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

Introduction: Reptiles are often overlooked when planning for conservation, as they are typically perceived as a persistent or tolerant group. Nonetheless, recent studies have shown their vulnerability. Identifying priority areas is crucial, and spatial prioritization is an essential analysis to optimize the scarce available resources for conservation. Furthermore, it is of the utmost importance to establish protected area networks that would keep their usefulness in the future, especially considering the enormous environmental changes that are currently occurring. Objectives: To evaluate the performance of the current protected area network (PA) and to identify potential areas for expansion, considering their persistence in time. Methods: We estimated species distributions for 177 reptiles on the Sierra Madre del Sur in Southeastern Mexico. The species were weighed according to their international conservation status, and future land use scenarios were incorporated to identify priority areas with Zonation software. Results: We found coincidences between priority areas for reptiles and zones previously identified for other groups. However, most regions with top priority rankings remain unprotected, considering the current established PA. Federal PA protects the highest percentage of priority areas, followed by areas voluntarily dedicated to conservation and state PA. We emphasize conserving natural land uses since they are the only ones that constitute the highest priority zones for reptiles. Conclusions: Our prioritization for reptile conservation entails efficient outcomes in terms of temporal permanence, amount of area to be protected, and coverage of species distribution, especially for small percentages of expansions to the current network of PA, making it an affordable proposal for implementation. Nonetheless, it is crucial to recognize that it is also important to consider social factors, possible conflicts of interest, and to evaluate the effectiveness of PA over time.

Introduction: The Sierra Madre del Sur in Mexico, known for its geological complexity and elevational gradient, hosts diverse ecosystems. The Loxicha region in Oaxaca, with five vegetation types and a 2 500 m elevation range, has the richest documented butterfly fauna on the Pacific slope. This study focuses on Lycaenidae butterflies, exploring their distribution, richness, and abundance along vegetation and elevational transects. Objective: To document geographic, elevational, and ecological patterns of Lycaenidae butterflies on the Pacific slope Loxicha region as part of a larger project on the distribution of diurnal butterflies in the state of Oaxaca, Mexico. Also, to compare Loxicha fauna with other regions to recognize biogeographical patterns at a larger scale. Methods: Spatial and temporal patterns of Lycaenidae diversity are based on systematic sampling conducted between 2005 and 2014 along elevational (80 to 2 500 m) and vegetational transects. Exclusive and characteristic species for each elevation and vegetation type are recognized. Results: A total of 123 species of Lycaenidae were recorded: nine species of Polyommatinae and 114 of Theclinae. The highest species richness occurs in May in tropical semi-deciduous forest. It decreases with increasing elevation. The results are compared with four other butterfly families. Lycaenid community similarity in the Sierra Madre del Sur and Pacific slope is correlated with elevation and vegetation type, though variability within each grouping is significant. Higher elevation faunal isolation also plays a role, as seen in other mountainous Papilionoidea taxa. Conclusions: Lycaenidae is one of the most diverse and least known butterfly families in Mexico. This is the fourth study on the Loxicha Region's lepidopteran fauna, confirming its high diversity among five Papilionoidea families. Systematic studies aid in understanding speciation and endemism, particularly for stenotopic species. The distribution of Lycaenidae in the Loxicha region is the most comprehensive to date for any region in Mexico.

