Rhipidocotyle gibsoni n. sp. from a Brazilian Freshwater Fish and Rhipidocotyle froesi n.sp. for r. baculum (linton, 1905) of Eckmann (1932) (Bucephalidae; Digenea)

Rhipidocotyle gibsoni n.sp. is described from Acestrorhynchus lacustris from Paraná River, brazil. It is most closely related to r. froesi n. sp. and to R. eckmanni in the shape of the cephalic hood, differing in the extent of the uterus, in the position of the vitelline follicles and in that the host is a freshwater fish. Rhipidocotyle froesi n. sp. is proposed for the marine specimens described by Eckmann (1932) as R. baculum (Linton, 1905).

Migration of sharks into freshwater systems during the Miocene and implications for Alpine paleoelevation

Trace-element and isotopic compositions of fossilized shark teeth sampled from Miocene marine sediments of the north Alpine Molasse Basin, the Vienna Basin, and the Pannonian Basin generally show evidence of formation in a marine environment under conditions geochemically equivalent to the open ocean. In contrast, two of eight shark teeth from the Swiss Upper Marine Molasse locality of La Moliere have extremely low delta O-18 values (10.3% and 11.3%) and low Sr-87/Sr-86 ratios (0.707840 and 0.707812) compared to other teeth from this locality (21.1%,22.4%o and 0.708421-0.708630). The rare earth element (REE) abundances and patterns from La Moliere not only differ between dentine and enameloid of the same tooth, but also between different teeth, supporting variable conditions of diagenesis at this site. However, the REE patterns of enameloid from the ``exotic'' teeth analyzed for O and Sr isotopic compositions are similar to those of teeth that have O and Sr isotopic compositions typical of a marine setting at this site. Collectively, this suggests that the two ``exotic'' teeth were formed while the sharks frequented a freshwater environment with very low O-18-content and Sr isotopic composition controlled by Mesozoic calcareous rocks. This is consistent with a paleogeography of high-elevation (similar to 2300 m) Miocene Alps adjacent to a marginal sea.

Thermal effect on the life-cycle parameters of the medically important freshwater snail species Lymnaea (Radix) luteola (Lamarck)

The snails Lymnaea (Radix) luteola exhibited marked variations in growth, longevity, and attaining sexual maturity at different temperatures and diets. At 10°C, irrespective of foods, pH and salinity of water, the snails had minimum life span, maximum death rate and lowest growth rate. At 15°C, the growth rate was comparatively higher and the snails survived for a few more days. But at these temperatures they failed to attain sexual maturity. Snails exposed to pH 5 and 9 at 20°, 25°, 30°, 35°C and room temperatures (19.6°-29.6°C); to 0.5, 1.5 and 2.5 NaCl ‰ at 20° and 35ºC; to 2.5 NaCl ‰ at 25°C and room temperatures failed to attain sexual maturity. The snails exposed to pH 7 and different salinity grades at 20°, 25°, 30°, 35°C and room temperatures became sexually mature between 25-93 days depending upon the type of foods used in the culture.

Gender-role alternation in the simultaneously hermaphroditic freshwater snail Physa acuta: not with the same partner

In simultaneous hermaphrodites, gender conflicts that arise from two potential mates sharing the same gender preference may be solved through conditional reciprocity (or gamete trading). Conditional reciprocity had initially been considered widespread, but recent studies suggest that its real occurrence may have been overestimated, possibly because most mating observations have been performed on isolated pairs of individuals. Some resulting patterns (e. g., non-random alternation of sexual roles) were indeed compatible with conditional reciprocity but could also have stemmed from the two partners independently executing their own mating strategy and being experimentally enforced to do so with the same partner. Non-random alternation of gender roles was recently documented in the simultaneously hermaphroditic freshwater snail Physa acuta. To distinguish between conditional and unconditional gender alternations, we observed copulations of individually marked snails reared at three contrasted densities. We showed that density affected the overall frequency of copulations during the first 2 days of the experiment with high-density boxes showing more copulations than low density boxes, but it did not affect gender alternation patterns. A change in gender role was observed more often than expected by chance over two successive copulations by the same individual, confirming previous studies. However, gender switches did not preferentially occur with the same partner. We conclude that gender alternation is not due to conditional reciprocity in P. acuta. It may rather stem from each individual having a preference for gender alternation. We finally discuss the mechanisms and the potential extent of this unconditional reciprocity.

