About the presence of Aplochiton zebra (Pisces, Aplochitonidae) and the absence of Galaxias maculatus (Pisces, Galaxiidae) in the littoral zone of an andean lake.

M.E. LATTUCA; S. ORTUBAY; M. BATTINI; V. CUSSAC

Melbourne, Australia

Congreso; Societas Internationalis Limnologiae XXVIII Congress.; 2001

Monash University, SIL

Lake Rivadavia, in Argentine Patagonia, drains through Futaleufú River to the Pacific Ocean. Repeated captures in the littoral zone, with seine and dip nets and electrofishing showed the presence of Aplochiton zebra and the remarkable absence of Galaxias maculatus, the main prey fish in others Andean lakes. We caught juveniles in summer and small adults in autumn, and confirm the juvenile identity comparing their multidimensional morphology with the adult one. Adulthood was assessed by gonad examination. Juvenile and adult diets and the number and type of otolith rings are being analysed now.