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19 resultados encontrados para: TEMA: Dimorfismo sexual en animales
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1.
Artículo
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Life history, activity pattern, and morphology of Crotalus tzabcan klauber, 1952 (Serpentes: Viperidae)
Carbajal Márquez, Rubén Alonso (autor) ; Cedeño-Vázquez, J.R. (autor) ; Martins, Marcio (autor) ; Köhler, Gunther (autor) ;
Disponible en línea
Contenido en: Herpetological Conservation and Biology Volumen 15, número 1 (April 2020), p. 228–237 ISSN: 1931-7603
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Resumen en: Inglés |
Resumen en inglés

The Tzabcan Rattlesnake (Crotalus tzabcan) is a highly secretive species that is difficult to observe and follow in the field and any information that can be generated is essential to gain a better understanding of its biology and ecology. Crotalus tzabcan is a large and heavy-bodied species, with a maximum snout-vent length of 1,667 mm and a total length of 1,818 mm. It is endemic to the Yucatán Peninsula, and very little is known about its natural history. We provide data on life history, activity, and morphology based on specimens that we obtained in recent field surveys, museums, and anecdotal observations. Crotalus tzabcan does not present sexual dimorphism in snout-vent length or total length, but males have heads and tails that are significantly longer than females. We observed an ontogenetic color change, where newborns and juveniles had a darker base color and blotches than adults. Crotalus tzabcan showed a unimodal activity pattern with peak activity in the summer. We observed crepuscular and nocturnal activity during the warmer months and diurnal activity during the cooler months. The timing of C. tzabcan reproductive events, based on behavioral evidence and activity, is similar to other pitvipers and rattlesnakes from temperate and tropical zones. We encourage additional research on behavior, physiology, histology, and on how environmental conditions influence life-history traits, to determine the reproductive cycle in both sexes more accurately, which could subsidize conservation strategies.


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Resumen en: Inglés |
Resumen en inglés

The male of Craugastor yucatanensis (Lynch, 1965) is described for the first time, as the original description was based on four females. The advertisement call is described and additional morphological data on females are presented. Also, information is provided on the sexual dimorphism and natural history of the species.


3.
- Artículo con arbitraje
*En hemeroteca, SIBE-San Cristóbal
Influencia de la asimetría natural en las rectrices y la longitud de la cola en la supervivencia aparente anual de la Fragata Magnífica (Fregata magnificens) adultas
González Jaramillo, Mónica (autora) ; Rangel Salazar, José Luis (autor) (1962-) ; De la Cueva, Horacio (autor) ;
Disponible en línea
Contenido en: Revista Mexicana de Biodiversidad Vol. 90, e902626 (marzo 2019), p. 1-9 ISSN: 1870-3453
Bibliotecas: San Cristóbal
Cerrar
SIBE San Cristóbal
59361-10 (Disponible)
Disponibles para prestamo: 1
Nota: En hemeroteca, SIBE-San Cristóbal
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Resumen en: Español | Inglés |
Resumen en español

Los caracteres de vuelo mediados por asimetría deben restringirse por efectos aerodinámicos. La asimetría natural y longitud de la cola pueden tener efectos desfavorables en el desempeño aerodinámico afectando negativamente la supervivencia de aves extremadamente aéreas. La Fragata Magnífica (Fregata magnificens) es un ave marina longeva, extremadamente aérea, con cola profundamente bifurcada y una extraordinaria división de labores entre sexos. Sus tipos de vuelo son: remonte o remonte dinámico, y vuelo rápido activo con maniobras acrobáticas. Exploramos el posible efecto de la asimetría natural y la longitud de la cola en la supervivencia aparente anual de la Fragata Magnífica, analizando 6 años (2000-2006) de datos de captura-marcaje-reavistamiento. Las fragatas mostraron diferencias significativas entre la longitud de las rectrices exteriores derecha e izquierda y diferencias de la asimetría de la cola entre sexos. Los modelos no detectaron un efecto claro de estas covariables individuales en la supervivencia aparente anual por sexo. Las estrategias de historia de vida como el tipo de vuelo, comportamiento reproductivo y muda de la cola, podrían restringir un efecto negativo en la supervivencia aparente. Estudios más largos de captura-reavistamiento y modelos adicionales podrían responder conclusivamente la asociación entre supervivencia y caracteres de vuelo en las Fragatas Magníficas.

