COMPARATIVE KARYOLOGICAL ANALYSIS OF FIVE SPECIES OF VIVIPARUS (GASTROPODA: PROSOBRANCHIA)

Karyological analysis was performed on Viviparus ater (Cristofori& Jan, 1832), V. acerosus Bourguignat, 1862, V. mamillatus (Kuster),V. viviparus (Linnaeus, 1758) and V. contectus (Millet, 1813),collected from different freshwater bodies of Switzerland, Hungary,Albania, Italy and Lithuania. The karyotypes of V. acerosusand V. mamillatus are described for the first time. The diploidnumber of chromosomes in V. contectus equals 14, whereas indiploid sets of other studied species, 18 chromosomes are present.The karyotype formula is in V. contectus (5m + 2sm, NF = 28,in V. ater, 7m + 1sm-m + 1 sm, in V. acerosus and V. viviparus,8m + 1sm, NF = 36, in V. mamillatus, 6m + 1m-sm + 1sm-m + 1sm,NF = 36. In females of V. ater, V. mamillatus and V. acerosus,the heteromorphism of chromosome pair no. 8 was observed, witha sex-determining mechanism — ZW female /ZZ male. Although,Z and W chromosomes are metacentric, significant differences(P > 0.05, or P > 0.001) in their size were determined.The interspecific significant differences (P > 0.05) in karyotypesof V. ater, V. mamillatus, V. acerosus and V. viviparus weredetected by using one-way ANOVA and Bonferronis Multiple Comparisontests. Only chromosomes of the pair no. 5 were of similar shapein all of these species. The smallest interspecific differencewas between V. viviparus and V. acerosus. The intraspecifickaryological differences in relative chromosome length and centromericindex of V. contectus from lakes Garda (Italy), Olauka andAsveja (Lithuania) were observed in the chromosome pair no.5. (Received 29 March 1999; accepted 19 October 1999)     

中国小蛹螺属一新种记述(前鳃亚纲,蛹螺科)

在整理广西陆生贝类标本中得小蛹螺属1新种,即具槽小蛹螺Pupinella(Pupinopsis)sulcatus sp.nov.,对新种进行了详细描述,并与近似种进行了比较。     

A COMPARATIVE STUDY OF CHROMOSOMES IN FOUR SPECIES OF THEODOXUS (GASTROPODA: NERITIDAE)

Karyological analysis was performed on Theodoxus baeticus (Lamarck,1822), T. valentina (Graells, 1846), T. velascoi (Graells, 1846)and T. fluviatilis (Linne, 1758), collected from freshwaterbodies of eastern Spain. Cells possessing diploid chromosomenumbers of 2n 5 25 were most common in the tissues of males,whilst 2n 5 26 was most prevalent in females. The sixth pairof chromosomes had only one homologue in mitotic cells of males,indicating the XO/XX sex-determining mechanism. The absolutelength of chromosomes ranged from 1.65 to 6.33 mm. The relativesizes of chromosomes varied from 3.92 to 13.33% of the totalhaploid set length. In all species chromosome pairs no. 1, 4,7-13 were composed of metacentric, pairs no. 5 and 6of submetacentricchromosomes. Pairs no. 2 and 3 were submetacentric, subtelocentricor submeta- subtelocentric according to the species studied.There were significant differences (P, 0.05) among the relativelength, as well as centromeric indices of different chromosomepairs across the species. Karyological differences were greatestbetween T. fluviatilis and three other Theodoxus species. (Received 6 March 2000; accepted 8 May 2000)     

THE GENETIC RELATIONSHIPS OF THREE TAXA IN THE LITTORINA SAXATILIS SPECIES COMPLEX (PROSOBRANCHIA: LITTORINIDAE)

