Female Snout-vent Length Research Articles

Variation in body size and reproductive characteristics among chromosomal races of the Sceloporus grammicus complex in México

Abstract Populations and chromosomal races of a species often show variation in life-history characteristics due to phylogeny and environmental factors. We analysed variation in snout–vent length (SVL) and reproductive variables, such as minimum SVL at sexual maturity, litter size and embryo volume in females of the Sceloporus grammicus lizard complex, which includes seven chromosomal races as well as hybrid zones among different combinations of races (F5, F5 + 6, potential but unverified F5 + 6, F6, FM1, FM2, FM2 × F5 hybrid zone, FM3, LS and unverified SGG). The SGG, F5 and LS females were larger than F6 and FM3 females. Females with non-vitellogenic follicles and vitellogenic follicles were smaller than females with embryos. The SVL of females containing embryos varied among chromosomal races, the largest being the same as indicated above, but the smallest was the FM2 × F5 hybrid zone. Litter size was similar among chromosomal races (5.8 embryos), while embryo volumes varied among them. Two patterns of reproductive activity were found: seasonal and continuous reproduction. Our results showed the influence of environmental factors of each locality, which supports the ecological hypothesis. The use of chromosomal races did not reveal a significant phylogenetic effect, because allozyme and molecular data show only small pairwise genetic distances among the S. grammicus populations on the Mexican Plateau.

Trophic ecology of the Atlantic Forest endemic tree frog Boana bischoffi (Boulenger, 1887) (Anura, Hylidae)

Studies of natural history are important to accumulate knowledge about aspects of diet, reproduction, and habitat use, which can assist the conservation biology for endangered groups, such as amphibians. Here we evaluated the trophic ecology and sexual size dimorphism of Boana bischoffi, a widely distributed and endemic tree frog species of the Brazilian Atlantic Forest. We analysed 80 individuals, covering the distribution of the species and combined our data-set with data from the literature. Gastrointestinal items were separated, accounted, and identified to the highest possible taxonomic resolution. Subsequently, the size and mass of prey items were measured. Afterwards, we calculated rates of relative importance for each prey category. The items of greatest relative importance were beetles (Coleoptera), termites (Isoptera), crickets (Orthoptera) but also harvestmen (Opiliones). We did not find a relation between female snout-vent length, mouth width and length with prey length. In males, the mouth length and width are related to prey length. We found a sexual dimorphism in size typical for hylid frogs, with females being larger than males. Our data expand the knowledge about the alimentary biology of B. bischoffi, but further research focusing on other aspects of the natural history such as possible intersexual dietary divergence and food niche overlapping, environmental prey availability and selection is still needed.

Reproductive strategies of a lizard community from an arid environment of Mexico

The goal of this study is to describe patterns of reproductive activity and associated characteristics in a lizard community from an arid environment in the southern Chihuahuan Desert region of Mexico. Results of this study showed variation in snout–vent length (SVL) in adults female and male among 18 species. A similar pattern occurred in body mass of males and females, which varied mainly among species and not substantially between sexes. Mean clutch/litter size and egg/embryo mass and volume varied among species, and egg/embryo mass and volume were positively correlated with female SVL. Oviparous species were larger in SVL than viviparous species; however, SVL in females, clutch/litter size and egg/embryo volume were similar between oviparous and viviparous species, but the oviductal mass of oviparous species was larger than in viviparous species. Clutch/litter size and oviductal mass were correlated with female SVL in both oviparous and viviparous species. This relationship was similar for egg/embryo volume in oviparous species, but not in viviparous species. Seven species showed a prolonged reproductive period, and five had short reproductive periods. The results of this study provide evidence of high diversity in reproductive strategies that have evolved among organisms that live in this environment.

Sexual size monomorphism may evolve in lizards with a body size maximizing reproductive performance for both sexes.

