Body Size Research Articles

Hand and foot morphology maps invasion of terrestrial environments by pterosaurs in the mid-Mesozoic

Pterosaurs, the first true flying vertebrates, played a crucial role in Mesozoic terrestrial ecosystems. However, our understanding of their ability to move around on the ground and, more broadly, their terrestrial paleoecology remains limited. Here, we demonstrate an unexpectedly high degree of variation in the hands and feet of pterosaurs, comparable with that observed in extant birds. This suggests that pterosaurs were adapted to a remarkably broad range of non-aerial locomotor ecologies. Small, early, long-tailed pterosaurs (non-pterodactyliforms) exhibit extreme modifications in their hand and foot proportions indicative of climbing lifestyles. By contrast, the hands and feet of later, short-tailed pterosaurs (pterodactyliforms) typically exhibit morphologies consistent with more ground-based locomotor ecologies. These changes in proportions correlate with other modifications to pterosaur anatomy, critically, the separation along the midline of the flight membrane (cruropatagium) that linked the hindlimbs, enabling a much more effective locomotory ability on the ground. Together, these changes map a significant event in tetrapod evolution: a mid-Mesozoic colonization of terrestrial environments by short-tailed pterosaurs. This transition to predominantly ground-based locomotor ecologies did not occur as a single event coinciding with the origin of short-tailed forms but evolved independently within each of the four principal radiations: euctenochasmatians, ornithocheiroids, dsungaripteroids, and azhdarchoids. Invasion of terrestrial environments by pterosaurs facilitated the evolution of a wide range of novel feeding ecologies, while the freedom from limitations imposed byclimbing permitted an increase in body size, ultimately enabling the evolution of gigantism in multiple lineages.

Indicators of morphofunctional adaptation of modern youth from three regions of the world: Bantu (Tanzania), Russians and Buryats

Introduction. The problem of human adaptation to modern realities, including living in cities, changing the traditional diet, and significantly reducing physical stress on the body in everyday life is becoming increasingly relevant all over the world. In this vein, experts from various fields of science pay attention to the study of general secular trends and a more detailed analysis of individual components of this phenomenon, including body composition and other somatic characteristics of specific social and/or gender and age groups of the population. Of particular interest are data on urban populations that have recently migrated from rural areas, against the background of significant socio-economic transformations in the countries of the Global South, as well as a comparison of data from different regions of the world to identify common and population-specific indicators of adaptation. Materials and methods. The paper presents data on students from three populations (684 individuals, 343 of them men and 341 women): Tanzanian (natives of the Bantu peoples from Dodoma), Russian (residents of Tula) and Buryat (residents of Ulan-Ude). The age ranges from 17 to 30 years, the average age was 21.28±2.75 y. A number of anthropometric characteristics and body composition were measured. Results. Our data indicate the presence of sexual dimorphism in each of the studied populations according to the complex of morphological characteristics and body composition. It is noteworthy that Russian students (Caucasians) had more pronounced sexual dimorphism compared to Tanzanians (Negroids) and Buryats (Mongoloids). Conclusion. Summing up, data on three populations representing samples of young people who are similar in social status and level of education, but differ in their racial and ethnic origin, as well as the environmental characteristics of the regions of residence, indicate the presence of distinct differences between the sexes in body size and its component composition. These differences were unidirectional in the three samples studied, and may reflect the generalized outcome of natural and sexual selection for Homo sapiens.

Standardization and optimization of the hiPSC-based PluriLum assay for detection of embryonic and developmental toxicants.

