Discrimination of cryptic species: Tabanus triangulum and Tabanus occidentalis (Diptera: Tabanidae) differ in size and shape / Distinção de espécies crípticas: Tabanus triangulum e Tabanus occidentalis (Diptera: Tabanidae) diferem em tamanho e forma

Abstract Horse fly females (Diptera, Tabanidae) are hematophagous and can vector pathogens that affect livestock. Complexes of cryptic species are common in Tabanidae, as exemplified by some species of Tabanus, including Tabanus triangulum and Tabanus occidentalis, both prevalent in the Southern region of Brazil. In this study, geometric morphometrics were employed to ascertain the wing venation in species identification. It was demonstrated that this tool effectively differentiates T. triangulum from T. occidentalis in the coastal plain of Rio Grande do Sul state, situated within the Pampa biome. The results indicate that T. triangulum and T. occidentalis occupy distinct regions of the morphological space, allowing their precise identification through geometric morphometrics, which is fast, affordable, and easy to implement.

Resumo Fêmeas de mutucas (Diptera, Tabanidae) são hematófagas e podem ser vetores de patógenos que afetam animais de criação. Complexos de espécies crípticas são comuns em Tabanidae, como exemplificado por algumas espécies de Tabanus, incluindo Tabanus triangulum e Tabanus occidentalis, ambas prevalentes na região Sul do Brasil. Neste estudo foi utilizada morfometria geométrica para avaliar a venação das asas na identificação de espécies. Foi demonstrada que essa ferramenta diferencia, efetivamente, T. triangulum de T. occidentalis na Planície Costeira do Rio Grande do Sul, situada no bioma Pampa. Os resultados indicam que T. triangulum e T. occidentalis ocupam regiões distintas do espaço morfológico, permitindo sua identificação precisa por meio da morfometria geométrica, a qual é rápida, acessível e fácil de implementar.

Characterization of Triatoma infestans (Klug, 1834) (Hemiptera: Heteroptera, Reduviidae) from Residual Foci in the States of Bahia and Rio Grande do Sul, Brazil, Using Geometric Morphology.

Triatoma infestans is one of the main vectors of Chagas disease in Latin America. Although the species is under control in most Latin countries, it is still necessary to maintain epidemiological surveillance. The present study aims to characterize T. infestans populations from residual foci in Bahia and Rio Grande do Sul, Brazil, comparing them with natural populations in Argentina and Bolivia. For this, we adopt the geometric morphometry of the heads. It is possible to report the morphometric variety of the studied populations. In addition, we show that the size of the heads contributes to the differentiation between populations, while the shape has less power to discriminate groups. Furthermore, we show that some natural populations have morphometric proximity to residual populations, suggesting a relationship between these triatomines. Our data do not support the origin of residual populations but demonstrate the importance of new studies with other techniques to understand the dynamics of distribution and reintroduction of these vectors in Brazilian territory.

Genetic and morphological polymorphisms of Aedes scapularis (Diptera: Culicidae), vector of filariae and arboviruses

Background Aedes scapularis is a neotropical mosquito that is competent to vector viruses and filariae. It is reputed to be highly morphologically and genetically polymorphic, facts that have raised questions about whether it is a single taxonomic entity. In the last five decades, authors have posed the hypothesis that it could actually be a species complex under incipient speciation. Due to its epidemiological importance, its taxonomic status should be determined with confidence. Aim and method Our objective was to investigate more deeply the polymorphism of Ae. scapularis to detect any evidence of incipient speciation of cryptic species. We then compared populational samples from the Southeastern, Northern and Northeastern regions of Brazil. The biological markers used in the comparison were: the complete mitochondrial DNA, the isolated mitochondrial gene cytochrome oxidase subunit I (COI) and wing geometry. Results and discussion As expected, high morphological/genetic polymorphism was observed in all Ae. scapularis populations, however it was not indicative of segregation or incipient speciation. There was no correlation between wing shape and the geographical origin of the populations analysed. A congruent observation resulted from the analysis of the COI gene, which revealed a high number of haplotypes (51) and no clusterization of populational samples according to the original biomes. In the phylogenetic analysis of the 13 mitochondrial protein-coding genes, the Ae. scapularis clade clustered with maximum support (100% bootstrap support and posterior probability of 1). No significant internal structure was observed in the Ae. scapularis clade, which was nearly a polytomy. Taken together, our results indicate that this species is not a species complex. Conclusion We conclude that there was no indication, in the analysed regions, of the occurrence of more than one taxon in the species Ae. scapularis, despite it being highly polymorphic. By ruling out the former species complex hypothesis, our phylogenetic results reinforce that Ae. scapularis is a single taxonomic unit and should be monitored with standardized surveillance and control methods.

