Multiple paternity in<Emphasis Type="Italic"> Rana dalmatina</Emphasis>, a monogamous territorial breeding anuran

Polyandry and sperm competition in anurans have rarely been documented. We investigated the genetic paternity inferred from allozyme variations in 650 tadpoles from four natural ponds in a territorial breeding anuran, Rana dalmatina. Multiple paternity was demonstrated, although R. dalmatina is regarded as a monogamous species. Polyandrous mating was not a common event, occurring only in 17.9% of clutches, with no significant differences among clutches. The proportions of tadpoles fathered by a second male did not significantly differ among ponds, showing that multipaternity was not restricted to a single site. Such a polyandry may result from synchronous multiple amplexus and should reduce the heterozygote deficit related to the breeding-pond fidelity usually exhibited by most anurans.     

抚仙湖马料河人工湿地水质净化效果评估研究

从污染物去除百分率、污染物削减量及污染物表面负荷去除量等不同角度对抚仙湖鸟料河人工湿地的水质净化效果进行了分析，结果表明TN、NH3-N和TP的平均去除率分别约为60％、60％和50％，平均掣减量约为14kg／d、5kg／d和1kg／d，去除污染物表面负荷平均为0．72g／m^2．d、0．22g／m^2．d、0．06g／m^2·d．     

Unexpected new species of deep-water Hydroidomedusae from Korsfjorden,Norway

Two new species of Hydroidomedusae, Parateclaia norvegica sp.nov. and Foersteria quadrata sp.nov., are described from specimens collected in Korsfjorden, western Norway. Neither genus has previously been observed in the North-Atlantic Ocean. The closest congenerics to the new species occur in the Mediterranean, where family Teclaiidae has been considered endemic. P. norvegica and F. quadrata were only collected at sites 500 m or deeper and are possibly deep-water benthopelagic species like their congenerics elsewhere. Sampling took place for the entire year 2003 at 2- to 4-week intervals. F. quadrata, the more numerous of the new species, was absent from the water column only during the spring months, the implications of which regarding its lifecycle are discussed. Hypotheses on speciation in the Foersteria species group and family Teclaiidae are shortly discussed.     

Impact of minimum winter temperatures on the population dynamics of Dendroctonus frontalis.

Predicting population dynamics is a fundamental problem in applied ecology. Temperature is a potential driver of short-term population dynamics, and temperature data are widely available, but we generally lack validated models to predict dynamics based upon temperatures. A generalized approach involves estimating the temperatures experienced by a population, characterizing the demographic consequences of physiological responses to temperature, and testing for predicted effects on abundance. We employed this approach to test whether minimum winter temperatures are a meaningful driver of pestilence from Dendroctonus frontalis (the southern pine beetle) across the southeastern United States. A distance-weighted interpolation model provided good, spatially explicit, predictions of minimum winter air temperatures (a putative driver of beetle survival). A Newtonian heat transfer model with empirical cooling constants indicated that beetles within host trees are buffered from the lowest air temperatures by approximately 1-4 degrees C (depending on tree diameter and duration of cold bout). The life stage structure of beetles in the most northerly outbreak in recent times (New Jersey) were dominated by prepupae, which were more cold tolerant (by >3 degrees C) than other life stages. Analyses of beetle abundance data from 1987 to 2005 showed that minimum winter air temperature only explained 1.5% of the variance in interannual growth rates of beetle populations, indicating that it is but a weak driver of population dynamics in the southeastern United States as a whole. However, average population growth rate matched theoretical predictions of a process-based model of winter mortality from low temperatures; apparently our knowledge of population effects from winter temperatures is satisfactory, and may help to predict dynamics of northern populations, even while adding little to population predictions in southern forests. Recent episodes of D. frontalis outbreaks in northern forests may have been allowed by a warming trend from 1960 to 2004 of 3.3 degrees C in minimum winter air temperatures in the southeastern United States. Studies that combine climatic analyses, physiological experiments, and spatially replicated time series of population abundance can improve population predictions, contribute to a synthesis of population and physiological ecology, and aid in assessing the ecological consequences of climatic trends.     

Effect of water temperature on the courtship behavior of the Alpine newt Triturus alpestris

Temperature is expected to have an effect on the behavioral patterns of all organisms, especially ectotherms. However, although several studies focused on the effect of temperature on acoustic displays in both insects and anurans, almost nothing is known about how environmental temperature may affect ectotherm visual courtship displays and sexual performance. The purpose of this study was to determine the effect of environmental temperature on the sexual behavior of Alpine newts (Triturus alpestris). We subjected T. alpestris to two different temperatures in controlled laboratory conditions. Temperature had a major effect on both male and female behaviors: at low temperature, the frequencies of several displays, including tail-raising during sperm deposition, are lowered. This variation is caused indirectly by temperature because it is due to female responsiveness, which is temperature-dependent. However, the fanning movement of the males tail during its main courtship display is independent of female behavior: at lower temperatures, the tail beats at a lower rate, but for a longer time. The similar reproductive success (i.e. sperm transfer) at the two temperature ranges indicates that breeding in cold water is not costly but instead allows males and females to mate early in the season. This is particularly adaptive because, in many habitats, the reproductive period is shortened by drying or freezing conditions, which may impair survival of branchiate offspring. This study also demonstrates the necessity of considering environmental parameters when modeling optimality and characteristics of ectotherm behaviors.Communicated by W. Cooper     