We used Takydromus septentrionalis, a sexually size-monomorphic lacertid lizard, as a model system to test the hypothesis that sexual size monomorphism may evolve in lizards where reproductive performance is maximized at a similar body size for both sexes. We allowed lizards housed in laboratory enclosures to lay as many clutches (for females) as they could or to mate as many times (for males) as they could in a breeding season. Size-assortative mating was weak but evident in T. septentrionalis, as revealed by the fact that male and female snout-vent lengths (SVLs) in mating pairs were significantly and positively correlated. Mating frequency (indicative of male reproductive performance) varied from 1 to 8 per breeding season, generally increasing as SVL increased in adult males smaller than 67.4 mm SVL. Clutch frequency varied from 1 to 7 per breeding season, with female reproductive performance (determined by clutch frequency, annual fecundity, and annual reproductive output) maximized in females with a SVL of 68.0 mm. Accordingly to our hypothesis, the reproductive performance was maximized in the intermediate sized rather than the largest individuals in both sexes, and the body size maximizing reproductive performance was similar for both sexes. Future work could usefully investigate other lineages of lizards with sexually monomorphic species in a phylogenetic context to corroborate the hypothesis of this study.

Data on the female reproduction of Chalcides mertensi Klausewitz, 1954 (Reptilia: Scincidae) from Tunisia

Chalcides mertensi is an Algero-Tunisian endemic three-toed skink. It inhabits perennial meadows in north-western Tunisia. The main characteristics of its reproduction traits were studied in six populations, by counting the total number of embryos in pregnant females in relation to their snout-vent lengths (SVLs) and measuring the lengths of newborn individuals. The species is viviparous, with SVLs of gravid females ranging between 103.2 and 220.3 mm, making this species one of the largest among its congeners. The maximal number of embryos per gravid female was 28, ranging between zero and 15 in each of the right and left oviducts. Selection apparently favoured larger females to maximize the number of embryos since a correlation between the number of embryos and female SVL was found. Births occurred during the first week of July, one month earlier than dates given for three-toed Chalcides species in Europe. The species produced one clutch each year.

Evolution of sexual dimorphism in the plateau brown frog fails to obey Rensch’s rule

Rensch’s rule describes sexual size dimorphism (SSD) that decreases with increasing body size when females are larger than males and SSD that increases when males are larger than females. The plateau brown frog Rana kukunoris, a species endemic to the eastern Tibetan Plateau, exhibits female-biased size dimorphism. Using data on body size from 26 populations and age from 21 populations, we demonstrated that SSD did not increase with increasing mean female snout-vent length (SVL) when controlling for sex-specific age structure, failing to support the Rensch’s rule. Thus, we suggest that fecundity selection (favouring large female size) balances out sexual selection (favouring large male size), which results in a similar divergence between males and females body size. In addition, sex-specific age differences explained most of the variation of SSD across populations.

Identifying traits that enable lizard adaptation to different habitats

AbstractAimSpecies adapt differently to contrasting environments, such as open habitats with sparse vegetation and forested habitats with dense forest cover. We investigated colonization patterns in the open and forested environments in the diagonal of open formations and surrounding rain forests (i.e. Amazonia and Atlantic Forest) in Brazil, tested whether the diversification rates were affected by the environmental conditions and identified traits that enabled species to persist in those environments.LocationSouth America, Brazil.TaxonSquamata, Lizards.MethodsWe used phylogenetic information and the current distribution of species in open and forested habitats to estimate ancestral ranges and identify range shifts relative to the current habitats. To evaluate whether these environments influenced species diversification, we tested 12 models using a Hidden Geographic State Speciation and Extinction analysis. Finally, we combined phylogenetic relatedness and species traits in a machine learning framework to identify the traits permitting adaptation in those contrasting environments.ResultsWe identified 41 total transitions between open and forested habitats, of which 80% were from the forested habitats to the open habitats. Widely distributed species had higher speciation, turnover, extinction, and extinction fraction rates than species in forested or open habitats, but had also the lower net diversification rate. Mean body temperature, microhabitat, female snout–vent length and diet were identified as putative traits that enabled adaptation to different environments, and phylogenetic relatedness was an important predictor of species occurrence.Main conclusionsTransitions from forested to open habitats are most common, highlighting the importance of habitat shift in current patterns of biodiversity. The combination of phylogenetic reconstruction of ancestral distributions and the machine learning framework enables us to integrate organismal trait data, environmental data and evolutionary history in a manner that could be applied on a global scale.

