Identification of 13 polymorphic microsatellite loci in the zebra finch,Taeniopygia guttata (Passeridae,Aves)

Polymorphic microsatellite loci were identified in order to determine paternity in a captive population of the zebra finch, Taeniopygia guttata. Primer sets from 93 published passerine microsatellite sequences were tested for cross‐species amplification. Thirteen loci were found to be polymorphic, of which, eight displayed null alleles and one locus (Ase50) was found to be Z‐chromosome linked.     

Consequences of reduced nutrient loading on a lake system in a lowland catchment: deviations from the norm?

1. Lake restoration from eutrophication often rests on a simple paradigm that restriction of phosphorus sources will result in recovery of former relatively clear‐water states. This view has apparently arisen from early successful restorations of deep lakes in catchments of poorly weathered rocks. Lakes in the lowlands, however, particularly shallow ones, have proved less tractable to restoration. This study of three lowland lakes provides insights that illuminate a more complex picture. 2. The lakes lie in a sequence along a single stream in a mixed urban and rural landscape. Severely deoxygenating effluent from an overloaded sewage treatment works was diverted from the catchment in 1991. Effects on two lakes, Little Mere (z_max <2 m) and Rostherne Mere (z_max 31 m) were followed until 2002. Mere Mere (z_max = 8 m), upstream of the former works, acted as a comparison for changes in water chemistry. Mere Mere showed no change in total phosphorus (TP), total inorganic nitrogen, or planktonic chlorophyll a concentrations. Increased winter rainfall was associated with higher winter soluble reactive phosphorus (SRP) and ammonium concentrations in its water. 3. Little Mere changed from a deoxygenated, highly enriched, fishless system, with large populations of Daphnia magna Straus, clear water and about 40% aquatic plant cover, to a slightly less clear system following diversion. Daphnia magna was replaced by D. hyalina Leydig as fish recolonised. Spring peaks of chlorophyll a declined but summer concentrations increased significantly. Annual mean chlorophyll a concentrations thus showed no change. Submerged plants became more abundant (up to 100% cover), with fluctuating community composition from year to year. Summer release of SRP from the sediment was substantial and has not decreased since 1993. The summer phytoplankton was apparently controlled by nitrogen availability perhaps with some influence of zooplankton grazing. SRP was always very abundant. The lake appeared to have reached a quasi‐stable state by 2002. 5. Rostherne Mere showed a steady decline in TP and SRP concentrations following effluent diversion apparently as a result of steady dilution by water with lower phosphorus concentration. Decline in phosphorus concentrations was much less rapid than expected because of internal remobilisation from the hypolimnion and sediments. There have been no changes in chlorophyll a concentration or of nitrogen availability and by 2002 the phytoplankton probably remained limited by a combination of mixing, grazing and nitrogen. 6. A seeming paradox is, thus, that immense changes in phosphorus budgets have shown no consequences for phytoplankton chlorophyll concentrations in either of the lakes, although the seasonal distribution has altered in Little Mere. Although these case studies deviate from others, for both shallow and deep lakes, they represent distinctive situations rather than undermining conventional models.     

Changes in Kit Fox Defecation Patterns During the Reproductive Season: Implications for Noninvasive Surveys

Abstract: Noninvasive survey methods based on analyzing DNA extracted from feces can be useful for carnivores that are difficult to study by other methods. Changes in fecal deposition patterns associated with reproduction in kit foxes (Vulpes macrotis) might affect results of such surveys. We used a trained dog to collect fresh scats on 2-km transects in the home ranges of 11 radiocollared female kit foxes in January, February, and March 2008 and determined sex of the individual that deposited the scats by amplifying the zinc finger protein gene. Female foxes give birth in mid-February to mid-March. We found a similar number of scats each month. In January, the sex ratio of the scats was not different from the expected 1:1. However, in February there were almost 2 male scats for every female scat and in March there were >8 male scats for every female scat. Comparing March to January, there were more male scats on all 11 transects and fewer female scats on 10 of 11 transects. Around the time pups are born, both sexes appear to show changes in fecal deposition patterns that make it easier to find male scats and harder to find female scats. Effects of these changes on survey results will vary depending on the purpose and design of the survey. Surveys to determine distribution and relative abundance would probably not be negatively affected by these changes. However, if surveys to estimate abundance are conducted during the reproductive season, they could result in an underestimate of population size unless the increased heterogeneity in scat detectability is taken into account.     

