Chemotaxonomic study of seed glucosinolate composition in Coincya Rouy (Brassicaceae)

A total of 68 populations belonging to the genus Coincya Rouy (Brassicaceae) from the Iberian Peninsula was examined for seed glucosinolate composition. The presence of progoitrin, epiprogoitrin, glucosinalbin and gluconapin was recorded plus a fifth glucosinolate that could not be identified. A geographical clinal variation between progoitrin and epiprogoitrin was observed in the more widespread taxa, C. monensis subsp. orophila (Franco) Aedo, Leadiay & Murioz Garm. and C. moncnsis subsp. cheiranthos var. recurvata (All.) Leadiay. The fewest types of glucosinatc were observed in taxa with morphological characters considered more primitive, viz. subsp. hispida and var. recurvata. On the other hand, more complex and diverse composition was observed in the taxon with more advanced characters, viz. C. rupestris subsp. rupestris Porta & Rigo.     

On the nomenclature and types of Chamaecytisus proliferus (L.f.) Link (Fabaceae: Genisteae), a fodder shrub from the Canary Islands

The name Cytisus proliferus L.f. is here considered perfectly acceptable and should not be replaced by Cytisus prolifer L.f. One specimen from The Natural History Museum, London is confirmed as the lectotype of Cytisus proliferus L.f. Two specimens from the collection of the Swiss botanist Hermann Christ from the Main Herbarium of the Zurich Botanical Garden were selected as lectotypes for Cytisus proliferus L.f. var. canariae H. Christ and Cytisus proliferus L.f. var. palmensis H. Christ. The name Cytisus proliferus Kit. is typified and a specimen from Paul Kitaibel's collection at the Botanical Department of the Hungarian Natural History Museum is assigned as its lectotype.     

Effect of Amphotericin B on Dopachrome Tautomerase Activity and Other Melanogenic Parameters in Cultured B16/F10 Melanoma Cells

The antifungal reagent Fungizone (amphotericin B and deoxycholate) caused an activation in dopachrome tautomerase and dopa oxidase activities of B16/F10 melanoma cells at the routine concentration (2.5 μg/ml) used for preventing molds and yeast growth in cultures of animal cells. However, higher amphotericin B concentrations caused a significant cell death and the inhibition of enzymatic activities. At the optimal concentration of Fungizone, the enzymatic activities and melanin content were augmented as incubation time increased. The detergent sodium deoxycholate alone exerted no effect on these melanogenic parameters, eliminating the possibility that this detergent was partially responsible for melanogenic modifications produced by Fungizone. After withdrawal of Fungizone from the reaction medium, the recovery of melanogenic parameters to normal values was slower for DCT than for tyrosinase. The behavior of dopa oxidase was very similar to that reported by Johnson and Bagnara (Pigment Cell Res. 3, 173–175) for tyrosine hydroxylase.     

Mandible shape in marsupial and placental carnivorous mammals: a morphological comparative study using geometric morphometrics

We analysed mandible shape of the orders Dasyuromorpha, Didelphimorphia, and Carnivora using two‐dimensional geometric morphometrics, in order to explore the relationship between shape, size, and phylogeny. We studied 541 specimens, covering most of the genera of the terrestrial Carnivora (115 species) and a wide sample of marsupials (36 species). The observed shape variation had an ecological component. As an example, omnivorous carnivores have thick mandibles and large talonids in the carnassials, while hypercarnivores possess short mandibles and reduced talonids. There is also a discrimination between different taxonomic groups (i.e. marsupials and Carnivora), indicating some kind of constraint. Size explains a large percentage of total variance (large species had shorter and stronger mandibles, with anteriorly displaced carnassials), was significant when phylogeny was taken into account with a comparative method, but not when size and shape were optimized on the phylogeny. Carnivora presents a larger disparity and variation in body size, which could be related to the difference in teeth replacement. The optimization of mandible shape on the phylogenetic tree indicates that functional aspects, such as diet, are a key factor in the evolution of the carnivore mandible, but also that there is a phylogenetic pattern that cannot be explained by differences in diet alone. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164 , 836–855.     

Trophic ecology of red roach (Rutilus arcasii) in a seasonal stream; an example of detritivory as a feeding tactic

1. Diel feeding activity and diet of red roach (Rutilus arcasii) were determined on five occasions (February, April, June, August and November 1985) in a seasonal, fluctuating stream subject to severe summer droughts and cold winter floods. 2. Except in June, the two age groups of the population (1 + and >1+) fed mainly on detritus and showed no significant differences either in their feeding intensity or in the relative contribution of the main diet components (detritus, plants and invertebrates). 3. The size, abundance and availability of drifting invertebrates influenced red roach feeding. When drift was scarce or inaccessible, both age groups fed on detritus, plants, or a combination of the two. These niche shifts were a trophic tactic aimed at maintaining feeding when other, more nutritional and energetically valuable foods were scarce. 4. A comparison with other populations suggested that a detritus-based diet had no major cost in the life history of the red roach. We hypothesize that the highly opportunistic trophic strategy of this Iberian endemic cyprinid is an adaptative response to seasonal Mediterranean streams.     

