Variation in Serripes groenlandicus (Bivalvia) growth in a Norwegian high-Arctic fjord: evidence for local- and large-scale climatic forcing

We examined the growth rate of the circumpolar Greenland Cockle ( Serripes groenlandicus ) over a period of 20 years (1983–2002) from Rijpfjord, a high-Arctic fjord in northeast Svalbard (80°10'N, 22°15'E). This period encompassed different phases of large-scale climatic oscillations with accompanying variations in local physical variables (temperature, atmospheric pressure, precipitation, sea ice cover), allowing us to analyze the linkage between growth rate, climatic oscillations, and their local physical and biological manifestations. Standard growth index (SGI), an ontogenetically adjusted measure of annual growth, ranged from a low of 0.27 in 2002 up to 2.46 in 1996. Interannual variation in growth corresponded to the Arctic climate regime index (ACRI), with high growth rates during the positive ACRI phase characterized by cyclonic ocean circulation and a warmer and wetter climate. Growth rates were influenced by local manifestations of the ACRI: positively correlated with precipitation and to a lesser extent negatively correlated with atmospheric pressure. A multiple regression model explains 65% of the variability in growth rate by the ACRI and precipitation at the nearest meteorological station. There were, however, complexities in the relationship between growth and physical variables, including an apparent 1 year lag between physical forcing changes and biological response. Also, when the last 4 years of poor growth are excluded, there is a very strong negative correlation with ice cover on a pan-arctic scale. Our results suggest that bivalves, as sentinels of climate change on multi-decadal scales, are sensitive to environmental variations associated with large-scale changes in climate, but that the effects will be determined by changes in environmental parameters regulating marine production and food availability on a local scale.     

Female morphology,web design,and the potential for multiple mating in Nephila clavipes: do fat‐bottomed girls make the spider world go round?

In animal species where females mate with multiple males, female mating success might be expected to covary with aspects of female morphology, such as size or shape. Spiders are especially interesting in this regard, as the females of several spider groups weave intricate webs that often accommodate multiple male spiders, all of whom are potential mates. Because web design is likely to be dependent on female size/shape, we use multivariate methods to assess the relationships among female morphology, web design, and reproductive ecology over a range of body sizes in the orb-weaving spider Nephila clavipes . Of the measured variables, only abdomen size explained a significant amount of the variation in number of males on a web, and this relationship holds even after statistically accounting for body size. Because abdomen size is an indicator of body condition in spiders, we suggest that condition is likely to be an important factor relating to potential mating success in female spiders. We found no evidence for an association between web design and number of males on a web, although our data indicate that larger females build webs that are both larger and further from the ground than those of smaller females.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 87 , 95−102.     

Predator regime influences innate anti-predator behaviour in the freshwater gastropod Lymnaea stagnalis

1. Predation incurs high fitness costs in aquatic organisms either through direct consumption or through avoidance responses that reduce time for activities such as feeding and reproduction. Hence, avoidance responses of aquatic organisms should vary to match closely the predation threat in their environment.
2. The freshwater gastropod Lymnaea stagnalis occurs in a variety of environments which vary in the presence or absence of predatory fish. We used naïve snails reared from six populations of this species experiencing different predator regimes (three co-occurring with molluscivorous fish and three without) to assess whether populations differed in the type and degree of their avoidance behaviours. Innate behavioural responses to four treatments (control, conspecific alarm cues, fish kairomones and fish kairomones paired with alarm cue) were compared in laboratory trials.
3. The primary anti-predator behaviour of L. stagnalis in response to fish kairomones was to crawl out of the water rather than seek refuge under water. This response was strongest when fish kairomones were paired with alarm cues, and varied depending on population origin; snails reared from populations co-occurring with predatory fish showed a stronger response than those raised from populations not experiencing such predators. In addition, populations co-occurring with predatory fish responded to the fish kairomones presented alone.
4. Our findings suggest that the degree of innate anti-predator behaviour shown by L. stagnalis , in terms of both the level of risk to which it responds and the degree of response, varies depending on the predator regime experienced by field populations. Together with previous work on cue association, this demonstrates that this gastropod is able to match its avoidance behaviour very closely to short and long term predation threats within its habitat.     

Range size in North American Enallagma damselflies correlates with wing size

1. Cross-species macroecological comparisons in freshwater invertebrates have been restricted by a lack of large-scale distributional data, and robust phylogenies. Here, we use data from the OdonataCentral database to explore body length–range size and wing length–range size relationships in damselflies from the genus Enallagma ; the recent publication of a phylogeny for this group meant that, as well as a cross-species analysis, we were able to assess relationships in a phylogenetically controlled manner.
2. For cross-species comparisons, only wing length showed significant (positive) regression relationships with range size and occupancy, although the inclusion of body length in multiple regressions increased the fit of the models. Damselflies with larger wings relative to their body length had larger distributions, a result confirmed by a significant positive relationship between range size and residuals from the regression of wing size on body size.
3. For the phylogenetically controlled analyses, only wing length contrast scores were significantly related to distribution patterns and entered into regression models; the significant positive relationships between wing length contrasts and both range size and occupancy contrasts suggested that evolutionary increases in wing length had occurred alongside range expansions.
4. Together these results suggest that species of Enallagma with larger wings (both absolute and relative to body length) tend to be more widely distributed in North America and that the evolution of wing size may have played a role in range expansion. No such relationships were evident for body size. We discuss the potential importance of wing morphometrics for studying the evolutionary ecology of freshwater insects.     

