Use of elliptic Fourier descriptors for quantification of male genitalia morphology

SOTO, IGNACIO

DROSOPHILA INFORMATION SERVICE

Oklahoma University

Año: 2005 vol. 88 p. 42 - 45

0070-7333

The aedeagus is the intromittent organ of male Drosophila. Aedeagus morphology isconsidered a main diagnostic character to species recognition in Diptera, and it is especially relevant in the repleta group. Due to the morphological complexity that it presents, its study asa quantitative character presents a methodological challenge. Drosophila buzzatii and D. koepferae are two cactophilic sibling species belonging to the buzzatii cluster of the repleta group. Otherwise sinmorphic, they are distinguishable by the genitalia of their males. Conspicuous shape differences between D. buzzatii and D. koepferae male genitaliapreclude the possibility of capturing the organ geometry by means of an adequate number of reliable homologous landmarks. However, outline methods can still be performed as long as the edge or contour of the organ can be considered homologous across individuals. I present an evaluation of the application of a geometric morphometrics methodology to assess the morphological variations that explain the interspecific differences in shape of the aedeagusin two sibling Drosophila species.