Sagamiscintilla thalassemicola (Bivalvia: Galeommatoidea: Galeommatidae) is a rare ectocommensal bivalve that lives on the proboscis of echiuran worms, Anelassorhynchus spp. (Annelida: Thalassematidae: Thalassematinae: Thalassematini), and has been known only from the temperate zones of Japan. In this study, we found S. thalassemicola on the proboscis of the large echiuran Ochetostoma sp. (Thalassematidae: Thalassematinae: Thalassematini) on intertidal flats of three islands of the Ryukyu Archipelago, southern Japan. These are the first records of S. thalassemicola on non-Anelassorhynchus hosts and also from the subtropical regions. Additionally, we also collected S. thalassemicola from an intertidal flat of Kushimoto, Wakayama, Kii Peninsula, Japan, which is an update of the easternmost record of this species. The genetic differences in the mitochondrial cytochrome c oxidase subunit I and nuclear internal transcribed spacer 2 genes among S. thalassemicola, including those with Ochetostoma sp. from the subtropical region and with Anelassorhynchus spp. from the temperate region, can be considered within the intraspecific variation. These suggest that S. thalassemicola uses different echiuran hosts in the temperate and subtropical regions, respectively.

Phenotypic differentiation among fish populations may be used for management of distinct stocks and helps in conserving biodiversity. We compared morphometric and meristic characters of the anchovy Anchoa januaria from shallow semi-closed bays between the south-eastern (Tropical, 23°S) and southern (Subtropical, 25°S) Brazilian coast. We hypothesized that differences between habitats and environmental conditions result in morphological divergence between conspecific populations. Fish size did not differ significantly between the two areas. Significant differences in the meristic and morphological characters were detected for individuals between the two areas, with specimens from the Subtropical region having significant larger head height, pectoral fin length and eye diameter compared with those from the Tropical region. Conversely, specimens from the Tropical region had significantly larger maxillary length, mouth length and body height than those from the Subtropical region. The number of rays for the dorsal and pectoral fins were higher for the specimens from the Subtropical region, whereas for the anal fin was higher for individuals from the Tropical region. Different morphological groups between the two regions were depicted by principal component analysis and discriminant function analysis, which suggest that morphological divergence is occurring. Local environmental influences and the lack of genetic interchange are likely to be the causes of such divergence. This is facilitated by the low tolerance of this species to marine waters that prevents connectivity between these stocks/populations.

We examine the relationship of biomass B and length L in the eastern oyster Crassostrea virginica by focusing on the scaling exponent b in the allometric equation B = aLb using four datasets: Delaware Bay, Chesapeake Bay, Galveston Bay and a regionally extensive compilation from the NOAA Mussel Watch Program. The average value of the scaling exponent in Delaware Bay and Chesapeake Bay is about 2. For Galveston Bay, the value is distinctly higher, near 2.6. Over all Mussel Watch sites, the value is again near 2. Within Delaware Bay, the salinity gradient exerts an important effect. Shells are longer for their meat weight at lower salinities. The range of scaling exponents revealed by Mussel Watch data is exceedingly large (b < 1 to >3). Scaling exponents below 2.5 are unusual in bivalves. Among bivalves, only other oyster taxa have comparably low scaling exponents averaging near 2. We propose that oyster biomass routinely scales nearer the square of the length rather than the cube and that this is a constraint imposed by the exigency of carbonate production for reef maintenance and accretion in the face of high rates of taphonomic degradation. The adaptation as a reef builder requires the formation of carbonate that rapidly breaks down, thus requiring that carbonate produced be maximized. A biomass-to-length scaling exponent of 2 provides a mechanism to maximize shell production relative to biomass, while at the same time providing maximum surface area for the all-important settling of oyster spat to maintain the population.