New approach methodologies (NAMs) for predicting embryotoxicity and developmental toxicity are urgently needed for generating human relevant data, while reducing turnover time and costs, and alleviating ethical concerns related to the use of animal models. We have previously developed the PluriLum assay, a NKX2.5-reporter gene 3D model using human-induced pluripotent stem cells (hiPSCs) that are genetically modified to enable the assessment of adverse effects of chemicals on the early-stage embryo. Aiming at improving the predictive value of the PluriLum assay for future screening purposes, we sought to introduce standardization steps to the protocol, improving the overall robustness of the PluriLum assay, as well as a shortening of the assay protocol. First, we showed that the initial size of embryoid bodies (EBs) is crucial for a proper differentiation into cardiomyocytes and overall reproducibility of the assay. When the starting diameter of the EBs exceeds 500 µm, robust differentiation can be anticipated. In terms of reproducibility, exposure to the fungicide epoxiconazole at smaller initial diameters resulted in a larger variation of the derived data, compared to more reliable concentration-response curves obtained using spheroids with larger initialdiameters. We further investigated the ideal length of the differentiation protocol, resulting in a shortening of the PluriLum assay by 24 h to 7 days. Following exposure to the teratogens all-trans and 13-cis retinoic acid, both cardiomyocyte contraction and measurement of NKX2.5-derived luminescence were recorded with a similar or increased sensitivity after 6 days of differentiation when compared to the original 7 days. Finally, we have introduced an efficient step for enzymatic dissociation of the EBs at assay termination. This allows for an even splitting of the individual EBs and testing of additional endpoints other than the NKX2.5-luciferase reporter, which was demonstrated in this work by the simultaneous assessment of ATP levels. In conclusion, we have introduced standardizations and streamlined the PluriLum assay protocol to improve its suitability as a NAM for screening of a large number of chemicals for developmental toxicity testing.

A mixed‐method exploratory study of weight‐based mistreatment at work

AbstractAcross two studies, this exploratory research examines stigma faced by larger‐bodied people by exploring the phenomenon of weight‐based mistreatment (WBM), defined as interpersonal disrespect levied on a person explicitly due to their larger body size, at work. Through qualitative research we first describe distinct forms of WBM experienced by 175 self‐defined overweight US employees, as well as consequences of WBM for bullied targets and their organizations. Next, through a quantitative survey distributed to a separate sample of larger‐bodied workers, our exploratory evaluation of WBM found that it is all‐too common in many forms, including overt and covert aggression, microaggression, incivility, and benevolent, yet disrespectful comments oriented around a person's weight. One or more forms of these behaviours were experienced by 75% of our 1008‐person sample, with overt and covert aggression being most common, and coworkers most often perpetrating WBM. Drawing on objectification theory, we observe a host of harmful consequences ranging from diminished engagement, worsened professional interactions, and a lack of self‐care. Altogether, results reveal WBM is a substantial problem, and thus they serve as a call to action for HR professionals, managers, and inclusion advocates to better understand the experiences of this vulnerable population.

Bluefin tuna sperm production is hastened by surrogacy in small Euthynnus

Pacific bluefin tuna (Thunnus orientalis) remains heavily depleted due to overexploitation. Aquaculture and stock enhancement based on artificial seedlings could be effective solutions to this problem. However, widespread adoption of seedling production is limited because spawning in captivity of bluefin tuna, a large pelagic top predator, requires much space, time, cost, and labour. To downsize and shorten their generation time, here, we show that xenogeneic germ cell transplantation enables a surrogate production of functional bluefin tuna sperm in hybrid little tuna (genus: Euthynnus), which attain sexual maturity at a smaller body size and shorter time. Intraperitonially transplanted bluefin tuna germ cells migrate towards and are incorporated into the gonads of little tuna larvae. These recipients produce functional donor-derived bluefin tuna sperm at a mere 8 months of age and 1 kg of body size. This result represents an advance toward compact, low-cost, and time-efficient seedling production that will improve the efficiency of bluefin tuna aquaculture.

Lung Structure and Longitudinal Change in Cardiac Structure and Function: The MESA COPD Study.

