长江丽棘虫种群生态的研究

长江丽棘虫（ＢｒｅｎｔｉｓｅｎｔｉｓｙａｎｇｔｚｅｎｓｉｓＹｕｅｔＷｕ,）隶于棘吻目,长棘吻科,是余仪,伍惠生在长江中游的鱼中采获并定为新种［１］。据他们调查,长江中游有１４种经济鱼类是该种棘头虫的终末宿主,黄颡鱼是终末宿主之一。有关这种寄生蠕虫的种群生物学研究尚未见到报道。１　材料和方法从１９９８年６月至７月中旬,随机购得渔民在江边捕获的黄颡鱼７６尾。在实验室内逐一测量黄颡鱼的全长、体长,称其重量,剖开鱼腹,完整地取出消化道,称鱼的空壳重,逐一解剖检查鱼的胃和肠道,记录检出的寄生蠕虫数量和寄生…     

古雪夫三代虫固着器的扫描电镜观察

古雪夫三代虫 (ＧｙｒｏｄａｃｔｙｌｕｓｇｕｓｓｅｖｉＬｉｎｇ)由林氏首次报道[1 ] 。近年来 ,随着南方鲇的人工养殖密度的不断提高 ,古雪夫三代虫引起的疾病愈来愈严重和普遍 ,主要危害 0 5ｋｇ及其以下的个体。其传播途径 ,疾病早期症状 ,在宿主体表的分布和药物防治已有报道[2 ,3] 。为进一步认识与致病作用密切相关的固着器的形态结构 ,本文进行了该三代虫固着器扫描电镜观察。1　材料和方法患三代虫病的南方鲇 (全长 1 0 2— 2 5 5ｃｍ)取自北碚嘉陵江养殖船内的网箱。用手术刀片轻刮病鱼体表 ,将黏液放于灭菌蒸馏水中 ,在双筒解…     

长江黄州江段长须黄颡鱼肠道内寄生棘头虫的生态研究

解剖检查了 133尾捕自长江黄州江段的长须黄颡鱼 ,发现寄主感染长江丽棘虫的感染率为 4 8.9% ,感染强度为 5 .4 (虫 /尾 ) ,平均密度为 2 .6 (虫 /尾 ) ,感染鲇异棘虫的感染率为 2 1.8% ,感染强度为 5 .5 (虫 /尾 ) ,平均密度为1.2 (虫 /尾 ) ,两种棘头虫在长须黄颡鱼种群中均为聚集分布 ;当两种棘头虫共同寄生在宿主肠道内时 ,其感染强度和单独感染时相比没有显著差异 ,但是 ,各自的生态位宽度均变小 ;两种棘头虫的正关联关系显著。     

Tat蛋白及其内化作用

人类免疫缺陷病毒 1型的复制受反式激活蛋白 (ｔｒａｎｓ ａｃｔｉｖａｔｉｎｇｐｒｏｔｅｉｎ ,Ｔａｔ)的调节。Ｔａｔ蛋白是一个小型蛋白 ,其分子大小依ＨＩＶ 1病毒的品系不同而有所差异 ,从 86到1 30个氨基酸残基不等[1] ,它由两个外显子编码。就 1 0 1个氨基酸的Ｔａｔ蛋白而言[2 ] ,第一个外显子编码 1～ 72氨基酸 ,第二个外显子编码 73～ 1 0 1氨基酸。在细胞内 ,Ｔａｔ蛋白对病毒基因的转录有重要作用。ＨＩＶ 1病毒的ｍＲＮＡ 5′端有一段序列叫做反式激活反应区域 (ｔｒａｎｓ ａｃｔｉｖａｔｉｏｎ ｒｅｓｐｏｎｓｉｖｅｒｅｇｉ…     

后唇科吸虫三新种(吸虫纲:复殖目)