The egg parasitoid Trissolcus vassilievi (Mayr) (Hymenoptera: Scelionidae) is a significant natural enemy of the sunn pest, Eurygaster integriceps Puton (Hemiptera: Scutelleridae), the most important pest of wheat in Iran. This study examined the developmental time and egg-to-adult survival of two geographically separate populations of T. vassilievi on two corresponding host populations at five constant temperatures ranging from 15.0 to 35.0±1°C. No wasps of either population emerged at 15.0°C and the temperature threshold for development was similar between populations, ranging from 13.1±0.3 to 13.8±0.4°C for males and 12.2±0.1 to 12.6±0.1°C for females, but the thermal constant varied with gender and parasitoid population. Development of wasps from the colder Tabriz location was slower, with thermal constants for males and females of 172.6±3.1 and 204.1±1.2 degree-days, respectively, compared to Varamin wasps with 164.7±3.0 and 195.6±1.3 degree-days, respectively. Based on genetic inheritance patterns, reciprocal crosses between the two populations were expected to result in females with thermal phenotypes intermediate to their parental populations, and males that resembled their mothers. However, female progeny of crosses more closely resembled their maternal population, indicating a maternal effect on thermal phenotype. Furthermore, the magnitude of the maternal effect on the thermal constant was asymmetric and was more strongly expressed by Varmin than Tabriz females. These results suggest the possibility of using selective crosses between wasp populations, in combination with artificial selection in the laboratory, to tune the thermal phenotype of parasitoids to specific regions prior to augmentative releases.

As a consequence of geographical variation in diapause mechanism in the cabbage beetle, Colaphellus bowringi, the southern strains enter diapause as an adult in response to long photoperiod, whereas the northern strains enter diapause in response to temperature. In the present study, we examined the inheritance of diapause by crossing a southern Xiushui strain (XS) with a most-northern Harbin strain (HB). The southern XS strain showed a clear short-day response for the induction of diapause, whereas the most-northern strain entered diapause regardless of photoperiod. Interestingly, the XS×HB progeny showed a short-day response, but the HB×XS progeny had no photoperiodic response, indicating that photoperiodic induction of diapause is influenced by maternal genotype. The incidence of diapause of F1 progeny was intermediate between their parents under short daylengths of 12 and 13 h. However, there was a sexual asymmetry, with the female parent exerting a greater effect on diapause incidence than the male parent, indicating a sex linkage in the inheritance of diapause induction. The χ2 test in C. bowringi revealed that the inheritance of diapause does not fit an additive hypothesis and also that the capacity for diapause is transmitted genetically (or possibly epigenetically) in a manner of incomplete dominance. These results suggest that a number of genetic factors are associated with differences in diapause capability in this beetle.

Walking speeds were calculated for nine clones of the peach potato aphid Myzus persicae collected from three countries along a latitudinal cline of its European distribution from Sweden to Spain (Sweden, UK and Spain), and the effects of collection origin and intra and intergenerational acclimation were investigated. Walking speeds declined with decreasing temperature, with maximum performance at temperatures closest to acclimation temperature (fastest median walking speed of 5.8 cm min–1 was recorded for clone UK 3, collected from the UK, at 25°C after acclimating to 25°C for one generation). Following acclimation at both 20°C and 25°C, walking ceased (as indicated by median walking speeds of 0.0 cm min–1) at temperatures as high as 7.5°C and 12.5°C. However, acclimation at 10°C enabled mobility to occur to temperatures as low as 0°C. There was no relationship between mobility and latitude of collection, suggesting that large scale mixing of aphids may occur across Europe. However, clonal variation was suggested, with clone UK 3 outperforming the majority of other clones across all temperatures at which mobility was maintained following acclimation at 10°C for one and three generations and at 25°C for one generation. The Scandinavian clones consistently outperformed their temperate and Mediterranean counterparts at the majority of temperatures following acclimation for three generations at 25°C.