Size variation and mating success in the stag beetle, Lucanus cervus

Abstract.  The stag beetle, Lucanus cervus , is Britain's largest beetle, with a patchy distribution in southern England. The literature suggests that it displays exceptional size variation, particularly in the males, but no analysis of size inequality has ever been conducted. In the present study, stag beetle adults are measured and allometric relationships derived between various parameters and total body length. Most of the specimens found each year are fragments and head width can be used as a good predictor of total body length in each sex. Body size differs between years and between localities and male beetles show a greater degree of size inequality than females. However, L. cervus does not show greater inequality in size than many other beetle species and populations of males are composed of a relatively large number of small individuals. These males are not at a disadvantage in mating because it is the ratio of male : female size that determines mating success. Very large males are less successful in mating and it is suggested that lack of mating success may act as an additional constraint on mandible size in this species. Size variation is most likely caused by variation in larval food resources, coupled with variation in local climatic conditions.     

The Uptake and Utilization of Bacteria, Amino Acids and Nucleic Acid Components by the Rumen Ciliate Eudiplodinium maggii

Washed suspensions of the rumen ciliate protozoon Eudiplodinium maggii grown in vitro and incubated anaerobically engulfed all the bacteria tested except for Bacteroides ruminicola and Klebsiella aerogenes. There was considerable variation (160–9100 bacteria/h/protozoon at an external concentration of 10¹⁰ bacteria/ml) in the rate at which the bacteria were engulfed, but Eu. maggii showed some preference for bacteria of rumen origin. Some of the bacteria were digested with the release of soluble materials into the medium. Free amino acids were incorporated from an 0.1 mM solution at rates of 0.13 to 0.84 pmol/h/protozoon. Evidence is presented that Eu. maggii could obtain half the amino acids required for growth by the engulfment and digestion of bacteria and half by the uptake of free amino acids. Eudiplodinium maggii incorporated uridine 5' monophosphate and also hydrolysed this to uridine and then to uracil which was reduced to dihydrouracil. These products all appeared in the medium. Ribose was incorporated by the protozoon and appeared as glucose in protozoal and bacterial polysaccharide; none was incorporated as such into protozoal nucleic acid.     

Resource partitioning and tolerance of monoterpenes in four species of spruce aphid

Abstract. The tolerance of four species of aphids to myrcene was assessed by measuring the mortality of aphids exposed to different amounts of this monoterpene.Each species was found to exhibit significantly different levels of tolerance to myrcene.which is explicable in terms of the likely concentration of myrcene at the feeding site of each species.
Tolerance to monoterpenes maybe specific only to those encountered in high concentrations at the feeding site.whereas others are found to be toxic.This suggests that each species has become physiologically adapted to tolerate different levels of the specific monoterpenes that occur in the microhabitats they occupy.     

Characterization of the T, L, I, S, M and P Cell Surface (Immobilization) Antigens of Tetrahymena thermophila: Molecular Weights, Isoforms, and Cross-Reactivity of Antisera

ABSTRACT. In the ciliate protist Tetrahymena thermophila the L, H, T, I, S, M and P cell surface proteins (immobilization antigens) are expressed under different conditions of temperature (L, H, T), culture media (I, S), and mutant genotype (M, P). Immunoblot and autoradiographic studies using antisera to purified protein show that the molecular weights of these proteins range from 25,000 to 59,000. The H, T, S, M and P antigens are recognized as single polypeptides, whereas L, I, and one allelic form of T each appear to consist of a family of polypeptides. Although antisera are specific in immobilization and immunofluorescence assays of surface protein in living cells, cross-reactivity is seen with denatured protein on immunoblots. It is hypothesized that the surface protein genes are organized into families of evolutionarily related isoloci.