Molecular identification and morphological variations of Dermacentor albipictus collected from two deer species in northern Mexico.

In total, 57 ticks were collected from six white-tailed deer (Odocoileus virginianus) and three mule deer (O. hemionus) in northern Mexico during the 2017, 2018 and 2019 hunting seasons. Morphological features of adult male and female ticks were observed and photographed using a stereo-microscope and scanning electron micrography. The ticks were identified as Dermacentor albipictus based on taxonomic keys. Molecular analysis using DNA amplification of the 16S rDNA and cytochrome oxidase 1 (COI) genes was employed to resolve the phylogenetic relationships from 18 strains of Dermacentor species. Bayesian phylogenetic analysis was performed in order to obtain a phylogenetic tree based on the concatenated sequence in the D. albipictus clade. The geometric morphometric analysis compared the body shape of ticks collected from specimens of two deer species by analyzing nine dorsal and ventral landmarks from both males and females. The results suggest that body shape variation in dorsal structures might be related to the host.

Unraveling the Morphological Variation of Triatoma infestans in the Peridomestic Habitats of Chuquisaca Bolivia: A Geometric Morphometric Approach.

Morphometrics has been used on Triatomines, a well-known phenotypically variable insect, to understand the process of morphological plasticity and infer the changes of this phenomenon. The following research was carried out in two regions of the inter-Andean valleys and two Chaco regions of Chuquisaca-Bolivia. Triatoma infestans adults were collected from the peridomestic (pens and chicken coops) along a geographic gradient in order to evaluate the morphological differentiation between groups and their pattern of sexual shape dimorphism. Geometric morphometric methods were applied on the wings and heads of T. infestans. The main findings include that we proved sexual dimorphism in heads and wings, determined the impact of environmental factors on size and shape and validated the impact of nutrition on head shape variation. These results show that geometric morphometric procedures can be used to provide key insight into the biological adaptation of T. infestans on different biotic (nutrition) and abiotic (environment) conditions, which could serve in understanding and evaluating infestation processes and further vector control programs.

Shell form and enzymatic alterations in Lottia subrugosa (Gastropoda, Lotiidae) transplanted to a contaminated site.

Studies have shown that shell morphology and enzymatic activities in mollusks are affected by contaminants exposure. However, the correlation between enzymatic activities and the biomineralization process are not fully understood. The present study used a transplant bioassay and field sampling to evaluate shell measurements and the activities of carbonic anhydrase, Ca2+-ATPase, and Mg2+-ATPase in Lottia subrugosa sampled in Brazilian sites under different contamination levels. Results showed that, in general, shells from the reference site (Palmas) were more rounded than the ones from the contaminated site (Balsa). Effects in enzymatic activities in specimens from transplant bioassay were attributed to the known high contaminant levels present at Balsa. While the lack of enzymatic activity alterations during field sampling was attributed to physiological adaptation to contaminants exposure. Enzymatic activities were not correlated to shell biometric parameters in field sampling, indicating that these enzymes were not related to shell alterations detected in the present study.

WingBank: a wing image database of mosquitoes

Mosquito-borne diseases affect millions of people and cause thousands of deaths yearly. Vaccines have been hitherto insufficient to mitigate them, which makes mosquito control the most viable approach. But vector control depends on correct species identification and geographical assignment, and the taxonomic characters of mosquitoes are often inconspicuous to non-taxonomists, which are restricted to a life stage and/or even damaged. Thus, geometric morphometry, a low cost and precise technique that has proven to be efficient for identifying subtle morphological dissimilarities, may contribute to the resolution of these types of problems. We have been applying this technique for more than 10 years and have accumulated thousands of wing images with their metadata. Therefore, the aims of this work were to develop a prototype of a platform for the storage of biological data related to wing morphometry, by means of a relational database and a web system named “WingBank.” In order to build the WingBank prototype, a multidisciplinary team performed a gathering of requirements, modeled and designed the relational database, and implemented a web platform. WingBank was designed to enforce data completeness, to ease data query, to leverage meta-studies, and to support applications of automatic identification of mosquitoes. Currently, the database of the WingBank contains data referring to 77 species belonging to 15 genera of Culicidae. From the 13,287 wing records currently cataloged in the database, 2,138 were already made available for use by third parties. As far as we know, this is the largest database of Culicidae wings of the world

Ecomorphological associations of scapulocoracoid form in Greater Antillean Anolis lizards.