Evaluating a developmental endocrine toxicity assay for Blanchard's cricket frog (Acris blanchardi) in outdoor enclosures

A developmental toxicity testing design was evaluated for larval and post-metamorphic Blanchard's cricket frogs (Acris blanchardi) raised in outdoor enclosures. Larvae were chronically exposed to 17β-estradiol (0.0–2.3 μg/L E2) from free swimming (Gosner stage 26) until metamorphosis. Juvenile frogs were allowed to mature within the enclosures for 60 days to assess effects of larval exposure on development, including body mass, snout-vent length (SVL), sex ratio, gonad size, and gonadal histopathology. Forty-eight percent of the initial 600 animals were recovered at the end of the study. Recovery was not influenced by E2 exposure, but larval losses were negatively impacted by unusually high spring rain events that flooded some larval tanks, and heat-related mortality of late stage larvae during summer. All surviving larvae completed metamorphosis within an average of 47 days. Overall, E2 exposure did not influence sex ratio, or the body mass, SVL, or gonad size of either males or females. Development of testes was not influenced by E2 exposure, but oviduct development in males was 4.5-fold greater in the highest treatment. Oviduct and ovary development in females exposed to the two highest E2 treatments were half that of control females. Although not treatment related and despite ad-lib feeding, variation in terminal body mass and SVL within enclosures was pronounced, with minimum – maximum differences ranging from 207 to 1442 mg for body mass and 1 mm to 15 mm for SVL. This design allowed us to assess the effects of larval exposure to a contaminant on post-metamorphic development of a native amphibian in a semirealistic field environment. With modifications to decrease flooding or overheating, this enclosure design and species is a good test system for assessing contaminant effects on development of an amphibian from early larval stages through reproductive maturity.

Reproduction and sexual dimorphism in the viviparous lizard Sceloporus palaciosi (Squamata: Phrynosomatidae) from the Trans‐Mexican Volcanic Belt, Mexico

AbstractIn this study, sexual dimorphism, reproductive cycles, litter size and offspring size of a population of the little‐known species Sceloporus palaciosi in central Mexico were analysed. Significant male‐biased sexual size dimorphism was recorded in snout–vent length (SVL), head length, head width, forearm length and tibia length. Both sexes showed asynchronous reproductive cycles, and males reached sexual maturity at a smaller SVL (33 mm) than females (37 mm). Testes volumes were small from January to February, testicular recrudescence began from March to June, and decreased in July, but increased again in August and September, followed by a second decrease from October to December. In females, vitellogenesis began from May until ovulation in December. Embryonic development extended from November to March, and a small number of females carried embryos through July. Mean litter size was 4.0 and was positively correlated with female SVL. The length of the reproductive period in S. palaciosi recorded in this study is longer than that recorded for other populations in other parts of this species range. Further studies are needed to clarify reproductive cycles in the other isolated populations of S. palaciosi, and then extended to other species and chromosome races in the Sceloporus grammicus complex.

Reproductive Cycle, Size and Age at Sexual Maturity, and Sexual Dimorphism in the Stream-Breeding Frog Crossodactylus schmidti (Hylodidae)

A reproductive strategy includes physiological, morphological, behavioral traits dependent on exogenous and endogenous regulators, including size/age at maturity, temporal variation in gametogenic cycles, and size-fecundity relationships. Sexual differences in reproductive investment, territoriality and resource use may result in sexual dimorphism on body size and other morphological traits. These life-history components are key for understanding the selective forces underlying male and female reproductive strategies in a population. We investigated the reproductive biology of the stream-breeding frog Crossodactylus schmidti through the histological analysis of testes, ovaries, and bone samples. Mature males and females and free-swimming tadpoles occurred in all months, though the monthly proportion of mature females was variable. Free spermatozoa, sperm bundles, and germ cell cysts in several stages occurred in testes of all except two males, whilst ovaries of most females presented all follicle stages, indicating continuous gametogenesis in both sexes. There was no significant seasonal variation in snout–vent length (SVL), body mass (BM) or in the gonadosomatic index for neither sex, further indicating a continuous pattern of reproduction. Minimum SVL and age at sexual maturity was 22.14 mm and 2 a, respectively, in males, and 21.78 mm and 3 a, respectively, in females; both sexes reached up to six years of longevity. Gonad mass increased with BM in both sexes, though this effect was much stronger in females. After controlling for age, females were significantly larger than males in SVL, BM, and MW (mouth width): the larger female body size suggests selection for increased fecundity, whereas the larger MW possibly favors the consumption of large, energetically important prey for sustaining the continuous egg production. Finally, there was a positive correlation between female SVL and number of thumb spines, but the number of thumb spines did not differ between the sexes; we briefly discuss a possible role of thumb spines in the courtship of C. schmidti based on field observations.