Introduction: Lipids in fish play a fundamental role in growth, reproduction, and homeostasis, maintaining cellular integrity. Objective: To assess the nutritional quality of seven fish species from Lake Campoma through analysis of their proximate composition and lipid profile. Methods: A total of 10 kg of each species Cichlasoma kraussii, Pimelodus clarias, Hoplias malabaricus, Aequidens pulcher, Hypostomus plecostomus, Hoplosternum littorale, and Centropomus mexicanus were collected through direct fishing in Lake Campoma. Samples were refrigerated and transported to the laboratory, where muscle tissue was dissected for subsequent analysis. Lipid fractions were determined using thin-layer chromatography with flame ionization detection (TLC-FID). Principal component analysis (PCA) was applied to explore the relationships among the evaluated parameters. Results: Centropomus mexicanus exhibited the highest lipid (2.33% w/w) and protein content (24.07%). In all analyzed species, phospholipids were the predominant lipid class (34–85%), followed by free fatty acids (7%), triacylglycerols (4%), and cholesterol (<34%). Water was the major component in the proximate analysis, ranging from 76.5% in C. kraussii to 82.5% in P. clarias, which may increase susceptibility to microbial spoilage if not stored properly. No clear association was observed between species and ash content. Conclusions: The evaluated species demonstrated high nutritional and energy value, supporting their inclusion in human diets. Phospholipids were predominant (up to 85%), followed by free fatty acids (7%) and triacylglycerols (>4%), with cholesterol levels below 37%. C. mexicanus stood out due to its high protein and energy content, while H. littorale and H. malabaricus were identified as the most nutritionally rich. These findings underscore the importance of these freshwater species as valuable sources of macronutrients and essential bioactive compounds.

Introduction: Pseudoplatystoma magdaleniatum, commonly known as striped catfish, is an endemic species of the Magdalena River basin, characterized by its large size and high commercial value. Given its critical endangerment due to overfishing, understanding its gastrointestinal tract morphology is crucial for conservation efforts and management in fish stocking programs. Objective: To characterize the morphology, histology, and histochemical qualities of the gastrointestinal tract of P. magdaleniatum, an endemic fish species in the Magdalena River basin, Colombia. Methods: Measurements of body height and weight of 22 captured adult individuals were taken, as well as of the organs comprising the digestive tract (esophagus, stomach, and intestine), and accessory and glandular organs (liver and gonads). Histological techniques, such as Hematoxylin and Eosin staining, were performed to characterize the organs structurally. Histochemical techniques were employed to describe the dynamics of mucins, and transmission electron microscopy was used. Results: The stomach and intestine exhibited four layers: mucosa, submucosa (absent in the esophagus), muscular, and serosa. The esophagus, with only three layers, was characterized by the presence of stratified squamous epithelium with goblet cells, club cells, and taste buds. Neutral mucins were detected along the esophagus, while acidic mucins were observed in the cranial and middle regions. The stomach featured a simple columnar epithelium with abundant gastric glands and exclusively neutral mucins. Finally, the intestine was characterized by a mucosal tunic of simple cylindrical epithelium composed of enterocytes and goblet cells, abundant folds, and the presence of sulfated and carboxylated neutral and acidic mucins. Conclusions: P. magdaleniatum exhibited a relatively short intestine for its size and weight. The histology of the gastrointestinal tract further supports adaptations for a protein-rich diet. These findings provide valuable insights for understanding the digestive physiology of this endangered species, which may inform conservation efforts and management strategies.

Introduction: Generalist trophic strategies and opportunistic feeding habits of nektonic fish species inhabiting oligotrophic streams in the Amazon Rainforest suggest that minor morphological and niche differences can mediate the occurrence of closely related species in sympatry, alleviating interspecific competition for resources. Objective: To analyze the ecomorphology, diet composition, vertical and horizontal habitat use, and foraging behavior of four Characiform species in syntopy, to understand resource partitioning and species coexistence. Methods: From August to October 2011 (dry season), up to 30 specimens of each species were collected from each of eight sampled streams in the Adolpho Ducke Forest Reserve, Amazonas, Brazil, for ecomorphological analyses, with up to 10 of these used for stomach content analysis. Foraging behavior was quantified through underwater observation of vertical and horizontal space use and foraging frequency in the water column. The dietary importance of food items was determined using the Feeding Index (FIi), and ecomorphological attributes were used to characterize body shape and fin morphology. Results: Differences were detected in foraging behavior and habitat use. Hyphessobrycon. aff. melazonatus predominantly occupied the stream margins, and the other species utilized the channel. Additionally, only H. aff. melazonatus exhibited a difference in stomach content composition. Ecomorphological characteristics showed divergence among species, particularly in body shape, mouth size, and orientation. Conclusions: The combined analysis demonstrated that differences observed here may mediate syntopic coexistence by alleviating interspecific competition through resource partitioning. The system’s sensitivity to anthropogenic impacts and climate change were highlighted on food availability and trophic relations of Amazon stream fishes and underscore the need for headwater stream conservation.

