Variation in the adult sex ratio and morphological traits of Cardisoma guanhumi (Latreille, 1828) in contrasting habitats in the southwest of the Gulf of Mexico

Variation in the adult sex ratio and morphological traits of Cardisoma guanhumi (Latreille, 1828) in contrasting habitats in the southwest of the Gulf of Mexico | Authorea try { document.documentElement.classList.add('js'); } catch (e) { } var _gaq = _gaq || []; _gaq.push(['_setAccount', 'G-8VDV14Y67G']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); Skip to main content Preprints Collections Wiley Open Research IET Open Research Ecological Society of Japan All Collections About About Authorea FAQs Contact Us Quick Search anywhere Search for preprint articles, keywords, etc. Search Search ADVANCED SEARCH SCROLL Ecology and Evolution This is a preprint and has not been peer reviewed. Data may be preliminary. 10 February 2025 V1 Latest version Share on Variation in the adult sex ratio and morphological traits of Cardisoma guanhumi (Latreille, 1828) in contrasting habitats in the southwest of the Gulf of Mexico Authors : Jared Leyva-Hernández , Martha Baena 0000-0002-5684-2771 [email protected] , Ivette Chamorro-Florescano , and Israel Huesca-Domínguez Authors Info & Affiliations https://doi.org/10.22541/au.173916558.82940509/v1 Published Ecology and Evolution Version of record Peer review timeline 420 views 223 downloads Contents Abstract Supplementary Material Information & Authors Metrics & Citations View Options References Figures Tables Media Share Abstract The habitat and its environmental conditions, when optimal, influence the reproduction and survival of organisms, since they can have an impact on demographic parameters such as adult sex ratio (ASR), density, and functional traits (morphological, physiological). However, understanding population dynamics and habitat properties can present significant challenges. Few studies evaluate these factors as a whole in contrasting habitats (such as mangroves and grasslands), especially in crab species such as Cardisoma guanhumi . We hypothesized that mangroves would be a favorable habitat for C. guanhumi at a local and regional scale because the environmental conditions (lower temperature, soft and clayey substrate) would have a positive effect on its population dynamics and morphological traits. In order to test this hypothesis, we selected 12 sites on the coasts of the Gulf of Mexico. We found an effect of habitat on ASR, which was male-biased in the mangrove and female-biased in the grassland at a local (by site) and regional scale. Furthermore, crab density was higher in the mangrove and decreased in both habitats as soil hardness increased. In addition, females were heavier and larger (quela, carapace, ventral plate) in the mangrove and these traits were positively related to burrow temperature in this habitat. Our results support the hypothesis that mangroves are the optimal environment for the development of C. guanhumi . This threatened species has thrived in modified habitats such as grasslands, and thus the conservation of these human-dominated habitats is fundamental. Introduction The habitat is a factor that can influence the demographic parameters of populations as well as the adult sex ratio (ASR) (Amos et al. 2013; Fromhage & Jennions 2016; Kappeler et al. 2023) and density of individuals (Julliard 2000; Reichard et al. 2014; Barreto et al. 2022). Although insufficiently explored, the habitat may also influence the morphological and physiological traits of a population (Yates et al. 2014; Attiwilli et al. 2021; Kappeler et al. 2023). Moreover, populations can interact with the habitat in different ways as a response to their spatial distribution and the environmental conditions (Xu et al. 2016; Alonso-Fernández et al. 2017; Whitmann et al. 2023). Optimal environmental conditions in the habitat (resource availability and favorable microclimate) are known play a role in the reproduction and survival of individuals, which in turn affects the ASR (Julliard 2000, Reichard et al. 2014; Jennions & Fromhage 2017; Edmands 2021; Bókony et al. 2024; Verma et al. 2024). However, the relationship between population spatial dynamics and habitat properties is complex and scarcely supported by field data (Whitmann et al. 2023; Marrera et al. 2025). The ASR includes individuals in a population that have reached sexual maturity whether they are sexually active or not (Hardy 2002; Fromhage & Jennions 2016; Ancona et al. 2017; Carmona-Isunza et al., 2017). Adult sex ratio and density are parameters that regulate the structure of a population and play a crucial role in population dynamics, since they influence reproductive success (competition for mates and resources) and fecundity and mortality rates, among others (Clutton- Brock 1991; Hardy 2002; Julliard 2000; Steifetten & Dale 2012; Ancona et al. 2017; Jennions & Fromhage 2017; Végvári et al. 2018, Schacht et al. 2022; Kappeler et al. 2023). Fisher’s classic work (1930) predicts