External morphological metrics have featured prominently in comparative studies examining the morphological convergence that characterizes anoline ecomorphs. To what degree the appendicular-skeletal morphology of Greater Antillean island Anolis lizards tracks their diversity and ecological adaptation, however, remains relatively unexplored. Here we employ computed tomographic scanning techniques to visualize in situ the scapulocoracoid of ecomorph representatives (trunk-ground, trunk-crown, crown-giant, twig) from three islands (Jamaica, Hispaniola, and Puerto Rico), and compare its three-dimensional geometry using qualitative-descriptive and quantitative-morphometric techniques. In contrast to our previous, similarly-conducted study of the pelvic girdle of these same species, the form of the scapulocoracoid varies markedly both within and between species, with much of the variation relating to phylogenetic relationship, specimen size, and assigned ecomorph category. Morphometric variation that correlates with size and/or phylogenetic signal varies between species and cannot be eliminated from the data set without markedly reducing its overall variability. The discovered patterns of skeletal variation are consistent with the demands of locomotor mechanics imposed by the structural configuration of the microhabitat of these ecomorphs. Most pertinently the ecomorphs differ in the anteroposterior length of the coracoid, the dorsoventral height of the scapulocoracoid, the dorsoventral height of the scapula in relation to the height of the suprascapula, and the relative positioning of the borders of the scapulocoracoid fenestra. In the examined ecomorph categories these skeletal differences likely relate to microhabitat usage by permitting different degrees of tilting and displacement of the scapulocoracoid in the parasagittal plane and influencing the sizes of muscle origins and the vectors of their actions. These differences relate to the amount of humeral adduction applied during its protraction, and to the structural stability of the shoulder girdle during acrobatic maneuvers, thus influencing the perch diameter that can be effectively negotiated, a critical factor in the microhabitat structure of Anolis ecomorphs.

Beyond Pairwise Interactions: Multispecies Character Displacement in Mexican Freshwater Fish Communities.

Competition has long been recognized as a central force in shaping evolution, particularly through character displacement. Yet research on character displacement is biased, as it has focused almost exclusively on pairs of interacting species while ignoring multispecies interactions. Communities are seldom so simple that only pairs of species interact, and it is not clear whether inferences from pairwise interactions are sufficient to explain patterns of phenotypes in nature. Here, we test for character displacement in a natural system of freshwater fishes in western Mexico that contains up to four congeneric species of the genus Poeciliopsis. We analyzed body shape differences between populations with different numbers of competitors while accounting for confounding environmental variables. Surprisingly, we found evidence for convergent character displacement in populations of P. prolifica, P. viriosa, and P. latidens. We also found that the convergence in body shape was not consistently in the same direction, meaning that when three or more competitors co-occurred, we did not find more extreme body shapes compared with when there were only two competitors. Instead, when three or more competitors co-occurred, body shape was intermediate between the shape found with a pair of species and the shape found with no competitor present. This intermediate shape suggests that evolution in multispecies communities likely occurs in response to several competitors rather than to simple pairwise interactions. Overall, our results suggest that competition among multiple species is more complex than simple pairwise competitive interactions.

Historical shell form variation in Lottia subrugosa from southeast Brazilian coast: Possible responses to anthropogenic pressures.

Mollusk shells can provide important information regarding environmental parameters. It is known that shell morphology is affected by both natural and anthropogenic factors. However, few studies have investigated alterations in shell morphology over a historical perspective and considering chemical contamination and climate changes. The present study assessed shell form (shape and size) variations of limpet (Lottia subrugosa) shells sampled from 1950 to 1981 (past) in comparison with organisms obtained in 2018 (present). Differences between shells from the past and present (2018) were detected, being shell weight and height the two most important affected parameters. The differences observed were attributed to the possible increase in contamination over the years due to human population growth and to climate change. Additionally, when shells from the past were evaluated according to the decade they were sampled, results indicate that it was necessary an interval of 40 years to shell form be altered within populations.

Anatomy and shell shape variability in a land snail Bostryx torallyi (Stylommatophora: Bulimulidae) / Anatomía y variabilidad de la forma de la concha en el caracol terrestre Bostryx torallyi (Stylommatophora: Bulimulidae)

Introduction: The gastropod Bostryx torallyi shows high variability in shell shape and coloration. Subspecies of this organism have been described based on shell characters but, since they were slightly different, they were synonymized afterwards. Until now, shell variability has been analyzed only descriptively and its anatomy is still unknown. Objective: In this study, I provide anatomical information of B. torallyi and apply a geometric morphometric analysis to evaluate the shell shape variation among specimens. Methods: To accomplish this, type material and numerous lots were examined and dissected out. Additionally, relative warp analysis, based on 9 landmarks in ventral view of the shell, was performed using 80 specimens of 9 localities from Bolivia and Argentina. Results: According to our results, geometric morphometrics is a suitable method to evaluate differences in shell shape among localities; for instance, distinctions in the shell were noticeable between gastropods of low and high altitudes. On the other hand, it was established that the coloration of this species is independent of large-scale factors since the examined specimens came from environments with similar conditions. Furthermore, the sculpture of the protoconch and anatomy of B. torallyi coincided with the other Argentinian species of the genus. Conclusions: Therefore, I concluded that a geometric morphometric analysis of shell shape is a good complement to traditional qualitative description of the characteristics of the shell in this species.