Unusual nutrition of the “Pompeii worm” Alvinella pompejana (polychaetous annelid) from a hydrothermal vent environment: SEM,TEM, 13C and 15N evidence

Morphological and histological studies of Alvinella pompejana (a polychaete living in the vicinity of hydrothermal vents of the East Pacific Ocean) were performed using light, scanning and transmission electron microscopy. The worms were collected in April–May 1979, during the Rise cruise by the submersible Alvin on the crest of East Pacific Rise at 21°N. The digestive tracts contained many sulfide particles (as determined by microprobe analysis) associated with organic matter and bacteria. Bacterial communities of different morphological types (cocci and filaments) were also observed at different levels of the worm's outer teguments. An atypical (possibly bacteria-derived) nutritional source of carbon and nitrogen for A. pompejana is indicated by the natural abundances of ¹³C:¹²C and ¹⁵N:¹⁴N in its tissues.Contribution No. 807 from Centre Océanologique de Bretagne, B.P. 337, F-29273 Brest Cédex, France     

Small effective number of parents (<Emphasis Type="Italic">N</Emphasis><Subscript><Emphasis Type="Italic">b</Emphasis></Subscript>) inferred for a naturally spawned cohort of juvenile European flat oysters <Emphasis Type="Italic">Ostrea edulis</Emphasis>

The great fecundity and very high larval mortality of most marine invertebrates and fish make possible substantial variance in the number of offspring contributed by adults to subsequent generations. The reproductive success of such organisms may thus resemble a sweepstakes lottery, in which a minority of progenitors succeeds in replacing an entire population, while the majority fails to procreate. One specific prediction of this hypothesis, that genetic diversity of newly settled cohorts should be less than that of the adult population, is tested in the present study. Microsatellite DNA markers were examined in naturally spawned juvenile European flat oysters Ostrea edulis (L.), collected over a 12-day period in 1993 from the western Mediterranean Sea, near Sète, France (43°32′N, 3°56′E) and grown out for a period of up to 10 months. Variation in these juveniles was compared to that in a pooled sample of adults collected in 1994 from two locations (Thau Lagoon and Port St. Louis) that had statistically homogeneous allelic frequencies. Though nearly twice as large as the pooled adult sample, the juvenile sample had only 60% of the adult allelic diversity. Analyses of linkage disequilibrium and kinship, as well as estimation of the effective number of parents, suggested that 10–20 adults produced this juvenile cohort. This observation supports the hypothesis of sweepstakes reproductive success and suggests that partial inbreeding may occur even in species with large populations and dispersing planktonic larvae. Electronic Supplementary Material Supplementary material is available to authorised users in the online version of this article at .     

Recurrent congenital toxoplasmosis in a woman with lupus erythematosus

We describe the case of a patient with systemic lupus erythematosus, treated by corticosteroids, who presented during two successive pregnancies with serological reactivation of toxoplasmosis associated with fetal lesions. The first infected fetus died in utero with signs of hydrops. The second fetus was treated in utero with a combination of sulfadoxine and pyrimethamine, administered to the mother, and is now well. The increasing number of immunocompromised pregnant patients with immunity to Toxoplasma gondii may lead to a higher risk of reactivation of maternal toxoplasmosis and congenital infection.     

50 Jahre Elektroneninterferenzen

On the occasion of the anniversary a recollection is given of the history of the discovery of electron diffraction.

     

Phylogeographic study of the dwarf oyster, Ostreola stentina, from Morocco, Portugal and Tunisia: evidence of a geographic disjunction with the closely related taxa, Ostrea aupouria and Ostreola equestris

Despite the economic importance of oysters due to the high aquaculture production of several species, the current knowledge of oyster phylogeny and systematics is still fragmentary. In Europe, Ostrea edulis, the European flat oyster, and Ostreola stentina, the Provence oyster or dwarf oyster, are both present along the European and African, Atlantic and Mediterranean, coasts. In order to document the relationship not only between O. stentina and O. edulis, but also with the other Ostrea and Ostreola species, we performed a sequence analysis of the 16S mitochondrial fragment (16S rDNA: the large subunit rRNA-coding gene) and the COI fragment (COI: cytochrome oxidase subunit I). Oysters were sampled from populations in Portugal (two populations), Tunisia (two populations) and Morocco (one population), identified as O. stentina on the basis of shell morphological characters. Our data supported a high degree of differentiation between O. stentina and O. edulis and a close relationship between O. stentina and both Ostrea aupouria (from New Zealand) and Ostreola equestris (from Mexico Gulf/Atlantic). The status of this geographic disjunction between these closely related species is discussed. Furthermore, although identified in a separate genus Ostreola by Harry (Veliger 28:121–158, 1985), our molecular data on O. stentina, together with those available for the other two putative congeneric species, O. equestris and Ostreola conchaphila, would favour incorporation of Ostreola in Ostrea. Finally, a PCR-RFLP approach allowed the rapid identification of O. edulis and O. stentina.