that the sex ratio is at equilibrium 1:1 when costs are similar. However, under natural conditions, the ASR tends to be biased towards one sex due to the selective pressure of different ecological factors (environmental conditions, habitat loss, resource availability). Therefore, the ASR is expected to be biased towards the sex with a better ability to exploit the environmental conditions of the habitat (Julliard 2000; Steifetten & Dale 2012; Végvári et al. 2018; Barreto et al. 2022; Kappeler et al. 2023). Some studies have shown a relationship between temperature and functional traits. In some species, temperature modulates anatomical specialization and biological processes. For example, body size can increase with temperature as a mechanism for heat gain (Bergmann 1847; Attini et al. 2021). Temperature is also a key factor in shaping the geographic distribution of species and the density and ASR variation of populations, especially in species that can establish in different types of habitats (Rohde 1992; Edmans 2020; Verma et al. 2024). In brachyuran crabs such as Ucides occidentalis, Cardisoma Crassum, and Cardisoma guanhumi , environmental conditions such as temperature (Burgos & Andrade-Garófalo 2018; Lombardo & Rojas 2022; Mota et al. 2023), vegetation cover, and/or soil hardness (Capistrán Barradas et al. 2003; Carmona-Suárez & Guerra-Castro 2018) have been found to primarily influence the density of individuals. Cardisoma guanhumi is a crab species distributed from the south of Florida to Brazil, including the Caribbean islands and West Africa (Govender et al. 2008). As a semi-terrestrial species, it can establish itself in different types of habitats, from dense mangrove forests with hydroperiods and humid soils to sparsely vegetated grasslands with higher temperatures than mangroves and superficially arid and compacted soils (Rodríguez-Fourquet & Sabat 2009; Giménez et al. 2015; Méndez & Cruz 2017). However, there is a debate about the effect of the habitat on some demographic parameters. Some studies have found that habitat modifications due to land-use change can result in more abundant and larger individuals in mangroves compared to pastures and grasslands (Arroyave-Rincón et al. 2014; Carmona-Suárez et al. 2018, Quiñones-Llópiz et al. 2021). Other studies have not found an effect of habitat but have found an effect of physical factors (shade, plant litter, and soil substrate) or landscape scale on the abundance and size of C . guanhumi (Novais et al. 2021; Riascos et al. 2024). Nevertheless, these results are from studies conducted in North and South America, where C . guahumi is generally less abundant and smaller in size. Thus, it is not known how habitat type and environmental conditions can influence demographic parameters such as ASR, density, and morphological traits in species like Cardisoma guanhumi (Latreille 1825) at a regional scale. We studied the response to these factors at a local (by study site) and regional scale on the coasts of Tamaulipas and Veracruz in the Gulf of Mexico. This approach allows us to infer mechanisms at an individual (by evaluating the effect on the offspring of individuals) and population level. Considering the above, we hypothesized that mangroves would be a favorable habitat for C. guanhumi at a local and regional scale because the environmental conditions (lower temperature, soft and clayey substrate) would favor its survival, and therefore, its population dynamics. We predicted that C. guanhumi populations in mangroves would show higher body condition (size, weight), higher density, and a biased ASR compared to those found in grasslands . The transformation of a natural habitat (mangroves) into grasslands can have a potential negative effect on the availability of suitable sites for reproduction (burrows) and food resources necessary for survival. Study area The present study was conducted at a regional scale on the coasts of Tamaulipas and Veracruz in the Gulf of Mexico (18.14° a 23.78° N; 94.14° to 97.90° W). Twelve sampling sites where the crabs were not harvested (to rule out anthropogenic effects) were established: two in Tamaulipas and 10 in Veracruz (Figure 1). Since C . guanhumi is able to occupy different habitats (as long as it has access to the water table) (Rodríguez-Fourquet & Sabat 2009; Mendes & Cruz 2017; Novais et al. 2021), we selected two types of habitats at a local and regional scale in the Gulf of Mexico: mangrove forests as a natural habitat and grasslands as a disturbed habitat. These two habitat types were selected in each site and sampled during September and October of 2021 and 2022, which are the months when adults present (Carmona-Suárez & Guerra-Castro 2018; Quiñones-Llópiz et al. 2021). Sampling design In each selected habitat (mangrove and grassland) per sampling site, we established five 50-m-long transects separated by a minimum distance of 10 m. To locate the burrows of C . guanhumi , we established three 5 x 5 m quadrats in each transect, resulting