Introducción: El gasterópodo Bostryx torallyi exhibe una gran variabilidad en la forma y coloración de su concha. Subespecies de este organismo han sido descritas con base en los caracteres de la concha; pero, dadas las sutiles diferencias, fueron luego sinonimizadas. Hasta el momento, la variabilidad de la concha ha sido analizada solo descriptivamente y su anatomía es aún desconocida. Objetivo: En este estudio, los objetivos fueron:proveer información anatómica de B. torallyi y usar un análisis de morfometría geométrica para evaluar la variación de la forma de la concha entre especímenes. Métodos: Para ello, se examinó y disectó material tipo y numerosos lotes. Adicionalmente, se realizaron análisis del "relative warp", basados en nueve "landmarks" en vista ventral de la concha, empleando 80 especímenes de nueve localidades de Bolivia y Argentina. Resultados: De acuerdo con los resultados, la morfometría geométrica resultó útil para demostrar diferencias en forma de la concha entre localidades; por ejemplo, se detectarondiferencias evidentes entre localidades de alta y baja altitud. Se determinó que la variación en la coloración de esta especie es independiente de factores a gran escala, dado que los especímenes examinados proceden de ambientes con condiciones similares. Por otro lado, la escultura de la protoconcha y la anatomía de B. torallyi resultaron coincidentes con la de otras especies de este género recolectadas en Argentina. Conclusiones: Se concluyó que el análisis de morfometría geométrica de la forma de la concha fue un buen complemento a la descripción cualitativa tradicional de caracteres de concha.

Variación fenotípica del erizo Eucidaris tribuloides (Cidaroida: Cidaridae) en el Corredor Arrecifal del Suroeste del Golfo de México

Introducción: La variación morfológica intraespecífica puede ser el resultado del desarrollo ontogénico, la variación genética o la heterogeneidad ambiental. En el último caso, los organismos están expuestos a diversas condiciones ambientales, lo que puede influir en el comportamiento y las adaptaciones morfológicas de las especies. Precisamente, el Corredor Arrecifal del Suroeste del Golfo de México (CASGM) está compuesto por arrecifes separados geográficamente que están expuestos a diferentes factores oceanográficos, así como atributos propios con múltiples variables ambientales. Por lo tanto, es posible encontrar diferencias morfológicas de las poblaciones de especies que se distribuyen en el corredor. Objetivo: Determinar la variación morfológica de la linterna de Aristóteles del erizo de mar Eucidaris tribuloides a lo largo del CASGM. Métodos: Se analizó la relación alométrica entre la altura de la linterna versus diámetro de la testa en 104 especímenes, también realizamos un análisis de covarianza para detectar diferencias alométricas entre grupos. Se analizó la variación de la forma de una rótula y una semipirámide de cada erizo de mar mediante morfometría geométrica. Resultados: Existen diferencias alométricas entre sistemas arrecifales. La forma de la rótula y semipirámide de los erizos de mar del norte son diferentes a los erizos del centro y el sur; sin embargo, no hubo diferencias de forma entre el centro y el sur. El tamaño centroide de la rótula y semipirámide de los erizos de mar del norte son significativamente más grandes que los del centro y el sur. Conclusiones: A lo largo del Corredor Arrecifal del Suroeste del Golfo de México, los individuos de E. tribuloides mostraron variación morfológica en sus estructuras analizadas, dichos resultados, pueden ser explicados por los gradientes latitudinales y ambientales del CASGM, además de los hábitos alimenticios de la especie y la disponibilidad del recurso alimenticio en el ambiente donde se establecen.