Introduction: The trophic structure of macroinvertebrate communities is of particular interest for understanding the functioning of the river ecosystems. Objective: To determine the community structure and functional feeding groups of aquatic macroinvertebrates in the Quilca-Chili basin. Methods: Two sampling campaigns were conducted at 26 stations, distributed across six sectors, from June to October 2022. The community structure was analyzed based on basic ecological parameters, including taxonomic richness, dominance, evenness, and diversity. Spatial variability was assessed through a similarity percentage analysis and non-metric multidimensional scaling using the Bray-Curtis distance index. The relationship with physicochemical variables was determined through canonical correlation analysis. Results: A total of 51 families were identified and assigned to functional feeding groups: predator, shredder, collector-gatherer, scraper, and filterer. The highest and lowest diversity was observed in the Sihuas sector and the Chili and Lluta sectors, respectively. Differences in community structure indices were found between the six sectors of the basin. The most abundant functional feeding groups were scrapers, while shredders and predators were the least abundant. Conclusion: The spatial distribution reflects the complexity and variability among physicochemical parameters and functional feeding groups in this basin.

Introduction: Lutjanus synagris is one of the most common demersal fishes in the Colombian Caribbean and is of interest to artisanal fisheries, although in decline. The study of its reproductive patterns provides insight into its biology relevant to the general study of tropical fishes. Objective: To assess the condition factor and gonadosomatic index, to determine the monthly incidence of mature fish, to estimate the mean length at sexual maturity (Lm), and to explore predictors affecting the condition factor and gonadosomatic index in the lane snapper L. synagris. Methods: Extirpated gonads of males and females were classified according to their maturity status and related to fish length. The condition factor and gonadosomatic index were estimated according to standard formulae. Their dependency on variables related to climate, geographic space, and behavior were assessed using linear models. Results: Condition factor was stable throughout the year, while the gonadosomatic index showed an increasing pattern from the first months of the year (dry season), reaching a peak in the second semester of the year. The incidence of mature fish was higher in about the same months as when the gonadosomatic index showed high values. An Lm of 26 cm total length was estimated for both sexes, 27 cm for males and 25 cm for females. Condition factor and gonadosomatic index were associated with several predictors, notably with moon phases. Conclusion: A spatial and temporal signal for the reproductive patterns of L. synagris was found but decoupled from climate seasonality. The reproductive rhythm of L. synagris was related to moon phases as the main environmental cue.

Introduction: The páramo grassland ecosystem is an important center of plant diversity and endemism. However, human activities, such as burning and livestock grazing, are altering the plant composition of the páramos. These changes may be associated with an increase in the abundance of shrubby species and a corresponding decrease in native grass cover. Objective: To evaluate the effects of human disturbance on the composition of woody plant species in páramo habitats. Methods: We conducted 36 transects across the páramo landscape of the Macizo del Cajas Biosphere Reserve in Southern Ecuador between April 2017 and November 2019, recording woody plant species (e.g., bushes and shrubs) along each transect. To explore variations in woody plant composition, we employed non-metric multidimensional scaling, using the proportion of disturbed area, páramo grassland, and elevation as predictor variables. Results: We recorded a total of 13 377 woody plants. The proportion of disturbed areas has an influence on the composition of the woody plant species. Shrubby species such as Diplostephium ericoides, Hypericum quitense, Valeriana microphylla, and Valeriana hirtella are more prevalent in transects with a greater proportion of disturbed areas. Conclusion: There was a greater presence of fast-growing woody plant species in response to human-induced disturbance. This suggests that native herbaceous species are gradually being replaced by woody encroachment, particularly in human-accessible páramos. Conservation and restoration efforts should take this phenomenon into account to prevent the accelerated spread of woody encroachment and enhance the availability of páramo grassland habitats.