Three species in the Littorina saxatilis complex (the ovoviviparousL. saxatilis and the two oviparous species L. arcana and L.nigrolineata) were screened for the products of up to 22 lociusing gel elec-trophoresis. Analysis of allele frequencies andderived genetic distances showed that, with rare exceptionsin L. saxatilis and L. arcana, conspecific populations clusteredtogether. Sympatric pairs of populations showed significantdifferentiation at many polymorphic loci. The results confirmedthe biological reality of the three taxa, and did not suggestthe existence of any previously unrecognized species. The speciesare genetically closely related to each other, with Nei geneticdistances ranging from 0.035 to 0.083. (Received 24 October 1989; accepted 18 April 1990)     

SPECIES RECOGNITION AND PATTERNS OF POPULATION VARIATION IN THE REPRODUCTIVE STRUCTURES OF A DAMSELFLY GENUS

The selection pressures imposed by mate choice for species identity should impose strong stabilizing selection on traits that confer species identity to mates. Thus, we expect that such traits should show nonoverlapping distributions among closely related species, but show little to no variance among populations within a species. We tested these predictions by comparing levels of population differentiation in the sizes and shapes of male cerci (i.e., the clasper structures used for species identity during mating) of six Enallagma damselfly species. Cerci shapes were nonoverlapping among Enallagma species, and five of six Enallagma species showed no population variation across their entire species ranges. In contrast, cerci sizes overlapped among species and varied substantially among populations within species. These results, taken with previous studies, suggest that cerci shape is a primary feature used in species recognition used to discriminate conspecific from heterospecifics during mating.     

几种植物组织及其原生质体过氧化物酶同工酶的比较研究

对马尾松幼苗子叶和胚轴、甘蔗、小麦、烟草、黄花菜等幼叶及其原生质体的过氧化物酶同工酶(POI)分别作比较研究。观察到凡经纤维素酶处理的各植物组织POI酶带数均多于未经纤维素酶处理的组织的酶带数;除个别例外,后者一般又比无壁原生质体的酶带数多。此种差异随植株生长年龄而增大,表明植物组织内大部分POI主要存于质外体中。     

REPRODUCTIVE PATTERNS OF THE HAWAIIAN MONK SEAL

We evaluated reproductive patterns of the Hawaiian monk seal ( Monachus schauinslandi ) using a combination of fitted age-specific reproductive curves and analysis of reproductive patterns of individual females. We review the difficulties inherent in the acquisition and modeling of reproductive data with emphasis on the significance of reproductive senescence to populations with dissimilar age/sex compositions. Validation of the fitted reproductive parameters was accomplished by Monte Carlo sampling of parameter distributions to compare the expected number of pups with the observed production. Although the fitted reproductive functions appear to provide an acceptable fit to the raw reproductive data, we found that the fitted curves did a poor job of predicting the actual pup production in individual years because of high variability among years. To further verify, and elaborate on, the patterns in the pooled (multi-seal, and multi-year) rates, we examined attributes of the reproductive performance of individual seals. The attributes included age of primiparity, reproductive rates computed over several age ranges, and the relationship between reproductive performance and seal longevity. Analysis of individual seal patterns reinforced the conclusion that reproductive senescence is operative in monk seal populations.     

INTER AND INTRA-SPECIFIC VARIATION OF THE SHELL OF TWO SPECIES OF THE TROPICAL FRESHWATER SNAIL BELLAMYA (MOLLUSCA: PROSOBRANCHIA)

Shell variation in two species of the tropical freshwater snailBellamya from two different habitats, was studied. The variation of the shell features studied, which includedthe shell width, spire height, aperture height and aperturewidth, were found to be related to shell height. Furthermore,significant difference in the shell shape was found not onlybetween the two species but also between males and females ofeach species. (Received 18 August 1983;     

