Ultramorphological features of the egg of Telmatoscopus albipunctatus (Williston) (Diptera, Psychodidae)

Ultramorphological features of the egg of Telmatoscopus albipunctatus (Williston) (Diptera, Psychodidae). Psychodidae flies, also known as sewage, sand and filter flies are important for medical and veterinary purposes. General information about life cycle and adult habits is available, but few species are known about the egg morphology. Therefore, in this study, the egg ultramorphology of Telmatoscopus albipunctatus (Williston, 1893) was analyzed by scanning electron microscopy to describe its structure, generating data for further comparison between different fly species and genera. General aspects of T. albipunctatus egg are similar to other Psychodidae; egg measuring approximately 0.4 mm in length and 0.1 mm in width. However, based on the continuous and discontinuous longitudinal ridge sculptures observed on the exochorion, which can be species-specific, we can infer that T. albipunctatus eggs can survive under dry or moist conditions, making their control much more difficult. Our data emphasize the advantages of the electron microscope approach in the study of the exochorion patterns. Eggshell morphology of T. albipunctatus can be used as basis for further studies and as a tool to compare different species of Psychodidae flies.

Aspectos ultramorfológicos do ovo de Telmatoscopus albipunctatus (Williston) (Diptera, Psychodidae). As moscas da família Psychodidae, também conhecidas como moscas de banheiro, são de importância médica e veterinária. Informações gerais sobre ciclo de vida e hábitos do adulto são facilmente encontradas, mas pouco se sabe sobre a morfologia do ovo. Dessa forma, neste estudo, a ultramofologia do ovo de Telmatoscopus albipunctatus (Williston, 1893) foi analisada por microscopia eletrônica de varredura com o objetivo de descrever sua estrutura, provendo importantes dados para futuras comparações entre moscas de diferentes espécies e gêneros. O aspecto geral do ovo de T. albipunctatus é similar a outros Psychodidae, medindo aproximadamente 0.4 mm de comprimento e 0.1 mm de largura. Entretanto, baseado nas esculturas contínuas e descontínuas do exocórion, as quais podem ser espécie-específicas, podemos inferir que os ovos de T. albipunctatus podem sobreviver sob condições de muita umidade ou seca, dificultando o controle da espécie. Nossos resultados ressaltam a importância do uso da microscopia eletrônica como uma ferramenta no estudo dos padrões do exocórion. A morfologia externa do ovo de T. albipunctatus pode ser usada como base para futuros estudos e como ferramenta para comparação de diferentes espécies de moscas do gênero Psychodidae.

Surface morphology of Mytella falcata gill filaments from three regions of the santos estuary

Bivalves have been extensively used to monitor aquatic habitats because their sedentary filter feeding habit results in the accumulation of elements from the environment. The genus Mytella is of special interest because its habit of burrowing in sediments can provide information about the substrate conditions in estuaries. Gill filaments have a large surface that is in constant contact with the water and therefore are used to monitor aquatic environments. In this study, we used scanning electron microscopy (SEM) to investigate the morphology of Mytella falcata gill filaments and to compare the gill structure in specimens from three sites (A, B and C) of the Santos estuary in southeastern Brazil. Site A presents low levels of pollutants, whereas sites C and B were directly affected by industrial discharges and harbor pollutants. The gill filaments of M. falcata have three types of cilia, namely, lateral cilia, eu-latero-frontal cirri and frontal cilia. Structures joining the inner and outer lamellae were found on the abfrontal surface, in addition to the presence of composite and simple cilia. A comparison of the filaments of bivalves from the three sites revealed no morphological alterations, but there was an accumulation of mucus on the frontal surface of the gill filaments of specimens collected at site B. This mucus may function as a protective barrier against pollutants. Bivalves from site C showed no such alteration, even though this site had the highest levels of pollutants. This lack of alterations may reflect the fact that these specimens were collected from concrete pillars where there would be less contact with pollutants. Our findings may reflect a long-term adaptation of these mollusks to chronic exposure to pollutants.