Caracterización morfométrica de los estadios de madurez de Oikopleura fusiformis (Tunicata, Appendicularia).

CAPITANIO, F; ESNAL G. B.

PHYSIS - A

ASOCIACIÓN ARGENTINA DE CIENCIAS NATURALES

Año: 1996 vol. 52 p. 13 - 17

0325-0342

The presen t study aims at characterizing morphome trically the ma turity stages of Oikopleura fusiformis as wellas determining the contribution of the different variables to the growth and sexual maturity of this species. One hundred and fifiy specimens were qualitatively classified into three maturity stages based upon microscopic observation of the gonads. Seven different parts of the trunk and tail were measured in order to differentiate the stages on a morphological basis. Al1 trunk variables were strongly intercorrelated, specially with the height of the genital cavity, and weakly correlated wifh tail variables. This implies a differential growth of the tail compared to that of ihe trunk.Four variables were selected using stepwise discriminant analysis to characterize the stages from a biometrical view point: genital cavity height and stomach lengfh were the principal variables, and to a lesser extent, trunk length and nofochord width. The classification of the specimens into ihree maturity stages according to this method permits to discriminate three well defined groups. However, the mature stage presented the highest percentage of wrongly classified specimens.