Consequences of the founder effect in the genetic structure of introduced island coral reef fish populations

Between 1955 and 1961, the Division of Fish and Game of the State of Hawaii (USA) undertook an introduction program which brought 11 species of families Serranidae and Lutjanidae (Pisces) from French Polynesia to the coral reefs off Oahu and Big Island in Hawaii. Only three— Cephalopholis argus, Lutjanus fulvus and Lutjanus kasmira —for which we have records of locations and number offish released, are known to have become established. Comparison of allozyme distribution of C. argus and L. kasmira between individuals collected in Hawaiian and Polynesian populations provided a unique opportunity to estimate the impact of genetic drift and selection processes caused by a founder event. We used temporal variance of allelic frequencies to estimate and validate effective population size within marine fish populations. Despite the fact that only 571 C. argus and 2435 L. kasmira were released, we did not observe major changes in polymorphism and heterozygosity. Using different models to estimate effective population size from temporal variance in allelic frequencies and the number of generations, we estimate that the effective population size is about 1–5% of the total population size. Such reduced effective population size explains why most of the species introduced in Hawaii (8/11) failed to become established. Our results have implications for conservation biology because they emphasize that in spite of the fact that only a few individuals bequeathed their characteristics to subsequent generations, no significant change in genetic diversity was observed; success of introduced species is therefore limited by the number of fish released.     

Infection of Atlantic salmon, Salmo salar L., by Gyrodactylus salaris, Malmberg 1957, in the River Lakselva, Misvær in northern Norway

Gyrodacrylus salaris was most probably introduced to the River Lakselva in 1975 through stocking of Atlantic salmon from an infected hatchery. The parasite population grew rapidly, and the parasite spread throughout the entire watercourse during the summer of 1976. This epidemic situation led to mortality among the young Atlantic salmon, and the density of salmon parr was heavily reduced from 1976 to 1977. The density of salmon parr has remained close to zero since then, while there are no apparent trends toward decrease or increase in the density of brown trout. In spite of the reduced density of young salmon, a new epidemic has developed each year among the few young 0+ and 1+ Atlantic salmon present in the river. Results from successive sampling during the summer of 1987, 1988 and 1989 indicate that most of the presmolt salmon are attacked during their first summer or autumn of life. The infection develops into an epidemic during the first autumn, winter or the next summer. The build-up of the parasite burden on the fish leads in turn to mortality. Norwegian Atlantic salmon probably have no resistance against G. salaris, since the parasite has recently been introduced to Norwegian rivers.     

植物园发展的动向

对国内外植物园近十余年来发展的动向进行评述,列举了近年来一系列重要的植物园国际会议与重大活动,指出当前国际植物园工作的中心任务首先是物种保护。总结和分析我国植物园发展的历史和现状、存在问题以及在园貌建设上与国际先进植物园的差距。这些差距主要表现在：（１）植物的收集量;（２）活植物数据的积累;（３）罕见植物的引种;（４）现代技术的应用。作者最后提出,我国植物园发展应把握的几个主要问题是：（１）既是多功能全方位发展,又应各具特色;（２）生物多样性是植物园永恒的主题;（３）植物园应着重物种迁地保护的研究和实践;（４）植物园应重视栽培和利用植物并着重以药用植物为对象。     

用数字和形态分类学方法研究扁穗苔属的等级问题

本文是针对大花嵩草组的等级问题,选用了本类群和相关类群资料;应用经典植物分类学的比较方法和数字分类学的信息系统分类,相似性相关系统分类和相似性距离系统分类的方法进行研究的结。数宇分类的树系和和经典形态分类的比较表反映出它不同于蒿草属,虽然它较接近苔草属和扁穗苔属,但它们的形态性状是不相同的,所以把它作为属的等级更加合适;同时我们也同意伊万诺娃的观点。     

台湾桤木引种气候生态适生区分析

选择了年平均温度、最冷月平均温度等9个影响台湾桤木(Alnusformosana)分布和生长的关键气候因子,运用模糊相似优先比法,探讨台湾桤木在我国的适生范围。结果表明,台湾桤木气候生态适生区主要分布在长江流域及其以南的部分中亚热带、南亚热带和热带地区,适宜区表现出明显的热带南亚热带性质,次适宜区以中亚热带性质为主。适生区的气候特点是:年均温度在15℃以上,极端最低温在-10℃以上,年降水量在1 000 mm以上,一年中降水量<50 mm的月份不超过5个月。适生区气象因子的主成分分析表明,第一主成分温度因子(年均温、≥10℃积温、最冷月平均温和极端最低温)影响台湾桤木的成活和分布,第二主成分和第三主成分(温度和降水)的综合作用影响台湾桤木的生长。四川和福建的引种实践表明,本预测具有一定的实用价值。     

Behavioral changes associated with introductions of male maned wolves (Chrysocyon brachyurus) to females with pups

Three male maned wolves were successfully introduced to their mates and 7‐ to 12‐week‐old pups at the Houston Zoological Gardens and Fossil Rim Wildlife Center in 1994 and 1995. The introductions took 3–7 weeks and had three stages: 1) allowing the male to see the female and pups through a chain‐link panel or a full chain‐link fence, 2) introducing the male and female without the pups present, and 3) introducing the male to the pups. For 7 days before Stage 2 and 7 days during Stage 3, the adults were observed for 150 hr. The amount of time they spent active and the amount of time they spent near the pups were recorded, as well as all behaviors they directed to the pups. After the males were introduced, the females' activity decreased, and the males' activity increased. The females spent less time near the pups after the introduction. The introduction did not affect the females' rates of affiliative or aggressive behaviors to the pups, and there was no difference between males' and females' rates of affiliative or aggressive behaviors. This introduction procedure offers an alternative to leaving the male with the pups from the time they are born. The adults' behavioral changes after the introduction show the benefits that occur when captive male maned wolves are allowed to help rear their pups. Zoo Biol 18:189–197, 1999. © 1999 Wiley‐Liss, Inc.     

水杉引种及迁地保护进展

对1947年以来发表的有关活化石——水杉(MetasequoiaglyptostrobodiesHu&Cheng)在世界范围内的引种及迁地保护文献进行了系统评述。从1947年开始,水杉已在我国以及亚洲、欧洲、大洋洲、非洲、北美洲、南美洲六大洲的53个国家引种和得到迁地保护,已成为其中一些国家重要的植物研究材料和著名的风景观赏树种和造林绿化树种,并且成为一种国际关系的纽带。国际自然保护联盟(IUCN)已在1999年选出水杉等9个针叶树作为世界范围内保护的植物,同时由于水杉对酸沉降污染的敏感性和在世界范围内的广泛适应性,因此可作为世界范围内酸沉降污染共同的生物监测指示种和重要研究材料。引种为水杉的保护提供了有效的途径,但引种的质量已成为一个今后值得研究和解决的重要问题。     

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.     

First genetic record of the non-native muzzled blenny Omobranchus punctatus (Teleostei: Blenniidae) in the Atlantic Coast of Central and South America

In this study we sequenced two mitochondrial (COI and 16S rRNA) and one nuclear (18S rRNA) gene fragment of an introduced muzzled blenny (Omobranchus punctatus) specimen collected from the Orinoco Delta (Gulf of Paria estuary) in Venezuela. This is the first genetic data generated for this species' introduced range in Central and South America, suggesting an introduction from the Indian Ocean.