Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

 The Mexican populations of the genus Dalbergia are severely diminished as a result of overexploitation and illegal traffic, as well as deforestation and fragmentation of their natural habitats. Here we present an updated list of the 20 species of the genus that are distributed in Mexico, 5 of which are endemic, along with an identification key. For each taxon we provide information on synonymy, life form, maximum height, distribution, altitude, vegetation types, common names, and conservation status. This checklist will contribute to the regulation and management of these species and constitute the foundation of Dalbergia conservation efforts in Mexico.

Evaluamos los cambios en la diversidad, estructura y composición de especies de escarabajos copronecrófagos (Coleoptera: Scarabaeidae: Scarabaeinae) en un paisaje bajo manejo forestal comunitario en el sur de México. Se dispusieron trampas de caída cebadas con excretas de cerdo y calamar en descomposición en sitios con diferente tratamiento forestal. En total, se registraron 3,608 individuos y 21 especies de Scarabaeinae. Registramos un mayor número de especies en el área sin intervención y cambios significativos en la composición de especies entre sitios. Dos escarabajos generalistas (Ontherus mexicanus y Onthophagus cyanellus) representaron 51% de la abundancia total. Nuestros resultados indican que el efecto relativo del manejo forestal sobre el ensamble de escarabajos es proporcional a la intensidad de corte. El impacto negativo sobre las comunidades de escarabajos puede contravenir al modelo deaprovechamiento silvícola, pues la pérdida gradual de especies a nivel local podría generar impactos significativos en la funcionalidad del ecosistema en el largo plazo. Es necesario establecer esquemas de monitoreo para la valoración del estatus de los elementos de la biodiversidad, con el fin de garantizar un manejo comunitario sustentable en áreas forestales en el Sur de México.

Some naidid oligochaetes establish commensal relationships with species of molluscs worldwide. In the present study, we report the finding of Chaetogaster limnaei in Illapel River, northern Chile. This worm was found inhabiting the mantle cavity of the freshwater gastropod Physa acuta, an invasive species in this country. The taxonomic status of C. limnaei was confirmed by molecular analysis based on mitochondrial 16S ribosomal RNA gene.

Se presenta una lista actualizada de los mamíferos nativos no voladores de Los Tuxtlas, región ambientalmente compleja y notable por su biodiversidad. Las selvas de Los Tuxtlas han perdido gran parte de su vegetación original y enfrentan presiones negativas que afectan a las especies y sus comunidades, modificando los patrones de diversidadalfa, beta y gamma. Para los programas de conservación y manejo ambiental, entre otros estudios, es básica la información taxonómica y de distribución actualizada, por lo que presentamos este listado basado en la revisión de ejemplares depositados en las colecciones científicas del Instituto de Biología, Universidad Nacional Autónoma de México y del Instituto de Investigaciones Biológicas, Universidad Veracruzana, y ampliado con la revisión documental en bases de datos online nacionales e internacionales. De esta manera, se confirma la presencia de 52 especies de mamíferos no voladores y se descartan 9 especies reportadas en diferentes fuentes bibliográficas, pero aún no confirmadas en esta región.

Se estudiaron especímenes de Pyrenomataceae etiquetados como “Helvella” depositados en los herbarios IBUG y XAL, que correspondieron a Jafnea semitosta. La determinación taxonómica se confirmó usando secuencias de región de LSU del ADNr. Este es el primer registro del género en México, con especímenes provenientes de Jalisco y Puebla.

El libro de Edna Suárez relata los acontecimientos que llevaron a una mejor comprensión de las bases moleculares de la evolución, principalmente entre las décadas de 1950 y 1970. Se proporciona una reconstrucción históricasustentada en el análisis de fuentes de información primarias y secundarias, así como entrevistas con algunos personajes importantes, como Emile Zuckerkandl, Walter Fitch, Richard Lewontin y Jonathan Marks. La autoranarra detalles de los desarrollos tecnológicos y debates conceptuales que llevaron al surgimiento de la biología molecular, contextualizándolos en el momento histórico en que se produjeron.

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.

A new deep-sea species of isopod is described and illustrated. The material was collected in soft substratum in the Bay of Campeche, SW Gulf of Mexico, at a depth of 2,548 m aboard the research vessel “Justo Sierra” on September 4, 2009. Gracilimesus tzasnae sp. nov. can be distinguished from all other known species by its antennula with 5 articles; uropod length vs. pleotelson 0.3×; pereonite 7 not reduced; pereopod 7 absent; pleotelson dorsal surface smooth and not separated in lateral fields. The new species represents the first described Gracilimesus in the Gulf of Mexico. We present a table with the most important diagnostic characters to separate all the known species of the genus Gracilimesus.

Two field trips were made during 2017 to Cayo Arenas and Cayo Arcas, southern Gulf of Mexico. Direct and indirect sampling methods focused on shell-less marine heterobranchs were carried out. As a result, 30 species of sea slugs are reported for the first time from these 2 remote reefs off the Yucatán Peninsula. From these, 7 species hold new distribution records for the Gulf of Mexico: Sclerodoris worki, Platydoris angustipes, Polycera odhneri,Hexabranchus morsomus, Limenandra nodosa, Petalifera ramose, and Hermaea cruciata. Hexabranchus morsomus is a considerable west geographical range extension from the known distribution range, so far restricted to the Caribbean Sea. Nine specimens were identified up to genus level: Cuthona sp., Haminoea sp., Petalifera sp. and Elysia sp. With the present contribution, the sea slug richness in the Campeche Bank increases to 94 species.

We studied the fish fauna of the Río Saín Alto (Río Aguanaval endorheic basin) in Zacatecas, Mexico, during the dry (May) and wet (October) seasons of 2011 in order to evaluate changes in the distribution of the species and its relationship with environmental variables. A total of 12 fish species (6 native and 6 exotic) were registered. The longitudinal distribution of the species in the river during both seasons combined was 2 native species (Gila conspersa and Catostomus nebuliferus) with ample distribution in the river (upper, middle and lower zones), 2 native species(Campostoma ornatum and Notropis nazas) in 2 zones of the river (middle and lower), 4 species (2 native: Astyanax mexicanus and Etheostoma pottsii, and 2 exotic: Cyprinus carpio and Oreochromis sp.) in the middle zone of the river, and 4 exotic species (Gambusia affinis, Lepomis cyanellus, Lepomis macrochirus, and Micropterus salmoides) with distribution confined to the lower zone of the river, especially in reservoirs. Species richness decreased with altitude and after a flooding event. The factor analysis model determined that both altitude and flow velocity werethe factors that best explained the variation in the distribution of fish species during the rainy season, especially for the exotic component.