五种石黄衣中次生代谢产物的高压液相色谱分析*

对于五种石黄衣Xanthoria中的次生代谢产物进行了高压液相色谱(HPLC)分析。它们是刺盘石黄衣Xanthoria alfredi、拟石黄衣X. fallax、丽石黄衣X. elegans、粉芽石黄衣X. sorediata和中国石黄衣X. mandschurica。分析结果表明,按照石黄酮(parietin)对拟石黄醛(fallacinal)与黄枝醇(teloschistin)在石黄衣中的相对含量百分比之商将五种石黄衣划分为E组 (Q>14) 和F组 (Q<1.20)。 其中丽石黄衣和粉芽石黄衣属于E组,裂片通常较狭窄,无假根;刺盘石黄衣和拟石黄衣属于F组,裂片通常较宽,具有假根。中国石黄衣中既有E组个体,又有F组个体。对于中国石黄衣的特殊现象仍需要进一步研究。此外,一份拟石黄衣标本的HPLC图谱亦显示了种内化学多样性。     

五种稻蝗染色体核型和C带带型的比较

本文研究了五种稻蝗Oxya chinensis、O. shanghaiensis、O. adentata、O. hyla intricara、O. agavisa的染色体核型和C带带型.玻片制备采用压片法,BSG法C带处理.结果表明:五种稻蝗染色体核型差异较小,具有属的保守性,但在C带方面则显示出一定的差别,种间染色体带型的差异大小与形态学上的差异程度具明显的正相关.其中小稻蝗和山稻蝗各自具有独特的带型结构,与其余三种显然不同,而中华稻蝗、上海稻蝗、无齿稻蝗虽在主要标志性染色体上带纹趋于一致,但在一些细微结构和统计数据方面存在一定差异.本文对五种稻蝗减数分裂中期Ⅰ的染色体数目和交叉定位也作了统计和比较,在染色体行为分析方面做了初步工作.据此,本文讨论了五种稻蝗的染色体分类问题.     

THE REPRODUCTIVE BIOLOGY OF COLUS JEFFREYSIANUS (GASTROPODA: PROSOBRANCHIA) FROM 2200 m IN THE N.E. ATLANTIC

The reproductive biology of Colus jeffreysianus, collected aspart of a time-series sampling programme at 2200 m in the NorthernRockall Trough, is described. The gross morphology of the reproductiveorgans of this deep-water species does not differ significantlyfrom confamilial species in shallow water. Gametogenesis inboth females and males is a continuous process with no apparentchange in the proportion of the various developmental stagesin relation to the time of year. No post-spawning individualswere found. Maximum oocyte diameter was 170 µM, suggestinglecithotrophic development. In the testis polymorphic spermatozoawere found. The reproductive pattern observed is discussed inrelation to feeding strategy and developmental type. (Received 22 April 1985;     

贵州环口螺科一新种(前鳃亚纲:中腹足目:环口螺科)

1998年7-8月作者在贵州南部地区考察,获得陆生贝类标本一批,经鉴定发现1新种,即茂兰腹皱螺Gastroptychia maolanensis sp.nov。隶属于前鳃亚纲,中腹足目,环口螺科,腹皱螺属。描述了新种形态特征,栖息环境,并对其近似种进行了讨论。     

中国栉属五新种(拟步科:朽木亚科)

本文描述了拟步科、朽木亚科、栉属（CteniopinusSeidlitz,1896）的五个新种：光滑栉Cteniopinusglabratussp.nov.;隆背栉Cteniopinusprotuberanssp.nov.;棕毛栉Cteniopinusbrunneicapilussp．nov．;异点栉Cteniopinusdiversipunctatussp.nov.和小栉Cteniopinusparvussp.nov.。模式标本保存在宁夏农学院昆虫标本室。     

REPRODUCTIVE PATTERNS SHAPE INTROGRESSION DYNAMICS AND SPECIES SUCCESSION WITHIN THE EUROPEAN WHITE OAK SPECIES COMPLEX

The reproductive system of hybrids is an important factor shaping introgression dynamics within species complexes. We combined paternity and parentage analyses with previous species characterization by genetic assignment, to directly identify reproductive events that occurred within a stand comprising four European white oak species. Comparing species status of parent pairs provided a precise quantification of hybridization rate, backcrosses, and intraspecific matings in two life stages. The detailed mating system analysis revealed new findings on the dynamics of interspecific gene flow. First, hybrids acted successfully as both male and female during reproduction. They produced acorns and seedlings that were as viable as those sired by purebreds. Second, species maintenance could be due to a relatively low level of interspecific mating contrasting with a large proportion of intraspecific crosses and backcrosses. Despite a high proportion of hybrids and extensive interspecific gene flow, partial species integrity is maintained by genetically controlled pollen discrimination, ensuring preferential matings within purebreds and high parental species fidelity in hybrid reproduction, which impedes complete collapse into a continuous hybrid swarm. Finally, we showed that pollen from the different species had unequal contributions to reproduction suggesting that introgression processes could ultimately lead to extirpation or expansion of some species.     