We tested the hypothesis that host tree age may act as a selective factor and lead to local adaptation of the hemlock looper (Lambdina fiscellaria), a geometrid Lepidoptera that has a wide geographical distribution and has evolved in different eco-zones characterized by different levels of floristic composition, age structure and fragmentation level. Considering that hemlock looper outbreaks mainly occurred in old forests, we compared the biological performances of two populations. The first population was collected in the northern virgin boreal forest, which is dominated by mature and overmature coniferous stands that have not suffered from human disturbance. The other population was collected in the southern mixed-wood forest, which is more diversified and has been modified by forest harvesting. Larvae were reared under controlled conditions on foliage from three age classes of balsam fir trees: juvenile, mature and overmature. Although we measured significant variations of biological performances between the two populations, no significant effect of the age of the balsam fir trees could be detected for males from both populations or for females from the southern population. However, northern females were strongly affected by the age of balsam fir trees on which they fed, as their pupal weight was 12% higher and their fecundity increased by 27% on overmature trees compared with juvenile ones. These results indicate that under the same selective pressure, females adapt their strategy to maximize their fitness, and thus they appear as the driving force of evolution through the local adaptation concept. Furthermore, the two populations evolved in distinct habitats and their adaptation reflects selective pressures occurring inside their original environment. This is the first report on local adaptation of an herbivore that is mediated by host tree age. Changes in forest age structure may have a considerable impact on insect local adaptation and presumably on their population dynamics.

China is experiencing a rapid increase in overweight and related conditions. This study describes the geographic variation in BMI levels and the prevalence of overweight and underweight in Chinese adults, and assesses their relations with regional Gross Domestic Product (GDP) per capita levels. BMI values and the prevalence of overweight and underweight in 143 522 adults from the Chinese National Nutrition and Health Survey (2002) were calculated according to geographic regions in China. Their correlations with GDP were assessed. Linear and logistic regressions were used to adjust for age, sex and city–country composition. BMI and the prevalence of overweight were highest in the Bohai coastal regions while lowest in southern provinces such as Guangdong, Guangxi, Yunnan, Hunan and Fujian. Mean BMI values ranged from 20·72 to 25·48 kg/m2, and the prevalence of overweight ranged from 6·6 to 53·9 %. BMI and the prevalence of overweight were positively correlated with economic development, particularly in the northern regions. However, for regions with similar GDP per capita levels, those in the south had substantially lower BMI and lower prevalence of overweight than those in the north. Interestingly, some southern regions with high GDP per capita had low BMI and low prevalence of overweight. The prevalence of underweight was highest in the south. Substantial geographic variations in the prevalence of overweight and underweight exist in China. Such variations cannot be fully explained by the differences in economic status. China is currently facing challenges of both overweight and underweight but priorities vary in different regions.

The purpose of this report is to examine Ontario's geographic variation in emergency department (ED) visits for conditions that may be treated in alternative primary care settings. We studied all visits to Ontario EDs in 2002/03 and calculated county-specific age-standardized rates. Overall in Ontario, there were 3174 ED visits per 100 000 population aged 1-74 for conditions that could be treated in alternate primary care settings, but rates varied widely across counties. They were higher in rural counties with rates up to 7-fold higher than the provincial average. Urban counties had lower rates, some were less than one-third of the provincial average. Further research is needed to determine the relationship between ED utilization and primary care capacity.

Many species of lizard use tail autotomy to escape from potential predators. While frequency of tail loss is an unreliable indicator of predation intensity it may enable inter-populational comparisons of predation costs. This reasoning was applied to a study of the metallic skink Niveoscincus metallicus. A total of 368 lizards was sampled from across four populations to compare the frequency and position of tail loss and ultimately to examine whether the implications of tail autotomy differ between populations. The overall frequency of tail loss was 72%, although between populations the incidence of tail autotomy varied from 61.4% (Laughing Jack Lagoon) to 78.2% (Dynnyrne). No sexual differences were observed in the frequency of tail loss; however, the incidence of autotomy increased with age. The estimated position of tail loss did not vary between the sexes, although individuals from Dynnyrne experienced more proximal tail breaks than the other populations. This resulted in the predicted energetic cost of tail loss being significantly higher in the Dynnyrne population and, when combined with a high frequency of tail loss and relatively smaller body size, suggests that this population incurs relatively high costs as a result of autotomy. Overall, measures of tail loss in N. metallicus were found to be useful for examining inter-populational variation in the cost of tail autotomy.

