Uniform Terminology for the Protozoan Subphylum Apicomplexa*

SYNOPSIS. Uniform names for the stages, processes and structures of apicomplexan protozoa are proposed and defined, and names that should be superseded are listed. The same names are used for the same stages of all members of the group. Gregarines are designated as either septate or aseptate rather than as polycystid or monocystid. The gregarine stage often called a sporadin is recognized for what it is, a gamont. The cyst formed around 2 gregarine gamonts in which zygotes are formed is a gametocyst; it contains oocysts which in turn contain sporozoites. The term “spore” is inappropriate for these oocysts. The apical complex includes the polar ring, conoid, rhoptries, micronemes and subpellicular tubules. The gregarine “pseudocyst” is actually a gametocyst residuum. The term micropore is preferred to cytostome for the apicomplexan structure, since it is visible only with the electron microscope.     

Host-related antennal variation in the polyphagous egg parasite Telenomus alsophilae (Hymenoptera: Scelionidae)

Abstract. The solitary egg parasite Telenomus alsophilae was reared from the eggs of six lepidopteran hosts of two families. One-way analyses of variance showed statistically significant differences among host classes for means of (a) lengths and widths of all female antennomeres; and (b) in twelve of twenty-three means of log-transformed ratios constructed from pairs of antennomere dimensions. Principal component analyses of dispersion matrices of both untransformed and log-transformed antennomere dimensions were conducted to examine patterns of variation among variables. In both analyses PCI was a general component and interpreted as a measure of overall size. One-way analyses of variance of projection scores of OTUs on each of the first five principal components showed significant differences among host classes for means of scores on (a) PCI (both analyses) and (b) PC4 for untransformed data and PC3 for log-transformed data. Differences among hosts classes for scores on the latter two components are interpreted to indicate that antennal variation results from factors in addition to simple size differences among host eggs and the allometric growth of body parts of parasites reared from them.     

Microsatellite loci for Cherrie's tanager (Ramphocelus costaricensis)

Cherrie's tanager (Ramphocelus costaricensis) is a common woodland bird of the Pacific lowlands of Costa Rica. Males and females have sexually dimorphic plumage and are socially monogamous. As part of a study of sexual selection in this species, we characterized six species‐specific polymorphic microsatellite loci and one cross‐species locus that works well in Cherrie's tanager to ascertain parentage.     

Multiscale topoedaphic heterogeneity increases resilience and resistance of a dominant grassland species to extreme drought and climate change

It is argued that the inclusion of spatially heterogeneous environments in biodiversity reserves will be an effective means of encouraging ecosystem resilience and plant community conservation under climate change. However, the resilience and resistance of plant populations to global change, the specific life‐history traits involved and the spatial scale at which environmentally driven demographic variation is expressed remains largely unknown for most plant groups. Here we address these questions by reporting an empirical investigation into the impacts of an unprecedented 3‐year drought on the demography, population growth rates (λ) and biogeographical distribution of core populations of the perennial grassland species Austrostipa aristiglumis in semiarid Australia. We use life‐history analysis and periodic matrix population models to specifically test the hypothesis that patch‐ and habitat‐scale variation in vital life‐history parameters result in spatial differences in the resilience and resistance of A. aristiglumis populations to extreme drought. We show that the development of critical soil water deficits during drought resulted in collapse of adult A. aristiglumis populations (λ?1), rapid interhabitat phytosociological change and overall contraction towards mesic refugia where populations were both more resistant and resilient to perturbation. Population models, combined with climatic niche analysis, suggest that, even in core areas, a significant reduction in size and habitat range of A. aristiglumis populations is likely under climate change expected this century. Remarkably, however, we show that even minor topographic variation (0.2–3 m) can generate significant variation in demographic parameters that confer population‐level resilience and resistance to drought. Our findings support the hypothesis that extreme climatic events have the capacity to induce rapid, landscape‐level shifts in core plant populations, but that the protection of topographically heterogeneous environments, even at small spatial scales, may play a key role in conserving biodiversity under climate change in the coming century.     

STUDIES ON OSCINELLA FRIT LINN.

Data, collected in Sweden during the year 1927, indicate the existence of considerable variation in extent of infestation of the grain of different varieties, sown at the same time. Also they suggest that sterility or "blindness" of grain may be a varietal character.     

Effects of enhanced ultraviolet radiation and carbon dioxide concentration on the moss Hylocomium splendens

In a laboratory experiment interaction effects of UV-B and CO₂ on photosynthesis and growth of the moss Hylocomium splendens were studied. The plants were exposed to two CO₂ levels (350 ppm and 600 ppm) and three UV-B levels (no UV-B, ambient UV-B and that corresponding to 20% ozone depletion) for 5 months. The effects were recorded by measuring the photosynthetic response and growth of the plants. There was a statistically significant change in photosynthetic efficiency and maximum photosynthetic rates due to time and to enhanced CO₂ concentration, whereas there was no effect due to UV-B. There was a decreased growth due to both UV-B and CO₂ and an interaction effect on growth (in length). The UV-B dose corresponding to the ambient level had a larger reducing effect on growth than the highest UV-B dose. This was a counter-intuitive result and the following tentative interpretation was made: differences in the measured UV-A/UV-B/PAR ratios between the treatments could explain the result provided there was a non-linear response to UV over the range of irradiance levels used.