Ten new microsatellite loci for the yellowhammer (Emberiza citrinella) and their cross‐species applicability among related taxa

We describe isolation and characterization of the first microsatellite loci specifically developed for a very common European passerine bird, the yellowhammer Emberiza citrinella. Nine out of our 10 loci are polymorphic within the species E. citrinella. Number of alleles ranged from two to 21 per locus and observed heterozygosity between 0.20 and 0.91. Four primer pairs also yielded reproducible results in other species of Emberizidae. These loci comprise a set of molecular markers for various applications, from moderately polymorphic loci suitable for population studies to highly polymorphic loci for pedigree analysis in Emberizidae.     

The Anchorage of Leek Seedlings: The Effect of Root Length and Soil Strength

The mechanical behaviour of single roots being extracted fromsoil was modelled as a process in which tension is transferredfrom the upper regions of the root to the soil via shear. Quantitativepredictions were made about the extraction forces and the shapeof the uprooting curves, and these were tested using leek radiclesof different lengths in soil of two different strengths. Results of uprooting tests were qualitatively similar to thepredictions. The pullout resistance rose with root length, untilthe breaking strength of the root was reached, at around 30mm: longer roots all broke before the tip was stressed. In wholeroot systems, therefore, failure will occur proximally beforethe line distal roots are mechanically stressed, so these canhave no anchorage function. Resistance to an upward force will be most economically achievedby having many strengthened proximal root axes, as in the adventitiousroot systems of grasses, sedges and stoloniferous dicots. Allium porrum, root, anchorage, shear, tension, soil     

First nest description, breeding behaviour and distribution of the Madagascar Serpent-Eagle Eutriorchis astur

The critically endangered, endemic Madagascar Serpent-Eagle Eutriochis astur was searched for and studied from 1993-98 on Masoala Peninsula, northeastern Madagascar. Fifteen individual serpent-eagles were detected at nine different localities throughout the Masoala Peninsula. The first nest of the Madagascar Serpent-Eagle was discovered on 7 November 1997. The nest was in an epiphytic fern Asplenium nidus supported by vines and branches, 20.1 m above the ground in a Potameia capuroni of 36.2 cm diameter at breast height. The epiphytic fern was lined with leaves in the centre and twigs were positioned to form a nest rim. The nest measured 76 times 57 cm and contained one white egg. The female and male incubated for 77% and 21% of 118 hours of nest observations, respectively. The egg hatched on 21 November 1997, and the young fledged 62 days later on 22 January. Chameleons Furcifer and Calumma spp., and leaf-tailed geckos Uroplatus sp., made up the most numerous prey types taken, representing 83% of the 133 identified prey. Currently, the Masoala Peninsula forest contains the greatest number of sightings and known density of serpent-eagles in Madagascar.     

Phylogeny of Trichomonads Based On Partial Sequences of Large Subunit Rrna and On Cladistic Analysis of Morphological Data

ABSTRACT. Several domains of large subunit rRNA from nine trichomonad species have been sequenced. Molecular phylogenies obtained with parsimony and distance methods demonstrate the trichomonads are a monophyletic group which branches very early in the eukaryotic tree. the topology of the trees is in general agreement with traditional views on evolutionary and systematic relationships of trichomonads. A clear dichotomy is noted between the subfamily Trichomonadinae and the subfamily Tritrichomonadinae. In the latter subfamily, a second division separates the " Tritrichomonas muris -type" species from the " Tritrichomonas augusta -type" ones. Previous evolutionary schemes in which the Monocercomonadidae were regarded as the most "primitive" and the Trichomonadidae as more "evolved" are not in agreement with our molecular data. the emergence of Monocercomonas and Hypotrichomonas at the base of the Tritrichomonas lineage suggests a secondary loss of some cytoskeletal structures, the costa and undulating membrane in these genera. This is corroborated by the early branching position of Trichomitus. which possesses a costa and an undulating membrane and has usually been placed among the Trichomonadidae on the basis of cytological characters. A cladistic analysis was applied to the available morphological characters in order to produce a hierarchical grouping of the taxa reflecting their morphological diversity. Supplementary key words. Evolution, molecular phylogeny, morphological cladistic analysis.     