Lung structure and cardiac structure and function are associated cross-sectionally. The classic literature suggests relationships of airways disease to cor pulmonale and emphysema to reduced cardiac output (CO) but longitudinal data are lacking. The Multi-Ethnic Study of Atherosclerosis Chronic Obstructive Pulmonary Disease (COPD) Study was a multi-center longitudinal COPD case-control study of participants 50-79 years with ≥10 pack-years smoking without clinical cardiovascular disease. Segmental airway wall area (WA) and percent emphysema were measured on computed tomography. Right and left ventricle (RV, LV) parameters were assessed on magnetic resonance imaging (MRI) in exams six years apart. Longitudinal and period cross-sectional associations were evaluated with mixed models adjusted for demographics, body size, and smoking. The 187 participants with repeated MRI were 67±7 years old; 42% had COPD; 22% currently smoked; and the race/ethnicity distribution was 54% white, 30% Black, 14% Hispanic, and 3% Asian. Greater WA at enrollment was associated with longitudinal increase in RV mass (3.5 g per 10mm2 WA, 95% CI: 1.1, 5.9). Greater percent emphysema was associated with stably lower LV end diastolic volume (-7.8 mL per 5% emphysema, 95% CI: -10.3, -3.0) and CO (-0.2 L·min-1 per 5% emphysema, 95% CI: -0.4, -0.1). Cardiac associations varied by lung structure over six years in this multi-ethnic study. Greater WA at enrollment was associated with longitudinal increases in RV mass; whereas greater percent emphysema was associated with stable decrements in LV filling and CO.

Association of genomically enhanced residual feed intake with performance, feed efficiency, feeding behavior, gas flux, and nutrient digestibility in growing Holstein heifers.

Residual feed intake (RFI), a metric of feed efficiency, is moderately heritable and independent of body size and productivity, making it an ideal trait for investigation as a selection criterion to improve feed efficiency of growing cattle. The objective of this study was to examine the differences in performance, feed efficiency, feeding behavior, gas flux, and nutrient digestibility in Holstein heifers with divergent genomically enhanced breeding values for RFI (RFIg). Holstein heifers (n = 55; BW = 352 ± 64kg) with low (n = 29) or high (n = 26) RFIg were selected from a contemporary group of 453 commercial Holstein heifers. Heifers were rotated between 1 of 2 pens, each equipped with four electronic feed bunks and one pen with a GreenFeed gaseous exchange monitoring (GEM) system. Individual dry matter intake (DMI) and feeding behavior data were collected for 84-d. Body weight (BW) was measured weekly and spot fecal samples collected at weighing. Phenotypic RFI (RFIp) was calculated as the residual from regression of DMI on average daily gain (ADG) and mid-test metabolic BW (BW0.75). A mixed model including the fixed effect of RFIg classification and random effect of group was used to evaluate the effect of RFIg classification on response variables. There were no differences (P > 0.05) in BW and ADG for heifers with divergent RFIg; however, low RFIg heifers consumed 7.5% less (P < 0.05) feed per day. Consequently, low RFIg heifers exhibited a more favorable (P < 0.05) RFIp (-0.196 vs 0.222kg/d, respectively). Low RFIg heifers had 8.7% fewer (P < 0.05) bunk visit (BV) events per day and tended to have a 11.2% slower (P < 0.10) eating rate. Low RFIg heifers had 7.7% lower (P < 0.05) methane (CH4) emissions (g/d), 6.1% lower (P ≤ 0.05) carbon dioxide (CO2) production (g/d), and 5.6% lower (P ≤ 0.05) heat production (Mcal/d) than high RFIg heifers. However, CH4 yield and CO2 yield (g/kg DMI), and heat production per unit DMI (Mcal/kg DMI) did not differ (P > 0.05) between heifers with divergent RFIg. Dry matter and nutrient digestibility did not differ (P > 0.05) between heifers with divergent RFIg. Overall, heifers selected to be more feed efficient exhibited more favorable energy efficiencies and feed efficiency phenotypes. Results suggest that selection based on RFIg provides opportunities to select cattle with favorable feed efficiency phenotypes to increase the economic and environmental sustainability of the cattle industry.

