Navegando por Palavras-chave "Morfometria Geométrica"

Agora exibindo 1 - 1 de 1
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Avaliação temporal da forma e composição de conchas de lottia subrugosa do litoral do estado de São Paulo
    (Universidade Federal de São Paulo (UNIFESP), 2019-03-08) Martins, Camila Pratalli [UNIFESP]; Castro, Ítalo Braga [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)
    The intense human occupation and the development of industrial and tourist activities in coastal areas have caused several environmental impacts, especially result of launching of domestic and industrial effluents without treatment in coastal waters. Alteration in the mollusc shells have been recently related to the exposure of contaminants. It is also known that the shells of these animals preserve an important history about their growth, mineralization conditions and environmental conditions in which they lived. Thus, this study carried out a temporal assessment of alterations in shape and composition of shells of the Lottia subrugosa gastropod (D'ORBIGNY, 1846) from coastal areas of the State of São Paulo. For that, an inventory of the L. subrugosa lots deposited in zoological collections, before 1985, in main Brazilian museums was carried out. Subsequently 50 living individuals were collected in the same areas of the selected lots. The shells (from the collections and obtained in the environment) were analyzed using techniques of biometry, 2D geometric morphometry and analysis of the elemental chemical composition. The results obtained by the comparison by locality, between organisms of the past and the present, did not demonstrate a clear pattern of alterations of the forms along the time. This was probably due to the restrictions imposed on the work, regarding the impossibility of determining the age of the organisms used and the lack of lots with temporal sequences coming from the study areas. On the other hand, when these same forms of organisms were analyzed together, between present and past, it was possible to perceive that the present organisms present a smaller variability of forms when compared with the group of the past. This same pattern, on the other hand, was not observed when investigating the biometric variations and the elemental composition. Considering the tools used in the present study, the geometric morphometry presented consistent answers for the quantification of differences in the shape of the shell of Lottia subrugosa in the temporal character, although it was not possible to infer direct relation with the environmental contamination. This technique has been shown to be a promising tool, relatively simple, inexpensive and accessible for quantification of changes in shape.