Male Body Size Research Articles

Variation in Relative Abundance, Population Structure, and Body Size of the Suwannee Alligator Snapping Turtle (Macrochelys suwanniensis) in the Suwannee River

Geological processes influence water chemistry and biological productivity along the Suwannee River and divide the mainstem of the river into 6 distinct ecological reaches (ERs) in Florida. Because of these distinctions, we hypothesized that the Macrochelys suwanniensis (Suwannee Alligator Snapping Turtle) population varies among ERs. During 2011–2013, we sampled two 5-km sites in each ER to investigate spatial variation in relative abundance, sex ratio, size-class distribution, and body size of M. suwanniensis. Capture rates and male body sizes were greater in the middle ERs than in the upstream and downstream ERs. Sex ratios were male-skewed only in the middle ERs. Additional research is needed to understand the ecological drivers of M. suwanniensis population dynamics in this river.

Genetic diversity and sperm characteristics are not associated in two bluethroat (Luscinia svecica) populations

Individual heterozygosity may influence the expression of fitness‐related traits, via genome‐wide or local genetic effects. Earlier studies have shown negative relationships between heterozygosity and sperm variation, predominantly in captive, highly inbred populations. Little is known about the possible influence of variation in heterozygosity on sperm traits in wild, outbred populations. We studied two populations of the bluethroat, one from the widely distributed northern subspecies Luscinia. s. svecica and the other from the smaller, more patchily distributed subspecies breeding along the French coast of Brittany L. s. namnetum. The two subspecies differed significantly in body size, plumage colour, sperm traits and the degree of genetic diversity. However, there was no evidence that sperm traits (total length and motility) were influenced by the degree of heterozygosity at the individual level. In contrast, we found that male body size was positively related to heterozygosity across both populations, indicating a possible relationship between overall genetic diversity and general vigour or ability to obtain food. We conclude that sperm traits are unrelated to levels of heterozygosity in the studied outbred and weakly genetically depauperate bluethroat populations.

Checking in at bee hotels: trap-nesting occupancy and fitness of cavity-nesting bees in an urbanised biodiversity hotspot

With urbanisation leading to loss of nesting resources, and increasing public interest in helping bees, bee hotels (trap-nests) are becoming popularised. However, their success is relatively understudied. The influence of habitat type in determining occupancy and emergence is also poorly known. Over two years across 7 bushland remnant and 7 residential garden sites, trap-nests were installed and completed nests collected monthly over spring-summer. Bees appeared to take a month to find the trap-nests, irrespective of month they were installed. A small percentage (13% and 6% in the two years) of tubes were occupied, but this was within the range of other trap-nesting studies. Smaller 4 and 7 mm diameter nests had a higher occupancy rate than 10 mm diameter tubes. An impressive number − 24 bee species – occupied the trap-nests. Representation however was dominated by five species. The species composition (species and their relative abundances) of cavity-nesting bees differed greatly between those using the trap-nests compared with those observed in the field. Bushland remnants tended to have more bee hotels occupied, and male body size of emerged bees was larger in this habitat. Unexpectedly native and total flower diversity reduced bee hotel occupancy, whereas native flower parameters tended to positively influence bee fitness. Overall installing bee hotels can provide additional nesting resources for native bees in urbanised areas, and providing high proportions of native flora in the vicinity should enhance fitness of the bees using them.

Island and Rensch’s rules do not apply to cave vs. surface populations of Asellus aquaticus

