La Funcionalidad Física Arrecifal, indicador de la diversidad funcional en ensamblajes de peces de arrecifes en el Parque Nacional Islas Marietas, Nayarit, México

Reef Physical Functionality, indicator of functional diversity on reef fishes assemblages from Islas Marietas National Park, Nayarit, Mexico

Luis Mario Montalvo Jaramillo (2023, [Tesis de maestría])

La ecología funcional se basa en el uso de rasgos funcionales; características de las especies (morfológicas, fisiológicas, comportamiento) medidas a nivel individual que influencian el rendimiento de una especie, siendo de gran utilidad para determinar cambios dentro del ecosistema. El presente trabajo busca evaluar la funcionalidad física como indicador de disponibilidad de hábitat de peces y su relación con la diversidad funcional. La funcionalidad física del arrecife se evaluó mediante el IFA integrando datos de cobertura coralina, complejidad estructural y tasa de calcificación. La estructura de los ensamblajes de peces se analizó mediante el cálculo de índices de diversidad funcional (riqueza, equitatividad y divergencia) con base en cuatro rasgos funcionales (tamaño corporal, movilidad, tipo de agregación y dieta). La relación entre la diversidad funcional del ensamblaje y el IFA se evaluó mediante un análisis de regresión lineal. El IFA fue influenciado de manera positiva por la presencia Pocilloporidos al generar un mayor aporte a la funcionalidad física (FF) y consecuentemente, una mayor provisión de hábitat. Por el contrario, el IFA disminuyó con la presencia de Porites panamensis debido a su baja tasa de calcificación.La diversidad funcional de los ensamblajes no presentó variaciones temporales, atribuible a una baja variabilidad entre los sitios debido a una alta cercanía, baja variacion batimétrica y alta conectividad. La relación entre el IFA y la riqueza funcional de los ensamblajes se atribuye a que sitios con mayor funcionalidad física otorgan disponibilidad de hábitat y refugio contra la depredación a especies crípticas, de talla pequeña y juveniles; ya que, especies de este tipo se asocian a hoyos similares a su tamaño corporal y la supervivencia de las mismas aumenta en sustratos más complejos.

Functional diversity it’s based on functional traits; characteristics of species (morphological, physiological, behavior) measured at individual level that impact their performance and have great utility to determine changes within the ecosystem. This work aims to evaluate physical functionality as indicator of fish habitat availability and its relationship with functional diversity. The physical functionality of the reef was evaluated using the RFI, integrating data on coral cover, structural complexity, and calcification rate. The structure of the fish assemblages was analyzed by calculating functional diversity index (richness, evenness, and divergence) based on four functional traits (body size, mobility, type of aggregation and diet). The relationship between functional diversity and RFI was evaluated using linear regression analysis. The RFI was influenced on positive way for the presence of Pocilloporids due to the great contribution to physical functionality (PF) creating more habitat availability. For the other hand, the RFI was influenced on negative way for the presence of Porites panamensis due their low calcification rate. The functional diversity of the assemblages did not present temporal variations, attributable to a low variability between the sites due high proximity, low bathymetric variation and high connectivity. The relationship between RFI and the functional richness of the assemblages is attributed to fact that sites with greater physical functionality provide more availability of habitat and refuge against predation to cryptic, small and juvenile species; species of this type are associate with holes similar to their body size and their survival increases in more complex substrates.

Pacífico Méxicano, Índice de Función Arrecifal, Diversidad Funcional, Arrecife Reef, Functional Diversity, Reef Functional Index, Mexican Pacific BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA OTRAS ESPECIALIDADES DE LA BIOLOGÍA OTRAS OTRAS

Enhancement of antibiotics antimicrobial activity due to the silver nanoparticles impact on the cell membrane

Roberto Vazquez-Munoz (2019, [Artículo])

The ability of microorganisms to generate resistance outcompetes with the generation of new and efficient antibiotics; therefore, it is critical to develop novel antibiotic agents and treatments to control bacterial infections. An alternative to this worldwide problem is the use of nanomaterials with antimicrobial properties. Silver nanoparticles (AgNPs) have been extensively studied due to their antimicrobial effect in different organisms. In this work, the synergistic antimicrobial effect of AgNPs and conventional antibiotics was assessed in Gram-positive and Gram-negative bacteria. AgNPs minimal inhibitory concentration was 10–12 μg mL-1 in all bacterial strains tested, regardless of their different susceptibility against antibiotics. Interestingly, a synergistic antimicrobial effect was observed when combining AgNPs and kanamycin according to the fractional inhibitory concentration index, FICI: <0.5), an additive effect by combining AgNPs and chloramphenicol (FICI: 0.5 to 1), whereas no effect was found with AgNPs and β-lactam antibiotics combinations. Flow cytometry and TEM analysis showed that sublethal concentrations of AgNPs (6–7 μg mL-1) altered the bacterial membrane potential and caused ultrastructural damage, increasing the cell membrane permeability. No chemical interactions between AgNPs and antibiotics were detected. We propose an experimental supported mechanism of action by which combinatorial effect of antimicrobials drives synergy depending on their specific target, facilitated by membrane alterations generated by AgNPs. Our results provide a deeper understanding about the synergistic mechanism of AgNPs and antibiotics, aiming to combat antimicrobial infections efficiently, especially those by multi-drug resistant microorganisms, in order to mitigate the current crisis due to antibiotic resistance. © 2019 Vazquez-Muñoz et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