The winter feeding ecology of Avocets Recurvirostra avosetta on intertidal areas. I. Feeding strategies

The behaviour of Avocets Recurvirostra avosetta feeding on emerged intertidal areas in a major wintering area, the Tagus estuary (Portugal), was studied during 2 years.
Avocets used four different feeding strategies. By far the most common was the Normal Feeding Strategy, in which the median sweeping rate was 28 sweeps per min and the percentage of swallowing movements (ingestions) was very high (median = 90%). No prey were visible in the bill while birds were using this strategy. Another less common feeding strategy was the Worm Feeding Strategy, in which the sweeping rate was higher (median = 46 sweeps/min) and the percentage of swallowing movements was much lower (median = 6%). While using the Worm Feeding Strategy, Avocets preyed on ragworms Nereis diversicolor. The Mixed Feeding Strategy and Scrobicularia plana Siphons Feeding Strategy were rarely observed.
In a detailed study on the use of the mudflats by Avocets, it was found that the density of birds on the upper shore was much higher than on the lower shore. There were differences in feeding behaviour between these two areas, although the same feeding strategy was used. On the lower shore, where there was a lower biomass of prey available, sweeping rates were higher and aggressive behaviour did not occur. On the upper shore, sweeping rates were lower and aggressive behaviour was frequent, with some birds defending territories. Nevertheless, estimated food intake rates were 1.5 times higher on the upper shore.     

UV radiation and phosphorus interact to influence the biochemical composition of phytoplankton

1. Numerous laboratory studies have shown that food quality is suboptimal for zooplankton growth. However, little is known about how food quality is affected by the interaction of potential global change factors in natural conditions. Using field enclosures in a high altitude Spanish lake, seston was exposed to increasing phosphorus (P) concentrations in the absence and presence of UV radiation (UVR) to test the hypothesis that interactions between these factors affected the biochemical and stoichiometric composition of seston in ways not easily predicted from studies of single factors. 2. Phosphorus enrichment increased the content of total fatty acids (TFA), ω3‐polyunsaturated fatty acids (ω3‐PUFA) and chlorophyll‐a : carbon (Chl‐a : C) and C : N ratios in seston. The pronounced increase in ω3‐PUFA was largely explained by the enhancement of 18:3n‐3 (α‐linolenic acid). In contrast, P‐enrichment lowered the content of highly unsaturated fatty acids (HUFA), the HUFA : PUFA ratio and, at high P loads, seston C : P ratio. Although phytoplankton assemblages dominated by Chlorophytes were not rich in HUFA, seston in the control had substantially higher 20:4n‐6 (arachidonic acid, ARA) content (79% of HUFA) than did P‐enriched enclosures. 3. The UVR increased the content of ω3‐PUFA and TFA in seston at the two ends of the trophic gradient generated at ambient and high concentrations of P, but decreased seston C : P and HUFA at all points on this gradient. ARA was not detected in the presence of UVR. 4. The interaction between P and UVR was significant for seston HUFA and C : P ratios, indicating that the effect of UVR in reducing HUFA (decreased food quality) and C : P ratios (enhanced food quality) was most pronounced at the low nutrient concentrations characteristic of oligotrophic conditions and disappeared as P increased. Therefore, any future increase in UVR fluxes will probably affect most strongly the food quality of algae inhabiting oligotrophic pristine waters although, at least in the Mediterranean region, these effects could be offset by greater deposition of P from the atmosphere.     

Application of a predictive model to detect long-term changes in nest-site selection in the Bearded Vulture Gypaetus barbatus: conservation in relation to territory shrinkage

In this study we examined long-term variation in the selection of nesting cliffs for the recovering population of the Bearded Vulture Gypaetus barbatus inhabiting the Spanish Pyrenees. We focussed on variables indicating a high probability of cliff occupancy as determined by a previously published model. Although the breeding population increased from 53 to 93 territories between 1991 and 2002, the breeding range expanded only slightly. New and old nesting cliffs had similar habitat features in relation to topography, altitude and degree of human influence, but the distance between occupied cliffs was reduced (from 11.1 to 8.9 km). Thus the probabilities of occupation predicted by the model were lower for newly colonized locales. Our study shows that territory compression may occur without serious modification of nesting habitat quality. These results may arise from the lack of strong territorial behaviour by Bearded Vultures and the availability of high-quality cliffs. The relatively low quality of sites in adjacent mountains may prevent the expansion of the breeding range, but conspecific attraction may also play a role. Our study confirms that monitoring changes in key variables important to habitat selection is useful in determining long-term trends in settlement patterns in heterogeneous environments. The results also suggest that the available nest-site selection model may accurately predict cliff occupancy by Bearded Vultures in those areas where the distance to the nearest neighbour is not a limiting factor. In particular, the model may be useful in establishing priority areas for reintroduction.