Ma. Leopoldina Aguirre-Macedo - Academia.edu (original) (raw)

Papers by Ma. Leopoldina Aguirre-Macedo

Nanomaterials

Through the execution of scientific innovations, “smart materials” are shaping the future of tech... more Through the execution of scientific innovations, “smart materials” are shaping the future of technology by interacting and responding to changes in our environment. To make this a successful reality, proper component selection, synthesis procedures, and functional active agents must converge in practical and resource-efficient procedures to lay the foundations for a profitable and sustainable industry. Here we show how the reaction time, temperature, and surface stabilizer concentration impact the most promising functional properties in a cotton-based fabric coated with silver nanoparticles (AgNPs@cotton), i.e., the thermal and bactericidal response. The coating quality was characterized and linked to the selected synthesis parameters and correlated by a parallel description of “proof of concept” experiments for the differential heat transfer (conversion and dissipation properties) and the bactericidal response tested against reference bacteria and natural bacterial populations (fro...

Microorganisms, Feb 16, 2023

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Journal of the Marine Biological Association of the United Kingdom, Sep 1, 2022

We present a preliminary taxonomic survey of the metazoan parasites from meso- and bathypelagic f... more We present a preliminary taxonomic survey of the metazoan parasites from meso- and bathypelagic fish hosts from the Perdido region, western Gulf of Mexico. In total, 187 individual fish were collected, belonging to five families and 12 species: Cyclothone acclinidens, Cyclothone alba, Cyclothone braueri, Cyclothone pallida, Cyclothone pseudopallida, Cyclothone sp., Manducus maderensis (Gonostomatidae), Notolychnus valdiviae (Myctophidae), Dibranchus atlanticus (Ogcocephalidae), Peristedion greyae (Peristediidae), Sternoptyx pseudobscura (Sternoptychidae), and Chauliodus sloani (Stomiidae). The metazoan parasites collected were the digenean Lethadena profunda from Cyclothone sp., four tetraphillidean larval cestodes from C. acclinidens, Cyclothone sp., C. sloani and P. greyae, a species of Echeneibotrium from D. atlanticus, a species of Anisakis from C. sloani, and the nematode Mooleptus rabuka from C. alba. Four of the parasite species found had already been previously recorded for the northern Gulf of Mexico. Additionally, we report two parasites not recorded before for meso- or bathypelagic fish in the entire Gulf of Mexico: M. rabuka from C. alba and Cyclothone sp.; and the copepods of the family Pennellidae from Cyclothone sp. and P. greyae.

Nanomaterials, Jan 23, 2023

Journal of Helminthology

A new species of the genus Stephanostomum is described for the southeastern Gulf of Mexico based ... more A new species of the genus Stephanostomum is described for the southeastern Gulf of Mexico based on morphological and nucleotide evidence. Stephanostomum minankisi n. sp. infects the intestine of the dusky flounder Syacium papillosum in the Yucatan Continental Shelf, Mexico (Yucatan Peninsula). Sequences of the 28S ribosomal gene were obtained and compared with available sequences of the other species and genera of the families Acanthocolpidae and Brachycladiidae from GenBank. A phylogenetic analysis was conducted, including 39 sequences, 26 of which represented 21 species and six genera of the family Acanthocolpidae. The new species is characterized by the absence of circumoral spines and spines on the tegument. Nonetheless, scanning electron microscopy consistently revealed the pits of 52 circumoral spines distributed in a double row with 26 spines each, and forebody spined. Other distinctive features of this species are testes in contact (sometimes overlapping), the vitellaria ru...

Bulletin of Environmental Contamination and Toxicology, 2021

In this study, we report molecular and metabolic responses of Sciaenops ocellatus during an acute... more In this study, we report molecular and metabolic responses of Sciaenops ocellatus during an acute oil exposure bioassay (100, 800 and 8000 mg 1-1 of crude oil). The global DNA methylation and expression profiles of key genes of the xenobiotic biotransformation system (cytochrome P450 1A [cyp1a] and glutathione S-tranferase [gst]), oxidative stress system (glutathione peroxidase [gpx], catalase [cat], aldehyde dehydrogenase [aldh]) and reproductive system (vitellogenin [vtg]) were evaluated. At the metabolic level, we evaluated the concentration of four polycyclic aromatic hydrocarbon (PAH) metabolites-hydroxybenzo[a]pyrene, hydroxypyrene, hydroxynaphthalene and hydroxyphenanthrene-in fish bile. The results of this study revealed that fish exposed to crude oil exhibited hypomethylation of DNA, up-regulation of cyp1a and gst and downregulation of gpx, cat, aldh and vtg and high concentrations of PAH metabolites with respect to the control.