Energetically costly weaponry in the large morph of male stag beetles

AbstractMales of many species develop disproportionately large weapons, and frequently the weapon size increases more quickly with body size in small than in large males—a trend often considered to result from the depletion of developmental resources limiting male weapon exaggeration. Based on the cost‐minimization hypothesis, a shallower weapon‐body size allometric slope in large than in small males could be selected for if the energetic maintenance costs of having oversized weapons increase faster in large than in small males. Whether males of different size groups that differ in the weapon‐body size allometric relationship also differ in the energetic costs of maintaining their weapons has not yet been investigated. Consequently, we studied this using the stag beetle (Cyclommatus mniszechi), in which males are larger in size and have larger mandibles than do females and are divided into two morphs: majors are larger and have longer mandibles than minors. In both male morphs, mandible size increases disproportionately with their body size, but it increases more quickly in minors than in majors. We measured the standard metabolic rate (SMR) of the three types of these beetles (the two male morphs and females) to investigate whether the energetic maintenance cost of carrying weapons differs among them. Body weight explained 80% of the variation in the SMR in the three types of beetles, and SMR increased more quickly with body weight in major males than in minor males or females. Weapon and body size also jointly explained approximately 80% of the variation in the SMR. Whereas SMR increased with body size in all three types of beetles (with a higher rate of increase in major males than in minor males or females), only the major males' SMR increased with weapon size. Overall, being heavier and larger and carrying oversized weapons are energetically costly in major males, something which could constrain the exaggeration of their weapons.

Microcotyle Tazeroutii n. sp. (Monogenea: Microcotylidae) from the Gills of the Boarfish Capros aper Linnaeus, 1758 (Teleostei: Caproidae) off the Algerian Coast, Western Mediterranean.

In this study we describe a new species Microcotyle tazeroutii n. sp. (Monogenea: Microcotylidae) found on the gills and operculum of the boarfish Capros aper (Caproidae) off the Algerian coast of the Western Mediterranean. Monogeneans were observed alive or recently dead on the operculum and gills using a dissecting microscope, measured and drawn for morphological study. Furthermore, a molecular analysis was conducted using a partial fragment of the mitochondrial cytochrome c oxidase subunit 1 (cox1) of two specimens of monogeneans and a tissue sample of the fish's gills in which the parasites were found to confirm the identity of fish. The new species Microcotyle tazeroutii n. sp., exhibits a combination of morphological features that differentiate it from all other known species within the genus, such as the shape and the size of body, the haptor length, the number and the size of clamps and testes, the number of spines of the genital atrium and the size of eggs. Additionally, a molecular analysis of the mitochondrial cytochrome c oxidase subunit 1 (cox1 gene) revealed significant interspecific differences between Microcotyle tazeroutii n. sp. and previously published sequences of other Microcotyle species. The morphological and molecular analyses revealed that Microcotyle tazeroutii n. sp. has unique characteristics that distinguish it from all previously identified species and confirmed the presence of Microcotyle within the Caproidae family for the first time.

Long‐term injury records reveal the role of biting in male–male combat in the Japanese giant salamander

Abstract Biting is a common male–male combat tactic across jawed vertebrates, in which teeth or bony beaks serve as weapons. Because biting can cause severe injuries in some species, bite scars provide critical information about the degrees and patterns of fights. Amphibians have a remarkable diversity in tooth morphology and arrangement. However, the functional ecology of amphibian teeth is poorly studied. For example, unlike aquatic suction‐feeding frogs that lost teeth, aquatic salamanders that suction‐feed prey retain numerous sharp teeth, suggesting that teeth as weapons may partially explain their retention. Here, we analysed long‐term injury records of one of the fully aquatic, suction‐feeding salamanders (Japanese Giant Salamander, Andrias japonicus) to examine the previously unexplored potential of amphibian teeth as weapons for male–male combat. The majority of the injuries were missing toes and limbs, which most likely occurred during intra‐specific combat. We explored associations between injuries and independent variables such as sex, body size, body condition and stream sections. We also investigated possible injury‐pattern biases along the lateral (i.e. right vs. left) and longitudinal (i.e. anterior vs. posterior) axes, which could reveal how these animals fight. We found that males had more injuries, larger individuals had more injuries, and males with poorer conditions had more injuries. There was no association between injuries and stream sections. In addition, we found that salamanders had more injuries on the right and posterior sides of the body. The lateral asymmetry in injuries is likely associated with turning asymmetry during combat. Our results revealed the intense male–male combats of giant salamanders, providing evidence of the use of teeth as weapons. Combats via biting in amphibians may be much more common and severe than currently known. Our research suggests the function of amphibian teeth as weapons, which is likely to be a vital selective agent shaping its remarkable diversity.

