Genetic relatedness in groups of the humbug damselfish Dascyllus aruanus: small, similar-sized individuals may be close kin

Kin selection plays an important role in the evolution of social behaviour in terrestrial systems. The extent to which kin selection influences the evolution of social behaviour in marine systems is largely unexplored. Generally, it is considered that kin selection is irrelevant in marine systems, because it is assumed that the dispersing larval phase of marine organisms will break up kin associations. Here, we challenge this assumption and investigate the opportunity for kin selection in a coral reef fish: the humbug damselfish Dascyllus aruanus . This fish lives in groups composed of a large male and a number of smaller females and nonbreeders. We use 10 polymorphic microsatellite loci to assess the relatedness of 265 individuals from 35 groups. The mean coefficient of relatedness among group members is 0.01 ± 0.04, suggesting that individuals are not associated with close relatives. However, the distribution of pairwise relatedness of individuals within groups has an overabundance of positive values, and indicates that there might be 35 pairs of close relatives within groups. Further analyses reveal that close relatives likely are similar in size and small in size, suggesting that they might have recruited together. We conclude that it is possible for kin selection to operate in D. aruanus , but kin recognition will be a prerequisite for such selection. This study reveals that individuals can be associated with close relatives, and there is a hidden potential for kin selection, during certain parts of the life cycle of coral reef fishes.     

Blood Biochemistry of Sea Turtles Captured in Gillnets in the Lower Cape Fear River,North Carolina,USA

ABSTRACT Mortality due to fisheries interactions has been implicated as a contributor to population decline for several species of sea turtle. The incidental capture of sea turtles in the coastal gillnet fisheries of North Carolina, USA, has received much attention in recent years, and mitigation measures to reduce sea turtle mortality due to gillnet entanglement are a high priority for managers and conservationists. Efforts to evaluate effects of gillnet entanglement on sea turtle populations are complicated by the lack of information on health status of turtles released alive from nets and postrelease mortality. We obtained blood samples from green (Chelonia mydas) and Kemp's ridley (Lepidochelys kempii) sea turtles captured in gillnets for 20–240 minutes to assess the impacts of gillnet entanglement on blood biochemistry and physiological status. We measured concentrations of lactate, corticosterone, ions (Na⁺, K⁺, Cl^-, P, Ca²⁺), enzymes (lactate dehydrogenase [LDH], creatine phosphokinase [CPK], aspartate aminotransferase [AST]), protein, and glucose in the blood and also performed physical examinations of turtles to document external indicators of health status (injuries, lethargy, muted reflexes). We evaluated the effects of entanglement time on blood biochemistry and to look for correlations between blood biochemistry and results of the physical examinations. We observed a significant increase in blood lactate, LDH, CPK, phosphorus, and glucose with increased entanglement time. Alterations in blood biochemistry were generally associated with a decline in health status as indicated by results of the physical examination. Although entanglement time plays an important role in determining the health status of sea turtles upon release from a gillnet, our results suggest that factors such as the depth and severity of entanglement may also have an effect on health status of turtles and the probability of postrelease survival. We were unable to set a maximum unattended gillnet soak time to minimize impacts on captured sea turtles, and therefore recommend that fisheries managers continue to enforce the net attendance regulations currently in place in the lower Cape Fear River, North Carolina, during the summer months.     

Some new Darwin vascular plant specimens from the Beagle voyage

This paper reports 24 newly discovered specimens of 21 species made by Charles Darwin in Argentina, Australia, Brazil, Chile, Ecuador and Uruguay while on the 1831–1836 voyage of HMS Beagle. They have been found in Cambridge University Herbarium and the herbaria of the Missouri Botanical Garden, Natural History Museum, London, New York Botanical Garden and the Royal Botanic Gardens, Kew, since the earlier publications of Porter. Included are type specimens of Calceolaria darwinii (isotype; = C. uniflora), Cuscuta gymnocarpa (holotype and isotypes), C. sandwichiana var. mimosae (isolectotypes = C. gymnocarpa), Ephedra frustillata (lectotype and isolectotypes), Ourisia breviflora (isolectotype), Polypodium paleaceum (syntype?; = Ctenitis sloanei) and Urera gaudichaudiana (holotype; = Laportea aestuans). © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159 , 12–18.     