in a total of 15 quadrats/habitat. The quadrats in the mangrove were placed at a distance of ≈ 30 m from the nearest body of water, avoiding flooded areas. The same design was used in each of the 12 sites. A total of 180 quadrats were established in mangrove habitats and 180 in grassland habitats along the coasts of Tamaulipas and Veracruz. We recorded the total number of crabs found inside their burrows in each quadrat in order to quantify the abundance and density of individuals per site and habitat. For this, we extracted the individuals from their burrows using a 2.5-m-long flexible crab hook, ensuring not to damage the morphological structures. We only recorded adult individuals, which were determined by a carapace width equal to or greater than 58.5 mm, since color is not always linked to body size (Rincón et al. 2014; Arroyave et al. 2014). The following parameters were recorded for each captured individual: sex, carapace width and length, width, length, and thickness of the largest quela, maximum width of the ventral plate, and body weight. We used an AutoTEC digital caliper to measure the structures (0.01 precision) and a TORREY LAB-500 portable digital balance (0.1 g precision and 500 g capacity) to weigh each individual. All the data were obtained in situ, and the surveyed and measured individuals were released alive in their respective habitat (mangrove or grassland). We also recorded the environmental temperature and the temperature inside the burrows using a digital thermometer. Burrow temperature was obtained by pointing a digital laser infrared thermometer (GM 550, 10 to 55 ºC) at the deepest accessible part of the burrow. Soil compaction was measured in both mangroves and grasslands using a Siless penetrometer. Statistical analysis Crab density was calculated as the number of individuals per quadrat (5 m 2 ). Adult sex ratio was estimated as: total number of males/ (males + females). This estimator is asymmetric around 0.5, where a value of 0 indicates a female-biased ASR and a value of 1 a male-biased ASR (Hardy 2002; Ancona et al. 2017). The effect of the variables of habitat (mangrove and grassland) and environmental conditions (soil hardness, environmental temperature, and burrow temperature) on the response variables (density and ASR) was analyzed with a linear mixed model (LMM) and a generalized linear mixed model (GLMM) with a binomial error distribution, respectively. Sampling site was considered as a random factor and habitat as a fixed factor. The spatial variation of the ASR of C. guahnumi on the coasts of Tamaulipas and Veracruz (Gulf of Mexico) was analyzed by a bootstrapping procedure (10,000) to determine the 95% asymmetric confidence intervals (Davison & Hinkley 1997) using the R package boot (Canty & Ripley 2024). To determine the relationship and reduce the dimensionality among the morphological variables, we performed a principal component analysis (PCA). We then used linear mixed models (LMMs) to evaluate whether the morphological traits of C. guanhumi (weight, carapace width, quela thickness, and ventral plate width) varied with sex (females and males), habitat, and environmental conditions (soil hardness, environmental temperature, and burrow temperature). Sampling site was considered as a random factor and habitat and sex as fixed factors. We used the R package lme4 (Bates et al. 2015) for the mixed models and all analyses and data visualization were performed in R version 4.4.1 (R Core Team 2024). Results We sampled a total of 3,618 crabs and found 1,042 females (28.8%) and 1,459 males (40.32%) in the mangrove and 709 females (19.6%) and 408 males (11.28%) in the grassland. The mean density (± SD) per quadrant was 13.89 ± 5.43 individuals in the mangrove and 6.41 ± 3.24 individuals in the grassland. Adult sex ratio (ASR) and crab density Of the environmental variables analyzed as predictors of ASR, the GLMM only showed a significant effect of habitat ( χ2 = 7.14, df = 1, P < 0.001, Table 1). The ASR was male-biased in the mangrove and female-biased in the grassland (Figure 2A). This difference in ASR between habitats (local scale) was also found among the 12 sites sampled along the coasts of Tamaulipas and Veracruz in the Gulf of Mexico, since the confidence intervals per habitat did not overlap, which indicates that the ASR is consistently biased towards each sex: male-biased in the mangrove and female-biased in the grassland (Figure 2B). The LMM showed a significant effect of habitat ( χ2 = 93.725, df = 1, P < 0.001), soil hardness ( χ2 = 8.91, df = 1, P < 0.001), environmental temperature ( χ2 = 22.64, df = 1, P < 0.001), and burrow temperature ( χ2 = 16.39, df = 1, P < 0.001) on density. Crab density was higher in the mangrove than in the grassland (Figure 3A) and decreased as soil hardness increased in both habitats (Figure 3B). In contrast, there was a positive relationship between temperature (environmental and burrow) and crab density, particularly in the mangrove. Both types