Comparative studies of Trypanosoma vespertilionis Battaglia and Trypanosoma dionisii Bettencourt & França

SYNOPSIS. In diphasic blood agar media Trypanosoma vespertilionis developed spheroid clusters as compared to rather long, sausage-shaped (sometimes branched) clusters formed by Trypanosoma dionisii. The former species attained a greater population density (∼6 × 10⁷ organisms/ml) than the latter (∼ 2 × 10⁷ organisms/ml). Greater numbers of epimastigotes, some in active binary divisions, were observed during the logarithmic phase of growth, and morphologic changes occurred during cultivation which correlated with increased acidity and a depletion of glucose. Maximum numbers of trypomastigote forms were found during the stationary and early death phases. Most of the forms observed after 20 days were sphaeromastigotes. Glucose concentrations decreased to 0 M in T. vespertilionis and to 4.4 × 10⁻⁵ M in T. dionisii cultures during the stationary and death phases. By the 12th day of incubation cultures of T. vespertilionis were more acid (pH 5.5) than those of T. dionisii (pH 6.5). No antigenic changes during cultivation of each of the parasites were detected by immunodiffusion. Trypanosoma vespertilionis and T. dionisii contained common and specific antigens. At least 2–3 common antigens were detected in extracts reacted against heterologous antisera. Specific antigens were observed as nonidentical lines formed by extracts reacted against homologous and heterologous antisera and with antisera absorbed with heterologous antigens. At least 2 specific antigens were evident in extracts of T. vespertilionis and 1 in extracts of T. dionisii.     

Ozone Alteration of Nitrate Reduction in Soybean

Soybeans [Glycine max (L.) Merr.] were harvested at various periods after a 2 h exposure to determine the effects of ozone on nitrate reductase and selected metabolites related to nitrate reduction. Ozone initially depressed the concentrations of reducing sugars, amino acids, and nitrate reductase activity. On subsequent days following exposure, amino acid and protein levels were higher than the respective controls while the levels of reducing sugars and nitrate reductase activity returned to control levels. The ozone depression of nitrate reduction was not the result of a direct ozone reaction with the nitrate reductase protein but rather an interference with reactions that supplied the NAD(P)H needed for nitrate reduction.     

Eimeria macusaniensis n. sp. (Protozoa: Eimeriidae) of the Alpaca Lama pacos

SYNOPSIS. A new species of coccidium, Eimeria macusaniensis n. sp., is described from the alpaca Lama pacos in Macusani, Peru. The oocysts are ovoid to piriform, 81–107 by 61–80 μ (mean 93.6 by 67.4 μ) with a micropylar cap and elongate ovoid sporocysts 33–40 by 16–20 μ (mean 36.3 by 18.3 μ).     

Coccidia (Protozoa: Eimeriidae) of the Alpaca Lama pacos*

SYNOPSIS. Three new species of coccidia are described from the alpaca Lama pacos from Peru. These are the first species of coccidia to be named from this host. The oocysts of Eimeria lamae n. sp. are ellipsoidal, occasionally ovoid, 30–40 by 21–30 μ (mean 35.6 by 24.5 μ) with elongate ovoid sporocysts 13–16 by 8–10 μ (mean 15.3 by 8.5 μ). The oocysts of Eimeria alpacae n. sp. are ellipsoidal, rarely ovoid, 22–26 by 18–21 μ (mean 24.1 by 19.6 μ), with ovoid sporocysts 10–13 by 7–8 μ (mean 11.0 by 6.8 μ). The oocysts of Eimeria punoensis n. sp. are ellipsoidal, occasionally ovoid, 17–22 by 14–18 μ (mean 19.9 by 16.4 μ), with ovoid sporocysts 8–11 by 5–7 μ (mean 9.2 by 6.1 μ).     