First evolutionary insights into the human otolithic system

The human otolithic system (utricle and saccule), housed within the bony vestibule of the inner ear, establishes our sense of balance in conjunction with the semicircular canals. Yet, while the morphological evolution of the semicircular canals is actively explored, comparative morphological analyses of the otolithic system are lacking. This is regrettable because functional links with head orientation suggest the otolithic system could be used to track postural change throughout human evolution and across primates more broadly. In this context, we present the first analysis of the evolution of the human otolithic system within an anthropoid primate setting. Using the vestibule as a morphological proxy for the utricle and saccule, we compare humans to 13 other extant anthropoid species, and use phylogenetically-informed methods to find correlations with body size, endocranial flexion, and head-neck posture. Our results, obtained through micro-CT of 136 inner ears, reveal two major evolutionary transitions in hominoids, leading to distinctive vestibular morphology in humans, characterized by otolithic morphology resembling squirrel monkeys (possibly due to reversal), with a pronounced supraovalic fossa. Finally, we find a positional signal embedded in the anthropoid bony vestibule, providing the foundation to further explore the evolution of human head-neck posture using inner ear morphology.

Residual feed intake and gain alters the performance and carcass traits in Nellore cattle.

The residual intake and gain (RIG) aims to select animals that present low feed intake in relation to the expected. This study aimed to evaluate the associations of selection for RIG with performance and carcass traits in Nellore cattle. Initially, residual feed intake (RFI) and residual gain (RG) were determined. From this, the RIG was calculated, and the animals were classified as efficient and inefficient for RIG. The efficient animals for RIG showed higher daily weight gain (DWG), Longissimus muscle area (LMA), and mid-test metabolic body weight (MMBW) than the inefficient ones. No significant correlations were found between subcutaneous fat thickness (SFT), marbling (MAR), LMA, MMBW, and the RIG. Thus, it's concluded that the RIG is a measure that can be used to identify and select animals with higher rates of DWG and LMA without changes in the dry matter intake (DMI), SFT, and MAR. However, this index should still be observed with caution, as it may be dependent on body size. Based on the findings, the selection of animals according to the RIG can be an important factor to generate phenotypic evolution in characteristics such as weight gain and rib eye area without adverse effects on the carcass fat deposition.

Temporal changes in streamflow can predict parasitism levels in freshwater prawns better than host traits

Abstract Understanding how changes in the hydrological regime drive parasite loads and dynamics remains a challenging issue in ecological parasitology. Temporal changes in streamflow and rainfall are key hydrological factors that could alter interactions between the parasite and host and affect parasitism levels. However, to investigate the effect of streamflow, rainfall and its mechanisms, it is important to control host traits that can also influence parasitism levels in freshwater systems. Here, we used a cymothoid‐palaemonid prawn model to test the combined effects of streamflow and rainfall accounting for host traits to predict variations in parasite loads in stream ecosystems. We collected the palaemonid prawns monthly for 2 years and measured the variation of rainfall and streamflow (i.e. stream discharge) at the time of prawn sampling. Our best model showed that streamflow can predict parasitism levels in prawns better than host traits. We found a higher prevalence and abundance of parasites in reduced streamflow compared to increased ones. We also found higher ectoparasite loads in females rather than males and occurring in autumn and winter rather than in spring and summer. Our results also showed that ectoparasite loads also suffer an effect of host body size, sex and moult stage, but not host age. Our findings show that reduced streamflow can facilitate host finding that favours parasite transmission in dry seasons and increase parasitism levels in stream systems. Temporal variability in streamflow can have a strong influence on parasite loads and dynamics compared to host traits in stream ecosystems. Identifying how interactions between aquatic invertebrates and parasites respond to variability in the hydrological regime can help to better understand and predict disease outbreaks as habitat reduction and disturbance continue in stream ecosystems.