ampicillin, antibiotic agent, aztreonam, beta lactam antibiotic, biapenem, chloramphenicol, kanamycin, silver nanoparticle, silver nitrate, antiinfective agent, metal nanoparticle, silver, antibiotic sensitivity, antimicrobial activity, Article, bact BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOFÍSICA BIOFÍSICA

Estudios de genética en poblaciones de abulón y sus aplicaciones en ordenamiento pesquero

RICARDO PEREZ ENRIQUEZ NOE DIAZ VILORIA JOSE LUIS GUTIERREZ GONZALEZ ALEJANDRA ARCINIEGA DE LOS SANTOS ADRIANA MAX AGUILAR Pedro Cruz Hernández Fernando Aranceta Garza (2016, [Artículo])

"Se presenta la integración de más de 10 años de investigación científica en genética de las poblaciones de abulón en México realizada en el CIBNOR. Esta investigación muestra cómo se pueden aplicar los marcadores genéticos tanto en estudios de genética poblacional como en identificación forense con la finalidad de contribuir al conocimiento aplicado para manejo de la pesquería. Se desarrollaron marcadores genéticos tipo microsatélites de ADN enfocados tanto al abulón azul Haliotis fulgens como amarillo Haliotis corrugata para diferenciación de poblaciones y análisis de parentesco. Un análisis de estructura genética de las poblaciones silvestres de ambas especies de abulón mostró homogeneidad genética en la costa del Pacífico en la región centro-sur de la Península de Baja California, México, pero con diferenciación genética en localidades distantes debido a un flujo genético limitado producto del aislamiento reproductivo. Por ello, no existen elementos que den soporte a un manejo pesquero delimitado por bancos en ambas especies. De manera particular, el abulón amarillo mostró una menor de diversidad genética que el azul, posiblemente debido a una mayor explotación pesquera histórica. Los resultados obtenidos en pruebas de parentesco han indicado que la retención larvaria en bancos específicos es reducida, por lo que ni la agregación de reproductores ni la liberación de larvas han mostrado ser estrategias eficientes para favorecer el incremento de reclutas en bancos definidos. Un análisis de perfiles genéticos con el gen de la lisina permitió la identificación de las especies de abulón que se capturan y enlatan en México. El análisis comparativo de perfi les genéticos, basado en el gen nuclear 18S de abulón y otros moluscos, detectó producto enlatado conteniendo especies de moluscos comercializadas falsamente como abulón, lo que puede constituirse como una herramienta forense en futuras disputas legales. Este tipo de aplicación es potencialmente utilizable con otros productos comestibles en los cuales se sospecha de prácticas fraudulentas, ya sea por captura o comercialización ilegal o por sustitución de contenidos en productos procesados."

"This is an integrative work of more than 10 years of research in population genetics of abalone in Mexico performed at CIBNOR. It shows how molecular tools have the potential to support abalone fisheries management through population genetics and forensic analyses. Microsatellite DNA markers were developed on blue (green for its name in English) Haliotis fulgens and yellow abalone (pink for its name in English) H. corrugata to be used for genetic differentiation on populations and for parentage analysis. The analysis of genetic structure on wild populations of both species revealed genetic homogeneity in the Pacific coast of the central region of the Baja California Peninsula, Mexico, with genetic differentiation on distant localities due to a limited gene flow as a result of reproduction isolation. From this result we suggest that no evidences were found supporting the management of the fishery based on individual abalone beds. Pink abalone shows lower genetic diversity than green abalone, possibly due to higher historical fishery exploitation. The parentage analysis suggested that larval retention within beds is reduced, indicating that neither broodstockaggregation nor the release of abalone larvae for stock enhancement are efficient strategies to increase recruitment in specific beds.

An analysis of the genetic profiles with the lysine gene allowed the identification of abalone species captured and processed in Mexico. The comparative analysis, based on the 18S gene, among abalone and other mollusks, detected canned product containing mollusks that are commercialized allegedly as abalone or ‘abalone type’, which could constitute a forensic tool in future legal disputes. This type of application can also be used with other edible products in which fraudulent practices are suspected either because of illegal catch or commercialization or substitution in processed products."