Body size is a trait of fundamental ecological and evolutionary importance that is often different between males and females (sexual size dimorphism; SSD). The island rule predicts that small-bodied species tend to evolve larger following a release from interspecific competition and predation in insular environments. According to Rensch’s rule, male body size relative to female body size increases with increasing mean body size. This allometric body size – SSD scaling is explained by male-driven body size evolution. These ecogeographical rules are rarely tested within species, and has not been addressed in a cave–surface context, even though caves represent insular environments (small and isolated with simple communities). By analyzing six cave and nine surface populations of the widespread, primarily surface-dwelling freshwater isopod Asellus aquaticus with male-biased SSD, we tested whether cave populations evolved larger and showed higher SSD than the surface populations. We found extensive between-population variation in body size (maximum divergence being 74%) and SSD (males being 15%–50% larger than females). However, habitat type did not explain the body size and SSD variation and we could not reject isometry in the male–female body size relationship. Hence, we found no support for the island or Rensch’s rules. We conclude that local selective forces stemming from environmental factors other than island vs. mainland or the general surface vs. cave characteristics are responsible for the reported population variation.

Asymmetric sex body size and reproductive fitness relation and offspring population parameters of Habrobracon hebetor (Say) (Hymenoptera: Braconidae)

Parasitoids show a strong relationship between body size and fitness, but it is unclear whether the relationship is asymmetric or symmetric in males and females of Habrobracon hebetor (Say) (Hymenoptera: Braconidae). This study investigated the effects of male and female body sizes on the reproductive fitness (e.g., longevity and fecundity) of the F0 generation and the population fitness (e.g., survival rate, body size, longevity, and fecundity) of the F1 generation at 28 ± 1 °C, 75 ± 5% relative humidity and 16:8 h light:dark period based on the age-stage two-sex life table theory. The results showed that the body size of F0 generation males and females significantly affected their reproductive fitness, but not the body size of the F1 generation. Larger females had longer lifetimes and oviposition days, and higher reproductive rates than smaller females. Moreover, only small ♀ × small ♂, but not large ♀ × small ♂, small ♀ × large ♂, and large ♀ × large ♂, had a significant impact on the life history parameters, population parameters, paralysis rate, and parasitism rate of the F1 offspring population. Interestingly, the population size, paralysis rate, and variability of the F1 offspring with different body sizes increased to a stable status after 50 days. The study also found that the Weibull function could not fit the survival rate of the parasitoid wasp well. These findings deepen our understanding of the ecology of H. hebetor population and provide important technical parameters for mass-rearing and application of these parasitoid wasps.

Relationship between Body Dissatisfaction and Body Size of Males in Their Twenties

Background/Objectives: This research aims to identify any relationships between body dissatisfaction and body size among males in their twenties.
 Methods: Participants were recruited for a year from August 2015 to July 2016. Participants were 100 males, of which 50 were white American males and 50 were Korean males in North Carolina, United States of America, who are aged between 20 and 29 years old. TC2-19 3D body scanner was used to measure the participant’s body size. A descriptive analysis of data for demographics and body satisfaction was conducted. The data were analyzed by correlation techniques and regression analyses with SPSS 24 for Windows.
 Results: The results of this research indicate that the participants who have lower BMI, WHR, WCR, or WSR tend to perceive higher evaluations of their appearance, pay more attention to their appearance and are more satisfied with their body areas. Participants who have higher BMI or WHR tend to be more anxious about being overweight. Participants who have lower weight, lower shoulder-to-shoulder and lower girth values tend to show higher AE, AO, and BAS. Participants who have a higher shoulder-to-shoulder, higher upper arm girth, higher chest girth and higher waist tend to have more preoccupation about being overweight.
 Conclusion/Implications: The results of this research can help fashion businesses consider targeting males’ body dissatisfaction in the design of their products by understanding the relationship between body dissatisfaction and body size of targeting males.