记述后唇科吸虫３新种,即东山后唇吸虫Ｏｐｉｓｔｈｏｌｅｂｅｓｄｏｎｇｓｈａｎｅｎｓｉｓ．ｓｐ．ｎｏｖ．东山异唇吸虫Ｈｅｔｅｒｏｌｅｂｅｓｄｏｎｇｓｈａｎｅｎｓｉｓ．ｎｏｖ．和兔头异唇吸虫Ｈｅｌｔｅｒｏｌｅｂｅｓｌａｇｏｃｅｈｐａｌｉｓｐ．ｎｏｖ模式标本式采自福建省东山县沿的棕斑兔头ＴｕｎＬａｇｏｃｅｏｐｈａｌｕｓｌｕｎａｒｉｓ ｓｐａｄｉｃｅｕｓ肠道内。     

Longgupo Hominoid Mandible Belongs to Ape

Ｉｎ 1 991 ,Ｈｕａｎｇｅｔａｌ.[1] ａｔｔｒｉｂｕｔｅｄｔｈｅＬｏｎｇｇｕｐｏｍａｎｄｉｂｌｅｔｏＨｏｍｏｅｒｅｃｔｕｓ ,ａｎｄｔｈｅｎｌａｔｅｒ[2 ]ｓｕｇｇｅｓｔｅｄｉｔｗａｓｃｌｏｓｅｔｏＨｏｍｏｅｒｇａｓｔｅｒ.ＷｏｏｄａｎｄＴｕｒｎｅｒ[3] ａｇｒｅｅｄｔｈｉｓａｔｔｒｉｂｕｔｉｏｎ .ＬａｒｉｃｋａｎｄＣｉｏ ｃｈｏｎ[4 ] ａｓｗｅｌｌａｓＣｉｏｃｈｏｎ[5] ａｔｔｒｉｂｕｔｅｄｉｔｔｏＨｏｍｏ .ＴｈｅｈｏｍｉｎｉｄｓｔａｔｕｓｈａｓｂｅｅｎｃｈａｌｌｅｎｇｅｄｂｙＷｏｌｐｏｆｆ[6 ] ,ＳｃｈｗａｒｔｚａｎｄＴａｔｔｅｒｓａｌｌ[7] ａｎｄＰｏｐｅ[8] ,ａｓｗｅｌｌａｓｂｙＥｔｌｅｒａｎｄＺｈｏｕ[9] ｗｈｏｆｕｒｔｈｅｒｉｎｄｉｃａｔ ｅｄａｎａｎｃｅｓｔｏｒ ｄｅｓｃｅｎｄｅｎｔｒｅｌａｔｉｏｎｓｈｉｐｂｅｔｗｅｅｎＬｕｆｅｎｇｐｉｔｈｅｃｕｓａｎｄｔｈｅＬｏｎｇｇｕｐｏｍａｎｄｉｂｌｅ .Ｂｕｔｔｈｅｒｅｉｓｎｏｄｅｔａｉｌｅｄｄｉｓｃｕｓｓｉｏｎｉｎａｎｙｏｆｔｈｅｓｅａｒｔｉｃｌｅｓ.Ｔｈｅｐｒｅｓｅｎｔａｕｔｈｏｒｗｏｕｌｄｌｉｋｅｔｏｐｒｅｓｅｎ...     

Application of radiation hybrid in gene mapping

Ｒａｄｉａｔｉｏｎｈｙｂｒｉｄ(ＲＨ)ｍａｐｐｉｎｇｉｓａｓｏｍａｔｉｃｃｅｌｌｇｅｎｅｔｉｃｍａｐｐｉｎｇｔｅｃｈｎｉｑｕｅｗｉｔｈａｒｅｓｏｌｕｔｉｏｎｏｆａｂｏｕｔ500ｋｂ.Ｉｔｈａｓｂｅｃｏｍｅａｇｅｎｅｒａｌｗａｙｔｏｃｏｎｓｔｒｕｃｔｈｉｇｈｒｅｓｏｌｕｔｉｏｎ,ｃｏｎｔｉｇｕｏｕｓｐｈｙｓｉｃａｌｍａｐｏｆｈｕｍａｎｃｈｒｏｍｏｓｏｍｅｓ[1].ＢａｓｅｄｏｎｅａｒｌｉｅｒｓｔｕｄｉｅｓｏｆＧｏｓｓａｎｄＨａｒｒｉｓ[2]ａｎｄｍｏｄｉｆｉｃａｔｉｏｎｌａｔｅｒｂｙＣｏｘａｎｄｃｏｗｏｒｋｅｒ…     