of temperature varied more in the mangrove than in the grassland (Figure 3C and D). Influence of the habitat on the morphological traits of C. guanhumi on the coasts of Tamaulipas and Veracruz (Gulf of Mexico) The PCA represented 92.88% of the total variation of the data. The first component represented 82.73% of the total variance, where carapace width and length and quela width were the best represented. The second component represented 10.15% of the total variation, where ventral plate width was the best represented variable, while the carapace and quela measurements showed an inverse relationship (Table 1 SM ). Carapace width (mean ± SD) measured 7.06 ±1.01 in the mangrove and 5.5±0.69 in the grassland for females and 5.28 ±0.8 in the mangrove and 6.93±0.81 in the grassland for males (Table 2 SM ). The minimal model from the LMM showed that sex ( χ2 = 693.162, df = 1, P < 0.001), burrow temperature ( χ2 = 33.094, df = 1, P < 0.001) and the interaction habitat:sex ( χ2 = 3524.938, df = 1, P < 0.001) had a significant effect on the weight of C. guanhumi (Table 2). The interaction shows that females are heavier in the mangrove, while males are heavier in the grassland (Figure 4A). We also found that weight increased with burrow temperature in the mangrove (Figure 4B). In the case of quela thickness, only sex and the interaction sex:habitat showed a significant effect (Table 2). Females had thicker quela in the grassland than in the mangrove and males showed the opposite pattern (Figure 5, Table 2 SM ). Sex, burrow temperature, and the interaction habitat:sex had a significant effect on carapace width (Table 3). The carapace of females was wider in the mangrove, while the carapace of males was wider in the grassland (Figure 6A). Carapace width increased with burrow temperature in the mangrove (Figure 6B). Finally, habitat, sex, burrow temperature, and the interaction habitat:sex had a significant effect on ventral plate width (Table 3). The ventral plate of females was wider in the mangrove than in the grassland (Figure 7A. Table 3). There was also a positive relationship between ventral plate width and burrow temperature, although it was more evident in the mangrove than in the grassland (Figure 7B). Discussion We investigated the influence of the habitat and environmental conditions (environmental and burrow temperature and soil hardness) on the ASR, density, and physiological and morphological traits of C. guanhumi at a regional scale across 12 sampling sites on the coast of the Gulf of Mexico. Four findings are particularly noteworthy . (1) There was an effect of habitat on ASR, where it was male-biased in the mangrove and female-biased in the grassland. (2) The difference in the bias towards males and females between habitats was observed at a regional scale. (3) Habitat, soil hardness, environmental temperature, and burrow temperature had an effect on crab density . (4) Sex, burrow temperature, and the interaction habitat:sex had an effect on weight and size (carapace, quela, and ventral plate). Our results support our prediction that C. guanhumi populations in mangroves have a higher body condition (size, weight), higher density, and a biased ASR compared to those in grasslands . To the best of our knowledge, this is the first study to jointly analyze demographic parameters (ASR and density) and morphological traits in C. guanhumi at a local and regional scale. According to our prediction, we found that habitat was the only predictor of ASR in C. guanhumi , since environmental and burrow temperature, soil hardness, and density did not have an effect on this parameter. These results indicate that the bias towards males in the mangrove and towards females in the grassland at a local (by site) and regional (on the coasts of Tamaulipas and Veracruz in the Gulf of Mexico) scale is not influenced by these abiotic factors but rather by land-use change. However, there are still not enough studies to understand the causes of variation in ASR, especially across spatial scales (Xu et al. 2016). Biases in the sex ratio and their variation may reflect adaptations related to changes in the spatio-temporal distribution of individuals and the characteristics of the habitat (climatic conditions, resource availability, among others) (Dittmar et al. 2011; Székely et al. 2014; Jennions & Fromhage 2017; László et al. 2018; Barreto et al. 2022). Cardisoma guanhumi has adapted to occupy different continental habitats, mainly through access to the water table (Govender & Rodríguez-Fourquet 2008; Rodríguez-Fourquet & Sabat 2009; Méndez & Cruz 2017; Novais et al. 2021). Furthermore, the flexibility of this crab species in terms of new food sources is leading to shifts in its demographic processes at all scales. For example, a higher abundance in modified habitats, such as cities, compared to natural habitats is related to a constant availability of food resources such as dead animals and human feces, which appear to be consumed by this species (Riascos