Unexpected decadal density-dependent shifts in California sea lion size, morphology, and foraging niche

Many marine mammal populations are recovering after long eras of exploitation.1,2 To what degree density-dependent body size declines in recovering species reflect a general response to increased resource competition is unknown. We examined skull size (as a proxy for body size), skull morphology, and foraging dynamics of the top marine predator, the California sea lion (Zalophus californianus), which have been steadily increasing over the last few decades and have approached or reached their carrying capacity in southern California.3 We show that, contrary to predictions, male California sea lions increased rather than decreased their average body size over a 46-year (1962-2008) recovery period. Larger males had proportionally longer oral cavities and more powerful bite strength, and their foraging niche expanded. Females between 1983 and 2007 maintained stable skull dimensions, but their isotopic niche was broader than contemporary males. Increased male body size is compatible with an intensification of density-dependent sexual selection for larger and more competitive individuals concurrent with an expanding foraging niche. High foraging variability among females would explain their body size stability during decades of population recovery. We demonstrate that body size reduction is not the universal response to population recovery in marine mammals and show that selective ecological dynamics could contribute to protecting populations against the increased density-dependent intraspecific competition. However, prey shifts associated with climate change will likely prevent California sea lions (and other marine mammals) from attaining these ecological dynamics, augmenting their vulnerability to resource competition and diminishing their capacity to overcome it.

Climate Change, Extreme Temperatures and Sex-Related Responses in Spiders.

Climatic extremes, such as heat waves, are increasing in frequency, intensity and duration under anthropogenic climate change. These extreme events pose a great threat to many organisms, and especially ectotherms, which are susceptible to high temperatures. In nature, many ectotherms, such as insects, may seek cooler microclimates and 'ride out´ extreme temperatures, especially when these are transient and unpredictable. However, some ectotherms, such as web-building spiders, may be more prone to heat-related mortality than more motile organisms. Adult females in many spider families are sedentary and build webs in micro-habitats where they spend their entire lives. Under extreme heat, they may be limited in their ability to move vertically or horizontally to find cooler microhabitats. Males, on the other hand, are often nomadic, have broader spatial distributions, and thus might be better able to escape exposure to heat. However, life-history traits in spiders such as the relative body size of males and females and spatial ecology also vary across different taxonomic groups based on their phylogeny. This may make different species or families more or less susceptible to heat waves and exposure to very high temperatures. Selection to extreme temperatures may drive adaptive responses in female physiology, morphology or web site selection in species that build small or exposed webs. Male spiders may be better able to avoid heat-related stress than females by seeking refuge under objects such as bark or rocks with cooler microclimates. Here, we discuss these aspects in detail and propose research focusing on male and female spider behavior and reproduction across different taxa exposed to temperature extremes.

Beyond Dimorphism: Body Size Variation Among Adult Orangutans Is Not Dichotomous by Sex.

Among extant great apes, orangutans are considered the most sexually dimorphic in body size. However, the expression of sexual dimorphism in orangutans is more complex than simply males being larger than females. At sexual maturity, some male orangutans develop cheek pads (flanges), while other males remain unflanged even after becoming reproductively capable. Sometimes flange development is delayed in otherwise sexually mature males for a few years. In other cases, flange development is delayed for many years or decades, with some males even spending their entire lifespan as unflanged adults. Thus, unflanged males of various chronological ages can be mistakenly identified as "subadults." Unflanged adult males are typically described as "female-sized," but this may simply reflect the fact that unflanged male body size has only ever been measured in peri-pubescent individuals. In this study, we measured the skeletons of 111 wild adult orangutans (Pongo spp.), including 20 unflanged males, 45 flanged males, and 46 females, resulting in the largest skeletal sample of unflanged males yet studied. We assessed long bone lengths (as a proxy for stature) for all 111 individuals and recorded weights-at-death, femoral head diameters, bi-iliac breadths, and long bone cross-sectional areas (CSA) (as proxies for mass) for 27 of these individuals, including seven flanged males, three adult confirmed-unflanged males, and three young adult likely-unflanged males. ANOVA and Kruskal-Wallis tests with Tukey and Dunn post-hoc pairwise comparisons, respectively, showed that body sizes for young adult unflanged males are similar to those of the adult females in the sample (all P≥0.09 except bi-iliac breadth), whereas body sizes for adult unflanged males ranged between those of adult flanged males and adult females for several measurements (all P<0.001). Thus, sexually mature male orangutans exhibit body sizes that range from the female end of the spectrum to the flanged male end of the spectrum. These results exemplify that the term "sexual dimorphism" fails to capture the full range of variation in adult orangutan body size. By including adult unflanged males in analyses of body size and other aspects of morphology, not as aberrations but as an expected part of orangutan variation, we may begin to shift the way that we think about features typically considered dichotomous according to biological sex.