Introduction: The fish of the Sciaenidae family are important for commercial and subsistence fishing on the Colombian Pacific coast. However, it is unknown how their trophic habits vary between climatic seasons. The objective of this research was to determine the variation of diet and the presence of microplastics (MP) in species of this family and its relationship with the environmental dynamics of the water of the Buenaventura Bay, colombian Pacific. Methods: Samples were taken in dry and rainy season of 2020 and 2021 in the internal and external areas of the bay. A total of (144) individuals of the species Larimus argenteus, Stellifer zestocarus and Stellifer melanocheir, were sampled using artisanal trawling and their stomach contents were classified into five categories of food prey corresponding to crustaceans (shrimp, crabs, isopods), fish, nematodes, detritus (organic material), and MP microplastics (fibers and fragments). The analysis of stomach contents used as trophic parameters, the frequency of occurrence (% FO) and the relative importance index (IRI %) of prey. These stomach contents were related to environmental variables salinity (PSU), temperature (° C), pH, dissolved oxygen (mg l−1) and water transparency (cm) through GAM models. Results: In general, Sciaenidae fish consumed mainly crustaceans in dry season. The fish as prey supplement their diet in both periods, but their consumption intensifies in rainy season. The detritus is consumed mostly in dry season, being able to relate to the consumption of crustaceans, while the nematodes are consumed mainly in rainy season, associated with the greater consumption of fish. L. argenteus consumed more crustaceans in dry season, associated with high salinities and low temperatures, while in rainy season the intake of fish increases. While, in low temperatures increased the intake of detritus in S. zestocarus. The highest MP content in L. argenteus was found in low salinity and pH, associated with rainy season and internal zone. Conclusions: The study suggests that the diet of Sciaenidae fish is influenced by the estuarine supply, subject to environmental variation.

Introduction: Leaves are among the most plastic organs in plants, and their structure, while shaped by phylogeny, can show considerable phenotypic plasticity within a species in response to environmental gradients. Monstera deliciosa, a tropical hemiepiphytic vine known for high leaf heteroblasty, adapts to diverse light conditions. This makes leaf structure a useful proxy for assessing whole-plant resource allocation strategies and adaptations to environmental changes. Objective: To measure the morphological and structural differences in sun and shade leaves using nine leaf traits (petiole length, leaf width and length, effective leaf area, fenestrated area, leaf perimeter, lobulation ratio, stomatal density, and specific leaf area -SLA-). Methods: We selected 20 widely separated M. deliciosa plants on the University of Costa Rica campus in 2022, positioned in contrasting sun and shade conditions, and measured one mature leaf per plant (ten per light environment). Results: Sun leaves had higher fenestrated area, perimeter, and stomatal density, suggesting structural adaptations to high light. These traits may enhance thermal regulation by facilitating heat dissipation. Sun leaves had lower SLA, indicating thicker, denser leaves better suited to high light and wind exposure. Lobulation ratios (leaf dissection) were not different between sun and shade conditions. A principal component analysis explained 82.88% of the variation in the leaf traits, with 39 % of the variation attributed to fenestrated area, leaf perimeter, and effective leaf area. Correlation analyses showed that fenestrated area, perimeter, and stomatal density were positively associated (and negatively related to SLA), emphasizing the functional convergence of these traits, adapting the leaf phenotype to light differences. Conclusions: M. deliciosa modulates leaf morphology and structure to adapt to distinctive light conditions, with fenestration, stomatal density, and SLA emerging as crucial traits. These findings underscore the significance of environmental differences in driving leaf shape and structure.