The stripe-backed weasel Mustela strigidorsa: taxonomy, ecology, distribution and status

1. The stripe-backed weasel Mustela strigidorsa is one of the rarest and least-known mustelids in the world. Its phylogenetic relationships with other Mustela species remain controversial, though several unique morphological features distinguish it from congeners. 2. It probably lives mainly in evergreen forests in hills and mountains, but has also been recorded from plains forest, dense scrub, secondary forest, grassland and farmland. Known sites range in altitude from 90 m to 2500 m. Data are insufficient to distinguish between habitat and altitudes which support populations, and those where only dispersing animals may occur. 3. It has been confirmed from many localities in north-east India, north and central Myanmar, south China, north Thailand, north and central Laos, and north and central Vietnam. Given the limited survey effort, the number of recent records shows that the species is not as rare as hitherto believed. Neither specific nor urgent conservation needs are apparent.

Elevated ability to compete for limited food resources by 'all-fish' growth hormone transgenic common carp Cyprinus carpio

Food consumption, number of movements and feeding hierarchy of juvenile transgenic common carp Cyprinus carpio and their size-matched non-transgenic conspecifics were measured under conditions of limited food supply. Transgenic fish exhibited 73 center dot 3% more movements as well as a higher feeding order, and consumed 1 center dot 86 times as many food pellets as their non-transgenic counterparts. After the 10 day experiment, transgenic C. carpio had still not realized their higher growth potential, which may be partly explained by the higher frequency of movements of transgenics and the 'sneaky' feeding strategy used by the non-transgenics. The results indicate that these transgenic fish possess an elevated ability to compete for limited food resources, which could be advantageous after an escape into the wild. It may be that other factors in the natural environment (i.e. predation risk and food distribution), however, would offset this advantage. Thus, these results need to be assessed with caution.

俄罗斯沙棘优良品种引种试验研究

三北"地区和黄土高原是中国沙棘亚种的分布中心,现已有大面积人工沙棘林,但其果小、刺多,产果量低,采果难。为此,作者于1997~2006年承担水利部"948"沙棘引进项目,以解决该地区沙棘优良品种缺乏问题。通过8年试验研究,引进俄罗斯大果无刺沙棘优良品种、类型40余种,分别在"三北"和黄土高原地区的7个主要试验基地进行引种试验,从中初步筛选出效果较好的9个优良品种、类型。它们生长发育良好,抗性较强,具高产、优质特性,并已开始利用引进的俄罗斯沙棘与当地中国沙棘杂交,培育出第一代杂交种。在引种选育和对俄罗斯沙棘生物生态学特性进行试验研究的基础上,对其良种的集约栽培和繁育做了试验和示范推广工作,产生了良好的生态、经济效益。通过本项目实施,为做好沙棘引种选育工作提供了良种,这对大面积建造高产、优质人工沙棘林和沙棘果园,加速黄土高原和"三北"地区的环境治理、发展地方经济具重要意义。