评《科学》发表的《中国南方百色盆地中更新世似阿舍利石器技术》

《Ｓｃｉｅｎｃｅ》2 0 0 0年 3月 3日出版的一期发表了中美科学家共同撰写的《Ｍｉｄ ＰｌｅｉｓｔｏｃｅｎｅＡｃｈｅｕｌｅａｎ ｌｉｋｅｓｔｏｎｅｔｅｃｈｎｏｌｏｇｙｏｆｔｈｅＢｏｓｅＢａｓｉｎ ,ＳｏｕｔｈＣｈｉｎａ》[1] (以下简称《百色旧石器》) ,同期刊登的还有记者的采访报道[2 ] 。随后国内媒体先后发表了采访两位中国作者的报道[3— 5] 。 2 0 0 1年 1月 1 7日百色旧石器的发现因“人类起源再添新证 ,百色旧石器挑战‘莫氏线’理论”被中华人民共和国科学技术部评为 2 0 0 0年中国基础科学研究十大新闻[6] 。2 0 0 1年 1 …     

嘉陵江岩原鲤、鲤鱼肠粘膜的扫描电镜观察

岩原鲤(Ｐｒｏｃｙｐｒｉｓｒａｂａｕｄｉ)是江河名贵鱼类之一[1][4],也是重要的养殖鱼类,对其肠粘膜结构的研究具有重要的实际价值。为此,我们在对其消化能力和营养价值研究的基础上[2],对肠道粘膜进行了扫描电镜观察,并与鲤鱼(Ｃｙｐｒｉｎｕｓｃａｒｐｉｏ)作了对比分析。1　材料和方法11　试验鱼　岩原鲤和鲤鱼均为1998年10月～12月从嘉陵江北碚段捕鱼船收购的鲜活鱼。岩原鲤体重870～1340ｇ,平均980ｇ,共6尾;鲤鱼350～1400ｇ,平均760ｇ,共6尾。12　材料制备及观察　常规解剖取出肠道。将部分鱼的肠道翻转,使粘膜面暴露出来,并用水冲洗…     

黄颡鱼肠道内寄生棘头虫位置分布的研究

长江丽棘虫和黄颡异１钩棘头虫单独在黄颡鱼肠中分布的相似性比例ＰＳ＝０．６８４。它们共同寄生在黄颡鱼肠道内,长江丽棘虫的寄生部位向前移,黄颡异钩棘头虫的寄生部位明显向后移,生态位宽度变窄,生态位重叠值下降。但是,它们的平均感染强度并未降低,种间正关联显著。     

A new species of Heterosentis Van Cleave, 1931 (Acanthocephala, Arhythmacanthidae), a parasite of pinguipedid fishes in the southwest Atlantic

A new species of arhythmacanthid acanthocephalan, Heterosentis martini n. sp., parasitic in the Argentinean sandperch Pseudopercis semifasciata (Cuvier) (Perciformes, Pinguipedidae) from the coasts of Argentina is described. Heterosentis martini n. sp. differs from all congeneric species by having 10 longitudinal rows of hooks in the proboscis, each with 7-8 hooks, consisting of 1 medium apical and 3 larger sub-apical hooks with root, and 3-4 smaller, basal, curved hooks with rudimentary roots and spines in both ventral and dorsal regions of the body. The most similar species, Heterosentis heteracanthus (Linstow, 1896) Van Cleave, 1931, and Heterosentis brasiliensis Vieira, Felizardo and Luque, 2009, also have 10 longitudinal rows of hooks, but H. heteracanthus differs from the new species by having only 3-5 (more frequently 4) hooks in each row, with only the anterior hook large and bearing a developed root. Heterosentis brasiliensis differs from the new species by possessing 2 sub-apical hooks in each row (instead of 3), similar body length but shorter proboscis, and trunk spines restricted to the ventral surface of body.     