Resumen en inglés

Flight traits mediated by symmetry should be constrained by mechanical or aerodynamic effects. Natural asymmetry and external tail feather length could have unfavorable effects on aerodynamic performance and affect the survival of highly aerial birds. The Magnificent Frigatebird, Fregata magnificens, is a long-lived, highly aerial seabird with a deeply forked tail, and an extraordinary division of labor between sexes. Its flight pattern is soaring and dynamic, it also has fast active flight and acrobatic maneuvers. We explore the possible effect of tail streamer asymmetry and tail length on annual apparent survival of Magnificent Frigatebirds by using 6 years (2000-2005) of capture-mark-resighting of live-encounter data analysis. Male frigatebirds showed significant differences between left and right tail streamer length, and tail asymmetry differences between sexes. Models did not find a clear effect of tail streamer asymmetry and tail length, as individual covariates, on annual apparent survival by sex. Natural variation in a secondary sexual trait like those explored here likely does not affect apparent survival. Life-history strategies such as flight pattern, breeding behavior, and tail moult may constrain any negative effects. Longer mark-resighting studies and additional modelling could answer conclusively the association between survival and flight traits in Magnificent Frigatebirds.


4.
Artículo
Revision of Sinonereis Wu & Sun, 1979 (Annelida: Nereididae)
Conde Vela, Víctor Manuel (autor) ; Wu, Xuwen (autor) ;
Contenido en: Zoosystema Vol. 41, no. 1 (October 2019), p. 153-161 ISSN: 1638-9387
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Resumen en: Inglés | Frances |
Resumen en inglés

The genus Sinonereis Wu & Sun, 1979 and the species Sinonereis heteropoda Wu & Sun, 1979 were described from Chinese waters, based on only epitokous specimens with modified dorsal cirri in chaetigers 5-7 and bare pharynx. In the same publication, another species based on only atokes was described, Nicon sinica Wu & Sun, 1979. We show that N. sinica is a junior synonym of S. heteropoda based on their affinities in chaetal and parapodial features. We redefine Sinonereis and formally synonymize N. sinica and S. heteropoda. Sinonereis closely resembles Nicon Kinberg, 1865 and Kainonereis Chamberlin, 1919, but Sinonereis differs from them by having napiform dorsal cirri in chaetigers 5-7, and by lacking notopodial dorsal ligules in chaetiger 3 in both atokes and epitokes.

Resumen en frances

Le genre Sinonereis Wu & Sun, 1979 et l’espèce Sinonereis heteropoda Wu & Sun, 1979 ont été décrits des eaux chinoises, seulement à partir de spécimens épitoques avec des cirres dorsaux modifiés sur les sétigères 5-7 et avec un pharynx nu. Dans la même publication, une autre espèce a été décrite à partir d’atoques uniquement, Nicon sinica Wu & Sun, 1979. Nous montrons ici que N. sinica est un synonyme junior de S. heteropoda basé sur leurs affinités pour les caractères des soies et des parapodes. Nous redefinissons Sinonereis et nous confirmons la synonyie entre N. sinica et S. heteropoda. Sinonereis ressemble fortement à Nicon Kinberg, 1865 et Kainonereis Chamberlin, 1919, mais Sinonereis s’en distingue par ses cirres dorsaux napiformes sur les sétigères 5-7, et par l’absence de languettes dorsales sur le sétigère 3, aussi bien chez les atoques que chez les épitoques.