Male secondary sexual traits may increase the risk of predation because mating signals make them conspicuous to predators and hamper evasive manoeuvres. Males of Xenotoca variata, a viviparous freshwater fish, show on their flanks bright and colourful spots (speckles), the number of which varies geographically. In this study, the association of this variation with the presence of the piscivorous snake Thamnophis melanogaster, which co-occurs with X. variata, was investigated. A test was also done to establish whether the snake distinguishes between male fish with contrasting numbers of speckles and if the perception of speckles is influenced by water turbidity. The amount of speckling and the prevalence of snakes in key localities was assessed by using one-way mirrors, and the effect of speckles on the predatory responsiveness of snakes was evaluated by presenting them with pairs of male fish in clear and in turbid water. In localities where snakes were infrequent there was a tendency for male fish to have many speckles. The snakes preferentially approached the males with more speckles than the males with fewer speckles. The direction of the preference did not change with the conditions of the water, but the magnitude was stronger in clear water than in turbid water. The snakes also approached first the males with more speckles. These findings indicate that predation risk by T. melanogaster may select against speckles and produce population differentiation.

For snakes, prey size and sex are two possible determinants of head and body size. In garter snakes Thamnophis sirtalis, females are generally longer and have greater body weights than males, and also have larger relative head sizes, which may facilitate foraging success. The selective pressures that account for sexual size dimorphism in garter snakes have not been unequivocally demonstrated. In this study, the body (length and mass) and head (head length, head width, jaw length, inter-ocular distance) sizes of garter snakes inhabiting two nearby but ecologically dissimilar sites with different types of available prey were compared. Overall, the adult female snakes were larger and had greater relative head sizes than males. Males from the two sites did not differ significantly in body or head sizes. However, the mean body length and mass of females from a site where vertebrates are included in the diet were greater than that of females feeding almost exclusively on earthworms. There were also significant site differences in all four head measurements in females, although the direction of the difference varied by site. Diet-induced morphological plasticity is well documented and was evident in this study, although the relative roles of genotype, ontogeny, and competing selective forces in the expression of such plasticity can only be ascertained through future experimental studies.

The pattern of correlations between geographic–environmental variables and geometric shape descriptors for the skull and mandible of Thrichomys apereoides was studied by recently developed combinations of geometry and multivariate statistical techniques. Environmental variables were obtained for each locality: altitude, mean temperature, rainfall, human population density, and vegetation type. The three views of the skull (dorsal, lateral and ventral) and the mandible were significantly associated with a latitudinal environmental gradient along the diagonal of open areas (caatinga and cerrado) throughout the range sampled. The populations from xeric environments presented relatively larger coronoid processes, larger jugals and wider snouts (related to the activity of jaw closing muscles). A correlation of patterns of shape variation from data sets of different skull views showed that lateral skull shape is the most informative view. Further studies are necessary to separate completely the contribution of genetic and environmental components to skull and mandible shape divergence among populations of T. apereoides.

This concludes a series of descriptive statistical reports on discrete cranial traits in 81 human populations from around the world. Four variants classified as vessel and nerve related characters were investigated: patent condylar canal; supraorbital foramen; accessory infraorbital foramen; and accessory mental foramen. A significant asymmetric occurrence without any side preference was detected for the accessory mental foramen. Significant intertrait associations were found between the accessory infraorbital and supraorbital foramina in the panPacific region and Subsaharan African samples. The intertrait associations between the accessory infraorbital foramen and some traits classified as hypostotic were found mainly in the samples from the western part of the Old World, and those as hyperostotic traits in the samples from eastern Asian and the related population samples. With a few exceptions, the occurrence of a patent condylar canal and a supraorbital foramen was predominant in females, but the accessory infraorbital and accessory mental foramina were predominant in males. The frequency distributions of the traits showed interregional clinality and intraregional discontinuity. A temporal trend was found in the Northeast Asian region in the frequencies of the accessory infraorbital and accessory mental foramina. The diversity of modern human discrete cranial traits may at least in part be attributable to differential retention or intensification from an ancestral pattern.

Five discrete hypostotic cranial traits, tympanic dehiscence, ovale-spinosum confluence, metopism, transverse zygomatic suture vestige, and biasterionic suture, were investigated in 81 human population samples. Except for ovale-spinosum confluence, marked asymmetric occurrences of the bilateral traits were not detected in the majority of the samples. Significant intertrait association was observed mainly between the biasterionic suture and other sutural variations including accessory ossicles. The traits showing relatively consistent sex differences across diverse populations were tympanic dehiscence, which is predominant in females, and biasterionic suture in males. On a world scale, the 5 hypostotic cranial traits showed distinctive patterns of geographical variation. Different clinal variations within and between macrogeographical areas such as western and eastern parts of the Old World were found for the frequencies of the traits. The Ainu may be the most distinct outlier in the eastern Asian region on the basis of the incidence of the traits, especially the transverse zygomatic suture vestige. The interregional variation without reasonable adaptive value and nonadaptive shift of the possible outliers presented in this study suggest that the genetic background for the occurrence of these traits cannot be excluded completely.