Introduction: Intraspecific morphological variation can be attributed to the result of genetic variation or influence of environmental heterogeneity. In the latter case, organisms are exposed to diverse environmental conditions which have an influence on their biological processes and can be seen reflected in the morphological adaptations of species. Indeed, Reef Corridor in the Southwest Gulf of Mexico (CASGM, in its Spanish acronym) is constituted of geographically separated reefs that are exposed to different large-scale oceanographic factors and show their own attributes with multiple environmental variables. Therefore, this can stimulate morphological variations of species populations that are distributed in this corridor. Objective: The aim of this study was to determine the morphological variation of the Aristotle's lantern of the sea urchin Eucidaris tribuloides along CASGM. Methods: The allometric relation between height of the Aristotle's lantern and diameter of the test of 104 specimens was analyzed, and we also used a covariance analysis to detect allometric differences between groups. Apart from that, the variation of the shape of a rotule and a demi-pyramid for each sea urchin were analyzed using geometric morphometry. Results: There are allometric differences among reef systems in the north, center and south of Veracruz. The shape of rotula and demi-pyramid of sea urchins of the north zone are different from the central and south area. However, there were no differences in shape between the center and the South area. The centroid size of rotula and demi-pyramid of the sea urchins of the North are larger than those in the center and the South. Conclusions: Along the Corridor of the Southwest of the Gulf of Mexico, specimens of E. tribuloides showed a morphological variation in their analyzed structures, these results can be explained by the geographical and environmental gradients of the CASGM, in addition to the feeding habits of E. tribuloides and the availability of the food resource in the habitat where they are established. As a stimulus to the morphological variation found in this research, the distance among the reef systems and the marine currents patterns are also considered.

Skull asymmetries in wild boar (Sus scrofa LINNAEUS, 1758) / Assimetrias do crânio de javalis (Sus scrofa LINNAEUS, 1758)

Organisms can develop different kinds of asymmetry when deviations from expected perfect symmetry occur. Among others are fluctuating asymmetry (FA) and directional asymmetry (DA). FA represents small random differences between corresponding parts on the left and right sides of an individual in bilaterally paired structures. It is thought that FA reflects an organism's ability to cope with genetic and environmental stress during growth. DA occurs whenever one side on the plane of symmetry develops more than the other side, and has a genetic component. In this research, we examined the expression of morphological symmetry in 38 skulls of different age groups of wild boar (Sus scrofa), on their ventral aspect, using two-dimensional coordinates of 27 landmarks. Analyses showed the presence of significant FA and DA in the entire sample, detecting also distinctive differences between age groups. The obtained results show that the shape differences in different age groups could reasonably be a consequence of a response to environmental factors for FA and a masticatory lateralization for DA.(AU)

Os organismos podem desenvolver diferentes tipos de assimetria quando ocorrem desvios da pefeita simetria esperada. Entre os diversos tipos de assimetria existentes duas merecem especial destaque: a flutuante (AF) e a directional (AD). A AF é representada por pequenas diferenças casuais entre as partes correspondents das laterais direita e esquerda de um indivíduo em estruturas pareadas bilateralmente; acredita-se que elas reflitam a habilidade de um organismo adaptar-se a fatores estressantes genéticos e ambientais observados durante o seu crescimentos. A AD ocorre quando um lado da assimetria plana desenvolve-se mais do que o outro e há um componente genético. No presente trabalho foi analisada a expresssão da simetria morfológica de 38 crânios de diferentes grupos etários de javalis (Sus scrofa), nos seus aspectos ventrais, com o emprego de duas coordenadas dimensionais de 27 pontos anatômicos homólogos. As análises efetuadas revelaram a existência de valores significantes de AF e AD em toda a amostra trabalhada, detectando inclusive diferenças entre os grupos etários. Os resultados obtidos demonstraram que as diferentes formas observadas nos diferentes grupos etários podem ser consequência de uma resposta a fatores ambientais para a AF e a lateralização da mastigação para a AD.(AU)

Skull asymmetries in wild boar (Sus scrofa LINNAEUS, 1758) / Assimetrias do crânio de javalis (Sus scrofa LINNAEUS, 1758)

Organisms can develop different kinds of asymmetry when deviations from expected perfect symmetry occur. Among others are fluctuating asymmetry (FA) and directional asymmetry (DA). FA represents small random differences between corresponding parts on the left and right sides of an individual in bilaterally paired structures. It is thought that FA reflects an organisms ability to cope with genetic and environmental stress during growth. DA occurs whenever one side on the plane of symmetry develops more than the other side, and has a genetic component. In this research, we examined the expression of morphological symmetry in 38 skulls of different age groups of wild boar (Sus scrofa), on their ventral aspect, using two-dimensional coordinates of 27 landmarks. Analyses showed the presence of significant FA and DA in the entire sample, detecting also distinctive differences between age groups. The obtained results show that the shape differences in different age groups could reasonably be a consequence of a response to environmental factors for FA and a masticatory lateralization for DA.