5.
- Artículo con arbitraje
Características biológicas del dzibabán (Melanoptila glabrirostris) en la Reserva de la Biosfera de Sian Ka’an, México
Roldán Clarà, Blanca (autora) ; LaPergola, Joshua B. (autor) ; Correa Sandoval, Jorge (autor) ;
Disponible en línea
Contenido en: Huitzil, Revista Mexicana de Ornitología Vol. 19, no. 1 (enero-junio 2018), p. 100-108 ISSN: 1870-7459
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Resumen en: Español | Inglés |
Resumen en español

En el presente estudio reportamos características morfométricas y reproductivas del dzibabán, Melanoptila glabrirostris, algunas de ellas descritas por primera vez. El dzibabán es un mímido tropical endémico de la península de Yucatán muy poco estudiado. El estudio lo realizamos en la costa norte de la Reserva de la Biosfera de Sian Ka’an, México, entre febrero y agosto de 2008. Presentamos medidas de culmen, tarso y masa corporal. Proponemos un método de sexado válido durante la temporada no reproductiva, ya que los machos presentaron longitud de cuerda alar mayor que las hembras. La coloración del ojo puede ser un criterio suplementario para determinar la edad, puesto que los individuos de segundo año presentaron frecuentemente coloración ocular marrón, similar a los individuos de primer año. La temporada reproductiva inicia en abril y termina a mediados de agosto. El ciclo del nido es de 27 y 32 días y el tamaño de nidada es de dos a tres huevos. El macho construye la mayor parte del nido y la hembra incuba los huevos. La mayoría de los nidos se construyó en la palma Thrinax radiata y el arbusto Pithecellobium keyense. En conclusión, el dzibabán comparte características similares con Dumetella carolinensis y las principales diferencias son debidas a su distribución tropical.

Resumen en inglés

In the present study, we report morphometric and reproductive characteristics of the Black Catbird, Melanoptila glabrirostris, some of them shown here for the first time. The Black Catbird is a tropical mimid endemic to the Yucatán Peninsula that is not well studied. Fieldwork was conducted in the North coast of the Sian Ka’an Biosphere Reserve, México, from February to August 2008. We present measurements of bill, tarsus, and body mass. We propose a method for sexing outside the breeding season because males had longer wing chords than females. We demonstrate that eye color can be an extra criterion for age determination because second-year birds more frequently had brown eyes, similar to the eye color of hatch-year birds. Breeding season lasted from April until at least the middle of August. The nest cycle was 27 to 32 days long, and clutch size was from two to three eggs. Mostly males built nests and females incubated the eggs. Most of the nests were built on Thrinax radiata palm and Pithecellobium keyense bush. In conclusion, the Black Catbird shares characteristics with Gray Catbird, and the main differences are due to its tropical distribution.


6.
- Artículo con arbitraje
Reevaluation and new species of Kainonereis Chamberlin, 1919 (Annelida: Polychaeta: Nereididae)
Conde Vela, Víctor Manuel ; Wu, Xuwen (coaut.) ; Salazar Vallejo, Sergio I. (coaut.) ;
Contenido en: Zoological Studies Vol. 57, no. 5 (February 2018), p. 1-24 ISSN: 1810-522X
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Resumen en: Inglés |
Resumen en inglés

Kainonereis Chamberlin, 1919 was proposed to include only one species, K. alata, based on epitokes provided with elytriform structures in chaetigers 5-7. The species was thoroughly described and illustrated, but its unique features were enigmatic and the genus is currently regarded as taxon inquirendum. In order to have a better understanding of its diagnostic features and determine how this genus differs from similar ones, type material of K. alata and two other species bearing elytriform structures-Nicon polaris Hartman, 1967 and Rullierinereis elytrocirra Sun and Wu, 1979, including additional material from Gulf of California and Caribbean Sea-were examined. Because the K. alata type material is in good condition and the presence of elytriform structures in chaetigers 5-7 is confirmed, this paper regards it as a valid genus. Given that the elytriform structures, or dorsal discs, together with a set of diagnostic features, are consistent in structure and position in all epitokes examined, they are regarded as homologous structures delineating Kainonereis. Consequently, K. alata is redescribed, the new combinations K. polaris comb. n. and K. elytrocirra comb. n. are proposed and redescribed, and two new species are described: K. chamberlini sp. n. from the Caribbean Sea, and K. peltifera sp. n. from the Gulf of California. Also, the discovery of an atoke on K. polaris comb. n. allowed us to better distinguish Kainonereis from the similar genera Nicon Kinberg, 1865 and Rullierinereis Pettibone, 1971. A key to identifying all known Kainonereis species is also included.


