Triatoma maculata is a wild vector of Trypanosoma cruzi, the causative agent of Chagas disease; its incursion in the domestic habitat is scant. In order to establish the possible domestic habitat of T. maculata, we evaluated wing variability and polymorphism of genotypic markers in subpopulations of T. maculata that live in different habitats in Venezuela. As markers, we used the mtCyt b gene, previously apply to evaluate population genetic structure in triatomine species, and the β-tubulin gene region, a marker employed to study genetic variability in Leishmania subgenera. Adults of T. maculata were captured in the period 2012–2013 at domestic, peridomestic (PD), and wild areas of towns in the Venezuelan states of Anzoátegui, Bolívar, Portuguesa, Monagas, Nueva Esparta, and Sucre. The phenotypic analysis was conducted through the determination of the isometric size and conformation of the left wing of each insect (492 individuals), using the MorphoJ program. Results reveal that insects of the domestic habitat showed significant reductions in wing size and variations in anatomical characteristics associated with flying, in relation to the PD and wild habitats. The largest variability was found in Anzoátegui and Monagas. The genotypic variability was assessed by in silico sequence comparison of the molecular markers and PCR-RFLP assays, demonstrating a marked polymorphism for the markers in insects of the domestic habitat in comparison with the other habitats. The highest polymorphism was found for the β-tubulin marker with enzymes BamHI and KpnI. Additionally, the infection rate by T. cruzi was higher in Monagas and Sucre (26.8 and 37.0%, respectively), while in domestic habitats the infestation rate was highest in Anzoátegui (22.3%). Results suggest domestic habitat colonization by T. maculata that in epidemiological terms, coupled with the presence in this habitat of nymphs of the vector, represents a high risk of transmission of Chagas disease.
Se estudió la composición, estacionalidad y hábitat de los peces de la Quebrada Cristales, afluente terciario del río La Vieja en el Alto Cauca, Colombia, desde junio 2004 hasta enero, 2005. Se capturaron 16 especies de cuatro órdenes y cinco familias; las capturas se efectuaron con métodos estándares en 14 estaciones de muestreo a lo largo de la quebrada. Brycon henni fue constante en la quebrada para ambos periodos climáticos y en las zona baja de la quebrada. Poecilia caucana es la especie con más alto porcentaje de ocurrencia para ambos periodos y la única especie constante para la zona alta. Apteronotus sp., Argopleura magdalenensis, Bryconamericus caucanus, Chaetostoma fischeri, Characidium caucanum, Imparfinis nemacheir, Lasiancistrus caucanus, Rhamdia quelen, y Roeboides dayi fueron especies accidentales y solo se capturaron a medida en cercanías a la desembocadura, observándose únicamente para la zona media y baja de la quebrada. Se evaluaron características fisicoquímicas y del hábitat. Muchas especies se encontraron asociadas a microhabitats con abundante vegetación ribereña y macrófitas acuáticas.
There are few studies on microplastic (MP) contamination in Colombia, and little is known about its impacts on continental aquatic ecosystems. This study evaluated, for the first time, the identification, abundance, and distribution of MP particles in the surface water of Luruaco Lake, in the low basin of the Magdalena River, Colombia, included in national programs in marine sciences and hydrobiological resources. Six stations and four samplings were established in the dry and rainy seasons. A total of 72 water samples were collected for microplastic extraction using hydrogen peroxide (H2O2) digestion, density separation with sodium chloride solution (NaCl), and filtration. The abundance of MPs ranged from 0 to 3.83 MPs·L−1, with an average of 1.90 MPs·L−1 in the rainy season and 0.25 MPs·L−1 in the dry season. According to the calculated coefficient of microplastics impact, the contamination in the surface water of Luruaco Lake is “maximum” to “extreme” for fibers with an average length of 2.05 mm and “minimum” to “average” for fragments that are 0.35 mm in size on average. Polyester (PES, 57.9%), polystyrene (PS, 47.0%), and polyethylene terephthalate (PET, 35.3%) polymers were more abundant in surface water. The temporal variation of the MPs indicates contamination related to the discharges of the tributary streams to the lake in the rainy season.
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