Mating pattern, female reproduction and sexual size dimorphism in a narrow-mouthed frog (Microhyla fissipes)

Abstract The difference in body size and/or shape between males and females, called sexual size dimorphism, is widely accepted as the evolutionary consequence of the difference between reproductive roles. To study the mating pattern, female reproduction and sexual size dimorphism in a population of Microhyla fissipes, amplexus pairs were collected, and the snout-vent length of males and females, female reproductive traits and fertilization rate were measured. If the body size of amplexed females is larger than that of amplectant males, this is referred to as a female-larger pair, a phenomenon that was often observed for M. fissipes in this study. Interestingly, snout-vent length of males in male-larger pairs was greater than that in female-larger pairs, however the post-spawning body mass, clutch size, egg dry mass and clutch dry mass did not differ between both types of pairs. Snout-vent length of males was positively related to that of females in each amplexus pair. After accounting for the snout-vent lengths of females, we showed that snout-vent lengths of males in male-larger pairs were greater than those of females in female-larger pairs. The snout-vent length ratio of males and females was not related to fertilization rate in each amplexus pair. The mean fertilization rate was not different between both amplexus pairs. These results suggest that (1) M. fissipes displays female-biased sexual size dimorphism and has two amplexus types with size-assortative mating; (2) the snout-vent length ratio of males and females in each amplexus type was consistent with the inverse of Rensch’s rule, and was driven by the combined effect of sexual selection and fecundity selection; (3) females with a larger body size were preferred by males due to their higher fecundity, while the body size of males was not important for fertilization success.

Hatchling survival to breeding age in Northern Pine Snakes (Pituophis melanoleucus) in the New Jersey Pine Barrens: Human effects on recruitment from 1986 to 2017.

To conserve threatened/endangered species, we need to understand the factors contributing to reproductive success and recruitment to reproductive stage. Obtaining this information is difficult for snakes because they are secretive, are not easy to locate at the same stage each year, and are sometimes sparsely distributed. We determined nest fate, hatchling growth and survival to age 5 years, and recruitment to breeding age of Northern Pine Snakes (Pituophis melanoleucus) in New Jersey Pine Barrens from 1986 to 2017. Pine Snakes are ‘threatened’ in New Jersey and in other states, and are at risk because of increased human population, habitat loss, predation, and poaching. Age of first-breeding was 4-years, based on snout-vent length of gravid and laying females, and snout-vent length of females followed as hatchlings to 5-years. Mean clutch size (+ 1 SE) was 9.5 + 0.3 (N = 53). The annual percent of nests in which eggs hatched averaged 25% (N = 288 nests), and varied among 5-year periods (5% to 30%/year). Of lab-reared hatchlings released into natal nests (N = 90), 26% (2015) and 32% (2016) reached hibernacula excavated in 2016 and 2017. The sex ratio of hatchlings reaching hibernation sites (N = 181) between 1986 and 2015 was skewed toward females (74/106, 59% females), and varied among 5-year periods (47–75% females). Once hatchlings reached a hibernaculum, there was a sex-related difference in survival. For hatchlings reaching a monitored hibernaculum, survival to 3-years was 35% in females and 40% in males, and to 4-years was 25% in females and 33% in males. Using these data, only 10% of females reached 3 years (first possible breeding age), and 7% survived to 4-years. Methodological problems with determining survival rates during these early critical years are discussed.

Atypical assortative mating based on body size in an explosive-breeding toad from a tropical island of southern China

Mating patterns exhibit considerable intra- and interspecific variation. Sexual selection can lead to the occurrence of random and assortative mating in different populations of the same species. Thus, understanding variation in mating decisions is crucial to understanding variation in the direction of sexual selection. We investigated natural mating patterns in Black-spectacled toads (Duttaphrynus melanostictus), an explosive-breeding species that breeds throughout the year. We captured amplectant pairs (137) and non-amplectant males (212) during breeding seasons from November 2016 to April 2017 in tropical-island population of southern China. Our study found no significant difference in snout-vent length (SVL) between amplectant and non-amplectant males. Female and male SVL were positively correlated with each other. Small females were paired more frequently with small males, less frequently with large males, but had no preference for or against medium males. Medium females exhibited no preference. Large females showed no preference for large males, but were paired less frequently with small males. These data suggested that successful amplectant males had body sizes representative of the entire population. Both random and size-assortative mating were present simultaneously in the same population and within the same breeding season. Female choice was important in shaping the mating behavior of Black-spectacled toads, promoting genotype-frequency stabilization and body-size diversity in the population.