7.
- Artículo con arbitraje
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Morphological diversity of the American crocodile (Crocodylus acutus) in the Yucatán Peninsula
Labarre, Didier ; Charruau, Pierre Alexandre Rémy Robert (coaut.) ; Platt, S. G. (coaut.) ; Rainwater, T. R. (coaut.) ; Cedeño-Vázquez, J.R. (coaut.) ; González Cortés, H. (coaut.) ;
Contenido en: Zoomorphology (2017) 136:387–401 Vol. 136, no. 3 (September 2017), p. 387-401 ISSN: 1432-234X
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Resumen en: Inglés |
Resumen en inglés

Recent evidence suggests that morphological divergence of the American crocodile (Crocodylus acutus) occurred in Greater Antilles under conditions of prolonged isolation and hybridization with the Cuban crocodile (C. rhombifer). We investigated morphological diversity in C. acutus in the coastal zone of the Yucatán Peninsula, where isolation and hybridization have also been reported. We compared the relationships among various morphological traits between insular and coastal populations. Our results suggest morphological diversity in the region, which is possibly related to population isolation and mechanical constraints imposed by differences in diet. A broad-snouted morphotype appears typical of island populations. Hybridization could also cause morphological variation, but its importance in this case remains to be confirmed. Sexual dimorphism of the American crocodile in the region appears to be less pronounced than for other crocodilians. We also provide population-specific size estimation models for two populations (Banco Chinchorro and Cozumel) to improve future monitoring.


8.
- Artículo con arbitraje
Complex population patterns of Eunica tatila Herrich-Schäffer (Lepidoptera: Nymphalidae), with special emphasis on sexual dimorphism
Cavanzón Medrano, Laura Elena (autora) ; Pozo, Carmen (autora) ; Hénaut, Yann (autor) ; Legal, Luc (autor) ; Salas Suárez, Noemí (autora) ; Machkour M'Rabet, Salima (autora) ;
Disponible en línea
Contenido en: Neotropical Entomology Vol. 45, no. 2 (April 2016), p. 148-158 ISSN: 1678-8052
Resumen en español

The species Eunica tatila (Herrich-Schäffer) is present in the Neotropical region and comprises three subspecies. In Mexico, only one subspecies is reported: E. t. tatila (Herrich-Schäffer). The Yucatan Peninsula, in southeastern Mexico, is located in a transitional geographical position, between southern Florida, the West Indies and Central America. It is part of a transitional region, important for the dispersion of insects from southern Florida via Cuba and the Yucatan Peninsula. Considering the possibility of the overlapping and delimitation of described subspecies, we sampled different populations in the Yucatan Peninsula to possibly assign a subspecies name and evaluate the magnitude of sexual dimorphism. We collected 591 individuals (♀284, ♂307) in conserved areas. The study of male genitalia led to the identification of Eunica tatila tatilista (Kaye) as a subspecies; however, hypandrium structure and wing pattern analysis suggest a mix of E. t. tatila and E. t. tatilista characteristics. The analysis of sexual dimorphism provided evidence of more complex wing morphs for females, with 12 patterns instead of four as previously described. Our results demonstrate the complexity of characterizing E. tatila and suggest that the Yucatan Peninsula is a transitional zone for subspecies of some butterflies.