The importance of mesophyll conductance in regulating forest ecosystem productivity during drought periods

Water availability is the most limiting factor to global plant productivity, yet photosynthetic responses to seasonal drought cycles are poorly understood, with conflicting reports on which limiting process is the most important during drought. We address the problem using a model‐data synthesis approach to look at canopy level fluxes, integrating twenty years of half hour data gathered by the FLUXNET network across six Mediterranean sites. The measured canopy level, water and carbon fluxes were used, together with an inverse canopy ecophysiological model, to estimate the bulk canopy conductance, bulk mesophyll conductance, and the canopy scale carbon pools in both the intercellular spaces and at the site of carboxylation in the chloroplasts. Thus the roles of stomatal and mesophyll conductance in the regulation of internal carbon pools and photosynthesis could be separated. A quantitative limitation analysis allowed for the relative seasonal responses of stomatal, mesophyll, and biochemical limitations to be gauged. The concentration of carbon in the chloroplast was shown to be a potentially more reliable estimator of assimilation rates than the intercellular carbon concentration. Both stomatal conductance limitations and mesophyll conductance limitations were observed to regulate the response of photosynthesis to water stress in each of the six species studied. The results suggest that mesophyll conductance could bridge the gap between conflicting reports on plant responses to soil water stress, and that the inclusion of mesophyll conductance in biosphere–atmosphere transfer models may improve their performance, in particular their ability to accurately capture the response of terrestrial vegetation productivity to drought.     

Strengthening the Natural and National Park system of Iberia to conserve vascular plants

The diversity of the Iberian vascular flora has been investigated using WORLDMAP versions 3.08 and 3.18. Two data sets scoring plant distributions as presences within the Iberian Peninsula were compiled; one for 2133 species at 50 × 50 km grid and the other for 801 species at 10 × 10 km map grids. Patterns of biodiversity were determined using the diversity measures of species richness, range-size rarity and character richness diversity. Using the diversity measures, combined with an area selection method, maps of priority areas were calculated using iterative procedures. Near minimum sets (NMSs) for both scales were calculated. Comparison of the NMS for the 10 × 10 km grid with the near minimum set for existing reserves (NMSER) showed that at least 2% more of the land surface would be required above and beyond the existing protected area network, currently comprising 6% of the area, to ensure representation of all species at least once as listed within the present data-base. It is demonstrated that reserve systems selected on a variety of different criteria are suboptimal when compared to particular groups of target organisms with a definite goal of representation for conservation. Calculating efficiency of existing reserve systems and accounting for all taxa identifies precisely the extra required areas for the protected area system to satisfy particular goals of representation.     

Does constrained oviposition influence offspring sex ratio in the solitary parasitoid wasp Venturia canescens?

Abstract.  1. In haplodiploid organisms, virgin or sperm-depleted females can reproduce but are constrained to produce only male progeny. According to Godfray's constrained model, when p , the proportion of females constrained to produce only male progeny, is not null in a panmictic population, unconstrained females should bias their sex allocation towards females to compensate for the excess of males. These unconstrained females should be able to adjust the sex ratio in response to local variation of p .
2. In this paper an experimental approach is used to test the hypotheses of this model in the solitary endoparasitoid Venturia canescens under both field and laboratory conditions. Specifically, it is tested whether unconstrained females use their encounters with conspecifics (either male or female) to estimate p and then adjust their sex ratio accordingly.
3. As assumed by Godfray's model, constrained females actively search for host patches in the field and under laboratory conditions produce the same number of offspring during their lifetime as unconstrained females. As predicted by the model, unconstrained females produce a sex ratio biased towards females both in the laboratory and in the field.
4. The results show that this bias is not a response to encounters with conspecifics previous to oviposition. The hypothesis that the bias is due to differential mortality between sexes during ontogeny is also rejected. The proportions of constrained ovipositions estimated in two natural populations explain only a small fraction of the sex ratio bias observed in V. canescens.     

Fine‐scale bird monitoring from light unmanned aircraft systems

Unmanned aircraft systems (UAS) are remote‐controlled devices capable of collecting information from difficult‐to‐access places while minimizing disturbance. Although UAS are increasingly used in many research disciplines, their application to wildlife research remains to be explored in depth. Here, we report on the use of a small UAS to monitor temporal changes in breeding population size in a Black‐headed Gull Chroicocephalus ridibundus colony. This method makes it possible to obtain georeferenced data on nest locations without causing colony disturbance, which would not otherwise be possible via direct ground observations.