overlapping in allele frequency distribution for the reference samples analysed, thus providing a reliable tool to identify hybrids.  

环境因素对香蕉叶斑病菌喙突脐蠕孢生长和产孢的影响

为进一步明确香蕉叶斑病菌喙突脐蠕孢的生物学特性,调查了部分环境因素(碳氮源、植物成分培养基)对供试菌株(CLER09、D087和JL05)的营养生长和产孢的影响。结果显示,分生孢子主要先从基部萌芽,在28℃下约培养10h后出现两端萌芽;供试菌株对测试的20种碳源及26种氮源显示相似的生长反应,均可利用除菊糖外的测试碳源及氮源进行营养生长和产孢;测试的6种植物成分培养基对供试菌株的营养生长效果皆优于PDA培养基;除燕麦培养基外,其余5种培养基对菌株CLER09和D087的产孢作用均优于PDA培养基;测试的6种培养基对菌株JL05的产孢作用均优于PDA培养基。不同植物成分培养基对该菌分生孢子形态影响较大,以米糠、象草培养基对菌株D087和JL05的分生孢子长度和玉米粉培养基对菌株CLER09的分生孢子宽度的增长效果最为明显。  

Physiological and morphological characteristics of yeasts isolated from waste oil effluents

Pichia membranaefaciens, Cryptococcus laurentii, Rhodotorula glutinis and Candida krusei were isolated from contaminated sites. A significant variability in cell forms and in assimilation profiles was observed in the C. krusei strains. The chitin synthase activity and chitin content allowed us to differentiate three strain types. The variability of the phenotypic traits was higher in C. krusei strains isolated from heavily polluted sites. This revised version was published online in July 2006 with corrections to the Cover Date.  

A new species of Gonystylus (Thymelaeaceae) from Sarawak, Borneo

A new species, Gonystylus othmanii Tawan (Thymelaeaceae) from Sarawak (Borneo) is described and illustrated. It is considered to be endemic to Sarawak. The morphological differences between the new species and related taxa are included.  

Diploids v . triploids of Rutilus alburnoides: spatial segregation and morphological differences

Rutilus alburnoides complex is a common and widely distributed Iberian cyprinid, whose natural populations include mainly diploid and triploid forms. The Guadiana populations of R. alburnoides were studied to determine whether habitat segregation and morphological differences exist between these forms. The ploidy level of each specimen was determined by measuring erythrocyte DNA content using flow cytometry. Evidence of spatial segregation between diploid males and the two female forms was found. Diploid males were best represented in the River Degebe, which was shallow, with higher temperatures (especially during the spring and summer), and silt and sandy substrate. Diploid females were found in deeper water, on steeper gradients and coarse substrata, while triploid females preferred higher current velocity and a high proportion of instream cover, especially during the spring. The ecological differences may reduce competitive interactions, and should promote a stable coexistence of the different forms. Morphological distinction between fish of different ploidy levels was not established, but differences were found between the males and females. Discriminant analysis allowed, with a 10% error, the separation of both sexes through six morphological characteristics that could be recorded in the field.