大型多钩槽绦虫在黄鳝体内寄生的研究

解剖检查了５００尾黄鳝。统计表明：黄鳝感染大型多钩槽绦虫的感染率为７．６％，感染强度是２．７，黄鳝感染此种绦虫为一个随机过程。大型钩槽绦虫在宿主种群中的分布符合负二项分布图式，其负二项分布参数ｋ＝０．０３４５，ｐ＝５．９０７８，长度在５ｃｍ以上的绦虫对宿主的正常生长有影响。     

金钱鱼体内惠州长宫吸虫种群动态分析

金钱鱼肠道内的惠州长宫吸虫,随着宿主体长的生长,其感染强度、平均丰盛度、平均拥挤度和宿主体长小于30mm的感染率呈逐渐增加的趋势,而宿主在不同体长组中,除了体长小于30mm以外,其感染率变化相对较稳定;在不同的月份中,吸虫在宿主体内的感染率从2月起呈逐渐下降趋势,感染强度则有逐渐增大倾向;平均丰盛度除从4～7月份有1个明显先上升后下降的变化外,其它月份变化差异不大。从吸虫在宿主体内的频率分布变化中,表明多数宿主不感染或只感染少量的吸虫,而少数宿主感染吸虫数量较大;吸虫种群在不同宿主体长组和不同月份的分布格局类型均为聚集分布,在不同宿主体长组中聚集分布强度随着种群密度增加而增强。       

Prevalence,geographic distribution,and fitness effects of Microphallus turgidus (trematoda: Microphallidae) in grass shrimp (Palaemonetes spp.) from coastal Georgia

Grass shrimp, Palaemonetes pugio Holthuis and P. vilgaris (Say), were collected at 11 localities along the coast of Georgia and surveyed for digenetic trematode metacercariae. The effect of trematode infection on grass shrimp fitness was also examined. Microphallus turgidas (Leigh) was the only trematode observed. The prevalence of metacercarial cysts of this parasite in P. pugio (75%) was higher than in P. vulgaris (24%), as were the mean intensity, abundance, and population density (no. cysts/cm host body length) of the parasite. Infected shrimp were found at every collection locality and parasite prevalence and density were greatest in P. pugio from higher salinity localities (> or = 20 parts per thousand [ppt]). There was no relation between host body size and parasite density in P. vulgaris, and parasite density increased with host body size in P. pugio, suggesting that the parasite does not affect host survival. There was no relation between parasite density and shrimp egg mass, but nonovigerous female P. pugio were more heavily infected than ovigerous ones. In addition, 1 metacercaria of M. turgidus in each of 2 specimens of P. vulgaris was parasitized by the haplosporidian Urosporidium crescens De Turk. This represents a new shrimp host record for this hyperparasite.     

Lernaea cyprinacea (Copepoda, Lernaeidae) from crucian carp Carassius carassius from the Dlinnoje Lake in the middle stream of the Vychegda River

Till 1996 the Vychegda River's flood lakes at the territory of the biological station of the Syktyvkar University were overflowed every spring by water so that fishing took place from time to time. In 1996 a low flood level and intensive fishing resulted in the change of the infection rate of crucians by Lernaea, as well as in the change of the size and sex ratios of the crucian population in the Dlinnoje Lake. Thus, the size pattern of the crucian population became simpler, and it led to the changes in parasite-host relation. As a result, the intensity of the invasion of crucians by Lernaea cyprinacea have increased and the distribution of the parasite in the host population does not fit by the negative-binomial distribution. Crucian females and males play an equal role in the maintenance of the parasite population. In 1984 crucian females of medium and large body length played the main role in that process. Functions of other host groups (fishes of small body length, males) were different. Up to 2001 a significance of "k"-exponent of the negative-binomial distribution, describing the number of copepods in the mature part of crucian population, changed with a small range that suggests a stability of parasite-host relationship in the investigated crucian groups. We suppose that after a period of an unstable state in 1997-2000 the population of the parasite reached a new stable state.     