Comparative transcriptome analysis revealed genes involved in the sexual size dimorphisms and expressed sequence tag-Simple Sequence Repeat loci validation in Odorrana graminea

Sexual size dimorphism (SSD) is widespread among animals and is characterized by differences in body size between sexes. Previous studies suggested SSD might reflect the adaptations of particular sexes to their specific reproductive or ecological roles. The large green cascade frogs (Odorrana graminea) exhibit obvious SSD that females are nearly twice the body size of males. However, the molecular mechanisms underlying SSD of O. graminea are still unknown. In the present study, we first obtained nearly 5 Gb of the transcriptome data through Illumina sequencing, and the de novo transcriptome assembly produced 189,868 unigenes of O. graminea. A total of 774 significantly sex-differentially expressed genes (DEGs) were identified. Of which, 436 DEGs showed significantly higher expression levels in females than those in males, whereas 338 DEGs showed significantly lower expression in females than those in males. We also found 10 sex-differentially expressed genes related to energy metabolism between sexes of O. graminea, and these DEGs were related to the estrogen signaling pathway, oxidative phosphorylation, fatty acid biosynthesis, gastric acid secretion, and nitrogen metabolism. We found that the differences in energy metabolism and steroid hormone synthesis might be the main driving force leading to the sexual growth dimorphism of O. graminea. In addition, a total of 63,269 potential EST-SSR loci and 4,669 EST-SSR loci were detected and validated in different populations of O. graminea and other species within Odorrana. The assembled transcriptome will facilitate functional genomic studies of O. graminea and the developed EST-SSR markers will contribute to the population genetics of the species within Odorrana. The sex-differentially expressed genes involved in energy metabolism might provide insights into the genetic mechanisms underlying the SSD of O. graminea.

CHARAKTERYSTYKA BIOMETRYCZNA CZERNICY AYTHYA FULIGULA (LINNAEUS, 1758) Z POMORZA ZACHODNIEGO (POLSKA)

The purpose of this work was to perform morphometric characteristics of the Tufted Duck Aythya fuligula obtained in Western Pomerania, according to their sex and age. The research material consisted of 197 Tufted Ducks obtained in December 2013. The biometric characteristics was performed on the basis of 20 measurements of linear and mass quantities. All internal organs measured and most of the individual body parts of the Tufted Duck were slightly larger in the case of males. Despite the differences in the body size of males and females, the studied birds showed similar variability in both length and mass. The differences between adult and young Tufted Ducks were not so well defined. Adult Tufted Ducks had significantly larger body mass, pectoral muscle mass and lung mass than juveniles. No significant differences were found in the linear values of the examined features.

When Rensch meets Foster: insular gigantism may reduce sexual dimorphism in anurans

According to the Island rule, insular populations exhibit gigantism in small species and dwarfism in large species. These contexts offer opportunities to test for complementary aspects pertaining to the evolution of body size, and particularly sexual size dimorphism (SSD). ‘Rensch's rule' states that SSD should vary with increasing body size, depending on the larger sex. As a consequence, it is expected that dwarfism or gigantism occurring in insular populations should influence the magnitude of SSD. Using anuran amphibians as a study system (because most anuran species express a female‐biased SSD and a marked lability in size), we investigated our hypothesis both in a specific comparison of continental and insular populations of a widespread coastal amphibian, and using a large‐scale analysis across anurans (10 species across 62 sites). Both datasets yielded similar results, with increasing body size in insular populations reducing the magnitude of SSD through an increase of male body size, as expected by Rensch's rule. Detailed data on insular populations considering both sexes are scarce, and future studies are required to complement the existing literature in order to test for the validity of our hypothesis at a wider scale and to infer the mechanistic causes of size variations, which remain unknown. In addition, further investigations are required to explore the consequences of insularity on the magnitude of SSD including various taxa (e.g. mammals, birds, lizards and snakes) in which the Island rule has found support, and considering taxa in which males are the larger sex.Keywords: amphibians, body size, insularity, Island rule, Rensch's rule, sexual dimorphism