Análisis forense, diversidad genética, gen 18S, genética de poblaciones, marcadores genéticos, retención larvaria Forensic analysis, genetic diversity, 18S gene, genetic markers, population genetics, larval retention BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA GENÉTICA GENÉTICA DE POBLACIONES GENÉTICA DE POBLACIONES

Gamma-diversity partitioning of gobiid fishes (Teleostei: Gobiidae) ensemble along of Eastern Tropical Pacific: Biological inventory, latitudinal variation and species turnover

OMAR VALENCIA MENDEZ (2018, [Artículo])

Gobies are the most diverse marine fish family. Here, we analysed the gamma-diversity (γ-diversity) partitioning of gobiid fishes to evaluate the additive and multiplicative components of α and β-diversity, species replacement and species loss and gain, at four spatial scales: sample units, ecoregions, provinces and realms. The richness of gobies from the realm Eastern Tropical Pacific (ETP) is represented by 87 species. Along latitudinal and longitudinal gradients, we found that the γ-diversity is explained by the β-diversity at both spatial scales, ecoregions and provinces. At the ecoregion scale, species are diverse in the north (Cortezian ecoregion) and south (Panama Bight ecoregion) and between insular and coastal ecoregions. At the province scale, we found that the species turnover between the warm temperate Northeast Pacific (WTNP), Tropical East Pacific (TEaP) and the Galapagos Islands (Gala) was high, and the species nestedness was low. At the ecoregion scale, historical factors, and phylogenetic factors have influenced the hotspots of gobiid fish biodiversity, particularly in the Cortezian, Panama Bight and Cocos Island ecoregions, where species turnover is high across both latitudinal and longitudinal gradients. At the provincial level, we found that the contributions of the β-diversity from north to south, in the WTNP, TEaP and Gala were high, as result of the high number of unique species. Species turnover was also high at this scale, with a low contribution from species nestedness that was probably due to the low species/gene flow within the provinces. These results highlight the importance and successful inclusion of a cryptobenthic fish component in ecological and biogeographical studies. © 2018 Valencia-Méndez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Article, biodiversity, biogeographic region, biogeography, gene flow, goby fish, nonhuman, phylogeny, species distribution, species diversity, taxonomic identification, teleost, animal, animal dispersal, fish, Pacific Ocean, phylogeography, Animal Di CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CIENCIAS AGRARIAS PECES Y FAUNA SILVESTRE PECES Y FAUNA SILVESTRE

Assessing the Response of Nematode Communities to Climate Change-Driven Warming: A Microcosm Experiment

RUTH GINGOLD WERMUTH (2013, [Artículo])

Biodiversity has diminished over the past decades with climate change being among the main responsible factors. One consequence of climate change is the increase in sea surface temperature, which, together with long exposure periods in intertidal areas, may exceed the tolerance level of benthic organisms. Benthic communities may suffer structural changes due to the loss of species or functional groups, putting ecological services at risk. In sandy beaches, free-living marine nematodes usually are the most abundant and diverse group of intertidal meiofauna, playing an important role in the benthic food web. While apparently many functionally similar nematode species co-exist temporally and spatially, experimental results on selected bacterivore species suggest no functional overlap, but rather an idiosyncratic contribution to ecosystem functioning. However, we hypothesize that functional redundancy is more likely to observe when taking into account the entire diversity of natural assemblages. We conducted a microcosm experiment with two natural communities to assess their stress response to elevated temperature. The two communities differed in diversity (high [HD] vs. low [LD]) and environmental origin (harsh vs. moderate conditions). We assessed their stress resistance to the experimental treatment in terms of species and diversity changes, and their function in terms of abundance, biomass, and trophic diversity. According to the Insurance Hypothesis, we hypothesized that the HD community would cope better with the stressful treatment due to species functional overlap, whereas the LD community functioning would benefit from species better adapted to harsh conditions. Our results indicate no evidence of functional redundancy in the studied nematofaunal communities. The species loss was more prominent and size specific in the HD; large predators and omnivores were lost, which may have important consequences for the benthic food web. Yet, we found evidence for alternative diversity-ecosystem functioning relationships, such as the Rivets and the Idiosyncrasy Model. © 2013 Gingold et al.

aquaculture, article, bacterivore, benthos, biodiversity, biomass, climate, community dynamics, controlled study, ecosystem, environmental temperature, microcosm, nematode, nonhuman, population abundance, species diversity, species richness, taxonomy CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA CIENCIAS DE LA TIERRA Y DEL ESPACIO OCEANOGRAFÍA OCEANOGRAFÍA