Inequalities in size and intensity-dependent growth in a mermithid nematode parasitic in beach hoppers

Inequality in body sizes is a common feature in populations of helminth parasites, with potential consequences for egg production and population genetics. Inequalities in body lengths and the effects of intraspecific competition on worm length were studied in a species of mermithid nematode parasitic in the crustacean Talorchestia quoyana (Amphipoda: Talitridae). The majority of the 753 worms recovered were relatively small, and an analysis using a Lorenz curve and Gini coefficient suggested that there were no marked inequalities in body lengths among the worms. Total worm length in the 356 infected amphipods (i.e. the sum of the lengths of all the worms in a host) increased steadily as a function of the number of worms per amphipod, whereas the length of the longest worm per amphipod peaked in amphipods harbouring intermediate numbers of worms. This last result was not significantly accounted for by the observed increase in host size with increasing intensity of infection, but resulted from a correlation between worm length and host size. As the number of worms per amphipod increased, the relative sizes of the second-, third-, and fourth-longest worms per host increased markedly. This means that relative inequalities in sizes become less pronounced, i.e. subordinate worms get closer in size to the longest worm, as the number of worms per host increases. The main consequence of this phenomenon is that worm sizes in the mermithid population are more homogeneous than they would be if intraspecific competition had stronger effects on worm growth.     

Aspects of the ecology and natural history of Paraergasilus rylovi (Copepoda, Ergasilidae) parasitic in unionids of Finland

The distribution of Paraergasilus rylovi in 17 populations of unionids was investigated. In 1 unionid population, the parasite was studied regarding host age, size, sex, and the reproductive period (occurrence of egg sacs). Results from pooled material from the years 1987--1989 and 1996 (southern Finland, 11 populations) indicated that Anodonta piscinalis (n = 1,359) is the main host (total mean prevalence 71% and intensity +/-SE of infection 16.4+/-0.6). Pseudanodonta complanata (n = 106) was infected occasionally (3% and 1.3+/-0.3), whereas Unio pictorum (n = 108) and U. tumidus (n = 17) were not infected. Results from 17 A. piscinalis populations showed that P. rylovi occurs in southern Finland but not in northern Finland. In A. piscinalis, the mean intensity of infection was higher in lake populations than in river populations. Both host age and length had a negative relationship with the intensity of P. rylovi infection. Host sex did not affect the intensity of infection. Egg sacs of P. rylovi were found from June to August. There was a tendency for higher intensities of infection in autumn. Infection by the digenean Rhipidocotyle fennica had no effect on the intensity of P. rylovi infection.     

Determinants and consequences of interspecific body size variation in tetraphyllidean tapeworms

Tetraphyllidean cestodes are cosmopolitan, remarkably host specific, and form the most speciose and diverse group of helminths infecting elasmobranchs (sharks, skates and rays). They show substantial interspecific variation in a variety of morphological traits, including body size. Tetraphyllideans represent therefore, an ideal group in which to examine the relationship between parasite body size and abundance. The individual and combined effects of host size, environmental temperature, host habitat, host environment, host physiology, and host type (all likely correlates of parasite body size) on parasite length were assessed using general linear model analyses using data from 515 tetraphyllidean cestode species (182 species were included in analyses). The relationships between tetraphyllidean cestode length and intensity and abundance of infection were assessed using simple linear regression analyses. Due to the contrasting morphologies between shark and batoid hosts, and contrasting physiologies between sharks of the Lamnidae family and other sharks, analyses were repeated in different subsets based on host morphology and physiologies (“sharks” vs. batoids) to determine the influence of these variables on adult tetraphyllidean tapeworm body size. Results presented herein indicate that host body size, environmental temperature and host habitat are relatively important variables in models explaining interspecific variations in tetraphyllidean tapeworm length. In addition, a negative relationship between tetraphyllidean body size and intensity of infection was apparent. These results suggest that space constraints and ambient temperature, via their effects on metabolism and growth, determine adult tetraphyllidean cestode size. Consequently, a trade-off between size and numbers is possibly imposed by external forces influencing host size, hence limiting physical space or other resources available to the parasites.