Environmental Pollution, 2021

We assessed the performance of taxonomic and several functional trait-based approaches in the ass... more We assessed the performance of taxonomic and several functional trait-based approaches in the assessment of spatial and temporal patterns of dusky flounder (Syacium papillosum) parasite assemblages along the Yucatan shelf to determine their potential as bioindicators of marine chemical pollution. Fish specimens were collected throughout three research cruises that took place in 2015, 2016 and 2018. In addition to the traditional taxonomic approach, four trait-based approaches were performed including community-weighted means (CWM), functional trait niche (FTN), functional groups (FGs), and Rao's functional diversity (FD). Significant spatial and temporal variations in parasite communities were detected using the taxonomic approach. In general, these variations were also reflected in the four trait-based approaches performed, indicating that changes in taxa composition and abundance also resulted in functional composition shifts. Resemblance matrices of both taxonomic and functional trait approaches were significantly correlated. Variations in taxonomic and trait-based composition using the four approaches were significantly correlated with depth, and at least one chemical pollutant variable. Feeding mode, transmission, life stage and attachment structure displayed spatial variability and significant correlations with predictor variables, which indicates that this set of attributes functions as a good surrogate for assessing variations in the functional composition of flatfish parasite communities in relation to pollution. FTN and CWM were the approaches that best detected spatio-temporal variation. CWM and FD were best suited for detecting pollution gradients. These results reveal the feasibility of using trait-based approaches to assess marine parasite communities as bioindicators of chemical pollution. Functional traits of marine metazoan parasites are as good indicators of the effect of oil pollution as taxonomic diversity. This may be a time-saving and cost-effective approach to performing environmental assessments.

Journal of Helminthology, 2020

We present a time series of 13 years (2003–2016) of continuous monthly data on the prevalence and... more We present a time series of 13 years (2003–2016) of continuous monthly data on the prevalence and mean abundance of the trematode Oligogonotylus mayae for all the hosts involved in its life cycle. We aimed to determine whether annual (or longer than annual) environmental fluctuations affect these infection parameters of O. mayae in its intermediate snail host Pyrgophorus coronatus, and its second and definitive fish host Mayaheros urophthalmus from the Celestun tropical coastal lagoon, Yucatan, Mexico. Fourier time series analysis was used to identify infection peaks over time, and cross-correlation among environmental forcings and infection parameters. Our results suggest that the transmission of O. mayae in all its hosts was influenced by the annual patterns of temperature, salinity and rainfall. However, there was a biannual accumulation of metacercarial stages of O. mayae in M. urophthalmus, apparently associated with the temporal range of the El Niño-Southern Oscillation (five ...

Journal of Helminthology, 2018

We describe the larval developmental stages and life cycle of the dracunculid nematode Mexiconema... more We describe the larval developmental stages and life cycle of the dracunculid nematode Mexiconema cichlasomae in both the intermediate, Argulus yucatanus (Crustacea: Branchiura), and definitive hosts, Cichlasoma urophthalmus (Perciformes: Cichlidae), from the Celestun tropical coastal lagoon, Yucatan, Mexico. The morphological analyses showed significant differences between the total length of L1 found in M. cichlasomae gravid female and L2–L3 in A. yucatanus. This result indicates that the M. cichlasomae larval development occurs in the intermediate host. We obtained sequences from the small subunit (SSU) ribosomal marker from larval stages of M. cichlasomae in A. yucatanus and adult nematodes in C. urophthalmus. Our morphological and molecular results support conspecificity between M. cichlasomae larvae in A. yucatanus and the adult stages in C. urophthalmus. We briefly discuss the phylogenetic position of M. cichlasomae among the Daniconematidae, and provide evidence of the monop...