Reproductive endpoints of Rhinella arenarum (Anura, Bufonidae): Populations that persist in agroecosystems and their use for the environmental health assessment

Degradation of the environment by agriculture affects the persistence and health of the amphibian populations. Characteristics related to reproduction of anuran can be used to evaluate the status of populations and as endpoints in environmental health assessment. In this in situ study the aspects related to the amplexus and ovipositions of the bioindicator species Rhinella arenarum that inhabits agroecosystems were analyzed. The hypothesis of this study is that perturbations of agroecosystems have a negative impact on the size of reproductive adults, on the size of ovipositions and eggs, and on the survival of eggs and embryos. Study area is located in the rural landscape of central Argentina. Four sampling sites were selected: C1, C2 and C3 are ponds on agroecosystems; and SM is a reference site that is not affected by agriculture or livestock. Abundance of amplexus pairs, oviposition and tadpoles per site was recorded. Individuals´ snout–vent length (SVL) in amplexus was measured. The fecundity was calculated like number of eggs per oviposition. The eggs' Gosner stage, the diameter eggs and the frequency of dead and abnormal eggs were recorded by oviposition. Killing-power between egg-embryo and egg-tadpole was calculated. The higher phosphate concentration was detected in all agroecosystems and nitrate was detected in C1 and C2. Conductivity, salinity and SDT were higher in C1 site Male SVL from the SM site was lower than the other sites while the largest SVL was of female from the C3 site. The higher frequencies of sprouted eggs and of dead eggs were recorded in the C2 site. Egg diameter was associated with SM and correlated negatively to SVL of the male and female. No correlation between female SVL and oviposition size was recorded. Killing-power in the passage from egg to tadpole classes was higher in the three agroecosystems. The hypothesis of this study was corroborated in part. Reproductive adults in agroecosystems did not have smaller body size. However, in the agroecosystem ponds, the eggs with smaller diameter were registered, the oviposition had higher frequency of abnormal eggs and the higher mortality was registered. This confirms the high sensitivity of the early stages to environmental disturbances and sustains their use as endpoints for the environmental health assessment.

Climatic and geographic predictors of life history variation in Eastern Massasauga (Sistrurus catenatus): A range-wide synthesis.

Elucidating how life history traits vary geographically is important to understanding variation in population dynamics. Because many aspects of ectotherm life history are climate-dependent, geographic variation in climate is expected to have a large impact on population dynamics through effects on annual survival, body size, growth rate, age at first reproduction, size–fecundity relationship, and reproductive frequency. The Eastern Massasauga (Sistrurus catenatus) is a small, imperiled North American rattlesnake with a distribution centered on the Great Lakes region, where lake effects strongly influence local conditions. To address Eastern Massasauga life history data gaps, we compiled data from 47 study sites representing 38 counties across the range. We used multimodel inference and general linear models with geographic coordinates and annual climate normals as explanatory variables to clarify patterns of variation in life history traits. We found strong evidence for geographic variation in six of nine life history variables. Adult female snout-vent length and neonate mass increased with increasing mean annual precipitation. Litter size decreased with increasing mean temperature, and the size–fecundity relationship and growth prior to first hibernation both increased with increasing latitude. The proportion of gravid females also increased with increasing latitude, but this relationship may be the result of geographically varying detection bias. Our results provide insights into ectotherm life history variation and fill critical data gaps, which will inform Eastern Massasauga conservation efforts by improving biological realism for models of population viability and climate change.

A new species of rain-pool frog (Dicroglossidae: Fejervarya) from western Thailand.

We describe a new species, Fejervarya muangkanensis sp. nov., based on a series of specimens collected from Ban Tha Khanun, Thong Pha Phum District, Kanchanaburi Province, Thailand. The new species is easily distinguished from its congeners by morphological and molecular data, and can be diagnosed by the following characters: (1) small size (adult male snout-vent length (SVL) 33.5 mm; female SVL 40.0-40.9 mm); (2) tympanum small, discernible but unclear; (3) poorly developed toe webbing; (4) no lateral line system in adults; (5) characteristic "Fejervaryan" lines present in females; and (6) femoral glands absent. Molecular phylogenetic analysis of mitochondrial 16S rRNA further supports it as a distinct lineage and distinguishes it from its congeners for which sequences are available.