Eimeria peltocephali n. sp., (Apicomplexa:Eimeriidae) from the Freshwater Turtle Peltocephalus dumerilianus (Chelonia:Pelomusidae) and Eimeria molossi n. sp., from the Bat, Molossus ater (Mammalia:Chiroptera)

The oocyst is described of Eimeria peltocephali n.sp. from faeces of the freshwater turtle Peltocephalus dumerilianus from Barcelos, State of Amazonas, Brazil. Sporulation is exogenous and fully developed oocysts are elongate, ellipsoidal or cylindrical, frequently curved to a banana-shape, 54.4 x19.1 (37.5 - 68.7 x 18.7-20.0 µm), shape-index 2.8 (1.8 -3.9). The oocyst wall is a single thin, colourless layer about 1 µm thick, with no micropyle. There is a bulky oocyst residuum, at first spherical to ellipsoidal, 19 x 16 (16. 2 -26.2 x 16 - 21.5µm) , but becoming dispersed on maturation. There are no polar bodies. The sporocysts, 19.1 x 6.8 ( 17.5 -21.2 x 6.2 -7.5 µm), shape- index 2.8 (2.3 -3.2), are usually disposed in pairs at each end of the oocyst, and bear an inconspicuous Stieda body in the form of a flat cap. The sporozoites are elongate and slightly curved around the residuum. No refractile bodies were seen. Eimeria molossi n.sp., is described from the molossid bat Molossus ater. Sporulation is exogenous and the mature oocysts are predominantly broadly ellipsoidal, 23.4 x 17.5 (18-30 x 15-22.5 µm), shape-index 1.3 (1-1.6). The oocyst wall is about 2 µm thick, and of three layers: an inner thin, colourless one and two outer layers which are thicker, yellowish-brown, prominently striated and in close apposition. There is no micropyle or oocyst residuum, but one and occasionally two polar bodies are usually present. Sporocysts are ellipsoidal, 10.2 x 7.5 (10-12.5 x 7.5 µm), shape-index 1.4 (1.3-1.7) with an inconspicuous Stieda body. Endogenous stages are described in the epithelial cells of the small intestine

Molecular and isotopic characterization of biomarkers in the Frick Swiss Jura sediments: A palaeoenvironmental reconstruction on the northern Tethys margin

Molecular and stable carbon isotope compositions of source-specific hydrocarbons have been used to reconstruct palaeoenvironmental conditions during deposition of the Middle Hettangian to Upper Sinemurian sediments on the northern epicontinental Tethys margin, Frick Swiss Jura. Increasing algal, cyanobacterial and phytoplanktonic (i.e., dinoflagellate) contributions associated with the C-13-enrichment of cyanobacteria derivatives (i.e., hopanes and monomethylalkanes) suggest enhanced primary productivity upsection. This is related to the C-13-enrichment of dissolved CO2 in the upper layers and the progressive increase of depth and oxygenation of the water column. In the Middle Hettangian shallow-water environments (lagoon), the occurrence of green sulfur bacteria (Chlorobiaceae) derivatives indicates that the lower part of the water column was strictly anoxic and rich in H2S. Since these bacteria require very low light intensity to grow, these euxinic conditions may be extended up to the photic zone, allowing for anaerobic photosynthesis. Light penetration depth is most likely reduced by high productivity and/or turbidity in the photic zone. In these sediments, C-13-depleted hopanoids (-39.5 parts per thousand) are most likely associated with phototrophic purple sulfur bacteria utilizing isotopically light organic carbon at the base of the aerobic zone. These purple sulfur bacteria may have consumed the H2S used by Chlorobiaceae in the deeper layers and thus, sustained the algae and cyanobacteria productivity in the upper layers. The C-13-depleted carbonate (-13.3 parts per thousand) may be partially related to the anaerobic oxidation of the organic matter during bacterial sulfate-reduction. (c) 2006 Elsevier Ltd. All rights reserved.

