TY - JOUR JF - Acarologia T1 - Morphometric definition of the notogaster of some species in the genus Oppia C. L. Koch (acari, oribatei). Application of the sinus concept VL - 12 IS - 3 SP - 583 EP - 604 PY - 1970 SN - 0044-586X SN - 2107-7207 PB - Les Amis d'Acarologia AU - Cancela da Fonseca, J.P. UR - https://www1.montpellier.inrae.fr/CBGP/acarologia/article.php?id=3411 DA - 1971-03-01 AB - Definition morphometrique du notogaster de quelques espfces du genre Oppia C. L. Koch (acariens oribates). Application du concept de sinus. - The sinus technique (’parasinus’: sn °) applied to the study of the form of the notogaster of sorne Oppia C. L. Koch species (6) shew that it was possible to consider its form abstractedly, and also possible to set apart the different forms even if the differences between them are apparently minimal. However, these differences are bigger if the values are multiplied by the actual minimal radius, in micra, of each species (’real corrected parasinus’: R sn 8°). The same technique pointed out that the anterior part of the notogaster is quite important to individualize form. This phenomenon can also be measured by the observed sensible differences in the corresponding ’form coefficients’, given by: P = ~ sn 8° The utilization of the Hiemaux distances and the cluster analysis shew up the existence of only two groups of gastronotical forms among the six species studied: one formed by O. minus and the other by the remaining species. This technique also allowed the ordination of the species of the Group II by increasing degree of similarity: a) anterior part: -O. obsoleta--+ O. subpectinata--+ O. cf. assimilis ->-O. cf. insculpta--+ O. paenectypa; b) posterior part:- O. cf. assimilis--+ O. obsoleta ->-O. paenectypa--+ O. cf. insculpta--+ O. subpectinata. ER -