et al. 2024). The variation in the ASR along the regional distribution of this species in the Gulf of Mexico may have significant implications for its reproductive biology and, consequently, for the survival of the population. The bias towards sexually mature males observed in the mangrove in the present study has also been recorded in regions with weak predation pressure, primarily in populations restricted to islands (Hernández- Maldonado & Campos 2015). The relationship between geographic distribution, population growth, and population viability may be complex in C . guanhumi and depend on a range of characteristics, including density and mating system. For example, according to our results, a low number of males in the grassland at a low population density suggests reduced female fecundity as a result of the limited capacity of males to fertilize all the females (Emlen & Oring 1977; Shuster & Wade 2003). In the case of the bias towards males in the mangrove, a different approach predicts adaptive behavioral responses to a biased ASR. This is the case of increased harassment of females in populations with a bias towards males (Le Galliard et al. 2005), which affects the ASR through sex-specific mortality rates (Kokko & Rankin 2006). On the other hand, a male-biased ASR in the mangrove may improve female fertility by increasing the chance of selecting a mate and, therefore, producing more viable offspring, as has been observed in other studies (Emlen & Oring 1997; Julliard et al. 2000; Shuster & Wade 2003). It would be interesting to explore these hypotheses based on mating systems theory in future studies. It is important to analyze the causes of variation in the ASR to understand the relationship between ASR, mating system, and population dynamics in this species. Temperature is an important factor in the establishment and development of C. guanhumi (Govender & Rodriguez-Fourquet 2008; Carmona-Suarez 2011; Giménez et al. 2015; Mendes & Cruz 2017). In the present study, we observed that environmental temperature influences the density of individuals. Furthermore, the temperature inside the burrow (where C. guanhumi spends most of its life and is always lower than the environmental temperature) has an effect on its development. Gómez- Cervantes (2020) reported that temperature is one of the main factors contributing to the optimal development of this species. In our study, we found that, at least in the mangrove, temperature favored an increase in weight and carapace and ventral plate size. The quela was the only structure that was not influenced by temperature. The size of most morphological structures increased at a lower burrow temperature in the mangrove (27.5 0 C – 32 0 C) compared to the grassland (32 0 C – 38 0 C). Crabs can experience heat stress in grassland habitats. An increased weight and structure size may compensate for a lower burrow temperature in the mangrove, while heat stress in grasslands may explain the more stable weight and size of the crabs in this habitat. The density of individuals was inversely proportional to soil hardness in both mangroves and grasslands. However, the soil in the burrows was more compacted in the grassland than in the mangrove, which explains the higher density of individuals in the mangrove compared to the grassland. Burrow construction and maintenance are costly activities due to the time and energy invested (reviewed in Lombardo & Rojas 2022). Thus, a higher crab density in the mangrove may be related to the continued use of burrows to ensure reproduction and protection from predators. The few studies that examine differences in the size of C. guanhumi between populations and habitats report a significantly larger size in mangrove forests compared to grasslands in Colombia (Arroyave- Rincón et al. 2014; Carmona-Suarez & Guerra-Castro 2018). However, size measurements were not obtained by sex as in the present study. These results indicate habitat segregation by condition and size in both sexes of C. guanhumi . This crab species shows sexual dimorphism in ventral plate size, where it is wider in females than in males (Quiñones-Llópiz et al. 2021). This pattern was observed in both mangroves and grasslands. However, the ventral plate of females was narrower in grasslands than in mangroves. This difference may have implications for the transportation of eggs, since females of this species undertake spawning migrations, traveling up to 12 km to release the larvae in a body of water (Gimenes et al. 2015). In addition to providing better shelter than grasslands, mangroves are located next to bodies of water. Therefore, spawning migrations are shorter in this habitat. The above suggests that females in mangroves carry a higher number of eggs, since they are protected by a wider ventral plate compared to females in grasslands. On the other hand, the carapace has been considered an indicator of growth in this species, as in Cardisoma crassum (Molina-Ortega & Vázquez-López 2018). Similarly to the