Is the blue-spotted phenotype more widespread in the eastern slow worm Anguis colchica (Nordmann, 1840) than the western slow worm Anguis fragilis Linnaeus, 1758 and does it correlate with the male body size? A case study from Central Europe

The blue-spotted phenotype in a slow worm can be considered as an alternative colour morph or a secondary sexual characteristic. This phenotype is known to entail an elevated predation risk; thus, its continuous presence in a population must be balanced by additional and positive fitness consequences. In this study, we show that blue-spotted males are characterised by a greater snout-vent length (SVL) than typical specimens. Importantly, the SVL of blue-spotted males reaches the magnitude of the average female size. This indicates that the presence of blue spots may involve a correlated positive effect on growth and body size. The greater body size of the blue-spotted males could enhance their survival and mating success, and thus facilitate the continued presence of a high fraction of this morph within the population. In addition, we found that the blue-spotted phenotype is more common in the eastern than the western slow worm, and the proposed fitness consequences of the blue-spotted phenotype might enhance its tendency to spread in the eastern Anguis lineage.

The effect of individual state on the strength of mate choice in females and males.

Animals are thought to gain significant fitness benefits from choosing high-quality or compatible mates. However, there is large within-species variation in how choosy individuals are during mating. This may be because the costs and benefits of being choosy vary according to an individual's state. To test this, I systematically searched for published data relating the strength of animal mate choice in both sexes to individual age, attractiveness, body size, physical condition, mating status, and parasite load. I performed a meta-analysis of 108 studies and 78 animal species to quantify how the strength of mate choice varies according to individual state. In line with the predictions of sexual selection theory, I find that females are significantly choosier when they are large and have a low parasite load, thus supporting the premise that the expression of female mate choice is dependent on the costs and benefits of being choosy. However, female choice was not influenced by female age, attractiveness, physical condition, or mating status. Attractive males were significantly choosier than unattractive males, but male mate choice was not influenced by male age, body size, physical condition, mating status, or parasite load. However, this dataset was limited by a small sample size, and the overall correlation between individual state and the strength of mate choice was similar for both sexes. Nevertheless, in both males and females individual state explained only a small amount of variation in the strength of mate choice.

Skeletochronology of the Levant Green Frog, Pelophylax bedriagae (Camerano, 1882), in Southern Iran

Skeletochronology is a reliable method for estimating the age and growth rate of many ectothermic vertebrates, including amphibians. The Levant green frog, Pelophylax bedriagae (Ranidae), is a relatively large frog distributed in the western and northern parts of Iran. The age structure of Pelophylax bedriagae was determined by examining 52 females and 39 males collected from Kohgilouyeh and Bouyerahmad Provinces (Yasouj and Basht). The age range of the two populations is three to 10 years. The maximum age for males and females is 10 and eight years, respectively. The highest age distribution for males is six years (17.6%) and four and six years (15.4%) for females. On average, males (6.2±1.4 years) are older than females (5.2±1.3 years). Male and female body size is correlated with age within both populations. However, despite being significantly different in average body size, the average age of the two populations (Yasouj vs. Basht) is not significantly different.