Long- and short-term responses to climate change in body and appendage size of diverse Australian birds.

Changes to body size and shape have been identified as potential adaptive responses to climate change, but the pervasiveness of these responses has been questioned. To address this, we measured body and appendage size from 5013 museum bird skins of 78 ecologically and evolutionary diverse Australian species. We found that morphological change is a shared response to climate change across birds. Birds increased relative bill surface area, tarsus length, and relative wing length through time, consistent with expectations of increasing appendage size as climates warm. Furthermore, birds decreased in absolute wing length, consistent with the expectation of decreasing body size in warmer climates. Interestingly, these trends were generally consistent across different diets and migratory and thermoregulatory behaviors. Shorter term responses to higher temperatures were contrary to long-term effects for appendages, wherein relative appendage size decreased after hotter years, indicating the complex selective pressures acting on birds as temperatures rise with climate change. Overall, our findings support the notion that morphological adaptation is a widespread response to climate change in birds that is independent of other ecological traits.

Body size decline during thermal evolution is only detected at mild temperature.

Body size is a key morphological trait that affects physiology and metabolism, as well as other relevant traits such as fertility and mating success. Some evidence points to a trend of shrinking body size with increasing temperature, but this is far from unequivocal. Here, we assess the evolution of body size under a warming environment in experimentally evolved Drosophila subobscura populations from two distinct geographical origins, tested in both ancestral and warming environments. We observed a decrease in body size in the warming populations, but only in the lower-latitude populations and only when tested in the ancestral (control) environment. The absence of a body size response in the warming environment may be owing to a balance between forces promoting thermodynamic stability-leading to a tendency for body size to decrease-and selection for increased reproductive output-leading to an increase in body size. Our findings indicate that body size variation is complex, with genotype-by-environment interactions occurring. This may explain the lack of consistency across studies. This highlights that predictions of body size evolution under climate warming are not straightforward and emphasizes the need for considering intra- and inter-specific variation in future studies.

Body size and early marine conditions drive changes in Chinook salmon productivity across northern latitude ecosystems.

Disentangling the influences of climate change from other stressors affecting the population dynamics of aquatic species is particularly pressing for northern latitude ecosystems, where climate-driven warming is occurring faster than the global average. Chinook salmon (Oncorhynchus tshawytscha) in the Yukon-Kuskokwim (YK) region occupy the northern extent of their species' range and are experiencing prolonged declines in abundance resulting in fisheries closures and impacts to the well-being of Indigenous people and local communities. These declines have been associated with physical (e.g., temperature, streamflow) and biological (e.g., body size, competition) conditions, but uncertainty remains about the relative influence of these drivers on productivity across populations and how salmon-environment relationships vary across watersheds. To fill these knowledge gaps, we estimated the effects of marine and freshwater environmental indicators, body size, and indices of competition, on the productivity (adult returns-per-spawner) of 26 Chinook salmon populations in the YK region using a Bayesian hierarchical stock-recruitment model. Across most populations, productivity declined with smaller spawner body size and sea surface temperatures that were colder in the winter and warmer in the summer during the first year at sea. Decreased productivity was also associated with above average fall maximum daily streamflow, increased sea ice cover prior to juvenile outmigration, and abundance of marine competitors, but the strength of these effects varied among populations. Maximum daily stream temperature during spawning migration had a nonlinear relationship with productivity, with reduced productivity in years when temperatures exceeded thresholds in main stem rivers. These results demonstrate for the first time that well-documented declines in body size of YK Chinook salmon were associated with declining population productivity, while taking climate into account.

Bergmann’s rule in global terrestrial vertebrates

Abstract To date, whether Bergmann’s rule, initially developed for individual species or closely related taxa, can be applied to broader taxa remains elusive. Using global distribution data for birds, mammals, reptiles, and amphibians, both species- and assemblage-based, we examined the role of species richness and related climate variables in shaping body size patterns across the globe and the Northern Hemisphere only and whether the temperature–body size relationship had a phylogenetic signal. The results show that when species in all four classes were combined, body size increased with latitude but declined with temperature, consistent with Bergmann’s rule. Each group showed somewhat unique patterns but was mostly consistent with Bergmann’s rule. The body size–temperature relationships were not constrained by phylogenetic relatedness. Warmer places had both large and many small-bodied species, whereas cold places had proportionally more large species. The temperature-dependent variations in body size have important implications for macroecology under climate change.

