Modelling intraspecific resting egg shape variation in a freshwater fairy shrimp Tanymastix stagnalis (L., 1758) (Crustacea, Branchiopoda)

The shape of the resting eggs of a large branchiopod crustacean, the Anostraca Tanymastix stagnalis , is represented very accurately by analytical expressions. The occurrence of atypical shape of some T. stagnalis eggs may be viewed as a simple change of the analytical expression describing the usual egg shape. Their unusual shape may be explained by a higher embryo volume within an envelope of a given size. Biological implications are briefly discussed and hypothesized in an evolutionary point of view.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 90 , 55–60.     

Adult movements between populations in the specialist butterfly Proclossiana eunomia (Lepidoptera, Nymphalidae)

Abstract.

• 1 The structure of local populations of a monophagous butterfly, the bog fritillary Proclossiana eunomia, was studied in a complex of suitable habitat patches separated by spruce plantations or fertilized pasture.
• 2 An unexpected high level of adult movements between habitat patches was detected by a mark—release—recapture technique. Local populations were connected by adult movements across unsuitable habitats, leading to a meta-population structure.
• 3 This evidence of the metapopulation structure of a specialist butterfly challenges the supposed relationship between habitat specialization and closed, isolated populations.
• 4 Males and females of P.eunomia exhibited different spatial behaviours; females were more likely to emigrate and dispersed further than males. These differences in spatial behaviour are related to the mating system.

     

Changes in the Content of Starch and Activities of some Enzymes of Carbohydrate Metabolism in Cotyledons of Germinating Seeds of Voandzeia subterranea

During the germination of the seeds of Voandzeia subterraneaL. Thouars, the content of starch in the cotyledons fell progressively.There was a substantial increase in amylase activity duringthe first 4 d. The activity of starch phosphorylase increasedafter 6 d when there was a rapid decline in amylase activity.The activities of hexokinase, glucose-6-phosphate dehydrogenase,and 6-phosphogluconate dehydrogenase increased, suggesting thepresence of an active phosphogluconate pathway in the cotyledons.     

Species‐specific influences of shrubs on the non‐dormant soil seed bank of native and exotic plant species in central‐northern Monte Desert

Deserts shrubs are well known to facilitate vegetation aggregation, mostly through seed trapping, and stress amelioration during and after plant establishment. Because vegetation aggregation effects are a by‐product of shrub presence, beneficiary species may not only be native, but also exotic. However, despite the high risk that exotic invasive species pose to ecosystem services, little is known of the role of desert shrubs on plant invasions. We assessed the influence of two shrub species on the non‐dormant soil seed bank (i.e. the number of seeds that readily germinate with sufficient water availability) of an invasive annual grass (Schismus barbatus) and of coexisting native species in a central‐northern Monte Desert (Argentina). Soil samples were collected beneath the canopies of two dominant shrub species (Bulnesia retama and Larrea divaricata) and in open spaces (i.e. intercanopies) in May 2001. Overall, the density of germinated seedlings of Schismus and that of the native species were negatively associated across microsite types. Schismus density was similar to that of all native species pooled together (mostly annuals), and was highest in Larrea samples (with no significant differences between Bulnesia and intercanopies). On the contrary, the density of all native species pooled together was highest in Bulnesia samples. Our results suggest that shrubs may contribute to plant invasions in our study system but, most importantly, they further illustrate that this influence can be species specific. Further research is needed to assess the relative importance of in situ seed production (and survival) and seed redistribution on soil seed bank spatial patterns.     

PCR primers for polymorphic microsatellite loci in the plant‐ant Azteca ulei cordiae (Formicidae: Dolichoderinae)

Twelve microsatellite loci were isolated from the Peruvian tropical plant‐ant, Azteca ulei cordiae (Hymenoptera: Dolichoderinae). High levels of within‐population variation were observed at most loci, with number of alleles ranging from four to 18, and heterozygosity from 0.118 to 1 per population sample. Cross‐species amplification of these loci was also successfully tested in several other species of the same ant genus Azteca.     

Isolation,characterization and evaluation of 11 autosomal STRs suitable for population studies in black and gold howler monkeys Alouatta caraya

We identified 11 polymorphic microsatellite markers for Alouatta caraya. Three markers were isolated from an enriched genomic library of A. caraya (AC14, AC17, AC45), five were previously described in Homo sapiens (TGMS1, TGMS2, D5S117, D8S165, D17S804), and three were identified for Lagothix lagotricha (1110, 1118, 157). Forty‐eight individuals from one Argentinean population were genotyped, yielding heterozygosity values between 0.146 and 0.792. These markers provide an exclusion power of 0.922 when neither parent is known (0.992 when one parent is known) and are suitable for parentage analysis, population genetics and phylogeographical studies of A. caraya, the southernmost primate in the New World.     

中国南部沿海增养殖业的调查与展望 ——来自广东饶平柘林湾和南澳深澳湾“海上渔村“的思考

针对沿海增养殖业对海洋生态的影响,对中国南部沿海2个增养殖业发达区——南澳岛深澳湾"海上渔村"和赤潮灾区饶平柘林湾进行了实地考察和取样分析.考察发现,目前中国南部沿海增养殖业普遍存在技术落后、缺乏科学技术指导和统一管理等问题, 对海洋生态造成了极大的危害;通过海水水质测定实验,发现这2个养殖区水样的平均含氮量较高(2.154 mg/L),氮磷质量比较高(22),处于富营养化状态;浮游植物平均密度较高(1 908.6个/mL),个体含叶绿素a量较低(1.74×10-6 mg/个),出现生态衰退现象.