Biology of Rhoophilus loewi (Hymenoptera: Cynipoidea: Cynipidae), with implications for the evolution of inquilinism in gall wasps

The sole described indigenous afrotropical cynipid, the South African endemic Rhoophilus loewi , was originally described as a gall inducer. As predicted by phylogenetic relationships, we confirm that R. loewi is instead an inquiline wasp. Although all other cynipid inquilines develop in galls induced by cynipid wasps, or very rarely cecidomyiid midges, R. loewi is the only cynipid inquiline of a lepidopteran gall, inducing secondary inquiline cells in galls induced by a cecidosid moth genus Scyrotis on Rhus species (Anacardiaceae). Rhoophilus is a lethal inquiline; its larval cells expand into the hollow interior of the host gall resulting in death of the gall inducer. Rhoophilus loewi is redescribed and the final-instar larva described for the first time. We describe host-plant associations, the morphology and phenology of gall formation, and the suite of parasitoid Hymenoptera associated with these galls. The community centred on Scyrotis galls is compared with those observed in other hosts of inquiline cynipids. Elucidation of the life history of R. loewi has fundamental implications for understanding the evolution of cynipid wasps.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 90 , 153–172.     

Winter field use and habitat selection by Eurasian Golden Plovers Pluvialis apricaria and Northern Lapwings Vanellus vanellus on arable farmland

Eurasian Golden Plovers Pluvialis apricaria and Northern Lapwings Vanellus vanellus winter in large numbers on Britain's farmland. Previous studies in mixed farming areas showed pronounced preferences for permanent pasture, but increasing numbers of plovers winter in eastern Britain where arable farmland dominates. We show that an area of intensive arable farmland supported significant numbers of both species from October to February in the absence of large areas of pasture. Habitat use varied seasonally as the habitats present changed. Throughout winter, use of cereal crops matched their availability: plovers selected harrow in early winter, sugar beet stubbles in midwinter and other crops in late winter. Pastures were rarely used at any time of the year. Flocks occupied only a fraction of the available fields, concentrating most in large fields with open boundaries and where manure had been applied. Daytime feeding was more likely during cold days after nights with a new moon, short duration of moonlight or low-intensity moonlight. These results show that plovers are currently able to utilize intensive arable farmland but future changes in management, such as cessation of manure applications and reductions in sugar beet cropping, could have detrimental effects.     

Between‐species facilitation by male fig wasps in shared figs

1. Facilitation is recorded from diverse plant–insect interactions, including pollination and herbivory. 2. The significance of facilitation resulting from the behavior of males of multiple fig wasp species inside figs was investigated. Female fig wasps emerge from natal figs via exit holes dug by males, especially male pollinators. When no males are present, the females struggle to escape and may die. 3. Ficus microcarpa L. is a widely‐established invasive fig tree from Southeast Asia. Its pollinator is absent in South Africa, so the tree cannot reproduce, but two Asian non‐pollinating fig wasps (NPFW) Walkerella microcarpae and Odontofroggatia galili occupy its figs. Abundance patterns of the two NPFW and the proportion of male‐free figs in South Africa, Spain (where the pollinator is introduced), and in China, where the native fig wasp community is diverse, were compared to determine the consequences of reduced species richness for insect survival. 4. Female fig wasps in male‐free figs were found to be trapped, and small clutch sizes contributed to the absence of males in both species. The presence of pollinators in Spain allowed most NPFW to develop in figs containing males. Far more male‐free figs were present in South Africa, elevating mortality rates among female NPFW. Facilitation of female release by males of other NPFW species nonetheless benefitted the rarer species. 5. Selection pressures in South Africa currently favour greater aggregation of NPFW offspring and/or less female biased sex ratios.     

DISPUTING THE ETHICS OF RESEARCH: THE CHALLENGE FROM BIOETHICS AND PATIENT ACTIVISM TO THE INTERPRETATION OF THE DECLARATION OF HELSINKI IN CLINICAL TRIALS

In this paper we argue that the consensus around normative standards for the ethics of research in clinical trials, strongly influenced by the Declaration of Helsinki, is perceived from various quarters as too conservative and potentially restrictive of research that is seen as urgent and necessary. We examine this problem from the perspective of various challengers who argue for alternative approaches to what ought or ought not to be permitted. Key themes within this analysis will examine these claims and argue they have implications for the interests of the research subject, research governance and regulation. Using our work with TREAT‐NMD, the neuromuscular clinical trials network, we posit that there is a place for advancing the discourse of moral rights and moral duties in the context of research, especially from the perspective of patients and their families, and for including the politics of patient activism and empowerment. At the same time we remain vigilant to the danger that the therapeutic misconception and other serious vulnerabilities for the patient population in clinical trials, are at risk of being overlooked.