Size‐associated energetic constraints on the seasonal onset of reproduction in a species with indeterminate growth

The seasonal onset of reproduction is constrained in many systems by a need to first accumulate energetic reserves. Consequently, the observation that larger individuals reproduce earlier may be due to a negative relationship between size and mass‐specific basal metabolic rate that is shared across diverse taxa. However, an untested prediction of this hypothesis is that individuals should be metabolically efficient enough to escape energetic constraints above a certain size threshold. Seasonally reproducing species, such as temperate fishes, that must recover winter energy losses before reproduction and exhibit indeterminate growth are ideal models to test this prediction. We harness decade‐long behavioral data on parental male smallmouth bass, Micropterus dolomieu, to investigate contributions of energetic allometry to differences in reproductive timing. At the population level, peak seasonal reproductive timing (i.e. the median date on which eggs were found in nests each year) was negatively related to degree days – a measure of thermal energy experienced – before reproduction. At the individual level, degree days accumulated by males before reproduction was related to male size and condition in every year, but the impact of temperature on reproductive timing by the largest males was relaxed in most years. Additionally, we used our data to replicate the analyses of two previous studies of M. dolomieu populations and found virtually identical negative associations between male body size and degree days accumulated before reproduction. Our results suggest that in smallmouth bass the onset of seasonal reproduction is constrained by basal metabolic rate – as indicated by total length – and that large individuals can escape size‐associated energetic constraints. We reveal a more complicated relationship between size and reproductive timing than earlier studies, which may be relevant for many species. Knowledge of this relationship is critical to understanding how a changing climate will influence population dynamics of economically, ecologically and recreationally important species like M. dolomieu.

Effects of male age, body size and mating status on female mate preference and offspring sex ratio in Pachycrepoideus vindemmiae (Hymenoptera: Pteromalidae)

Mate choice is one of the main components of sexual selection, with females usually considered to be the selective sex. Male status is an important factor that affects female choice and to a large extent female mating preference. Pachycrepoideus vindemmiae (Rondani) (Hymenoptera: Pteromalidae) is an important solitary ectoparasitic idiobiont parasitoid that attacks several fly species and thus can be used as a biological control agent. We explored the influence of male status on mate selection, fecundity and offspring sex ratio. The results show that (1) P. vindemmiae females prefer to mate with young and large males and tended to choose males with only one mating experience; (2) the age, body size and mating status of males did not significantly affect female fecundity; and (3) the proportion of male offspring was larger when females mated with older, small and more often mated males. These results show that P. vindemmiae females prefer to mate with young and large males that had mated few times, and that mating with these males results in a higher proportion of female offspring. In addition, this study also indicates the way of rearing P. vindemmiae that produce more female offspring for use as biological control agents.

An evolutionary explanation of female-biased sexual size dimorphism in North Sea plaice, Pleuronectes platessa L.

Sexual size dimorphism (SSD) is caused by differences in selection pressures and life-history trade-offs faced by males and females. Proximate causes of SSD may involve sex-specific mortality, energy acquisition, and energy expenditure for maintenance, reproductive tissues, and reproductive behavior. Using a quantitative, individual-based, eco-genetic model parameterized for North Sea plaice, we explore the importance of these mechanisms for female-biased SSD, under which males are smaller and reach sexual maturity earlier than females (common among fish, but also arising in arthropods and mammals). We consider two mechanisms potentially serving as ultimate causes: (a) Male investments in male reproductive behavior might evolve to detract energy resources that would otherwise be available for somatic growth, and (b) diminishing returns on male reproductive investments might evolve to reduce energy acquisition. In general, both of these can bring about smaller male body sizes. We report the following findings. First, higher investments in male reproductive behavior alone cannot explain the North Sea plaice SSD. This is because such higher reproductive investments require increased energy acquisition, which would cause a delay in maturation, leading to male-biased SSD contrary to observations. When accounting for the observed differential (lower) male mortality, maturation is postponed even further, leading to even larger males. Second, diminishing returns on male reproductive investments alone can qualitatively account for the North Sea plaice SSD, even though the quantitative match is imperfect. Third, both mechanisms can be reconciled with, and thus provide a mechanistic basis for, the previously advanced Ghiselin-Reiss hypothesis, according to which smaller males will evolve if their reproductive success is dominated by scramble competition for fertilizing females, as males would consequently invest more in reproduction than growth, potentially implying lower survival rates, and thus relaxing male-male competition. Fourth, a good quantitative fit with the North Sea plaice SSD is achieved by combining both mechanisms while accounting for sex-specific costs males incur during their spawning season. Fifth, evolution caused by fishing is likely to have modified the North Sea plaice SSD.