9.
Artículo
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Dimorfismo y proporción sexual de poblaciones naturales de adultos de Rhyssomatus nigerrimus
López Guillén, Guillermo (coaut.) ; Valdez Carrasco, Jorge (coaut.) ; Gómez Ruiz, Jaime (coaut.) ; Martínez Zarate, Carol Janett (coaut.) ; Cruz López, Leopoldo Caridad (coaut.) ;
Contenido en: Southwestern Entomologist Vol. 41, no. 3 (September 2016), p. 837-844 ISSN: 2162-2647
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Resumen en español

El picudo de la soya, Rhyssomatus nigerrimus Fahraeus, es una plaga que se alimenta en vainas y plantas de soya en el Noroeste y Sureste de México. Conocer los caracteres sexuales secundarios que permiten diferenciar entre machos y hembras de R. nigerrimus es importante porque tiene aplicación en trabajos de investigación encaminados a estudiar su bioecología, comportamiento y control. El objetivo de este trabajo fue determinar el dimorfismo y la proporción sexual de adultos de R. nigerrimus. Se encontró que la proporción sexual de machos y hembras fue de aproximadamente 1:1. Se concluyó que es posible separar adultos de R. nigerrimus a través de sus caracteres sexuales secundarios, especialmente el mucro de la tibia anterior.

Resumen en inglés

The weevil Rhyssomatus nigerrimus Fahraeus is a pest that feeds on pods and plants of soybeans in Northwester n and Southeast Mexico. It is important to determine sexually dimorphic characters of R. nigerrimus for rapid separation of sexes for bioecology, behavior, and control studies. The objective of this work was to determine the sexual dimorphism and ratio of R. nigerrimus adults. The sexual proportion between males and females was approximately 1:1. We concluded that it is possible to separate adults of R. nigerrimus by sex based on secondary sexual characters, especially the mucro on the protibia.


10.
- Artículo con arbitraje
Dimorphism and population size of the Mexican redrump tarantula, Brachypelma vagans (Araneae: Theraphosidae), in Southeast Mexico
Hénaut, Yann ; Machkour M'Rabet, Salima (coaut.) ; Rojo, Roberto (coaut.) ;
Contenido en: Revista Mexicana de Biodiversidad Vol. 86, no. 3 (Septiembre de 2015), p. 737–743 ISSN: 1870-3453
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Resumen en: Español | Inglés |
Resumen en español

El dimorfismo sexual es muy común en las arañas, pero también existen diferencias morfológicas entre poblaciones en función de las temporadas y la disponibilidad en los recursos. Pocos estudios han analizado el dimorfismo en tarántulas. La tarántula mexicana de cadera roja Brachypelma vagans, listada en el CITES, presenta una distribución amplia. Sin embargo, se conoce poco sobre sus poblaciones por áreas geográficas y sobre cómo el patrón de distribución de estos organismos, puede afectar las características morfológicas individuales. Tampoco se ha estudiado el dimorfismo sexual en el género Brachypelma. Nuestro estudio se enfoca en determinar si existen dimorfismos sexual y geográfico en poblaciones específicas de B. vagans. Se observó que la abundancia de tarántulas encontradas por población suele ser diferente de acuerdo con las áreas geográficas donde fueron observadas. Registramos datos morfológicos de tarántulas adultas en 6 sitios geográficos distribuidos en el sureste de México. Encontramos dimorfismo sexual únicamente en un sitio que presenta un número de arañas muy alto y donde las hembras son más pequeñas que en otras localidades. Nuestros resultados, considerando la variación en número de individuos por localidades a lo largo del sureste mexicano, tienen consecuencias para la conservación de esta especie.

Resumen en inglés

As a general rule, spiders exhibit sexual dimorphism and their populations may differ in size according to season duration and resource availability. However, few studies have focused on dimorphism in tarantulas. Mexican redrump tarantulas, Brachypelma vagans, listed in CITES, have an exceptionally wide distribution. Surprisingly, there are no studies on the possible relationship between the abundance of tarantulas perpopulation and the geographical areas where they are present, or on how the distribution pattern of this spider may affect individual morphological characteristics. Furthermore, there are no studies on sexual dimorphism within the genus Brachypelma. The aim of the study is to determine the existence of sexual and geographical dimorphism in populations of B. vagans. It was observed that the abundance of spiders per population may vary according to the geographical areas where they were recorded. In six localities in southern Mexico, we recorded morphological data on adult tarantulas. Sexual dimorphism was clearly observed at the site that presented numerous spiders characterized by much smaller females. Since the results of this study demonstrate differences in tarantula number of individuals per locality in southern Mexico, they make an important contribution to the conservation of this species.