FIVE NEW SPECIES OF THE GENUS PYGOPHORA FROM CHINA (DIPTERA: MUSCIDAE)

Abstract This paper reports five new species of Pygophora Shiner from China, namely P. immacularis Cui et Xue, P. orbiculata Cui et Zhang, P. capitata Cui et Xue, P. digitata Cui et Xue and P. choui Cui et Xue.
The type-specimens are kept as follows: P. immacularis , in the Institute of Zoology, Academia Sinica; P. capitata , in the Entomological Museum, Northwestern Agricultural University; the rest, in the Department of Biology, Shenyang Normal College.     

中国尾秽蝇属五新种(双翅目:蝇科)(英文)

本文记述尾秽蝇属Pygophora Schiner 5新种,即异斑尾秽蝇P. immacularis Cui et Xue、球尾秽蝇P. orbiculata Cui et Zhang、锤尾秽蝇P. capitata Cui et Xue、指尾秽蝇P. digitata Cui et Xue和周氏尾秽蝇P. choui Cui et Xue。 模式标本异斑尾秽蝇存于中国科学院动物研究所;锤尾秽蝇存于西北农业大学昆虫博物馆;其余存于沈阳师范学院生物系。     

PATTERNS OF CHARACTER DIVERGENCE AND THE EVOLUTION OF REPRODUCTIVE ECOTYPES OF DALECHAMPIA SCANDENS (EUPHORBIACEAE)

The variation of four floral characters (resin-gland area, gland-stigma distance, gland-anther distance, and anther-stigma distance) was analyzed across 15 populations of Dalechampia scandens occurring sympatrically, in various combinations, with five other congeners. Univariate and multivariate analysis of variance and a posteriori comparison tests indicate that there are significant statistical patterns of character divergence away from sympatric congeners for three of the floral characters. These characters, which on the basis of common garden studies appear to be under genetic control, may not vary independently; i.e., genetic control may be overlapping. The characters appear to be functionally related. Populations of Dalechampia scandens occurring sympatrically with congeners possessing relatively large resin glands, large gland-stigma distances and large anther-stigma distances (e.g., D. dioscoreifolia and D. affinis) have significantly smaller resin glands, gland-stigma distances and anther-stigma distances than do populations occurring sympatrically with congeners with relatively small resin glands, gland-stigma distances, and anther-stigma distances (e.g., D. cissifolia, D. heteromorpha and D. schottii). Populations of D. scandens not sympatric with other Dalechampia species generally have intermediately sized structures. The pattern of bidirectional divergence is consistent with the evolutionary scenario that selection against interspecific pollination has resulted in local ecotypic differentiation and character displacement in populations sympatric with ecologically similar congeners.     

中国裂唇螺属一新种记述(前鳃亚纲,中腹足目,蛹螺科)

笔者在整理福建龙岩地区陆生贝类标本时,经比对鉴定发现1新种,龙岩裂唇螺Schistoloma longyanensis sp.nov..隶属前鳃亚纲、中腹足目、蛹螺科、裂唇螺属.对新种形态特征、栖息环境作了记述,并与近似种进行了比较讨论.     

飞虱科五新种描述

在我国南部地区采得的同翅目、飞虱科(Delphacidae)标本中,经鉴定和研究,发现五个新种,分隶于四个属,现将此五新种描述于后。 模式标本均存放于安徽农学院。 一、剜缘飞虱属Indozuriel Fennah