Contextualising the bizarre: The integrated functioning of rib puncture as an antipredator defence in the Iberian ribbed newt (Pleurodeles waltl)

Abstract Numerous prey traits are the result of the pervasive evolutionary pressure imposed by predators. Mirroring their fundamental role in the fitness of prey, some antipredator defences can evolve into elaborate strategies. Such is the case of the Iberian ribbed newt (Pleurodeles waltl), a semiaquatic urodele that inhabits multiple types of inland waterbodies in central and southern Iberian Peninsula and north‐western Africa. It possesses sharp, protractile ribs, which can thwart predators by emerging through skin ‘warts’ they pierce, becoming impregnated with the toxicants these warts produce, and making the newts difficult to swallow. Plus, the orange colour of these warts contrasts with the predominantly dull dorsum. In this work, I studied the interactions between the number of these warts, the saliency of wart colour against dorsum colour of each individual (i.e., the difference in colour between the warts and the dorsum), rib response time (i.e., the time needed for the ribs to emerge in response to a standardised stimulus), body size, and locomotor performance in males and females in either their aquatic or terrestrial stage. I also conducted a field experiment to determine whether predators more frequently attacked plasticine models with conspicuous or inconspicuous warts. I found that wart colour saliency functions as a decoy, attracting predator attacks towards this well‐protected body part. Plus, many of the antipredator defences studied, namely the number of warts, their colour saliency, rib response time, body size, and locomotor performance, were interrelated. Accordingly, more salient warts indicated a faster rib response, suggesting that these defences are coordinated with each other. Plus, locomotion was considerably slower in the terrestrial than in the aquatic stage. Moreover, warts were more salient, and thus more efficient attracting predator attacks, in newts in the slower terrestrial stage. However, rib response was faster in the aquatic stage, which coincides with the newt's activity peak, and therefore with the height of its conspicuousness to predators. Remarkably, faster newts display less salient warts and a slower rib response, which suggests a trade‐off between both defences. Nonetheless, some of these trends are reversed in females, among which faster individuals also display a faster rib response. This could be a likely consequence of reduced predation pressure. These results further the understanding of how prey integrate and tune multiple antipredator defences according to factors that influence predation pressure, such as sex and life stage.

Reproductive notes and larval development of Macrogenioglottus alipioi (Anura: Odontophrynidae) from the northern Atlantic forest

&#x0D; &#x0D; &#x0D; &#x0D; The neotropical monotypic genus Macrogenioglottus, described to enclose M. alipioi, is a forest leaf litter frog with a wide geographic distribution in eastern Brazil, despite being considered a rare species. Herein, we present some reproductive data of this species from a population of the north of the São Francisco River, Northeastern Brazil. We present information on the amplexus, egg clutch, advertisement, and release calls, along with a description of its larval development. Adults were observed only after heavy and continuous rains, in a temporary pond located inside the forest. Males call in chorus at the edge of the pond. The advertisement call consists of a pulsatile single note, with no substantial variation in relation to the other population of the species, but which promptly differs this genus from the remaining Odontophrynidae. The amplexus is axillary. One female deposited 298 pigmented eggs in a plastic bag. The tadpole reaches its larger size at Stage 39, being the largest tadpole within the family. At the end of metamorphosis, the froglet snout–vent length is equivalent to tadpole total length at stage 26–27, indicating substantial postmetamorphic growth until adulthood. Data on body size of males and females are also provided. The uniqueness of some larval traits and mainly on some call attributes supports the systematic distinction of Macrogenioglottus.&#x0D; &#x0D; &#x0D; &#x0D;