Os organismos podem desenvolver diferentes tipos de assimetria quando ocorrem desvios da pefeita simetria esperada. Entre os diversos tipos de assimetria existentes duas merecem especial destaque: a flutuante (AF) e a directional (AD). A AF é representada por pequenas diferenças casuais entre as partes correspondents das laterais direita e esquerda de um indivíduo em estruturas pareadas bilateralmente; acredita-se que elas reflitam a habilidade de um organismo adaptar-se a fatores estressantes genéticos e ambientais observados durante o seu crescimentos. A AD ocorre quando um lado da assimetria plana desenvolve-se mais do que o outro e há um componente genético. No presente trabalho foi analisada a expresssão da simetria morfológica de 38 crânios de diferentes grupos etários de javalis (Sus scrofa), nos seus aspectos ventrais, com o emprego de duas coordenadas dimensionais de 27 pontos anatômicos homólogos. As análises efetuadas revelaram a existência de valores significantes de AF e AD em toda a amostra trabalhada, detectando inclusive diferenças entre os grupos etários. Os resultados obtidos demonstraram que as diferentes formas observadas nos diferentes grupos etários podem ser consequência de uma resposta a fatores ambientais para a AF e a lateralização da mastigação para a AD.

Skull asymmetries in wild boar (Sus scrofa LINNAEUS, 1758) / Assimetrias do crânio de javalis (Sus scrofa LINNAEUS, 1758)

Organisms can develop different kinds of asymmetry when deviations from expected perfect symmetry occur. Among others are fluctuating asymmetry (FA) and directional asymmetry (DA). FA represents small random differences between corresponding parts on the left and right sides of an individual in bilaterally paired structures. It is thought that FA reflects an organism's ability to cope with genetic and environmental stress during growth. DA occurs whenever one side on the plane of symmetry develops more than the other side, and has a genetic component. In this research, we examined the expression of morphological symmetry in 38 skulls of different age groups of wild boar (Sus scrofa), on their ventral aspect, using two-dimensional coordinates of 27 landmarks. Analyses showed the presence of significant FA and DA in the entire sample, detecting also distinctive differences between age groups. The obtained results show that the shape differences in different age groups could reasonably be a consequence of a response to environmental factors for FA and a masticatory lateralization for DA.(AU)

Os organismos podem desenvolver diferentes tipos de assimetria quando ocorrem desvios da pefeita simetria esperada. Entre os diversos tipos de assimetria existentes duas merecem especial destaque: a flutuante (AF) e a directional (AD). A AF é representada por pequenas diferenças casuais entre as partes correspondents das laterais direita e esquerda de um indivíduo em estruturas pareadas bilateralmente; acredita-se que elas reflitam a habilidade de um organismo adaptar-se a fatores estressantes genéticos e ambientais observados durante o seu crescimentos. A AD ocorre quando um lado da assimetria plana desenvolve-se mais do que o outro e há um componente genético. No presente trabalho foi analisada a expresssão da simetria morfológica de 38 crânios de diferentes grupos etários de javalis (Sus scrofa), nos seus aspectos ventrais, com o emprego de duas coordenadas dimensionais de 27 pontos anatômicos homólogos. As análises efetuadas revelaram a existência de valores significantes de AF e AD em toda a amostra trabalhada, detectando inclusive diferenças entre os grupos etários. Os resultados obtidos demonstraram que as diferentes formas observadas nos diferentes grupos etários podem ser consequência de uma resposta a fatores ambientais para a AF e a lateralização da mastigação para a AD.(AU)

Relationship between the cranial base and the mandible in artificially deformed skulls.

OBJECTIVES: There is controversy regarding the relationship between mandibular position and alterations of the cranial base that provoke a more anterior location of the glenoid fossa. Artificially deformed skulls display marked alterations of the cranial base. This study evaluates mandibular changes as function of the morphology of the cranial base in these skulls. MATERIAL AND METHODS: A geometric morphometric study was performed on lateral cephalometric X-rays of three groups of skulls: 32 with anteroposterior deformity, 17 with circumferential deformity and 39 with no apparent deformity. RESULTS: In artificially deformed skulls, the cranial base was deformed causing the mandibular condyle to be in a more anterior position. There was a complete remodelling of the mandible involving narrowing and elongation of the mandibular ramus, rotation of the corpus of the mandible and increased vertical height of the symphysis. Forward displacement did not occur. Integration between mandible and cranial base is not altered by deformation of the skull. CONCLUSIONS: Deformity of the cranial vault exerts an influence on the mandible, supporting the theory of modular units in complete integration. This also supports the theory that mandibular prognathism is a multifactorial result and not a direct effect of displacement of the cranial base.