Journal of Applied Microbiology, 2019

The aim of this study was to investigate the dynamic changes in the bacterial structure and poten... more The aim of this study was to investigate the dynamic changes in the bacterial structure and potential interactions of an acclimatized marine microbial community during a light crude oil degradation experiment. Methods and results: The bacterial community effectively removed 76.49% of total petroleum hydrocarbons after 30 days, as evidenced by GC-FID and GC-MS analyses. Short chain alkanes and specific aromatic compounds were completely degraded within the first six days. High-throughput sequencing of 16S rRNA gene indicated that the starting bacterial community was mainly composed by Marinobacter and more than 30 non-dominant genera. Bacterial succession was dependent on the hydrocarbon uptake with Alcanivorax becoming dominant during the highest degradation period. Sparse Correlations for Compositional data algorithm revealed one OTU of Muricauda and an assembly of six OTUs of A. dieselolei and A. hongdengensis as critical keystone components for the consortium network maintenance and stability. Conclusions: This work exhibits a stabilized marine bacterial consortium with the capability to efficiently degrade light crude oil in six days, under laboratory conditions. Successional and interaction patterns were observed in response to hydrocarbon consumption, highlighting potential interactions between Alcanivorax and keystone non-dominant OTU's over time.

Discoveries, ideas and lessons learned by scientists who published in the Journal of Parastiology, 1914 - 2014, 2016

Diversity

During a research of gill ectoparasites on damselfishes (Pomacentridae) and butterflyfishes (Chae... more During a research of gill ectoparasites on damselfishes (Pomacentridae) and butterflyfishes (Chaetodontidae) from the Cayo Arcas reef in the Campeche Bank (Gulf of Mexico), the following monogenoids (Platyhelminthes) were found: Paraeuryhaliotrema pomacentris n. gen., n. sp. (Dactylogyridae) on beaugregory Stegastes xanthurus (Poey, 1860) (Pomacentridae) that is characterized, in part, by possessing a haptor armed with a dorsal, ventral anchor-bar complexes, seven pairs of similar hooks; two pairs of eyespots; overlapping gonads; a copulatory complex composed of a male copulatory organ (MCO) and an accessory piece; MCO tubular with a bulbous base from which arises a coiled shaft in the clockwise direction; and a dextral vaginal pore; Neohaliotrema variabilis n. sp. on bicolor damselfish Stegastes partitus (Poey, 1868) (type host), beaugregory Stegastes xanthurus (Poey, 1860) and beaugregory Stegastes leucostictus (Müller & Troschel, 1848); Neohaliotrema manubrium n. sp., Neohaliotre...

$Research paper thumbnail of Metazoan parasite infracommunities of the dusky flounder (Syacium papillosum) as bioindicators of environmental conditions in the continental shelf of the Yucatan Peninsula, Mexico$

Parasites & Vectors, 2019

Background: We assessed metrics of the metazoan parasite infracommunities of the dusky flounder (... more Background: We assessed metrics of the metazoan parasite infracommunities of the dusky flounder (Syacium papillosum) as indicators of aquatic environmental health of the Yucatan Shelf (YS) prior to oil extraction. We sampled the dusky flounder and its parasites along the YS, mostly during the 2015 north wind season (November-April). Our aims were: (i) to determine whether the parasite infracommunity metrics of S. papillosum exhibit significant differences among YS subregions; (ii) to determine whether the probability of the occurrence of its parasite species and individuals were affected by environmental variables, nutrients, heavy metals and hydrocarbons at the seascape level; and (iii) to determine whether there were statistical differences between the parasite infracommunity metrics of S. papillosum from YS and those of Syacium gunteri from the Campeche Sound. Multivariate statistical analyses and generalised additive models (GAMs) were used to examine the potential statistical associations between the contaminants, environmental variables and parasite community metrics, and the maximum entropy algorithm (MaxEnt) was used to characterise the habitat's suitability for the parasite's probability of occurrence. Results: We recovered 48 metazoan parasite species from 127 S. papillosum, with larval cestodes and digeneans being the most numerically-dominant. Multivariate analyses showed significant differences in parasite infracommunity metrics among Western YS, Mid YS and Caribbean subregions, with the latter being the richest in species but not in individuals. The GAM and MaxEnt results indicated a negative effect of top predators (e.g. sharks and rays) removal on parasite metrics. The parasite infracommunities of S. papillosum were twice as rich in the number of species and individuals as those reported for S. gunteri from the Campeche Sound. Conclusions: The significant differences among subregions in parasite metrics were apparently due to the interruption of the Yucatan current during the north wind season. The fishing of top predators in combination with an influx of nutrients and hydrocarbons in low concentrations coincides with an increase in larval cestodes and digeneans in