Green vs. Lempert functions: a minimal example

The Lempert function for a set of poles in a domain of Cn at a point z is obtained by taking a certain infimum over all analytic disks going through the poles and the point z, and majorizes the corresponding multi-pole pluricomplex Green function. Coman proved that both coincide in the case of sets of two poles in the unit ball. We give an example of a set of three poles in the unit ball where this equality fails.

Evaluation of subsidies programs to sell green cars: Impact on prices, quantities and efficiency

During the recent period of economic crisis, many countries have introduced scrappage schemes to boost the sale and production of vehicles, particularly of vehicles designed to pollute less. In this paper, we analyze the impact of a particular scheme in Spain (Plan2000E) on vehicle prices and sales figures as well as on the reduction of polluting emissions from vehicles on the road. We considered the introduction of this scheme an exogenous policy change and because we could distinguish a control group (non-subsidized vehicles) and a treatment group (subsidized vehicles), before and after the introduction of the Plan, we were able to carry out our analysis as a quasi-natural experiment. Our study reveals that manufacturers increased vehicle prices by the same amount they were granted through the Plan (1,000 €). In terms of sales, econometric estimations revealed an increase of almost 5% as a result of the implementation of the Plan. With regard to environmental efficiency, we compared the costs (inverted quantity of money) and the benefits of the program (reductions in polluting emissions and additional fiscal revenues) and found that the Plan would only be beneficial if it boosted demand by at least 30%.

Scolex Morphology of Proteocephalid Cestodes Parasites of Neotropical Freshwater Fishes

The morphology of the scolices and metascolices of 29 proteocephalid species, parasites of freshwater fishes from Brazil was compared by using scanning electron microscope, light and laser microscopy. The following species were evaluated: Proteocephalus vazzolerae, P. piramutab, Robertiella paranaensis, Travassiella avitellina, Monticellia loyolai, M. spinulifera, M. belavistensis, Houssayela sudobim, Zygobothrium megacephalum, Gibsoniela mandube, Cangatiella arandasi, Nomimoscolex sudobim, N. lopesi, N. admonticellia, N. piraeeba, N. pirarara, Harriscolex kaparari, Crepidobothrium eirasi, Spatulifer rugosa, Megathylacus brooksi, Choanoscolex abscisus, Amphoteromorphus peniculus, A. piraeeba, Paramonticellia itaipuensis, Peltidocotyle rugosa, Othinoscolex lenha, Rudolphiella rugata, R. piranabu, Jauella glandicephalus. Some features as overall shape of scolex, suckers, apical sucker, frontal glands and several kinds of metascolex were analyzed. The taxonomic importance of scolex and metascolex is discussed.

Neopolystoma fentoni n. sp. (Monogenea: Polystomatidae) a parasite of the conjunctival sac of freshwater turtles in Costa Rica

Neopolystoma fentoni n. sp. is described from the conjunctival sac of Kinosternon leucostomum (Duméril, Bibron, and Duméril 1851) and Rhinoclemmys pulcherrima (Gray 1855) from the Guanacaste Conservation Area in Costa Rica. The new species differs from all other species of Neopolystoma, except N. elizabethae Platt 2000 in possessing a circle of eight genital spines that are recurved and possess a crescent-shaped base. N. fentoni n. sp. differs from N. elizabethae in lacking cecal diverticula and in a number of morphometric criteria.