Morfoecología de gremios en escarabajos (Coleoptera: Passalidae) en un gradiente altitudinal en robledales de la Cordillera Oriental, Colombia / Morphoecology guild in beetles (Coleoptera: Passalidae) along an altitudinal gradient in oak forests of the Eastern Cordillera, Colombia

ResumenLos escarabajos pasálidos son componentes importantes de los bosques tropicales debido a que facilitan el reciclaje de nutrientes propios de madera en descomposición, ya sea por acción directa (consumo) o indirecta (facilitando la acción de otros organismos). En la actualidad los estudios ecológicos dentro del grupo son escasos y se han centrado en respuestas a cambios ambientales relacionados con su recurso alimenticio. En el presente estudio se caracterizó la composición gremial de escarabajos pasálidos, distribuida en un gradiente altitudinal, de acuerdo a sus características de aprovechamiento del recurso. Se cuantificaron aspectos morfoecológicos de importancia adaptativa para la explotación diferencial del recurso (medidas corporales, puntos homólogos en cuerpo y alas y series de Fourier en protibias). Se reconocieron cinco especies, 198 grupos familiares y tres gremios: el subcortícola, el alboduramícola y el generalista. La riqueza de la comunidad disminuyó conforme aumentó la altitud. Los cambios entre las variables morfométricas lineales se vieron influenciadas por la altitud; por su parte, los datos morfogeométricos se comportaron independientes del gradiente. El análisis de marcadores morfológicos (morfogeométrico) arrojó información relevante para la delimitación de los gremios ya establecidos en esta familia. Dentro de estos, la forma general del cuerpo junto a las tibias anteriores, aportaron la mayor información de agrupación gremial. La cuantificación de dichos marcadores evidenció la relación entre los tipos de aprovechamiento del recurso, ya que al ser estructuras importantes en el movimiento y consumo de la madera en microzonas particulares, permite plantear roles funcionales puntuales. Reconocer estas variables en interacción con aquellas ecológicas brinda herramientas para el entendimiento de la riqueza y los aportes funcionales de los escarabajos pasálidos al ecosistema.

AbstractBess beetles are important components on tropical forest dead wood nutrient cycling, since they act as direct consumers and ease the consumption by another organism (indirect). Studies of bess beetle ecology are scarce and have focused on communities responses to environmental changes on alimentary resources. We characterized the bess beetles guild composition in an elevation gradient, according to their differential use of resources (microhabitat) and morphological traits quantification (geometric and lineal), as a potential tool to improve our understanding on resource use and functional ecology of beetles. Three guilds (underbark, sapwood-heartwood and generalists feeders), five species and 198 familiar groups were recognized; their richness decreased as elevation increased. Changes in linear morphometric measures were influenced by elevation; morphogeometrical measures were not associated with the elevation gradient, only grouping at guild level were observed. Morphological markers analysis (morphometric) provided information to guild delimitation. Body and metatibiae shape contributed with the best information to guild grouping. Quantification of those structural markers proved the relationship between resource repartition, because they are involved in movement on wood galleries and wood consumption, this fact allowed to propose specific functional roles. The identified patterns have contributed on the understanding of functional processes in Passalidae communities and their role in ecosystem function.

Phenotypic Plasticity In Response To Seasonal Variation In Populations of Culex (Melanoconion) Bastagarius.

The present study aimed to determine the effects of seasonal variation on phenotypic variation in Culex bastagarius, using geometric morphometric analysis based on wing shape and size. Samples were collected in the Guapiaçu Ecological Reserve, in Rio de Janeiro, Brazil. Mosquitoes were captured once every 2 months (December 2012-January 2014) using light traps. The results of geometric morphometric analysis revealed variations in wing size; however, variability was not evident in wing shape. The present study provides novel data regarding phenotypic plasticity of Cx. bastagarius that have been scarcely addressed in the past.

Morfometría geométrica del corazón de hyla plicata a través de un gradiente altitudinal en el eje neovolcánico mexicano / Geometric morphometric of the heart in hyla plicata through an altitudinal gradient in the mexican neovolcanic axe