Systematic Parasitology, 2016

Two new dicyemid species are described from the endemic cephalopod Octopus maya Voss & Solis-Rami... more Two new dicyemid species are described from the endemic cephalopod Octopus maya Voss & Solis-Ramirez collected off Yucatan, Mexico. The renal sacs of 40 juvenile and adult octopuses from four localities were examined. Dicyema hochbergi n. sp. is a medium-sized species that reaches 2,245 lm in length. The vermiform stages consist of 18-24 peripheral cells, a conical calotte and the extension of the axial cell between the base and middle of the metapolar cells. Infusoriform embryos consist of 39 cells with urn cell containing one germinal cell, two nuclei and solid refringent bodies. Dicyema mexcayae n. sp. is a relatively small species that reaches 1,114 lm in length. The vermiform stages are constituted by 14-16 peripheral cells, an elongate calotte and the axial cell extending forward to the middle of the metapolar cells. The infusoriform embryos consist of 37 cells, two solid refringent bodies and urn cells with two nuclei each. The present study represents the first description of a dicyemid species from O. maya and increases the number of described species from Mexican waters to 11.

Parasites & Vectors, 2014

Background: Because agriculture and offshore oil extraction are significant economic activities i... more Background: Because agriculture and offshore oil extraction are significant economic activities in the southern Gulf of Mexico, high concentrations of nutrients and hydrocarbons are expected. As parasite communities are sensitive to environmental impacts, these contaminants should have an effect on metrics such as species richness, relative abundance and similarity. Consequently, these community metrics can be used as indicators of aquatic environmental health. Our objectives were to describe the parasite communities of the shoal flounder Syacium gunteri and to determine potential thresholds above which environmental contaminants become major controlling factors of parasite community metrics. Methods: The study area included 33 sampling sites in the southern Gulf of Mexico, where benthic sediments, water and shoal flounder individuals were collected. Data on ecto-and endo-parasites from flounder and nutrients, contaminants and physicochemical variables from the water and sediments were obtained. The statistical associations of the parasite community metrics at the component and infracommunity levels and the environmental data were analysed using redundancy analysis (RDA). Results: Overall, 203 shoal flounder were examined for parasites, recovering 13 metazoan parasite species, and 48 physicochemical (e.g. temperature, nutrients) and contaminant (e.g. hydrocarbons, heavy metals) variables were obtained. The larval stages of the cestode Oncomegas wageneri and the nematodes Pseudoterranova decipiens and Hysterothylacium sp. were numerically dominant at the component and infracommunity levels. The parasite community metrics had significant negative statistical associations with both nitrate and total PAHs. With the exception of these two chemicals, which exceeded the threshold effect levels (TELs), no other environmental variable exceeded the range considered safe for marine organisms. Conclusions: The community metrics chosen generally had robust statistically significant associations with both physicochemical and contaminant variables, which supports the ecological relevance of these parameters as indicators of aquatic environmental health. Within the study area, the shoal flounder and their parasites live in a polluted environment with relatively high levels of hydrocarbons and nitrate. Regarding nitrate, we emphasise that if uncontrolled sewage discharge continues in the southern Gulf of Mexico, hypoxic conditions similar to those caused by the Mississippi river can be expected in the near future.