The importance of the littoral epiphyton as food for commercial fish in the recent African man-made lake, Nyumba ya Mungu reservoir, Tanzania

Nyumba ya Mungu reservoir is a man-made lake in the Kilimanjaro region of northern Tanzania. The commercial fisheries are principally based on the cichlids, Sarotherodon pangani Lowe, S. jipe Lowe, S. esculentus Graham, and Tilapia rendalli Boulenger.
Examination of gut contents revealed that the dominant species, S. pangani and S. jipe , fed on the epiphyton attached to the vegetation in the littoral zone, S. esculentus was a phytoplankton filter feeder, and T. rendalli consumed macrophytes and associated epiphytes.
A fish exclosure quantitatively demonstrated that the epiphyton community was appreciably depleted by the grazing of fish. After 35 days the mean epiphyton density on the submerged surfaces of Cyperus articulatus L. within the exclosure was 285 times 10³ individuals cm^-2 shoot, but only 181 times 10³ individuals cm^-2 shoot on grazed surfaces outside the exclosure. The differences were statistically significant, and corresponded to a difference in biomass of about 6.5 g organic dry weight m^-2 lake surface. Vertical profiles of periphyton density on Cyperus indicated that fish grazed mainly below a depth of 100 mm from the water surface.
The littoral epiphyton → commercial fish food chain, which may be unique, is considered to predominate in Nyumba ya Mungu, and is compared with the major food chains of commercial fish in some other African natural and man-made lakes.     

Genome size evolution and polyploidy in the Daphnia pulex complex (Cladocera: Daphniidae)

Genome size was estimated in 49 clones of the Daphnia pulex complex from temperate and subarctic locations using flow cytometry and microsatellite DNA analyses. Significant genome size differences were found in diploid species belonging to the two genetically distinct groups (the pulicaria and the tenebrosa groups), with clones from the tenebrosa group having genome sizes 22% larger than those in the pulicaria group. Combined flow cytometry and microsatellite DNA analyses revealed that nearly all polyploid clones in the D. pulex complex are triploid and not tetraploid, as was previously suggested. Sequencing analyses of the ND5 gene to position clones in their respective clades within the D. pulex complex have uncovered three triploid clones of Daphnia middendorffiana with a D. pulex maternal parent. This result was unexpected because Daphnia pulicaria has always been identified as the maternal parent of these hybrid polyploid clones. Triploid clones likely owe their origins to interactions between sexual and asexual populations. Further interactions in the tenebrosa group have generated tetraploid clones but these events have been rare.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 68–79.     

Identification of the adipokinetic hormone of the large milkweed bug Oncopeltus fasciatus

Abstract The adipokinetic hormone (AKH) of the large milkweed bug Oncopeltus fasciatus is isolated from an acidified methanolic extract of 200 corpora cardiaca, purified by single step reversed phase high‐performance liquid chromatography (HPLC) and N‐terminally deblocked using pyroglutamate aminopeptidase. The sequence is identified by Edman degradation and matrix assisted laser desorption/ionization‐time of flight mass spectroscopy as pGlu‐Leu‐Asn‐Phe‐Ser‐Pro‐Asn‐Trp amide. This structure is confirmed by chemical synthesis and coelution of native and synthetic peptide on HPLC. The AKH of O. fasciatus is identical to Tenmo‐HrTH, a member of the adipokinetic/red pigment‐concentrating hormone peptide family that had been isolated earlier from several tenebrionid beetles. Tenmo‐HrTH causes a significant rise in the concentration of haemolymph lipids when injected into adult male and female O. fasciatus, but displays no hyperglycaemic activity. There is no indication of the presence of other AKHs in O. fasciatus. The large milkweed bug represents the first member of the seed bugs (Lygaeidae) for which the endogenous AKH has been identified.     

Interacting effects of elevated CO2, nutrient availability and plant species on a generalist invertebrate herbivore

By affecting plant growth and phytochemistry elevated CO₂ may have indirect effects on the performance of herbivores. These effects show considerable variability across studies and may depend on nutrient availability, the carbon/nutrient‐balance in plant tissues and the secondary metabolism of plants. We studied the responses to elevated CO₂ and different nutrient availability of 12 herbaceous plant species differing in their investment into secondary compounds. Caterpillars of the generalist herbivore Spodoptera littoralis were reared on the leaves produced and their consumption and growth rates analysed. Elevated CO₂ resulted in a similar increase of biomass in all plant species, whereas the positive effect of fertilization varied among plant species. Specific leaf weight was influenced by elevated CO₂, but the effect depended on nutrient level and identity of plant species. Elevated CO₂ increased the C/N ratio of the leaves of most species. Caterpillars consumed more leaf material when plants were grown under elevated CO₂ and low nutrients. This indicates compensatory feeding due to lower tissue quality. However, the effects of elevated CO₂, nutrient availability and plant species identity on leaf consumption interacted. Both the effects of CO₂ and nutrient availability on the relative growth rate of the herbivore depended on the plant species. The feeding rate of S. littoralis on plant species that do not produce nitrogen‐containing secondary compounds (NCSC) was higher under low nutrient availability. In contrast, in plants producing NCSC nutrient availability had no effect on the feeding rate. This suggests that compensatory feeding in response to low nutrient contents may not be possible if plants produce NCSC. We conclude that elevated CO₂ causes species‐specific changes in the quality of plant tissues and consequently in changes in the preferences of herbivores for plant species. This could result in changes in plant community composition.