Se ha descrito que el medio aéreo representa menos problemas a los organismos en relación con la hipoxia a excepción de circunstancias especiales, como la exposición a grandes alturas o las madrigueras. El ambiente de gran altitud es desafiante en diversos sentidos, dado que existen factores bióticos y abióticos que pueden interactuar para determinar la distribución y sobrevivencia de los organismos. Para conocer estos aspectos, la biología se apoya en la ecomorfología, área que ayuda a definir las diferencias morfológicas con respecto al cambio del hábitat y en la morfometría geométrica que permite analizar estadísticamente esos cambios. En el presente estudio, se evaluaron diferentes poblaciones de la rana Hyla plicata que es una de las especies que se distribuyen a mayor altitud en México, (1500 m hasta los 3700 m). Por lo que el objetivo de este estudio, fue analizar la morfología del corazón en Hyla plicata a través de un gradiente altitudinal. Para ello se colectaron organismos en cuatro localidades, una de ellas fue en La Cima (Distrito Federal a 3016 m), y tres ubicadas en el Estado de México: Buenavista (3200 m), El Cerrillo ( 2632 m) y San Juan Atezcapan (1860 m). Los organismos colectados se disectaron para extraer el corazón con la finalidad de digitalizarlos mediante fotografías, y analizarlos con puntos geométricos y de esta forma evaluar la forma del órgano. Los resultados indican que las localidades de mayor altitud presentan aurículas y ventrículos más ensanchados, lo que señala que esta estructura evolucionó y se adaptó para efectuar un bombeo más eficaz de la sangre y posteriormente dirigirla hacia los diferentes tejidos del cuerpo. Esta adaptación en la morfología del corazón, permitió que Hyla plicata se adaptara a los ambientes de alta montaña como se ha visto en otros vertebrados que habitan zonas de mayor altitud.

It has been reported that the air environment is less problematic for organisms in relation to hypoxia except for special circumstances, such as exposure to high altitudes or burrows. The high altitude environment is challenging in different ways, since there are biotic and abiotic factors may interact to determine the distribution and survival of organisms. For these aspects, biology is based on the ecomorphology, area that helps to define the morphological differences with respect to habitat change and geometric morphometrics to analyze statistically those changes. In the present study, we evaluated different populations of the frog Hyla plicata is a species that are distributed at higher elevations in Mexico (1500 m to 3700 m). For the purpose of this study was to analyze the morphology in Hyla plicata heart through an altitudinal gradient. The organisms were collected at four sites, one was located in La Cima (Distrito Federal to 3016 m), and three in the Estado of Mexico: Buenavista (3200 m), El Cerrillo (2632 m) and San Juan Atezcapan (1860 m). The organisms collected were dissected to extract the heart for the purpose of scan them through photographs, and analyzed with geometric points and thus evaluate the shape of the organ. The results indicate that higher altitude locations have enlarged atria and ventricles, indicating that this structure evolved and adapted to effect a more efficient pumping of blood and then direct it to different body tissues. This adaptation in the morphology of the heart, allowed to adapt to Hyla plicata in high altitude environments as seen in other vertebrates that inhabit higher elevations.

Morphometric pattern in Caretta caretta (Linnaeus, 1758)(Cheloniidae) hatchlings from nests with different embryo development rates / Variações morfológicas de filhotes recém-eclodidos de Caretta caretta (Linnaeus, 1758) (Cheloniidae) oriundos de ninhos com diferentes taxas de desenvolvimento embrionário

The geometric morphometric analysis of the shell of Caretta caretta hatchlings revealed that morphological variations may be related to incubation duration. Based on the overlapping of anatomical landmarks of the carapace and the plastron, it was possible to discriminate hatchlings from slow and fast developing clutches. Carapace and plastron of hatchlings from nests where incubation lasted less than 55 days are rounder as compared to the hatchlings from nests where incubation took 67 days. The differences observed in shell shape in terms of incubation duration were statistically significant, though carapace and plastron shape overlapping was observed in several individuals. Our results indicate that the incubation duration explains only a small part of the total variation in the shell shape as a whole. Yet, in spite of the low discriminant function coefficient, cross-validation tests indicated that 84.7 percent and 77.8 percent of the hatchlings were correctly categorised concerning the carapace and plastron, when the descriptive variable is incubation duration.

A análise da morfometria geométrica do casco de filhotes recém-eclodidos de Caretta caretta revelou que existem variações morfológicas que podem ser relacionadas à duração da incubação. Com base na sobreposição de marcos anatômicos da carapaça e do plastrão, foi possível discriminar filhotes oriundos de ninhos com taxa de desenvolvimento embrionário rápido daqueles filhotes provenientes de ninhos em que o desenvolvimento embrionário foi mais lento. A carapaça e o plastrão de filhotes oriundos de ninhos com duração de incubação inferior a 55 dias são mais arredondados que os dos filhotes provenientes de ninhos com mais de 67 dias de incubação. A variação da forma casco em função da duração da incubação foi estatisticamente significativa, mas ocorreu uma sobreposição na forma da carapaça e do plastrão de numerosos indivíduos. Os nossos resultados indicam que o comprimento da incubação foi capaz de explicar apenas uma pequena parte da variação total do conjunto da forma do casco. Mas, apesar do baixo coeficiente de determinação da função discriminante, testes de validação cruzada indicam que 84,7 por cento dos filhotes foram classificados corretamente em relação à carapaça e 77,8 por cento em relação ao plastrão, considerando a duração da incubação como o descritor.