Science of The Total Environment, 2009

The suitability of using helminth communities as bioindicators of environmental quality of the Yu... more The suitability of using helminth communities as bioindicators of environmental quality of the Yucatan coastal lagoons status was tested on the checkered puffer (Spheroides testudineus) in four coastal lagoons along the Yucatan coast. The concentration of chemical pollutants in sediments, water quality parameters, helminth infracommunity characteristics, as well as fish physiological biomarkers, including EROD (7-ethoxyresorufin-O-deethylase) and catalase activities, were measured. Results from sediment analyses demonstrated the presence of hydrocarbons, organochlorine pesticides and polychlorinated biphenyls at varying concentrations, some of which exceeded the Probability Effect Level (PEL). Significant negative associations among organochlorine pesticides, infracommunity characteristics and fish physiological responses were observed in most of the lagoons. Results suggest that EROD activity and parasite infracommunity characteristics could be useful tools to evaluate the effects of chemical pollutants on the fish host and in the environment. Importantly, certain parasites appear to influence biomarker measurements, indicating that parasites should be considered in ecotoxicological studies.

Journal of Helminthology, 2012

Although many studies on the taxonomy of digenean trematodes of marine fishes have been completed... more Although many studies on the taxonomy of digenean trematodes of marine fishes have been completed in the Eastern Indo-Pacific (EIP) marine ecoregion, only a few have considered metacercarial stages. Here, the results are presented of a taxonomic survey of the digenean metacercariae of fishes from Palmyra Atoll, a remote and relatively pristine US National Wildlife Refuge located 1680 km SSW of Hawaii. Up to 425 individual fish were collected, comprising 42 fish species, from the sand flats bordering the lagoon of the atoll. Quantitative parasitological examinations of each fish were performed. Morphological descriptions of the encountered digenean metacercariae are provided, together with their prevalence, mean intensities, host and tissue-use. Up to 33,964 individuals were recovered representing 19 digenean metacercaria species from eight families. The species composition of digeneans in lagoon fishes at Palmyra Atoll is a subset of what has previously been reported for the EIP. Fu...

Estuarine Coastal and Shelf Science, Dec 1, 2019

Coastal lagoons are important aquatic systems with strong physicochemical gradients, where the pa... more Coastal lagoons are important aquatic systems with strong physicochemical gradients, where the participation of microorganisms in biogeochemical cycles has been well recognised; however, to date, the microbial diversity and distribution in these environments remains under-investigated. Here, three distinguished regions (oligohaline, marine and the mixing) of a transitional coastal lagoon were explored to characterise the structure and composition of benthic microbial communities through 16S rRNA gene Illumina-sequencing, for both Bacteria and Archaea domains. Principal coordinate analysis showed differences in the community structure according to the analysed zones. PERMANOVA analysis evidenced that, of the measured variables, sample zonation and salinity were the main environmental factors explaining the variance of the prokaryotic assemblages. Differentially abundant microbial taxa were detected for each region of the lagoon by LEfSe analysis. Representative members of anaerobic methanogens/methanotrophs (Methanosaetaceae, ANME 1-b and WSA2) were enriched in the oligohaline sediments, while the coastal marine zone had a community represented mainly by Sandaracinaceae, Aminicenantes and Thaumarchaeota (Group-C3). The sediments in the mixing zone had higher abundance of Flavobacteriaceae, Syntrophobacteraceae and uncultured Thermoplasmatales, Bathyarchaeota and Lokiarchaeota. This study expands the available information of the composition and distribution of uncultured Bacteria and Archaea in transitional coastal lagoons, contributing to a systematic understanding of the functioning of these ecosystems.

ZooKeys, Nov 27, 2019

Here, we present the results of a taxonomic survey of the nematodes parasitizing fishes from the ... more Here, we present the results of a taxonomic survey of the nematodes parasitizing fishes from the lagoon flats of Palmyra Atoll, Eastern Indo-Pacific. We performed quantitative parasitological surveys of 653 individual fish from each of the 44 species using the intertidal sand flats that border the atoll's lagoon. We provide morphological descriptions, prevalence, and mean intensities of the recovered seven species of adult nematode (Pulchrascaris chiloscyllii, Capillariidae gen. sp., Cucullanus bourdini, Cucullanus oceaniensis, Pseudascarophis sp., Spinitectus (Paraspinitectus) palmyraensis sp. nov., Philometra pellucida) and three larval stages (Pulchrascaris sp., Hysterothylacium sp., Cucullanus sp.). We recorded: Pulchrascaris chiloscyllii