other structures, variation in carapace width in C . guahumi is related to adaptive strategies according to the habitat and burrow temperature. Other studies have shown that carapace width responds to habitat loss, as well as to local fishing pressure (Silva et al. 2014; Hernández-Maldonado & Campos 2015; Govender 2019). A distinctive trait of C . guanhumi is the size of its quela, since they are the largest and most conspicuous part of the body of most individuals. Exaggerated morphological structures are often associated with sexual selection (Andersson 1994), but natural selection can also favor extreme morphologies that enhance foraging or locomotion (Bro‐Jørgensen et al. 2008). The quela is a multifunctional structure in C . guanhumi , since it is used for feeding, fighting, and protection. The crabs also use their quela to dig burrows over 2 m deep, where they spend most of their lives (Mendes & Cruz 2017). Given the variety of functions, the quela performs and the distribution of this species in contrasting habitats such as mangroves and grasslands, morphological changes would be expected in this structure. There is evidence that the environment can limit the size of structures. For example, the cranial appendages of bovids and cervids are shaped by their environment, where species inhabiting open grasslands exhibit larger structures and those inhabiting dense forests have smaller or absent structures (Caro et al. 2003; Cabrera & Stankowich 2020). In other crab species, such as Cambarus chasmodactylus , ecological factors like the vegetation composition and substrate influence their distribution and quela morphology depending on whether they are found in lotic or lentic sites in rivers or streams (Graham 2021). Our study shows that quela thickness in C . guanhumi varies with sex and habitat, where females in mangroves and males in grasslands have thicker quela. This may be a response to the conditions of these habitats, since the soil is compacted in grasslands and soft and silty in mangroves. The diet of this species also differs between these two habitats, where it collects fallen leaves and fruits in mangroves, while it has been observed clipping the vegetation to feed on it in grasslands (Herreid 1963). Conclusion The results of our study indicate that C. guanhumi is sensitive to the type of habitat. At a regional scale, in the coast of the Gulf of Mexico, C. guanhumi showed a preference for mangroves. This habitat had suitable conditions (burrow temperature and soil hardness) that favored a higher crab density and a male-biased sex ratio. Furthermore, there were differences between sexes in morphological and physiological traits, which, particularly in females, varied with the habitat and environmental conditions. These traits showed that females in mangroves were in better condition than those in grasslands. The demographic and morphological responses to contrasting habitats show that this species has different requirements. This suggests that crabs in mangroves are more likely to survive and reproduce than those in human-modified environments such as grasslands. This type of study provides key information on the population ecology of this species for the implementation of conservation measures, since it may be threatened by commercial exploitation by persisting in modified environments such as grasslands. Acknowledgments Special thanks to the Secretaría de Ciencia, Humanidades, Tecnología e Innovación (Secihti) for the scholarship provided to the first author. Author contributions Conceptualization: MLB, IACFJLH, JLH. Field sampling: JLH. Data analysis: IHD, JLH. Figure editing: IHD. Writing: MLB. Review: MLB, IACFJLH, IHD, JLH. Conflict of interest The authors declare no conflict of interest. Ethical considerations This study did not involve the killing of any individuals; they were all released into their respective burrows after collecting the data. 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Collection Ecology and Evolution Keywords invertebrate marine natural history population ecology terrestrial Authors Affiliations Jared Leyva-Hernández Universidad Veracruzana Facultad de Ciencias Biologicas y Agropecuarias Poza Rica -Tuxpan View all articles by this author Martha Baena 0000-0002-5684-2771 [email protected] Universidad Veracruzana View all articles by this author Ivette Chamorro-Florescano Universidad Veracruzana Facultad de Ciencias Biologicas y Agropecuarias Poza Rica -Tuxpan View all articles by this author Israel Huesca-Domínguez Universidad Veracruzana View all articles by this author Metrics & Citations Metrics Article Usage 420 views 223 downloads .FvxKWukQNSOunydq8rnd { width: 100px; } Citations Download citation Jared Leyva-Hernández, Martha Baena, Ivette Chamorro-Florescano, et al. Variation in the adult sex ratio and morphological traits of Cardisoma guanhumi (Latreille, 1828) in contrasting habitats in the southwest of the Gulf of Mexico. 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