Assessing the effects of sodium on fire ant foraging in the field and colony growth in the laboratory

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A comparison of direct and indirect methods for measuring leaf and surface areas of individual bushes

Indirect estimates of leaf area from measurements with three commercially available instruments (DEMON, LAI-2000 and Sunfleck Ceptometer) were compared with directly measured areas of individual Retama sphaerocarpa bushes. The three indirect methods gave good estimates of the total surface area of individual bushes. For the DEMON, the method of log-linear averaging of transmitted radiation gave estimates closer to directly measured surface area than the method of averaging transmission linearly. For the LAI-2000, estimated surface area index multiplied by canopy projected area gave the best agreement with directly measured values. For measurements with the Sunfleck Ceptometer, values of surface area estimated from the transmission of photosynthetic quantum flux density, without correcting for diffuse radiation, gave the best agreement with directly measured values. Surface areas estimated by the three instruments were not significantly different from directly measured total (leaf + branch + stem) surface areas. Leaf surface area could be calculated from estimated total surface area minus directly measured branch surface area. Measured branch surface area was linearly related to canopy projected area.     

Some Implications of Climatic Change for Agriculture in Europe

Initial results are reported of a study to evaluate the broad-scalesensitivity of agriculture in Europe to climatic change. Thestudy relates an agroclimatic index, effective temperature sum(ETS), to the cultivable limits of grain maize. A computer mappingsystem for the European region is adopted to map ETS on thebasis both of present-day and of possible future mean temperatures.In this way, changes in climate can be depicted as geographicalshifts of the limit of potential grain maize cultivation. The results indicate that a mean annual temperature increaseof only 1 °C (within the present-day range of inter-annualvariability) would open up large areas in southern England,the Low Countries, eastern Denmark, northern Germany, and northernPoland to potential grain maize cultivation. An increase of4°C would move the limit into central Fennoscandia and northernRussia. The latter changes are similar to those projected bygeneral circulation models (GCMs) for an equivalent doublingof atmospheric carbon dioxide, and represent rates of northwardshift of approximately 200–350 km/°C in western Europeand 250–400 km/°C in eastern Europe. Results using information from GCM transient-response experimentsindicate that such shifts could occur as soon as the 2050s ifthe current exponential growth in emission rates of greenhousegases were to continue unabated. The rate of shift of the grainmaize limit implied for this high (and improbable) emissionsscenario is in the order of 150–200 km per decade overthe next 70 years, slower than this during the next few decades,but faster thereafter. It is probable that the actual rate willbe lower than this, but even values of half those calculated,if sustained, would still represent rates of shift in agroclimaticpotential that are unprecedented in the historical record.     

Microsatellite markers for evolutionary studies in the sexually deceptive orchid genus Chiloglottis

The orchids in the genus Chiloglottis are pollinated exclusively by sexual deception. We describe 20 variable microsatellite loci that will facilitate the study of the evolution and ecology of this specialized pollination system. Two loci were isolated from Chiloglottis trilabra, with the rest derived from Chiloglottis valida. All loci were polymorphic in C. valida (H_E 0.07–0.87). Most loci amplified, and were variable within close relatives of C. valida, and a number amplified more broadly, including outside the genus.     

Larval food affects oviposition preference,female fecundity and offspring survival in Yponomeuta evonymellus

1. Yponomeuta evonymellus is a monophagous moth that feeds on Prunus padus which is native to Europe. In recent years, larval feeding and egg clusters have also been observed on non‐native Prunus serotina plants; however, survival of larvae on this new host is very low. 2. The objective of the present study was to determine how the feeding of larvae on each of the two host plants impacts oviposition, offspring survival and fecundity in Y. evonymellus. Our hypothesis was that, under controlled conditions, females will lay eggs on the host on which they fed as larvae. We also hypothesised that the lower survival of young larvae feeding on P. serotina was due to the smaller buds and leaves present in this species, relative to those of P. padus. 3. A dual‐choice experiment conducted under laboratory conditions demonstrated that females preferentially chose to oviposit on the plant species on which they fed as larvae. In the experiment, potential fecundity and offspring survival were significantly higher on P. padus than on P. serotina. The reduced performance of Y. evonymellus on P. serotina was correlated with a smaller bud mass and volume, lower leaf mass and surface area, and difficulty in constructing a protective tent against unfavourable weather conditions. 4. In summary, the identity of the host plant species during larval feeding determines adult oviposition preference for that host species. The survival of larvae on P. serotina growing in the nature is low, but for phenology‐related reasons.