The Tete veld rat Aethomys ineptus Thomas & Wroughton, 1908 is a newly recognized, widely distributed species in southern Africa. Analysis of geographic variation among samples of A. ineptus from southern Africa across a more comprehensive geographical range than has previously been considered suggests that the species has a clinal pattern of variation in which overall cranial size was positively and significantly correlated with longitude. While the suggested clinal pattern of cranial size variation may be valid, the status of some operational taxonomic units, however, may require further refinement involving additional sampling as well as other systematic techniques, such as DNA analysis, cytogenetics and geometric morphometrics. These additional studies may have to include geographic information systems, step-wise multiple regression, and trend-surface analysis involving a wide range of environmental parameters to identify factors that may explain the nature and extent of the delineated pattern of geographic variation within A. ineptus from southern Africa. Consequently, the seven previously recognized subspecies recently assigned to A. ineptus in southern Africa (A. chrysophilus tzaneenensis Jameson, 1909; A. c. pretoriae Roberts, 1913; A. c. magalakuini Roberts, 1926; A. c. capricornis Roberts, 1926; A. c. tongensis Roberts, 1931; A. c. fouriei Roberts, 1946; and A. c. harei Roberts, 1946) are only provisionally synonymized.

Diets of the Eurasian badger Meles meles were studied by scat analysis in three localities of eastern and central Poland, representing pristine forests and rural landscapes with little wood cover. In spring, earthworms constituted 82–89% of biomass consumed by badgers in all localities. In summer and autumn, the proportion declined to 56% in the pristine forest, and to 24% in the mosaic of forests, fields, and orchards. Supplementary resources at this time were amphibians (in forests) or garden fruits (in a rural landscape). Literature on badger diet composition in Europe showed that earthworms and vegetable matter were the dominant food types of badgers, but their roles changed with latitude. The share of earthworms grew from nil at 37–40°N to 40–70% at 55–63°N; the opposite trend was observed for vegetable food. Also, of two major supplementary resources, vertebrates were taken by badgers more often at northern latitudes, and insects in the south. In consequence, the food niche of badgers was broadest at 45–55°N and became narrow at both lower and higher latitudes. Moreover, in the temperate zone of Europe, the degree of habitat transformation by humans significantly affected badger feeding habits. In forests, badgers relied predominantly on earthworms (on average, 62% in diets). In farmlands and pastures, earthworms and plant material (usually garden fruit and cereals) played equally important roles (34% each). This biogeographical pattern of feeding habits can be explained by variation in abundance and availability of earthworms.

Seventeen populations of T. hermanni in Greece differed substantially in mean adult body size, over a range of about one and a half times in length and three times in mass. Females were the larger sex in all populations; the degree of sexual size dimorphism did not vary with mean body size. The proximate cause of the variation of body size among populations was differences in the duration of growth, rather than egg or hatchling size or the growth rates of juveniles. The age at maturity (α) increased with body size in the 17 populations, while the Bertalanffy growth constant (k) decreased with body size. The quantities αM and M/k (where M is the instantaneous mortality rate) were invariant with body size, suggesting that differences between populations were adaptive rather than the result of short-term disturbance. Body size was greater in cooler areas, and increased with both latitude and altitude. This pattern is opposite to that found in most ectotherms (the reverse Bergmann's rule), and to that which occurs between tortoise species. Several hypotheses about the possible ultimate causes of variation of body size were rejected, including adaptation to long-term habitat disturbance (land use), character displacement, social factors, energetics, thermoregulation, r-K selection, the length of the season available for incubation, or differences in juvenile mortality. The most likely ultimate cause of size variation between sites is differences in adult mortality, the correlation with environmental temperature being through the frequency of fires.