Intraspecific body size variation across distributional moments reveals trait filtering processes.

Natural populations are composed of individuals that vary in their morphological traits, timing and interactions. The distribution of a trait can be described by several dimensions, or mathematical moments-mean, variance, skew and kurtosis. Shifts in the distribution of a trait across these moments in response to environmental variation can help to reveal which trait values are gained or lost, and consequently how trait filtering processes are altering populations. To examine the role and drivers of intraspecific variation within a trait filtering framework, we investigate variation in body size among five wild bumblebee species in the Colorado Rocky Mountains. First, we examine the relationships between environmental factors (climate and floral food resources) and body size distributions across bumblebee social castes to identify demographic responses to environmental variation. Next, we examine changes in the moments of trait distributions to reveal potential mechanisms behind intraspecific shifts in body size. Finally, we examine how intraspecific body size variation is related to diet breadth and phenology. We found that climate conditions have a strong effect on observed body size variation across all distributional moments, but the filtering mechanism varies by social caste. For example, with earlier spring snowmelt queens declined in mean size and became negatively skewed and more kurtotic. This suggests a skewed filter admitting a greater frequency of small individuals. With greater availability of floral food resources, queens increased in mean size, but workers and males decreased in size. Observed shifts in body size variation also correspond with variation in diet breadth and phenology. Populations with larger average body size were associated with more generalized foraging in workers of short-tongued species and increased specialization in longer-tongued workers. Altered phenological timing was associated with species- and caste-specific shifts in skew. Across an assemblage of wild bumblebees, we find complex patterns of trait variation that may not have been captured if we had simply considered mean and variance. The four-moment approach we employ here provides holistic insight into intraspecific trait variation, which may otherwise be overlooked and reveals potential underlying filtering processes driving such variation within populations.

Application of menthol anesthetics for body size measurements of the sea angel Clione elegantissima (Mollusca: Gymnosomata)

Understanding body size variation has been a central goal in ecology for almost half a century. However, it is difficult to measure the size of soft-bodied invertebrates accurately, such as members of the genus Clione, which expand and contract their bodies. To allow for accurate body length measurements, anesthetic menthol was used to temporarily relax the bodies of Clione elegantissima collected from the southern Okhotsk Sea. A standard solution was prepared using 1.4 g l-menthol dissolved in 250 mL ethanol. Three test solutions were then prepared using 0.1, 0.25, or 0.5 mL of the standard solution and dissolved in 20 mL of filtered seawater. Using a menthol-based anesthetic, the animals extended their body parts (including foot lobes, wings, and head tentacles), remained motionless, and showed no reaction to pricking with forceps. All tested animals returned to their actual sizes within 1–15 min after placing them back in filtered seawater, indicating that the menthol-based solutions were effective and harmless. The best concentration for measuring the body size C. elegantissima was 0.1 mL of the standard solution. It allowed not only bodies but head tentacles to stretch, providing to the full-length of Clione samples for body size measurements. We suggest that this anesthetic can be used as a new standard for body measurements and morphological observations in Clione species.

The Challenge and Necessity of Talking About Weight at Work

The topic of weight at work is challenging to discuss because of strong cultural, medical, and social ideas about what health means, how body size relates to work capacity, and the malleability of weight. Yet people in larger-sized bodies report economic and interpersonal mistreatment at work at alarming rates. This necessitates that employers begin thinking more deeply about the lived experiences of their larger-bodied workers. To aid their consideration, this article describes how the objectification of body size creates a situation where judgment and punishment of people based on their body size is normalized, and how victims of weight-focused mistreatment rarely speak about their experiences because they feel in some way deserving of their mistreatment. When the objectification process is better understood, employers stand ready to make more precise and meaningful changes to how they approach the problem of weight stigma at work, and entry points for this change are discussed here.