The Mating System and Reproductive Life History of Female Timber Rattlesnakes in Northwestern Arkansas

Vertebrate mating strategies and life history patterns show great variation within and among species. Variation in reproductive tactics results from a combination of phylogenetic and environmental factors, and detailed natural and life history data among taxa are required to provide a comparative perspective or to infer evolutionary forces. Collection of such data in secretive species can often only be accomplished through long-term monitoring or the use of molecular tools. We used a combination of monitoring via radiotelemetry and microsatellite DNA markers to describe the reproductive ecology of a population of Timber Rattlesnakes, Crotalus horridus, in northwestern Arkansas. Female C. horridus in northwestern Arkansas were smaller at maturity and produce small litters compared to most estimates for other populations. Female snout–vent length and not the body condition of preparturient females was positively related to litter size and total litter mass. Both pregnant females and females found in associa...

Sex allocation and secondary sex ratio in Cuban boa (Chilabothrus angulifer): mother’s body size affects the ratio between sons and daughters

Secondary sex ratios of animals with genetically determined sex may considerably deviate from equality. These deviations may be attributed to several proximate and ultimate factors. Sex ratio theory explains some of them as strategic decisions of mothers improving their fitness by selective investment in sons or daughters, e.g. local resource competition hypothesis (LRC) suggests that philopatric females tend to produce litters with male-biased sex ratios to avoid future competition with their daughters. Until now, only little attention has been paid to examine predictions of sex ratio theory in snakes possessing genetic sex determination and exhibiting large variance in allocation of maternal investment. Cuban boa is an endemic viviparous snake producing large-bodied newborns (∼200g). Extremely high maternal investment in each offspring increases importance of sex allocation. In a captive colony, we collected breeding records of 42 mothers, 62 litters and 306 newborns and examined secondary sex ratios (SR) and sexual size dimorphism (SSD) of newborns. None of the examined morphometric traits of neonates appeared sexually dimorphic. The sex ratio was slightly male biased (174 males versus 132 females) and litter sex ratio significantly decreased with female snout-vent length. We interpret this relationship as an additional support for LRC as competition between mothers and daughters increases with similarity of body sizes between competing snakes.

Male size does not correlate with fertilization success in two bufonid toads that show size-assortative mating

Abstract We examined sexual size dimorphism (SSD), mating pattern, fertilization efficiency and female reproductive traits in two bufonid toads (Bufo gargarizans and Duttaphrynus melanostictus) to test the idea that importance of male body size for egg fertilization success depends on the mating pattern. Female-biased SSD was evident only in D. melanostictus. Female B. gar-garizans laid fewer larger eggs nearly three months earlier than did female D. melanostictus. Fertilization efficiencies on average were higher in B. gargarizans (95%) than in D. melanostictus (91%). Though differing in the degree of SSD, body size, breeding season, clutch size, egg size and fertilization efficiency, the two toads were similar in four aspects: (1) both showed size-assortative mating; (2) females did not tradeoff egg size against egg number; (3) male size, clutch size and clutch dry mass were greater in male-larger than in female-larger pairs after accounting for female snout-vent length (SVL); and (4) the ratio of male to female SVL did not affect fertilization efficiency. Our data show that: (1) a female preference for large males is likely not important in terms of egg fertilization success; (2) a male preference for large females is likely important because larger females are more fecund; and (3) size-assortative mating arises from a male preference for large females. Our study demonstrates that male size is not always important for egg fertilization success in anurans that show size-assortative mating.

Reproductive Activity in Females of the Oviparous LizardSceloporus aeneus

Abstract We studied the reproductive cycle of female Sceloporus aeneus from a population southeast of Mexico City (Milpa Alta), Mexico, from April 1993–March 1994. Females have a seasonal reproductive pattern with maximum activity in spring, a pattern typical of temperate oviparous species of the genus. Each female produces up to two clutches per breeding season, with a clutch size ranging from 4–10, which is not correlated with snout-vent length of females.